invacar LightBulbFun's Invacar & general ramble thread, index on page 1, survivors lists on Pages 24/134 & AdgeCutler's Invacar Mk12 Restoration from Page 186 onwards, still harping on...

[LightBulbFun]

  On 07/04/2025 at 16:40, LightBulbFun said:

so I am little bit stuck as to what to do now, as it clearly wont be a simple case of chuck a new drive belt on as I had hoped, I suppose the fix from here would be remove pulleys, somehow straighten out the gear-selector rod and fit new pulleys with new belt

Expand  

alright having given this a bit of thought, and realising @Zelandeth's CVT system doesn't even have the lock washers im worried about so if I cant salvage the existing ones ill just do as he did and apply a bit of loctite  

https://autoshite.com/topic/29443-zels-motoring-adventuresvolvo-renault-rover-trabant-invacar-a-sinclair-c5-updated-3003/page/149/#findComment-2612460

 

I am thinking with this, plan, with my brother coming in the 10th, ill try our collective bests to remove the old pulleys, and if thats successful then try our bests to fit a new set of pulleys and belt, (either on the day or sometime later depending on when I get the pulleys in hand (as they are not kept at the house)

the bent gear-selector -rod does not prevent the selection of drive or reverse etc, so I think ill just live with that, until such time as I can get REV to somewhere where that can be sorted. (although I do have concern over if the bent linkage putting any undue stress on any internal parts of the gearbox or not)

I have a commitment I am really hoping to have REV sorted for on the 25th of April, its that gathering of lighting enthusiasts/collectors at a good friends place in kidderminster that I have mentioned beforehand, the last one was in October and I did not quite have REV back in time for that one, so I already pretty strongly committed to the one in April so I would hate to let him down as he has been wanting me to attend for many years now and I have otherwise been unable to due to lack of personal transport etc

 

 

 

[Dobloseven]

Do the pulleys slide on,or are they on a taper?Is a puller needed?Best of luck with it anyway,those pulleys look well rusty and can't have done the belt any good.

[mintwth]

  On 07/04/2025 at 18:07, LightBulbFun said:

I do have concern over if the bent linkage putting any undue stress on any internal parts of the gearbox or not

Expand  

How's the linkage connected at either end? 

If it can be removed, then it should be easier to straighten (or to take it somewhere to get it straightened). 

[LightBulbFun]

  On 07/04/2025 at 18:18, Dobloseven said:

Do the pulleys slide on,or are they on a taper?Is a puller needed?Best of luck with it anyway,those pulleys look well rusty and can't have done the belt any good.

Expand  

Page 55 incase anyone wants to follow along at home so to speak  

https://zelandeth.org/cars/ac-model-70/DHSS-Workshop-Manual-For-The-Model-70-Three-Wheeler.pdf

the rusty pulley surface actually felt pretty smooth despite the looks  (although I did not spend long in there when I suddenly realised it was in a jammed state and could potentially snap closed at any provocation!) but as you say having a fresh set of pulleys in and of itself wont be a bad thing  

  On 07/04/2025 at 18:30, mintwth said:

How's the linkage connected at either end? 

If it can be removed, then it should be easier to straighten (or to take it somewhere to get it straightened). 

Expand  

excerpt from one of @Zelandeth's posts that shows how it goes together, tho looking at the angle his is sitting at, perhaps is not as badly twisted was I thought, but ill have to try and get a picture of it

  On 11/08/2020 at 18:38, Zelandeth said:

The gear selector was originally attached to the selector arm on the box by a roughly 1/4" diameter roll pin, held in place by a split pin.  I was missing this because the replacement selector I fitted (the original one in TPA was totally siezed) didn't have it, and no amount of effort was able to shift the original one from the linkage.  Originally I fitted a bolt in this location and used a locknut arrangement to try to stop it loosening itself over time.  Apparently this didn't work as since then I've lost two bolts.

Annoyingly the replacements I have, presumably because they're a metric size, don't fit.  The smallest size I've got that fits drops straight through, the next size up won't fit.  Adding an extra washer to the smaller one adds enough length that I can't then get the split pin in.  So we will need to use a bolt then for the time being.

