Ulster Rep Rebuild - Gearbox release bearing pressing on clutch arms

[Ned]

Hello everyone, my dad Erich and I are on the middle of an Ulster Rep rebuild, and we've run into an issue mounting the gearbox to the engine. 

With the gearbox fully seated, the clutch bearing in the gearbox is pressing down on the clutch arms just enough to cause it to slip, without depressing the clutch pedal. 

It seems like the release bearing we have won't fully seat onto the assembly, as there is a bit of a gap between the base of the assembly and the top of the bearing cage, even after hammering it on.    

This setup looks to be a later type clutch release, with our setup using a leaf spring instead of the coil spring to pull the bearing back.     

The clutch assembly is also a later type, with mousetrap springs and roller surfaces on the clutch arms, but no blind spline on the input shaft.     

Since we are using a 3 speed crash box with the later type release, which was made to work with 4 speed gearboxes, we were wondering if the distance between the release bearing and the clutch arms could be widened in some way to avoid pressing into the clutch. Any help would be appreciated!

Cheers

Ned Volkstorf

[Erich]

Hi All, I'll note that the system worked fine before we went to the the later type toggles with the T shaped pressure bits. I had gotten advice that these were the way to go, so when my friend, Chris(Garner) rebuilt the engine a couple of years ago, he installed these later T type toggles which the mouse trap springs. At this point, we have a real dog's dinner. Three speed box, four speed bearing carrier without the spring or keeper(a mystery) and a leaf spring to pull the bearing away. On the other side we have a clutch with the four speed toggles and springs.

Best,

Erich

[Charles P]

The standard solution to this sort of issue is to cut some 5/16 washers into a “C” shape and space the gearbox away from the bell housing. That usually solves the problem.
Using a four speed release bearing on a three speed box is a pretty frequent modification. My car has no return spring or mousetraps and works just fine.

Charles

[Steve kay]

Charles beat me to it. Agricultural though that may sound, the additional washer spacing is widely recommended and seems to work perfectly. Tweezers or delicate pliers are required for gently inserting the horseshoe washers.

[Howard Wright]

+1 for horseshoe washers, saved me taking out the engine and bending the toggles!

Howard

[Terrytuned]

If you are using a 4speed release bearing on a 3speed g/box you need to remove the stop on the front cover. Also check the 2 centre bolt heads are not stopping to bearing carrier returning fully.    

[Erich]

Hi All, what is confusing is that I don't know what changed, except the bearing and I think new clutch when Chris rebuilt it. And if I use the horsehoe washers, won't that push the G/B into the tunnel and firewall and screw up things like the handbrake cover?

Erich in Mukilteo

[AustinWood]

It only needs thin washers to act as spacers. It will make no difference to the gearbox/brakes.
It can be checked by fitting a gearbox onto the engine with the clutch thrust in place before fitting in the car.. There should be some free play in the thrust race position. Only needs a small amount.
If there's too much then clutch pedal is reduced leading to the famous Austin clutch acting as a switch that is very fierce.

[Bob Kneale]

Check that the clutch driven plate is able to contact the flywheel surface. It Could be that the flywheel nut lockwasher isn't fouling the domed inner ring of the driven plate. If the diameter of that washer is greater than the maximum diameter of the nut, i.e.greater than the diameter across opposite points then the washer will interfere with the clutch, and it will never fully engage . I've had this trouble in the past and turning down the washer to a smaller diameter solved the problem. Worth checing before you try something more complicated!
Cheers and Happy New Year.
Bob

[Erich]

I had a thought(always a dangerous thing). Since the original thrust bearing easily slipped onto the carrier and the current one doesn't seem to go all the way on, leaving 3/32 spacing, what about machining the carrier more to move the bearing further onto the carrier. Would this not solve the issue the same way that putting washers onto the g/b bellhousing connection?

Erich in Mukilteo