Corse I CV joints

[hollytree]

Hi all
Great day at Stoneleigh yesterday... until I went home.
Loud bang from rear and on rolling slowly a lot of drag.
Nothing obvious and nothing rubbing.
Drove a bit more and all OK. Got to exit of park and few more bangs. Still nothing obvious, so drove off taking thing as easy.
Got as far as Northampton junction of M1 and bangs started again but lose worse. Crawled on M-way and got a lorry to pick us up and take home.
Will go and start looking shortly, but I think it might be CV joint breaking up.

Is there any history of CV joint failures on Corse I.
I have 17" rears and the offset angle on the left shaft looks about 30deg.
Is there a limit of how much offset the driveshaft can comfortably operate at?

Any other ideas?

Steve

[hollytree]

Car on stands at rear.
Took left drive shaft off. Nothing obvious, no broken bits.
Rear right wheel all still connected, no noise, spins freely.
Left hub all OK, spins freely.

This all starting to point to left drive shaft and CV joint(s).

Do I just order new CV joints and fit them.
Alfa 164 ones?
Should I be looking at anything special?

Steve

[ProtoTipo]

Do I just order new CV joints and fit them.
Alfa 164 ones?
Should I be looking at anything special?

Steve

Does anything bind on either shaft, lengthways through the full suspension travel with the spring removed?

If you need new CVs I would think any known, good quality make would be fine.

[john]

The normal Corse I set up is Ford outer, Alfa inner. I have part numbers but not to hand for a day or two.

[john]

Was there any evidence that the boot had wound up indicating that the outer part if the joint has revolved more than the inner?

[hollytree]

No evidence of over twisting when look at rubber covers.
The outer felt "notchy". I took the circlip off the drive shaft and slid the shaft out.
The inner and out cage and all the balls dropped out.
No broken bits or obvious signs of damage.
Placed the the balls back in from the outside (is it all meant to come apart)
Put it all back in the main housing, one ball rolled off.
It is all in place now, but with only 5 balls and jammed rock solid.
Cant get it apart now!

[hollytree]

The normal Corse I set up is Ford outer, Alfa inner. I have part numbers but not to hand for a day or two.

John
Thanks
When you send the PNs i will do all 4.
Ta
steve

[hollytree]

Are there any known problems with Corse I rear geometry.
Are the CV alignment angles OK with 17" wheels
Normal position left and right below
steve

12978

12977

[john]

I don't think you have a problem because you are running 17" wheels because the rolling diameter is not radically different to 15" or 16". What ride height do you have under the chassis at the rear? It's not jacked right up is it?

[Strat Fan]

Are there any known problems with Corse I rear geometry.
Are the CV alignment angles OK with 17" wheels
steve

The Corse CV's have plunge at either end, if the shaft is to long or too short the cage and balls can move beyond their operating range and cause the joint to baulk or jam. I would expect the cage to be damaged.
Yes, you can assemble and disassemble the CV's once they are off the shaft. There is a right way and a wrong way to reassemble them though, the grooves in the two halves need to opposed to each other to allow the CV to work as it should ie rotate and plunge. If you assemble them 1/6th of a turn out they will lock and not rotate.
Wheel diameter should not be an issue unless the engine is mounted ridiculously low which I do not think it is. I think you need to check the distance between the flanges vs the length of the drive shaft with the CV's in their central position.

[ProtoTipo]

Steve,
Why are the spring seats at different heights, left to right?

[Strat Fan]

Are there any known problems with Corse I rear geometry.
Are the CV alignment angles OK with 17" wheels




The other thing you need to look at is the length of the dampers and their position relative to the ride height of the car?
Have you got too much travel which is leading to too much droop.
How high is the drive flange above the bottom of the chassis
How much rear camber are you running etc etc
The right hand shaft is longer so is subjected to less angle change,
As Chris says why is one spring pan higher up the damper than the other?
The shaft looks to be almost parallel to the lower wishbone so the length change through motion should not be excessive.
More information is needed to determine why it has failed

[hollytree]

Steve,
Why is are the spring seats at different heights, left to right?

More weight on left (gearbox?).
Thats what i needed to set them at for the same clearances in the arches.