It was at this point I had a bit of a brainwave.  There are two pivot joints on the gear linkage of this type.  The lower one (the source of my problem), then an identical one where the rod actually pushes/pulls on the actual gear selector on the box.  The lower one is an absolute swine to get to other than from underneath because there is a load of pulley and belt in the way.  The top one however is near enough level with the top of the gearbox pretty much and is readily accessible.

So I took the standard coupler out of the top pivot and installed that in the hard to get to bottom location.  I then fitted a bolt and lock nut to the top one.

The fact that I can actually get to it makes it possible to easily do the locknut up *way* more tightly than I probably managed last time.  I also put a blob of thead lock on it. 

At least if it does drop off again in future replacing the thing will be a five minute job as it's dead easy to get at.

Expand  

 

[Zelandeth]

 

  On 07/04/2025 at 18:30, mintwth said:

How's the linkage connected at either end? 

If it can be removed, then it should be easier to straighten (or to take it somewhere to get it straightened). 

Expand  

I suspect that the linkage rod will be sortable just by physically pulling on it - I don't remember them being particularly substantial.  The bendage will almost definitely just be from getting whacked by the belt when it let go - fact that it runs within the safety cage around the belt means it's very vulnerable to that.

  On 07/04/2025 at 18:18, Dobloseven said:

Do the pulleys slide on,or are they on a taper?Is a puller needed?Best of luck with it anyway,those pulleys look well rusty and can't have done the belt any good.

Expand  

They're straight shafts with a keyway - and as I recall a non-captive key which can and will make a bid for freedom when the pulleys are removed.  I seem to recall getting the one on the primary to line up properly when putting it back together involved a certain amount of swearing as well.

Between bits of belt having got in there and potentially having been subjected to and over-speed when the belt snapped (the primary is only rated for 5,000 rpm), it may just be stuck and need a bit of persuasion to move back to the rest position.  I'd give the primary a bit of a poke and prod and see if you can get it to reset without removing it if possible.  Primarily because I remember getting the bolt out of mine being an absolute PAIN.  It was absolutely wicked tight, and there's really no good way to lock the pulley in place.  Ideal situation is to get an impact gun onto it which I don't doubt would shock it loose in moments - but you can't because the bulkhead is in the way.  This also makes properly tightening the bolt when the new pulley is on equally difficult - the bolt in the primary of mine managed to work itself loose at some point, which I was alerted to by a jingling noise at low speed which turned out to be the washer under the bolt.  Even with Locktite in there I still don't fully trust the bolt to stay put.

Those locking collars however look to be the ideal solution - I don't have those!  So long as they don't get physically broken when removed those should be fine for reuse as they just slot in place over the bolt once the pulley has been secured and then bolted down.  I may have to look at coming up with something similar in the future as I really don't trust those bolts to stay in place without them, and had always wondered if i was missing some locking hardware.  Turns out I am!

Secondary is far less of a pain to remove simply because it's directly coupled to the wheels, so by having a helper hold the brakes firmly on it's easier to actually apply force to.

In your case I'd be seeing if you can get the bits of belt out of there and get the primary to reset properly and if so just concentrate on changing the secondary.  "fairly smooth" really isn't good enough in this case, the pitting you can see there definitely will have been causing excess drag and overheating of the belt at speed.  That may well be where the bit of missing performance you'd been looking for was hiding - it was like night and day when I got the new pulleys on TPA.  It will also affect how willing the belt is to move fully down into the groove which may well throw the gearing curve off.  There's a lot of energy being transferred through there and this type of setup is horrendously inefficient and lossy at the best of times, so any additional friction is bad news.

If you can get the bits of shredded pulley out of there and make things move again I'd not discount just slapping a new belt on for now to get you mobile again though - it's something that is definitely needing to be changed, but the original belt (which may well have been compromised to start with given we don't know its age or how it was stored or how worn it was to start with) lasted this long, so if you need to get the car to somewhere to have the secondary pulley swapped over I'd consider that to be a viable option.

