Project Dollywobbler's Invacar - Ongoing

[dollywobbler]

Here's a shopping shot.

[Talbot]

it says don't even attempt repairs.

There's a challenge if ever I heard one...

 

Have you still got the spare transmission from the other car?

[dollywobbler]

Yes. Still have that. Am wondering about swapping the pulleys over and seeing if that changes anything. Meeting a friend for tea later, buy may yet get some tinkering time.

[RayMK]

I enjoyed the latest TWC video.  Fabulous country lanes, exciting weather, surprising speed around bends and all done on three wheels.  Who needs more  ?

 

When you showed the CVT operating with the car on stands, the left hand pulley appeared to have a step change when slowing down.  This may make it reluctant to change ratio when under load and slowing down up hill.  Lubricating the pulley shafts could improve matters if there's any access and of course provided that the lubricant stays put and is not sprayed over the belt.  Perhaps there is a wear step on the shaft(s).  Some CVTs key the sliding half of the pulley to the shaft using ball bearings in axial slots.  The balls can chatter at frequently experienced ratios - usually those applicable to cruising speed - and a step in the shaft groove is carved out.  Under load, this can prevent ratio change unless the throttle is briefly relaxed.  Just a thought, but I have no idea what your CVT looks like inside.  

[PhilA]

Watching the video it seemed quite reluctant to change ratio down when climbing the hill and when it did, it seemed to jump quite a bit in one go. Was that the case or is that just my perception from the film?

 

If so, maybe the pulley shaft has a notch causing it to stick at maximum when it's got road wheel load on the belt/pulleys?

 

 

Phil

 

 

Edit: RayMK beat me to it

[PhilA]

Plus my experience of these things is limited to golf carts...

[RayMK]

Watching the video it seemed quite reluctant to change ratio down when climbing the hill and when it did, it seemed to jump quite a bit in one go. Was that the case or is that just my perception from the film?

 

If so, maybe the pulley shaft has a notch causing it to stick at maximum when it's got road wheel load on the belt/pulleys?

 

 

Phil

 

 

Edit: RayMK beat me to it

 

Great minds think alike   (possibly).  I've had a couple of CVT Volvo 66s over the years and currently have a Mitsubishi Mirage with a modern interpretation of the CVT belt principle.  Notchy ratio changes can have a number of causes but the shaft sliders are a favourite starting point in investigations.  

[SiC]

Do you have a spare camera to aim at the engine/pulley system when you're driving? Would make an interesting video (at least for me) but may help diagnose what's going on.

[PhilA]

Ray, my experience is that under load the engine revs mostly stay high with the sound of it laboring less (as the speed of the pulleys decreases and they slip back down the ratio).

 

There shouldn't be an "Oh, there it goes" moment anywhere, from what I understand unless there's a pawl or ratchet arrangement to make it stay put longer.

 

Phil

[RayMK]

Ray, my experience is that under load the engine revs mostly stay high with the sound of it laboring less (as the speed of the pulleys decreases and they slip back down the ratio).

 

There shouldn't be an "Oh, there it goes" moment anywhere, from what I understand unless there's a pawl or ratchet arrangement to make it stay put longer.

 

Phil

 

My Volvos had a low ratio hold switch which allowed engine vacuum acting on a large diaphragm in first set of pulleys to modify the CVT response.  This was mainly intended for increased engine braking when going downhill.  The diaphragms also operated to give a more rapid CVT response when accelerating.  The Mirage, being modern, with its CVT 'pushbelt'  controlled by oil pressure and electronics is very smooth and usually holds 2000rpm when accelerating gently to 70mph.  A heavy foot causes the ratio to change to hold 3000rpm until cruising speed is reached. A similar but more rapid effect is available by using the 'sport/low ratio' detent position on the autobox lever.  Left to operate normally, CVTs as you stated should hold almost constant revs whilst the ratio is adjusted to suit load and speed.  Mr DW has not mentioned any ratio hold controls apart from the bungee cord.  The problem with dismantling a CVT without a manual is that bits normally fall out on releasing components, leaving an interesting chinese puzzle to solve.  People with experience of dismantling Invacars are probably getting thin on the ground but finding someone would be useful.  If I wasn't such a cripple I'd be interested in having an Invacar.  It looks like great fun.  Hang on........ .

