Ongoing Vitesse clutch trouble.

[Steve P]

Sure i posted on this a while ago but cannot find it,so here goes...

Mk 1 Vitesse CV,2.5 PI engine with Saloon o/d box,Sprint cross shaft upside down with trimmed slave lever.

Last year the car became difficult to get in gear,i checked all the hydraulics and they seemed ok,swapped the slave cylinder just because i had one,no difference.

I looked at the slave pushrod to see if it was too short,it had to be trimmed as the full length one wont fit on this setup,i bought another one and made it 3/4 of an inch longer than the one in there,drove it,hey presto,easy to get in gear,no crunching.

Put it all back together,tunnel and carpet in etc. decided to go down the coast,first attempt at hard acceleration resulted in big slippage..

Tried another pushrod in between the 2 lengths,ok while moving but cant get it in gear when stationery.

It definitely seems to be not enough pedal travel,i wondered if because i still have the Vitesse master cylinder with a saloon slave maybe this may be the issue?,obviously when the clutch is brand new it might not matter?.Engine and clutch is about 15000 miles old.

Pretty sure it was a decent spec AP clutch.

Sorry for the long post but i really don`t want to take the box out unless absolutely necessary.

Steve

 

 

[Clive]

What carrier are you using for the relief bearing? I used the same setup as you on my vitesse, and found the carrier was too short really, made the clutch heavy and difficult. I never dd fix it....but I think there is a different carrier. And I can't remember if it is off another car or a "special". Mike Papworth may be able to help.

I suppose the other option is to use a larger master cylinder...cheap landrover ones are 0.75 bore.

[Nick Jones]

The saloon/Sprint/Stag box is somewhat notorious for problems with the attachment for the fork to the cross-shaft....... though this wouldn't explain your slippage problems.

Pretty sure that my PI had a 5/8" MC, which should be what your Vitesse has?

Saloon clutch lever usually has a choice of holes for pushrod attachment, does yours?  Do you know whether the slave cylinder is 7/8" (original I think) or 1" (Landrover).  You might also want to take a look at the arc of movement of the external clutch lever.  Ideally it should reach vertical about half-way through the operating arc. If substantially offset one way or the other then motion is lost.

You could try making and adjustable pushrod so you can get the ideal length, but if there is no lost motion and still not enough stroke you really have not option but to try a 0.7" MC.  This will make the pedal action heavier but usefully increase slave travel.

As an aside, or illustration, I have the same issue, though probably for different reason(s).  I have a Toyota W58  5 speed gearbox fitted. This uses a hybrid bell housing and hybrid clutch. The clutch itself is a BW pressure plate with a specially made Helix friction plate. The release bearing is a Toyota one that happens to have the right diameter and profile.  The release mechanism is hydraulic and is the Toyota system complete, including slave cylinder.  The master is Girling.  When first assembled it had a 5/8" cylinder, was wonderfully light in operation and biting point close to the top. However, over first 5k miles of use the pedal action got steadily heavier and the biting point lower until getting gears was problematic unless pedal mashed into the carpet.  Couldn't find any air or lost motion so I fixed the symptoms with a 0.7" MC. This has also worked for about 5 - 6K but once again the biting point has gone from near the top to near the bottom and I was considering my next move when the MC started leaking a bit and I've ended up fitting a 3/4" MC because I had one handy - which has got the clutch working properly again, though rather heavier than it was.  Clearly there is something wrong with the geometry, but I can't see what as the Toyota mechanism is very similar in operation to the original Vitesse one...... In my case it's possible that the fact that the Vitesse clutch is quite alot smaller in diameter than the really quite large Supra one, the greater angle change of the diaphragm fingers with wear is causing the problem.  It's pretty irritating though.

Nick

[sulzerman]

Hello 

I have had this problem with my saloon, all parts need to be in perfect condition any play / wear and it won't work!  I had wear in the release mechanism which allowed slight play. 

Hope this helps

[Clive]

Just double checked a thought. Dolly sprint slave cylinders are 7/8 bore, the same as vitesse 1600.