[mintwth]

  On 07/04/2025 at 19:07, Zelandeth said:

suspect that the linkage rod will be sortable just by physically pulling on it

Expand  

Worth doing before going on a long drive? The bend must change the travel at the gearbox end (since a bent linkage will effectively be shorter than a straight one) but might not be enough to matter

[plasticvandan]

Seems a bit daft putting a new belt on rusty pulleys,especially if you have new ones.the old ones could then be skimmed perhaps and kept on the shelf. You already know the answer to the gear linkage,straighten it out. Maybe one for a garage to do.

[Yoss]

I've liked rather than sad faced your breakdown post for the simple reason that it all seemed like a relatively painless affair on a nice day. We've all had our first major breakdown and they don't all go as smoothly as that. 

I was daft enough for the first couple of years of driving to not even have breakdown cover. And I was driving around in 25 year old Triumph 1300s. Your weakness is CVT belts, mine was input shafts. They're just not up to the job. First time one went I was on my way home from a BMC Farina pub meet. You just go to change gear and suddenly you have no drive. Fortunately a friend was just behind me so he towed me home in his Wolseley Six. 

You can sit there selecting gears without using the clutch because the engine is no longer attached to the gearbox. So it's basically the same problem as yourself but for different mechanical reasons. 

Look at this. 

Three Triumph FWD input shafts. The first has snapped at the circlip groove. The second the spines have stripped. The corresponding splines in the input gear  will have done the same and so the shaft just spins and the car goes nowhere. The third is the uprated 1500 shaft with longer splines plus they moved the circlip groove to the sensible end. It was ridiculous to expect 75hp in the 1300 TC to go through those short splines and putting the circlip groove at that end was ridiculous as all the power of the engine has to go through that before it can even get to the inadequate splines. 

The 1500 design is much better though you have to change the corresponding gear in the gearbox that the shaft sits in too. I put the whole 1500 gearbox in mine. But that's still not the end of the problem. I was overtaking a car on the A30 near Shaftesbury and when I changed back up in to 4th gear there was a bang and loss of drive with all the symptoms of input shaft failure. Obviously ever since the early days I've always carried a spare shaft in the glove box as you can have the thing out in 10 minutes. So whipped the shaft out and it looked fine. So the clutch came out next, which is only another 10 minutes once you've got the shaft out. 

Can you see the problem? 

What with that and the Rotoflex driveshaft couplings the whole drive system isn't really up to the job so I feel your pain. Doesn't stop me using it or worrying that I might not get where I want to be. You just deal with it when it happens. 

[plasticvandan]

Wouldn't be surprised if that is the cause of the belt failure if that silver bit really is the jagged remains of the pulley face,those pulleys are toast.

[BorniteIdentity]

On the basis that you’ve had one high-speed grenading rubber issue, it’s worth checking your tyres too. Were they replaced when it was recommissioned? Date codes are worth checking…

[Zelandeth]

  On 07/04/2025 at 20:11, plasticvandan said:

Seems a bit daft putting a new belt on rusty pulleys,especially if you have new ones.the old ones could then be skimmed perhaps and kept on the shelf. You already know the answer to the gear linkage,straighten it out. Maybe one for a garage to do.

Expand  

Absolutely agreed.  I'd definitely say change it - Just saying that if push comes to shove and the car needs to get to a garage to have it changed if it can't be done at home, I'd not be too worried about driving across town if it came to it.  If of course things can be unjammed, if not it's a pretty moot point of course.  It really does need to be changed though.

The primary pulley sheaves are aluminium so tend to fare better over time than the steel ones on the secondary.

Pulling the secondary pulley apart once it's off the car and refacing the sheaves shouldn't be too difficult I'd think, but admittedly I've never tried!  Can't hurt to keep usable spares if we can though.

[SiC]

I'd be putting your replacement pulleys on with a new belt to get it going with the best chance of success. Then take the rusty pulleys to a machine shop to be resurfaced and keep them as a spare with a coat of wax or something like that to stop them rusting up again. 