[hollytree]

The other thing you need to look at is the length of the dampers and their position relative to the ride height of the car?
Have you got too much travel which is leading to too much droop.
How high is the drive flange above the bottom of the chassis
How much rear camber are you running etc etc
The right hand shaft is longer so is subjected to less angle change,
As Chris says why is one spring pan higher up the damper than the other?
The shaft looks to be almost parallel to the lower wishbone so the length change through motion should not be excessive.
More information is needed to determine why it has failed

Got the suspension all correctly set up a couple of times, and a checked again on Saturday before driving up on Sunday.
Did the springs before I broke my leg. They are 600lb ones. Possibly too soft?
I have that much clearance to stop the tyres hitting the bodywork at the 10 oclock position when cornering hard.

EDIT
Looks like the outer CVs 86mm PCD are ref VKJA 8688 or PJ11N
Inners PJ89N

[Paul]

I wouldn't have thought 600lb springs too soft - my Corse I has 450lb in the rear which I'm happy with from a ride/stiffness trade-off standpoint (this in on a way without anti-roll bars). I solved the issue of wheels hitting the bodywork in bump by removing (quite a bit of) material from both the arch lip on the clam and the inner arch area on the main tub until I got enough clearance. Now it's the damper bump stops that limit travel. This gave me roughly equal bump and droop distances. Otherwise either my ride height would have been off and/or very little bump and too much droop.

[hollytree]

Talking to the ever helpful Craig, it is apparent that whilst the double wishbone rear is a great idea, nobody ever actually completed the design in that, the top mounts of the dampers are too high to stop the wheels hitting the bodywork, and I don't think droop was thought about to limit damper extension to stop drive shafts pulling on the CV joints.
AVO can add more bump stops to the top of the damper rods, though really the triangular top damper mounts need to be revised to lower the top damper fixing hole.
AVO are also going to put stops on my damper rods to reduce droop a bit.
I will see where that all ends up.

[strat24v]

Rally cars used a cable to limit droop.

[gtmpaul]

Rally cars used a cable to limit droop.

My brothers Astra rally car has them on the rear to stop the beam dropping to much and the springs coming off their seats.

[john]

Yes, the Corse I design seems always to have been in a state of flux. You can see differences in virtually all photographs of the early cars and not just between the Honda and Alfa engined cars. Damper and spring lengths were never sorted properly and those triangular top mounting plates front and rear just added to the confusion. Lionel just ordered part numbers supplied by Hugh Carson with out much thought as to if they were right or not. IIRC we tried different lengths of damper on Micks first car but he resolved matters with extra bump stops in the end. Steve Ellis fabricated new damper mounts front and rear.
I guess the lesson is for anyone building to check suspension movements very thoroughly with the springs off to make sure nothing binds up or reaches the limit of its travel throughout its range.
Looks like you have the part numbers for new joints now Steve? Shaft length is another matter.

[hollytree]

The original inner and outer joints both had single circlips on the drive shaft with 2 holes in the end for circlip pliers.
The new inner - Alfa - came with the same style circlip.
The new outer - Ford - came with something that looks like a concave thrust washer and a circlip without any holes.

Does anybody know what I do with these 2 parts, or do I just replace the original circlip?

EDIT
It is for certain applications, but not how I will be using it. So original circlip back on.
12989

[hollytree]

Changed the bearings
Got the dampers back from AVO. Had the damper rods shortened by 1.5 inches.
Added 2 more bump stops to each damper. They now have 3 bump stops each - shows how wrong the damper top mounts are in respect of wheel/body position.
Put it all back together and lowered the rear of the car about an inch (was high before to avoid hitting body as I didnt have enough bump stops)
Have about 2" suspension travel in compression and about 2" in extension
Drive shafts at much better angle now.
At full droop now have 1-2 mm of shaft plunge
Car feels a lot better, and no noise.

[Two-Eight-Six]

Any photos - before and after, even?

[hollytree]

before at top of thread.
after below
Steve
13016

[Two-Eight-Six]

Thanks, Steve.

I can see the drive shaft looks a lot happier, with less of an extreme angle, but blue rings (are they the bump stops, or would they be at top of travel...?) and the height of adjustment nut look the same as in first photo.

Any change at top of damper, apart from shortened rod length?