The saloon is a 1" bore. So you are getting less movement than needed from your 0.65 master cylinder. (as you are effectively using a sprint setup in terms of mechanism etc)

If you change to a 0.75 master( the easiest route) it will get the size ratios back to match the sprint setup. 

(a sprint slave has a bigger hydraulic connection, the vitesse 1600 slave would fit your setup perfectly and is the other option. I have a vitesse 1600 slave on my sprint gearbox, with 0.65 spitfire etc master and it is perfect)

[Pete Lewis]

I would guess the slipage was due to the extended rod being  too long and the slave bottomed out

I remember your first post as I didnt realise the slave was fitted above not below the crosshaft

Can you measure the travel the slave is giving for a full pedal depress ???

Whats the angle of the  operating lever   \ |  /  ?

[Steve P]

Thanks for the replies,clutch master is the original whatever size that is.Slave is a PI one which looks the same as the one i had on there which was probably a normal saloon one.

Slippage was due to the rod being too long and the clutch not disengaging enough,i will go to my lockup later and have a look at the travel of the arm,it definitely doesn`t feel there`s enough travel.

Only one option for the pin on the arm Nick.

I remember when first built i had a bearing carrier that was half an inch longer than standard but the clutch didn`t feel right,i put a brass one on it and it has been fine until the issues started.

I think the fact i could get it in gear without issue with the long rod in probably means the friction plate isn`t knackered.I will investigate Clives combo of master and slave.

 

Cheers

Steve

[Pete Lewis]

Have you tried bleed with the slave piston pushed in fully to reduce volume , it can sometimes help get any trapped wind 

Pete

[Steve P]

I can try that Pete,i`ve ordered a Vitesse 1600 slave to see what that does.

Steve

[Steve P]

More advice needed..

tried to fit a 1600 slave today,shortened the rod by about an inch as the slave sits further forward,problem is the pipe fitting is smaller on the 1600 slave.

Looked at various suppliers and all list one pipe for sixes and one for four cylinder units,no idea whether to get a new pipe or just a fitting and a flaring tool,if so what size?.

 

Cheers

Steve

[Pete Lewis]

1600 is a 7/8" bore slave , i thought all pipe union threads were 3/8unf    1/4 " pipe  single flare

good old parts list only shows pipe as assy, so cant get to a part number to check the union thread and my old one  is lost in the back of the shed 

 

 

[NonMember]

All the clutch plumbing on the small chassis cars was 1/4" pipe with 3/8" UNF fittings. The clutch plumbing on Dolomites is different - larger fittings. I can't remember off-hand which the big saloons used (since Steve mentioned earlier that the old slave was a PI one).

[Nick Jones]

Saloons have 7/16 UNF fittings, not sure on the pipe size

Nick

[Steve P]

Got the pipe fitting changed by my local old school garage.Fitted the 1600 slave and...no difference,can`t get the bloody thing in gear and the arm seems to be so close to the

bell housing when clutch is pressed there must be something going on with the carrier.

I suppose it will have to come out,which is a right royal pita.

Must change my signature to 0 triumphs working.

Steve

[Pete Lewis]

So it could be the dreaded taper dowel  bolt has sheared , , if it has with luck there is a small hole in the withdrawl lever to drift the remains out otherwise you can't get the lever off the shaft 

There is a heavt duty toughen  ????     dowel avalable from some suppliers

 ive done 3 big boxes and all have had a failed dowel bolt

Pete

 

[Clive]

13 hours ago, Steve P said:

Got the pipe fitting changed by my local old school garage.Fitted the 1600 slave and...no difference,can`t get the bloody thing in gear and the arm seems to be so close to the

bell housing when clutch is pressed there must be something going on with the carrier.

I suppose it will have to come out,which is a right royal pita.

Must change my signature to 0 triumphs working.

Steve

I think a call to Mr Papworth may be worthwhile. As my previous post, I am pretty sure the std vitesse bearing carrier is too short and messes the angles up. I wonder if a stag/sprint or maybe 1850 carrier may be more suitable.