[LightBulbFun]

  On 07/04/2025 at 20:28, Yoss said:

I've liked rather than sad faced your breakdown post for the simple reason that it all seemed like a relatively painless affair on a nice day. We've all had our first major breakdown and they don't all go as smoothly as that. 

Expand  

yeah as far as major breakdowns go, this one could not of gone better so to speak, these days I suppose I should count myself lucky for just having a hard shoulder to be able to dive into!

  On 07/04/2025 at 21:35, BorniteIdentity said:

On the basis that you’ve had one high-speed grenading rubber issue, it’s worth checking your tyres too. Were they replaced when it was recommissioned? Date codes are worth checking…

Expand  

suitably modern Falken SN807 'Sincera' 145R10's  

  On 07/04/2025 at 21:55, Zelandeth said:

If of course things can be unjammed

Expand  

I did while I was taking those photographs, give things a bit of a shove and pull but nothing wanted to budge, admittedly I did not try my hardest at that point, so ill give things another poke on the 10th

  On 07/04/2025 at 21:55, Zelandeth said:

Pulling the secondary pulley apart once it's off the car and refacing the sheaves shouldn't be too difficult I'd think, but admittedly I've never tried!  Can't hurt to keep usable spares if we can though.

Expand  

  On 07/04/2025 at 22:26, SiC said:

Put your replacement pulleys on with a new belt. Take the rusty pulleys to a machine shop to be resurfaced and keep them as a spare with a coat of wax or something like that to stop them rusting up again. 

Expand  

I was kinda under the impression that to take the pulleys apart you have to be very careful not to have it suddenly ping apart and take your face off as there are some nicely loaded springs'n'things(TM) in there as I understand it? so I am not sure if a machine shop would be very keen on trying?

 

[Andrew353w]

  On 07/04/2025 at 20:11, plasticvandan said:

Seems a bit daft putting a new belt on rusty pulleys,especially if you have new ones.the old ones could then be skimmed perhaps and kept on the shelf. You already know the answer to the gear linkage,straighten it out. Maybe one for a garage to do.

Expand  

It's the same with Dafs. The earlier ones had stainless steel pulleys which never rusted, but, in an effort to save a few Guilders these were changed for ordinary steel one, that were then chrome-plated. Unfortunately the chrome rubbed off & the pulley surfaces then rusted if the car wasn't regularly used, and the rust ate into the belts. You might be able gently to file some of the rust away, but having them properly re-surfaced would be the best solution. 

[Andrew353w]

  On 07/04/2025 at 22:40, LightBulbFun said:

I was kinda under the impression that to take the pulleys apart you have to be very careful not to have it suddenly ping apart and take your face off as there are some nicely loaded springs'n'things(TM) in there as I understand it? so I am not sure if a machine shop would be very keen on trying?

 

Expand  

I use a wedge-shaped piece of hardwood to part the secondary halves of the pulleys on my Daf, so the same method might work on your Invacar. Whatever you do, DON'T prise them apart with tyre levers or similar, as this would place excessive pressure on one part of the mechanism, thereby damaging it. G-E-N-T-L-Y does it! 

[Zelandeth]

  On 07/04/2025 at 22:40, LightBulbFun said:

yeah as far as major breakdowns go, this one could not of gone better so to speak, these days I suppose I should count myself lucky for just having a hard shoulder to be able to dive into!

suitably modern Falken SN807 'Sincera' 145R10's  

I did while I was taking those photographs, give things a bit of a shove and pull but nothing wanted to budge, admittedly I did not try my hardest at that point, so ill give things another poke on the 10th

I was kinda under the impression that to take the pulleys apart you have to be very careful not to have it suddenly ping apart and take your face off as there are some nicely loaded springs'n'things(TM) in there as I understand it? so I am not sure if a machine shop would be very keen on trying?

 

Expand  

There are strong spring in there, but they're the sort of springs you need to be very careful with rather than like the ones in spring brakes or suspension that are downright lethal.  It's not uncommon in performance applications where similar setups are used for the pulleys to be dismantled to mess with the weights and spring rates to tune things.  If everything is healthy it's possible to move the sheaves by hand (just about) which gives you an idea how much tension is involved.  