[hollytree]

the blue springs are helpers, for when they go go full droop.
The adjustment looks the same, but dont forget the dampers are effectively 40mm shorter.
Please below post about springs/dampers. Neil is the real brain.

https://www.stratosec.com/Forum/showthread.php/2459-Corse-I-rear-spring-rates?highlight=corse+spring

[hollytree]

Well
Went for a short drive with the new CVs fitted. Got 400yds and loud bang again..........
Set off for home, and all quiet so carried on with my short drive.
After 2 miles parked up and crawled under.
Right hand side CVs cold and hub/disc cold.
Left hand side inner CV cold.
Outer CV and hub hot!

So either the new CV with 2 mins use on it is defective, or the wheel bearing may have been the culprit all along?
Anyone have any ideas what causes the load bangs?

Anyone have any idea what bearing is in the rear hub of a Corse I, and how difficult to get in/out?

Ta
steve

[ChrisC]

Are you sure it is nothing to do with brake pads, usual cause of things getting hot around hubs.

[strat24v]

Is one cv plunging to its limit and a ball popping part way out? What are you using to limit the plunge?

[hollytree]

Is one cv plunging to its limit and a ball popping part way out? What are you using to limit the plunge?

There are no limits on the shafts to stop excess plunge. The shaft goes in through the gaiter, through the bearing and then a circlip goes on to stop it all falling out.
This is the same both ends of the driveshafts, both the inner and out CVs.
I have checked and now limited the droop, so that at full extension there is still side-to -side movement, so that the circlip is not trying to pull on the cages.
I have also jacked up the car and spun the wheels when at full droop when holding and pushing the driveshafts fully towards the gearbox, and fully towards the hub to see if any noise,contact etc. All negative.

[hollytree]

Are you sure it is nothing to do with brake pads, usual cause of things getting hot around hubs.

Will now look at those, but what would be the loud bang and feeling of big knock to the car?

[strat24v]

There are no limits on the shafts to stop excess plunge. The shaft goes in through the gaiter, through the bearing and then a circlip goes on to stop it all falling out.
This is the same both ends of the driveshafts, both the inner and out CVs.
I have checked and now limited the droop, so that at full extension there is still side-to -side movement, so that the circlip is not trying to pull on the cages.
I have also jacked up the car and spun the wheels when at full droop when holding and pushing the driveshafts fully towards the gearbox, and fully towards the hub to see if any noise,contact etc. All negative.
So in effect, the only thing that is limiting the inner races, shaft and balls from exiting sideways are the rubber boots? I'd look at some sort of soft compressible thing in the joint. Didn't they used to use half a tennis ball or something?

[Strat Fan]

So in effect, the only thing that is limiting the inner races, shaft and balls from exiting sideways are the rubber boots? I'd look at some sort of soft compressible thing in the joint. Didn't they used to use half a tennis ball or something?

If the shafts are the correct length then balls should not be able to reach the point where the balls can fall out of the CV body, the inner flange will prevent the shaft migrating too far inwards and the out stub shaft would prevent it moving too far outwards. If the shaft is too short then there could be cause for concern. Hawk & LB don't have this issue because the outer CV's only rotate, they do not plunge so it is not possible for the shafts to tramp side to side. There is nothing wrong with a double plunge shaft as plenty of cars use them but the length of the shaft is key to its success/reliability.

[hollytree]

If the shafts are the correct length then balls should not be able to reach the point where the balls can fall out of the CV body, the inner flange will prevent the shaft migrating too far inwards and the out stub shaft would prevent it moving too far outwards. If the shaft is too short then there could be cause for concern. Hawk & LB don't have this issue because the outer CV's only rotate, they do not plunge so it is not possible for the shafts to tramp side to side. There is nothing wrong with a double plunge shaft as plenty of cars use them but the length of the shaft is key to its success/reliability.

There are no inner restraints on the shafts that I got. The only inner restraint is clamping the gaiter to the shaft, but I have used one hand to turn each wheel, and the other the force the shaft in both directions when the wheel is turning to listen/feel for any issues. Nothing.

I may have to think about the tennis ball or a squash ball. Anyone remember the Kawasaki KH250 air cooled triple. The middle pistons used to size because they ran hot. A mate of mine bought one that was not running well. We took the heads/barrels off, to find the middle piston missing, and the small end just going up and down inside a tennis ball.

