Project Dollywobbler's Invacar - Ongoing

[plasticvandan]

How i would love an Invacar,not least because I'm weird enough to use it to go to work,and with my legs getting worse as I get older there is a bit of sensibility there,but also so I could take it to see my 86 year old grandad,who now has a sort of selective dementia,whereby he's sort of living in the 50s and 60s in his mind when he was happiest,and he spent ten years working on,servicing,breakdown callout and driver training the things,he always has a story about them for me,he's probably one of the few able bodied people left to have invalid carriage on his licence.

[omegod]

He'd make a cracking subject for a hubnut special episode,  

[plasticvandan]

I took round an early 60s DHSS master catalogue with pics and specs of every different model that was available for issue,that was a huge memory jogger,followed by "where the hell did you find this!?"

[dollywobbler]

Today, I've been doing battle with the transmission. I managed to change the drive belt, but it's now squealing more than ever. I tried more tension, no change. I tried less tension, still ear-splittingly noisy. The pulleys are noticably buffed up to a mirror finish, presumably because of last weekend's mega-trek with squealing belts. A bit stuck now. I could take the pulleys from my spare transmission and swap them over, but it's not a fun job, and does require two people. I think I'm filing it under CAN'T BE ARSED for now.

[bub2006]

Try talcum powder

[dollywobbler]

Sod it. I'm feeling exhausted and have too much else on my plate at the moment. TWC can have a rest for a bit. Squeezed her into the far corner of the garage, so I can still get the 2CV in without too much bother.

[rantingYoof]

Is this a subliminal message that you're about to try and rescue a 929?

 

In all seriousness, I've been wondering how on earth you've kept your pace up in respect of videos and work and everything else!

 

Sent from my GT-I9505 using Tapatalk

[Squire_Dawson]

With fan belts at least, if the pulleys are glazed the advice is to get to work with coarse emery cloth. This is one of the few areas you want friction, to enable the belts to grip.

[Squire_Dawson]

Also, please treat the poor thing to some decent headlamp trim!

[dollywobbler]

Also, please treat the poor thing to some decent headlamp trim!

 

I have some. I just can't bring myself to remove the rusty remnants. I like them!  Thanks for the tip about roughing up the surfaces. I think it needs it. Next time I have some motivation anyway...

[Noel Tidybeard]

if you can get the pulleys off both trans whist TWC is restificating why not get them all sand blaster to give a nice not smooth finish?

[Eddie Honda]

Probably not a good idea

[dollywobbler]

Have just been chatting to a DAF fan who reckons polished pulleys are a good sign, because it shows the belt is riding up correctly. Recorded some video up my driveway of the pulleys, and the first one didn't seem to change ratio at all. That was only 20mph though. Definitely time for a break from this one. Workload is high, weekends are chock full. Plans are coming together for the Fox. 

[Sigmund Fraud]

Have just been chatting to a DAF fan who reckons polished pulleys are a good sign, because it shows the belt is riding up correctly.

 

He's right ! Are the replacement belts the correct profile ?

[dollywobbler]

Looks identical to what came off. It's a NOS belt.

[plasticvandan]

so a 40 year old hard rubber belt,is it not worth trying to get it matched for a new one?

[dollywobbler]

so a 40 year old hard rubber belt,is it not worth trying to get it matched for a new one?

 

I don't reckon so. They were packaged well. I doubt a drive belt would be that soft anyway given the stresses it'll be under.

[PhilA]

Oil ingress? The aux belt on my Renault is under moderate loads particularly with the aircon and the power steering fluid getting on it causes it to screech like a banshee when it slips.

 

Phil

[dollywobbler]

Oil ingress? The aux belt on my Renault is under moderate loads particularly with the aircon and the power steering fluid getting on it causes it to screech like a banshee when it slips.

 

Phil

 

Nope. Pulleys are nice and dry. It leaks in many places, but not onto the pulleys.