I still wouldn't suggest it if you're not confident in what you're doing and haven't taken measures to kerb the enthusiasm for rapid, spring powered, uncontrolled disassembly, but pulling apart and servicing the pulleys is definitely something that is possible if done properly.

Has anyone ever checked with Comet to see if the exact units we need here or spares for them are actually still available new?  The (current) 500 or 780 series looks to be a pretty close match at a glance. 

https://www.cometclutches.com/products/torque-converters/

Note that these are available in a few different configurations - so it's not just a case of one size fits all (as I remember Dollywobbler discovering a few years ago).

Would be good to confirm that rather than just depending on an ever decreasing pool of old stock parts.  If not I'm happy to ping them an email to see what they say.

[LightBulbFun]

  On 08/04/2025 at 11:26, Zelandeth said:

There are strong spring in there, but they're the sort of springs you need to be very careful with rather than like the ones in spring brakes or suspension that are downright lethal.  It's not uncommon in performance applications where similar setups are used for the pulleys to be dismantled to mess with the weights and spring rates to tune things.  If everything is healthy it's possible to move the sheaves by hand (just about) which gives you an idea how much tension is involved.  

Expand  

ironically I had a spare NOS secondary pulley kicking around here at home, that @st185cs kindly gave to me as a bonus item when I caged a few spare belts from him, when he dropped REV off back in 2021, so playing around with that previously I have some idea how that one is supposed to behave (however I have never had a chance to play with a primary pulley), but I sent that secondary pulley up with REV when she went away for a couple years and then when REV came back to the FoD before coming home, the box the pulley was in stayed at the FoD while REV came back home! 

  On 08/04/2025 at 11:26, Zelandeth said:

Has anyone ever checked with Comet to see if the exact units we need here or spares for them are actually still available new?  The (current) 500 or 780 series looks to be a pretty close match at a glance. 

https://www.cometclutches.com/products/torque-converters/

Note that these are available in a few different configurations - so it's not just a case of one size fits all (as I remember Dollywobbler discovering a few years ago).

Would be good to confirm that rather than just depending on an ever decreasing pool of old stock parts.  If not I'm happy to ping them an email to see what they say.

Expand  

it would be interesting to know for sure  I know from @dollywobbler's tests with TWC that "close enough" even if they physically look the same, is not good enough, the Model 70 CVT pulley set is Model 795, now typically I can only a few references to this 

but from what I have seen, these different "Model No's" of pulley sets, are made by mixing and matching specfic types of primary and secondary pulleys,  in that, you might be able to take 1 pulley from one set and one pulley from another set, to then make a 795 set, if that makes sense?

so I have always wondered, although I cant directly find any 795 sets listed online, I have wondered if comet might still make the correct pulleys individually that can be combined to make a 795 set

I note for example they still list the Model 790 so I do wonder if they could still do a Model 795 if asked?

 

so yeah I would ask them if they still are able to supply Model 795 pulley sets or not, if you are pinging em an email

[Zelandeth]

I'll ping them an email when I'm next at an actual computer.  

At the end of the day it's just a matter of finding pulleys with the correct size and profile, the right weights, right springs and belt that's the right profile and weight (and we've established the Dayco 2020 seems to do just fine on that count).  So provided we can figure out exactly what bits were used originally I'd be reasonably hopeful that we could get somewhere.

Or at the very least hopefully establish which pulleys are physically identical that we could use potentially as a rebuild candidate by transferring weights, springs etc over from an original set.

[Remspoor]

With all of that yellow hair I thought you had run over Michael Fabricant.  And that was the remains of his wig. Unfortunately I see he has turned up on TV again.

Is not the gear rod/linkage a solid bar?

[plasticvandan]

Can still see part of the belt in the pulleys wedging it open.

[LightBulbFun]

  On 08/04/2025 at 18:01, plasticvandan said:

Can still see part of the belt in the pulleys wedging it open.