[dollywobbler]

Bleaurgh.

 

I enjoyed the latest TWC video.  Fabulous country lanes, exciting weather, surprising speed around bends and all done on three wheels.  Who needs more  ?

 

When you showed the CVT operating with the car on stands, the left hand pulley appeared to have a step change when slowing down.  This may make it reluctant to change ratio when under load and slowing down up hill.  Lubricating the pulley shafts could improve matters if there's any access and of course provided that the lubricant stays put and is not sprayed over the belt.  Perhaps there is a wear step on the shaft(s).  Some CVTs key the sliding half of the pulley to the shaft using ball bearings in axial slots.  The balls can chatter at frequently experienced ratios - usually those applicable to cruising speed - and a step in the shaft groove is carved out.  Under load, this can prevent ratio change unless the throttle is briefly relaxed.  Just a thought, but I have no idea what your CVT looks like inside.  

 

Yes, I had noticed that, so bit the bullet this afternoon and whipped the pulleys off again. Sure enough, the power pulley was squeaking as I operated it, so I spent a goodly while lubing it up inside. The shaft shows pitting in places, so I tried to clean that up as best I could. The spares one is entirely seized, so that's no quick fix. 

[dollywobbler]

Transmission woes remain, but that's ok. TWC has been stuck in the garage, buried by building materials for a week or so. She burst free into the sunshine today for a quick, and hilarious, razz about the countryside. 

[dollywobbler]

Having got a bit fed up with the iffy transmission, I decided to head out to a local-ish car run anyway. I'm glad I did! 30 miles later, I met this lot of lovelies.

 

Here's a rather nice shot taken by the Hillman Husky owner later on.

 

After a huge queue to get out on the run, not helped by emergency roadworks about 300yds from the start point, we got under way, and TWC did pretty well. Until we got to a big hill. That was a 20mph slog all the way up, but it was notable that only the Volvo stayed with me as we hurtled down the other side!

 

Here's a photo taken by me when we brought Aberdyfi to a standstill. There's an Audi R8 two cars in front of me, but one lady came up to me to say my car was her favourite. WINNING. Generally, this car makes ladies smile in a way my face just doesn't.

 

110 miles later, we arrived back home. Phew!

 

Transmission now sounds awful. There's a proper nasty bearing noise on the overrun. It goes much quieter under power. Next appearance is at the NEC in November, and I was planning to drive her there. It's a similar mileage to today. Maybe I should wuss out for once...

[busmansholiday]

... Maybe I should wuss out for once

Might as well cancel the event then !

[dollywobbler]

Might as well cancel the event then !

 

Oh she'll still be there, I just wonder about the sanity of driving over 100 miles there. Quiet Welsh roads are one thing, Birmingham quite another.

[SiC]

Next appearance is at the NEC in November, and I was planning to drive her there. It's a similar mileage to today. Maybe I should wuss out for once...

Noooo! Please don't! I'm just about to book my tickets for the NEC and would love to see this.

[dollywobbler]

Noooo! Please don't! I'm just about to book my tickets for the NEC and would love to see this.

 

I won't wuss out of the appearance, only the method of transport. She was sounding bloody awful by the time we got back.

[dollywobbler]

Fun times (and another crap phone mount).

[Braddon81]

Fancy another?? Seen this posted as a field find on Facebook. It's in West Wales....☺️

[SiC]

It's not TWC after DW taking a corner a bit too exuberantly?

[dollywobbler]

Wow. I can confirm it isn't TWC. Where's that then?