[LightBulbFun]

all this rubber band strife makes me wonder if its possible to fit some sort of chain in place of the main drive belt? (obviously no permanent modifications, I would personal want it to be something that can easily swapped over back to stock )

 

Im very much one for keeping things as stock but if for whatever reason the belts refuse to play ball then yeah Figured id pitch the chain drive idea since i dont think anyone else has?

[Louise2cv]

Would that not require a different kind of transmission? A gearbox? Or something.

[LightBulbFun]

Would that not require a different kind of transmission? A gearbox? Or something.

good point

 

thats what i get for trying to contribute something about cars 

 

I was thinking literally the engines output goes via a main belt of some kind but IIRC from DWs Videos and pictures the Gearbox bolts directly onto the engine like a normal engine gear box setup

So i guess when DW says drive belt he is referring to the CVT bit which yeah I dont think you can replace with a chain...

[Louise2cv]

Don't get me wrong, it was a question not a statement. I have no real idea how it works.

[RayMK]

CVT belt set-ups have to have some means of loading the sidewalls of the belt so that power* can be transmitted.  One of the pulleys usually contains the centrifugally activated gear change mechanism while the other adjusts to suit, maintaining tension on the belt by powerful spings operating on the pulley axis.  Basic belt tension to meet specification  is adjusted by moving the pulleys closer or further apart but if the spring loading is not operating correctly (through wear, crud or breakage) the belt may still slip.  

 

Note: my experience is from owning a couple of Volvo 66s which were of course DAFs with Swedish make-up (i.e. Huge bumpers).

[Eddie Honda]

I was working on a DAF55 once. The owner was struggling to fit a pair of NOS belts he had. The belts were OEM and had number on them, but their size wasn't. It was like they had shrunk in the wash...

 

Anyway, back to TWC. If the belt is squealing then it must be slipping. Why is it slipping? When is it slipping? Is the tension correct? Is it losing this tension under certain conditions and hence squealing?

 

A vehicle can still work* with rather slack belts. They'll initially squeal when moving off, but then self tension, however the gearing is all to cock.

 

Pulleys should be nice and smooth. If they have corrosion/sharp edges to pitting on them they'll eat belts.

[dollywobbler]

I was working on a DAF55 once. The owner was struggling to fit a pair of NOS belts he had. The belts were OEM and had number on them, but their size wasn't. It was like they had shrunk in the wash...

 

Anyway, back to TWC. If the belt is squealing then it must be slipping. Why is it slipping? When is it slipping? Is the tension correct? Is it losing this tension under certain conditions and hence squealing?

 

A vehicle can still work* with rather slack belts. They'll initially squeal when moving off, but then self tension, however the gearing is all to cock.

 

Pulleys should be nice and smooth. If they have corrosion/sharp edges to pitting on them they'll eat belts.

 

Squealing when slowing from 20mph, or when reaching 30mph all the way up to 50 now. It was quietening down above 40. It seems to be far worse with the new belt, and it feels like the engine is over-revving above 40.

[PhilA]

Sounds like the sprung side that supports the tension when the centrifugal side changes isn't sliding correctly, perhaps?

[dollywobbler]

Sounds like the sprung side that supports the tension when the centrifugal side changes isn't sliding correctly, perhaps?

 

Sprung side does seem to be changing ratio correctly (second pulley). What I can't work out is how the ratio adjusts on pulley one. I can only comment up to 20mph, but it doesn't seem to be gearing up. Perhaps tension related. I have tried different tensions with no appreciable difference. Belt shouldn't be super-taught at rest position, but the service manual has NO information about what the tension should be.

[catsinthewelder]

Can you try in really early one morning when it isn't too hot?  We were really struggling at the mower racing with the belts getting too hot and either slipping or coming off the pulleys.

[Sigmund Fraud]

Ian, does your manual have a diagram of the CVT system ?

 

The DAF system uses two variators (i.e. both pulleys change gear), but there are simpler versions of the CVT (i.e. the Mobylette Mobymatic) which use a single variator. Perhaps the Invacar system is like the latter ?

 

Regarding the slipping belt, aging rubber may be the reason. Even when stored correctly, a 40-year-old belt is bound to have hardened significantly.