Expand  

yeah I noticed that when poking about the other day, but the question is how to get it out of there without losing fingers in the process! luckily I still have the worlds-biggest-pair-of-tweezers from back when we used to keep snakes many years ago (used for grabbing a mouse by the tail and shaking it about to convince the noodle its still "alive") so I plan to use that to try fish out as many bits of fluff and drive-belt as I can from from the primary pulley, and I suppose for the secondary pulley (if I dont just end up replacing it) ill poke it with a sharp pry bar or such and hopefully cut the remains bits up small enough that it just pings clear under the spring pressure of the pulley sheave  trying to close

[dollywobbler]

That's not ideal. Well done for speedily getting to a relatively safe space. I took have learnt that the odd thwacking sound is a warning.

You should easily be able to do a pulley swap. It isn't too difficult. 

As for the earlier oil on the ground, the driveshaft seals use that term very loosely. A bit of camber can be enough to cause a leak.

[Zelandeth]

  On 09/04/2025 at 05:39, dollywobbler said:

That's not ideal. Well done for speedily getting to a relatively safe space. I took have learnt that the odd thwacking sound is a warning.

You should easily be able to do a pulley swap. It isn't too difficult. 

As for the earlier oil on the ground, the driveshaft seals use that term very loosely. A bit of camber can be enough to cause a leak.

Expand  

Seconded on both points - pulley swap is simple enough IF you can get the bolts out, that aside it's literally just "slide old ones off, make sure key is slotted into the keyway properly, align pulley, slide on, bolt on." Plus adding the locking tabs in your case.

I found on mine that a 3/8" socket extension through the ventilation holes in the back of the primary pulley was the most practical way of locking it more or less in place.

That poor ratchet definitely didn't get abused by having a 6' breaker bar slotted over it...nope, I deeeeeeefinitely used the bigger one.

TPA's gearbox also drools a fair bit from the driveshaft seals - has never lost enough to impact the level between when I changed it though.

[Pieman]

  On 08/04/2025 at 16:22, Remspoor said:

With all of that yellow hair I thought you had run over Michael Fabricant.  And that was the remains of his wig. Unfortunately I see he has turned up on TV again.

Expand  

You didn't have to suffer him as your local MP for years!

[LightBulbFun]

  On 09/04/2025 at 17:04, Zelandeth said:

That poor ratchet definitely didn't get abused by having a 6' breaker bar slotted over it...nope, I deeeeeeefinitely used the bigger one.

Expand  

thats why on the trip I did to Halfords for when @egg came to help me with the brakes, I picked up a dedicated 3/8th inch breaker bar  (because changing the drive belt and inspecting the pulleys has been on TheList(TM) for a while, and we had planned to do the drive-belt then, but the brakes ate up all the time) I just need a scaffolding pole now to slide over it  (in this particular case im hoping getting my brother to jump/heave on it will get things to yield)

[Zelandeth]

  On 09/04/2025 at 17:36, LightBulbFun said:

thats why on the trip I did to Halfords for when @egg came to help me with the brakes, I picked up a dedicated 3/8th inch breaker bar  (because changing the drive belt and inspecting the pulleys has been on TheList(TM) for a while, and we had planned to do the drive-belt then, but the brakes ate up all the time) I just need a scaffolding pole now to slide over it  (in this particular case im hoping getting my brother to jump/heave on it will get things to yield)

Expand  

My usual breaker bar is what is usually referred to as The Exhaust Pipe of Persuasion - it's a bit off the end of a Saab 900 Turbo tailpipe.  This is short enough that it's not completely impossible to use in closeish quarters.

There is also a 6-ish foot bit of actual scaffold pole out back for when I'm really serious!

[barefoot]

Did this manage to crack 400 miles since being brought back to life before shitting its transmission and manifold?

[LightBulbFun]

  On 09/04/2025 at 17:55, barefoot said:

Did this manage to crack 400 miles since being brought back to life before shitting its transmission and manifold?