[LightBulbFun]

is that a current photo? Defo worth chasing after the more invacars saved the better

 

(he says trying to find an invacar himself from a 9 year old picture... can you tell I really want a/like invacars?  )

 

also woo! more TWC updates she seems to pick up and go pretty damn well now on flat ground. also sounds like (literally ) that the belts are no longer slipping anymore?

 

also those external shots of TWC on the move where really cool! (and the new windscreen/dash facing angle is pretty cool too )

[greengartside]

I was just thinking of you! Something like this would be ideal, no?

[dollywobbler]

 

also woo! more TWC updates she seems to pick up and go pretty damn well now on flat ground. also sounds like (literally ) that the belts are no longer slipping anymore?

 

also those external shots of TWC on the move where really cool! (and the new windscreen/dash facing angle is pretty cool too )

 

There's still something pretty badly wrong with the transmission. She shouldn't struggle that much on hills. I reckon one reason she's so quick on the flat is because she's going into 'high ratio' too early. On the flat, the engine has enough grunt to just get you moving. The slightest hill soon has the speed bleeding away though. If you're in the sweet spot of torque at about 45mph, she can just about hold her own, but once the gradient knocks off a bit more pace, you're a worried passenger. Given the gearbox is now making some horrific bearing noises (at least, I assume it's that and not a rear wheel bearing, I will check) I am wondering about swapping transmissions. 

[LightBulbFun]

I was just thinking of you! Something like this would be ideal, no?

 

thats what im thinking too 

 

hence why I have this thread http://autoshite.com/topic/32723-help-finding-an-abandoned-invacar-and-general-ramble-thread and if anyone happens to have an invacar sitting around getting in the way, gimme shout 

 

 

 

There's still something pretty badly wrong with the transmission. She shouldn't struggle that much on hills. I reckon one reason she's so quick on the flat is because she's going into 'high ratio' too early. On the flat, the engine has enough grunt to just get you moving. The slightest hill soon has the speed bleeding away though. If you're in the sweet spot of torque at about 45mph, she can just about hold her own, but once the gradient knocks off a bit more pace, you're a worried passenger. Given the gearbox is now making some horrific bearing noises (at least, I assume it's that and not a rear wheel bearing, I will check) I am wondering about swapping transmissions. 

 

thats a good point I dont think the transmission out of TPA was ever tested was it?

 

if the grinding noise is from the gearbox where do you think it would be coming from specifically and do you think its repairable?

[dollywobbler]

 

if the grinding noise is from the gearbox where do you think it would be coming from specifically and do you think its repairable?

 

Plenty of bearings inside a gearbox. It could be a wheel bearing though. Won't know until I can investigate, but we're trying to fit a bathroom at the moment, so no time for tinkering!

[Zelandeth]

Given you've always had issues with her wanting to jump out of gear it does suggest there might be excessive play somewhere.

 

Time to get selector on the gearbox from TP freed off maybe...

 

Sadly while I've got quite a few bits and pieces by way of spares, a gearbox isn't one of them.

 

 

I need to get to a post office this week so will try to get the spare governor packed up and on the way to you anyway as it sounds like that's the root cause of your hill troubles.

[dollywobbler]

Given you've always had issues with her wanting to jump out of gear it does suggest there might be excessive play somewhere.

 

Time to get selector on the gearbox from TP freed off maybe...

 

Sadly while I've got quite a few bits and pieces by way of spares, a gearbox isn't one of them.

 

 

I need to get to a post office this week so will try to get the spare governor packed up and on the way to you anyway as it sounds like that's the root cause of your hill troubles.

 

Thanks. Happy to discuss money, as I guess it'll cost a fair whack to post.

[Braddon81]

Wow. I can confirm it isn't TWC. Where's that then?

It's down in Pembrokeshire. Amongst a field of other decomposing chod.

[dollywobbler]

Something rather beautiful about that. When I visited Wales as a child, the countryside was always littered with rusty old shite. Probably why I fell in love with the place (and feel the need to replicate it in my garden).