[strat24v]

Only thing I can think of is the shaft pushing sideways under load and a ball or two being right on the shoulder of the inner or outer race then it jumping back in.
It would be worth trying something like a squash ball perhaps?
Have you had cvs fitted, both centred then taken shaft dimensions at full bump, full droop and neutral/centre position?

[hollytree]

took the caliper off and see attached.
Something was still in the hole. It looked like some sort of fixing to align the pad material to the backing plate, but was twisted on the hole in the friction material, and where has the rest gone.
That might explain the hot running of that hub/outer CV yesterday13020

[Guy Mayers]

Remains of a pad wear indicator?

[hollytree]

Remains of a pad wear indicator?

No
Nothing like that on the other pad, and no corresponding hole
There is about 10mm of pad left. Both pads are the same thickness as well.
Maybe something was in that hole and kept slipping out and jamming between pad and disc and then randomly going back in again.
I will refit pad and take another drive and see

[Strat Fan]

Remains of a pad wear indicator?
Seems like a good shout-
13021
Probably had the wire cut off when first installed.

[Strat Fan]

This is what I would expect to see at the rear of a Corse I installation.
13023
Damper wise a 15" open length coilover with 92mm of travel would give 130mm of wheel movement.

[hollytree]

Craig
I had 16" dampers and got them shortened to 14.5". The problem is, that to stop the tyre hitting the body behind the door at the 10 o'clock position. Not the clamshell arch.
I also need 3 bump stops on the damper rod, that takes a lot of the travel straight out of the damper.

[Strat Fan]

Craig
I had 16" dampers and got them shortened to 14.5". The problem is, that to stop the tyre hitting the body behind the door at the 10 o'clock position. Not the clamshell arch.
I also need 3 bump stops on the damper rod, that takes a lot of the travel straight out of the damper.

If its not hitting the outer body then its easier to modify the fibreglass to gain clearance for the wheel.
I am only guessing to some degree but it sounds as though you still have too much droop on the suspension to achieve clearance on the tyre at full bump.
With the ride height you are running you already have 40mm of droop on the driveshaft, add to that a further 50mm of actual droop and that is 90mm of droop on the drive shaft which has got to be less than ideal.
Any body mod that is not external can either be painted in with an aerosol or covered with a stone chip material to hide the modification.
If your dampers were 16.5" open and 10.5" closed then you had 6" of travel at the damper (less the bump stop), on a Corse the wheel to damper ratio is 1.4:1 approx. so you effectively had 8.4" of wheel movement which is almost 4" more than you require. If you have had the damper reduced to 14.5" open length and they are still 10.5" closed then you now have 4" of damper travel which equates to 5.6" of wheel movement which is still more than you need but you can limit this with the bump stops as you have mentioned.
I would be looking to either reduce the ride height by modifying the inner arch shape or I would be looking to move the wheel rearward slightly provided this does not move the wheel from the centre of the arch.
Too much droop cannot be good for the shafts or the geometry
I would also like to know that your drive shafts are the correct length because a shaft which is too short risks the balls being pulled out of the race and this will then break the retaining cage.

[Darkspeed]

https://youtu.be/unBUhRf8MB0

[Strat Fan]

Thank you Andrew,

I had wondered if phasing would help prevent the shafts thrusting.
If it helps buy a few degrees as well then this would be good is Steve's installation.

Regards

[Darkspeed]

May well be all covered but its worth double checking.

I have a note that's has been on my whiteboard in the garage for 18 months that say's 16.5" shock! Why? even a 14" does 6" travel with the 1.36 ratio. I have a few sketches and thoughts to reduce the leverage ratio, bring the required spring poundages down, give the dampers and easier life and also reduce the travel - 3 droop and 2+1(bump stop) I do not want to limit droop and loose travel in roll - which is where a rear ARB may also help in this situation.

Lots of articulation may have been the aim to give better performance when yumping through a forest but I have no idea if that was the actual aim of the DWB rear. But I do like that the Prototype had it first ;)

Is the engine a little high at the gearbox end or is that just the photo angle.