But worth checking the crossshaft bolt too. They are always a PITA.

[Steve P]

Hello Clive,i have a specially made extension for the carrier which increases it by about an inch,i think because i have a Vitesse flywheel which is shallower anyway.

The extension was originally fitted,i cant for the life of me remember why i changed it,i remember the original carrier was steel and i fitted a brass one and all was ok until now.

Going to start taking it out at the weekend.

Steve

[Steve P]

Spoke to Mike Papworth,he reckons it`s taper pin..

Steve

 

[Pete Lewis]

Rimmers uprated dowel pin  is 158777UR

bear in mind a failed pin can damage the shaft location and a new pin can fail quickly , theres a lot of mention about lapping the dowel ,  to make a nice fit

cant see triumph ever did that on the assy line .,  but all taper dowels like these can be a swine to undo they get a real grip and you need a decent fitting socket to not tear the square head to bits 

always worth a browse is theres  some alternatives mentioned 

http://www.buckeyetriumphs.org/technical/clutch/ClutchShaft/ClutchShaft.htm

[Steve P]

Thread update..

Finally wrestled the box out today,nothing wrong with the taper pin or cross shaft which is a bit disappointing,the bearing is definitely noisy and knackered,can`t get the clutch off as it`s got imperial hex head bolts and i can`t find one to fit it.Hopefully it`s just worn out but i thought it would do more than the 12k its done.

I have a bearing carrier extender which i will try and post a picture of to see what people more knowledgeable than me think on the travel issue.

Steve

[Steve P]

Got the clutch out today,only about 2mm of friction material each side of the plate,cover is ok.Plate is an 8.5 inch 10 spline.

Need to get the geometry of the operation right before i put it back together.

Any advice appreciated,e mailing Mike Papworth now.

Steve

[Nick Jones]

A thought.

You seem to be saying that the friction plate has worn very quickly and you had problems with overt slip when you tried longer pushrods, yet still had problems with failure to clear.

As I’m sure you know, the cone angle of the clutch diaphragm fingers when everything is bolted up to the flywheel gives a pretty good wear indication. When you first fit a new clutch, the fingers will be near flat, but as you approach the worn-out point they become noticeably conical. This means that when you set a release mechanism up with a new clutch you need to be sure that everything has enough travel to allow the carrier assembly to move back gradually as wear occurs. Without this, you will get a situation where the clutch cannot fully release, so will bite less well, slip a bit more and wear faster. You may also get a situation, when  the limiting factor is mechanical, where the hydraulics don’t reset between operations so you don’t get a full stroke.

I think that is a long winded way of saying that you check that your carrier is not (counter intuitively) too long.

Nick

[Steve P]

Hi Nick,

I removed the extension and fitted the brass carrier i had when it was first fitted,i think the issue is the angle of the operating arm is past vertical towards the bell housing when clutch not depressed and almost touching the bell housing when fully depressed,i think this means the carrier is too short because of the difference in the Vitesse and saloon flywheels.

Steve

[Nick Jones]

Ah, ok.  I would agree with your diagnosis Doctor.  The extreme angle is costing you motion.  Dolly Sprint carriers are very long.  Certainly too long, but could be shortened.

Nick

[Steve P]

Update:

Finally got the Vitesse back together after deciding to try a different clutch described as "stage 3",it has a friction plate that is very thin and resembles fine grade sandpaper,the cover has a 3 sided metal disc on the fingers,after doing some measurements on travel,with my brass carrier it altered the geometry to what i thought would be better,i.e \ before depressed and vertical when pressed.

The pedal felt ok so i got it running and it went into gear fine,shuffling backwards and forwards in the garage seemed ok,finally drove it without the tunnel on on Saturday,the bite point is right at the top of the pedal,the clutch is very light but,it doesn`t slip so i am going to bolt it back together and see how it goes.

Fingers crossed it lasts.

Steve