Expand  

489 miles or there abouts is how long the drive belt lasted from her first drive around the FoD to depositing itself all over the M25  (her Manifold is fine AFAIK?)

in REV's defence the drive-belt/pulleys has always since day 1 been something I have wanted to look at/change on precaution, its something I have mentioned a fair few times over the years, my folly was not pushing harder in getting something done about it, but its no different to buying a car with unknown cambelt history, (as I have no service history for REV prior to me getting her and I know that she had been off the road since 2002 otherwise) so I dont blame REV the failure, the system once fully serviced is generally pretty reliable on a whole, as evidenced by the 8000 miles or so Dollywobbler and Zel have done combined, without any major issue

I would love to know what the service interval was for the drive-belt, I have never actually been able to find any dedicated service information for the Model 70, although I know in general they where given minor services every 3000 miles and major services every 6000 miles, but what those services encompassed I am not sure, but I would not be surprised if the major one included a drive-belt change, I suppose you could look at what the belt service intervials where for ATV's or DAF's to get some idea? (although I recall reading that DAF's sometimes had special extra durable belts)

[Zelandeth]

  On 09/04/2025 at 18:23, LightBulbFun said:

489 miles or there abouts is how long the drive belt lasted from her first drive around the FoD to depositing itself all over the M25  (her Manifold is fine AFAIK?)

in REV's defence the drive-belt/pulleys has always since day 1 been something I have wanted to look at/change on precaution, its something I have mentioned a fair few times over the years, my folly was not pushing harder in getting something done about it, but its no different to buying a car with unknown cambelt history, (as I have no service history for REV prior to me getting her and I know that she had been off the road since 2002 otherwise) so I dont blame REV the failure, the system once fully serviced is generally pretty reliable on a whole, as evidenced by the 8000 miles or so Dollywobbler and Zel have done combined, without any major issue

I would love to know what the service interval was for the drive-belt, I have never actually been able to find any dedicated service information for the Model 70, although I know in general they where given minor services every 3000 miles and major services every 6000 miles, but what those services encompassed I am not sure, but I would not be surprised if the major one included a drive-belt change, I suppose you could look at what the belt service intervials where for ATV's or DAF's to get some idea? (although I recall reading that DAF's sometimes had special extra durable belts)

Expand  

I'm sure I remember reading somewhere a maximum wear measurement for the belt somewhere which was checked in terms of how much width had been lost.  I suspect this would just have been checked at each service and it replaced as required based on that or any perishing being evident.  

I think the one which went pop on TPA had only been on there a couple of hundred miles if that, the reinforcement on it had just decomposed due to poor storage (as was a common theme with a huge number of the spares I got with KPL).  Replacement has been on there for at least a couple of thousand miles now and was still looking fine when I last checked - a proper health check is something which will need to happen sooner than later as I really did a half arsed job of that last year.

Belts would probably last near enough forever in normal town use - high speed driving though puts massive stresses on it - pulleys are probably spinning somewhere in the region of 4000rpm, and you'll know yourself that the belt isn't light - that's a LOT of centrifugal force pulling on the belt - in addition to the actual torque being transferred for the drive.

Which downpipe is it that you've got an issue with?  As of a few hours ago I have a pair of good ones in my possession (along with a few other goodies).

Exhaust bodges never last long, so be good to just get that changed over sooner than later.

[LightBulbFun]

offside rear right is the one thats mostly recently blown and then pasted, but the nearside left has been holed and then welded previously, so I think ideally they could both do with replacing in the long term, and while I do have a set of NOS downpipes in the 'Stash, I was wondering if I could get a set made up in stainless steel for longevity, and further to that, would having a whole batch of them made be worth it/drive the individual unit cost down? for example I would gladly pay to have 10 sets of downpipes made up in stainless steel, if the unit cost was much lower

of course if in the in-between someone would be willing to help me fit those used good ones, I would not complain, but I know exhaust work is generally a gruelling task, hence why I am thinking of going straight for some stainless ones if thats possible to do  

 

as an aside has that heat-exchanger been modified? the exhaust pipe on it looks longer then it should be, but not sure if its just the angle of the photo etc, heres my NOS example for comparison

 

glad to see you got the springs with the clutch shoes too  I have seen a case where the springs themselves had failed, so its good to have the complete package just incase