[Strat Fan]

I have a note that's has been on my whiteboard in the garage for 18 months that say's 16.5" shock! Why? even a 14" does 6" travel with the 1.36 ratio. I have a few sketches and thoughts to reduce the leverage ratio, bring the required spring poundages down, give the dampers and easier life and also reduce the travel - 3 droop and 2+1(bump stop) I do not want to limit droop and loose travel in roll - which is where a rear ARB may also help in this situation.



Is the engine a little high at the gearbox end or is that just the photo angle.

There are plenty of improvements that can be made to the independent rear set up, toe adjustment, damper position, geometry, travel etc etc.
I don't understand the long damper especially when its combined with the wishbone ratio.
The top wishbone is not really long enough to account for 8" of wheel movement and this amount of travel will certainly push the CV's close to their limits.
Neil had just changed his rear dampers and added a rear anti roll bar but I do not know what the dimensions and the outcome/results were.
For me the upper wishbone inner pivot on the Alfa cradle is too high on the chassis which makes the wishbone almost horizontal even at a normal ride height. The Honda cradle on yours however may well be different.
Anyway before we go off topic and reinvent the double wishbone chassis...….

[Darkspeed]

Anyway before we go off topic and reinvent the double wishbone chassis...….

Indeed - over a cup of tea at some point soon :o

[hollytree]

Right
Inner and outer CVs on both left and right drive shafts check, and left(the short side) both replaced.
Both calipers off, checked, copperslipped etc and refitted.
Dampers lowered so less misalignment on CVs.
Go 100yds and still bang! (feels like large heavy hammer thump on car) and feeling that something is sticking/dragging.
Stop the car, jump out and it pushes/rolls in both directions no trouble.
Turn round and drive home, and all OK.
WTF is going on?

Jacked the rear of the car up, both wheels off ground and put car in gear.
Turning one wheel, there is probably 5mm of rim rotation before a clunk and the other wheel starts to turn in the other direction.

Could I have an intermittent differential problem?
Can i take the cover off with engine in situ and inspect it?
Anyone have any instructions on how to get it out, and if I do should I put LSD in.
The box and diff was new (supposedly) when I bought all the bits.

Steve

[strat24v]

That does sound like diff problems or a shaft bearing problem.

[hollytree]

I guess wheel bearings in the uprights next before I start on the diff or the clutch.
It is just so weird. As soon as i stop the car rolls freely. I drive home, jack it up and there are no funny noises, no signs of rubbing. Nothing!
Steve

[Strat Fan]

I guess wheel bearings in the uprights next before I start on the diff or the clutch.
It is just so weird. As soon as i stop the car rolls freely. I drive home, jack it up and there are no funny noises, no signs of rubbing. Nothing!
Steve

If you've already jacked it up and turned the wheels then you would have felt something on the wheel bearings.
It could well be a faulty diff and the standard ones can fail (I have one that has let go on a 3.2 GT) see - http://www.autolusso.co.uk/gearbox-rebuilds.html In this case the car went with a bang and lost drive, I then managed to engage a gear and limped it home before it would not drive anymore. In my case it is terminal but if it is your diff failing then you may be able to save your gearbox by checking now. As they say swapping to the Quaife helps prevent this failure.
You should be able to drop the diff without removing the box from the car, it is possible in the other replicas so you could be lucky.
The fact that one wheel goes the opposite way when you turn the other suggests that at least some of the parts are where they are supposed to be. You would still be able to push the car back and forth irrespectively, it is just when you try to drive the car that the problem would arise.
Happy hunting

[Normb666]

That reminds me of a box failure I had in a Fulvia - big bang, stop, roll car, all OK, drive a bit, still OK, then big bang again. Turned out one of the gears shed some teeth and all was fine as long as the bits were at the bottom of the box, but they kept getting picked up and...well, you can guess the rest...

As Craig says, get that diff out pronto before any loose bits take the rest of the box out!! Don't know if you can have a good look round in the casing with the diff off to check for debris?

Good luck and let us know...

[hollytree]

So does the Quaife from Autolusso fit a 16v 12v gearbox (i hope thats what it is, the box came with all the bits when I bought it all.)
It was supposed to be a new box, and was painted bright clean red.
I put a new clutch cover and plate on the engine when I fitted it.


