ZF Transmission - Clutch Release Bearing Issue

[Chuck]

We are in the process of installing a McLeod hydralic clutch release bearing on our ZF.

The back of the bearing is beveled to fit nicely over the input shaft bearing cover. But there are three bolts securing the bearing cover, so the nice beveled surface is not longer a proper fit. ( I may not be using the right terminology. Hopefully the pictures will make the issue clear).

I am guessing I could replace the bolts with a recessed screw and bevel the opening so they are flush, but before doing anything I would like to see if anyone has dealt with this issue.

 

[Jack Houpe]

Chuck your missing part of it, there is another piece that slides on first with slots cut out for the bolts THEN the hydraulic part goes on.

 

[Markus]

Chuck,

you need to "mill out" some slots for the bolt heads (see pictures below). When you put everything together, make sure the bolt heads reside in the slots....
With my bellhousing (quick time) the distance on the pics was correct.

I hope this helps,

Markus

 

[Chuck]

Markus:

Excellent idea. I was debating about whether that was the best approach, and you just answered the question. Sure beats trying to counter sink those bolts.

I am still about 3/4" short with the KEP bell housing, but a space should solve that issue.

Of course still considering the external slave option . . . .

Thanks.

 

[Chuck]

Markus:

Another question. The slots resting over the bolt heads will prevent the insert from turning, but the bearing could still rotate on the threads of the insert. What keeps it from turning on the threads? Or is that not an issue.

 

[Markus]

Chuck,

there is nothing which prevents it from turning.

So far it is not a problem but I could imagine that it could become a problem so please take a close look to Frank Catt's suggestion: http://www.gt40s.com/forum/gt40-tec...lutch-hose-routing-pedal-stop.html#post280656

If you are 3/4" short you should have plenty of space left to come up whith a solution.

FYI, I'm currently collection all the components to convert to an exernal slave.... The internal solution work great right know but when it fails again I will kick it out.

Markus

 

[DaveM]

Chuck-as Jack says you are missing the beveled part with bolt clearances. I believe that is also the spacer you need to machine for proper bearing to clutch clearance. DO NOT machine the bolts on the transmission. The release bearing will not turn because of the internal o rings. I've got 4 thousand miles on mine with no problems.

 

[Chuck]

Chuck,

FYI, I'm currently collection all the components to convert to an exernal slave.... The internal solution work great right know but when it fails again I will kick it out.

Markus

Ummmm. Not exactly a vote of confidence for the HRB . . . .

Did the first one fail due to overextension of the master cylinder?

McLeod made a first generation HRB with banjo fittings and a second generation with Elbo swivel fittings. Had heard that the second generation were less prone to seal failure. Do you recall whether your first HRB that failed was the former or the later?

 

[Markus]

Chuck,

please see my other post http://www.gt40s.com/forum/gt40-tec...tch-hose-routing-pedal-stop-2.html#post281136

The leaking of the HRB was not the root cause, it was a result of the root cause. The root cause was the missing clutch pedal stop!!
After fixing the root cause (fixing the damaged clutch cover plate and installation of a clutch pedal stop) the very same HRB was working just fine.
Like discussed previously on this forum, the problem with the HRB is all the work you have to go through when you have to replace/fix it.

On a race weekend you just replace the external slave in 30 minutes; with a broken HRB you drive home (unless your're a hardcore mechanic ).

Markus

P.S. I do have the second hand generation HRB