If am going to pull the engine, perhaps now is the time to get the rear damper mounting plates made correctly for a Corse I. Any body have the dimensions, or know where I could get some plates made up, if I can make up some templates?


Oh well, engine out and I can tidy up the rubber grommit thing round the gearshaft rod whilst I am at it. Anyone got any good product details for this.

[Guy Mayers]

The Quaife ATB Differential fits the 12v box. I've got one assembled here for the new build that's stalled...
Guy

[strat24v]

Junk the linkage and buy a cable shift.

[hollytree]

Junk the linkage and buy a cable shift.

I asked Craig that, and he told me to stay with rod.
I will do whatever people think best

[hollytree]

Right
Rear clam off. Both driveshafts off. Both calipers off. Exhaust off.
Left wheel bearing definitely gone. Rumbles and no spin. Right is quiet and quick flick it will turn nearly 360 deg on its own.
When taking right caliper off, this fell out from somwhere?
It is about 12mm x 6mm x 2mm , is rubber backed, stamped 5 on front and seems to show "contact" wear. Any ideas?

I think I will try to keep engine in, change wheel bearings and the right side CVs. (lefts done last week)
I will see if I can do diff to LSD in situ, and ask Craig about fitting cable shift.

Steve13040

[Strat Fan]

wheel weight?

[ah_sprite]

Looks like a wheel weight to me!

[hollytree]

Looks like a wheel weight to me!

Good spot, that might be it, but I just took the left hub apart.
The inner section came out nicely, but the outer with the wheel flange took a bit of brute force, and tapping of a big socket
No evidence of any grease in the hub , and the outer bearing does not want to move off the shaft. Will have to find someone in St Albans to press the bearings off and press the new ones in.
A big pile of black duct fell on the floor and really smells of burning.

I think I may have found the problem.

Looks like Granada Scorpio 5 stud bearing for rear is FBK090 and FBK089

[hollytree]

The Quaife ATB Differential fits the 12v box. I've got one assembled here for the new build that's stalled...
Guy
Guy, is that a hint you might want to sell it?
Regards
Steve

[Guy Mayers]

Not at the moment but it is in the way of me working on the first car which is showing a real reluctance to run properly. Must update that thread...

[Strat Fan]

The inner section came out nicely, but the outer with the wheel flange took a bit of brute force, and tapping of a big socket
No evidence of any grease in the hub , and the outer bearing does not want to move off the shaft. Will have to find someone in St Albans to press the bearings off and press the new ones in.
A big pile of black duct fell on the floor and really smells of burning.

I think I may have found the problem.

Looks like Granada Scorpio 5 stud bearing for rear is FBK090

Be very careful not to damage the alloy divider which sits between the two bearing races, once that is broken the upright is scrap. The divider is approx. 4mm wide and is part of the casting. If someone over presses or abuses the bearings they can shear off and that's it ruined.

[hollytree]

Well I got the suspension setup on Friday and getting all the settings green I went for a quick spin.
There was a bang and all drive lost. Strange because when I revved the engine slightly with the clutch engaged the speedo showed 15mph.
This meant the LHS drive shaft was turning as the speedo sensor is on that CV joint.
Quick grab of the drive shaft and it was obvious the outer CV joint was shot.
Got the car home on a trailer - big thanks to ClassicLine recovery.

Took the CV joint apart and obvious the cage was cracked.
Got a new one fitted and checked everything with damper spring off .
My rear dampers were 16 1/2" on full extension. This is too much and i have sent them to AVO to shorten to 15" where the drive shaft spins with zero resistance.
At 15" i have very little travel before the wheel hits the bodywork at the 10 o'clock position.
Bought longer bolts for the bottom rear wishbone mount and with a spacer to push the wishbone back say 10mm, i get roughly 25mm more travel before the wheel hits the body work. Had to do a bit of trig there.
Marked the toe by using long steel ruler against the hub and making pen mark on the bodywork, then when when I pushed the rear wishbone back I adjusted the trailing arm to get the same approx toe in.
All the rear suspension moves full travel smoothly by hand with no binding and i think I should now have plenty of droop and bump without hitting the bodywork and without stressing the CV joint at stupid angles on full droop.
I also have plenty of room for plunge at full droop with nothing binding.

Pity the car came with 16 1/2" dampers in the first place.

steve

Steve