ZF Transmission - Clutch hose routing / Pedal stop

[Julian]

There has been similar experience in Pantera circles, where the HRB's were initially a popular swap until a string of failures, many of which resulted in the need for a new clutch disc as well. Those failures may well have been with the earlier style bearing, but the stigma has stuck.

 

[Chuck]

Chuck,

Why don't you simply use an external slave cylinder to actuate the clutch?

Good question. I actually have the parts to put in an external slave cylinder. Guess I like to live dangerously. . . . .

With the external would have to fabricate the support bracket, etc. Thus the thought was the internal would be easier. Maybe not . . .

 

[Chuck]

Chuck,
McLeod supplied a spacer already beveled on one side with my throwout assembly. I believe I was about 3/4" short too.

I saw that spacer listed in the McLeod literature. That would solve the spacing problem pefectly.Unfortunately it was not included with my kit. Hope to get some answers on Monday.

 

[Steve C]

Chuck,

Another vote for the external slave. Bracket and slave easily sourced.

Steve P2125 withe ZF and external slave

 

[Ron McCall]

Good question. I actually have the parts to put in an external slave cylinder. Guess I like to live dangerously. . . . .

With the external would have to fabricate the support bracket, etc. Thus the thought was the internal would be easier. Maybe not . . .

If you need a source for the parts you need, try John at Design Enterprises (410-876-7721)
here in Maryland. He can quickly and easily make you anything you need.
Another reason for the external version is that inside the bellhousing is a pretty harsh environment for the HRB to live in.

 

[Chuck]

Thanks for the tip Ron. Really all I would need to do is fab a mounting plate for the slave cylinder. Should not be too hard to do.

Still debating. . . . . in or out . . . .

 

[Jim Rosenthal]

Ron, do you have an external release system on your RCR GT40? Which bellhousing did you use? I am assuming you used a 10.5" Ford single-plate clutch, am I right- and a ZF transaxle?

I used an ERA bellhousing specifically to get the ability to put a 10.5" clutch in there. I am still wondering whether to take the HRB out.

 

[Richard]

I went with the external unit for many of the reasons stated but also after helping a friend set up his HRB.

I'm using a ZFQ but because I didn't buy one of their bellhousings I had to make up a bracket for the slave cylinder. It wasn't to bad, basically a 1/4" steel plate bolted to the trans.

It's important to get the angle between the pivot arm and center line of the slave cylinder correctly aligned. I set mine up so the pivot arm was 90deg to the slave cylinder shaft half way through it's travel. I'm using a bearing that designed to run against pressure plate fingers 100% of the time so there isn't any adjustment to worry about.

Works great and will be easy and less messy to fix if I ever need to. IMHO.

 

[Ron McCall]

Ron, do you have an external release system on your RCR GT40? Which bellhousing did you use? I am assuming you used a 10.5" Ford single-plate clutch, am I right- and a ZF transaxle?

I used an ERA bellhousing specifically to get the ability to put a 10.5" clutch in there. I am still wondering whether to take the HRB out.

Jim,

I have a Pantera sourced ZF,external slave ,Kennedy bellhousing and 164T Aluminum flywheel with McLeod twin disc clutch . Works like a champ!
I tried a McLeod single 11" clutch and it woudn't hold the power.

 

[Markus]

Chuck,

I want to re-emphasize the use of a pedal stop. I did not have one and I "overtravelled" the clutch cover plate....... the beginning of a long story.

Markus

 

[Chuck]

Markus: What size master cylinder were you using that caused the over travel? 3/4"?

 

[Jack Houpe]

Chuck I believe all the SPF cars are 3/4 inch. Lynn has a thread on making a pedal stop. Its pretty easy.

Richard that is nice work!

I run the same set up as Ron, twin disk lightened flywheel with BUT in the internal hydraulic bearing. I guess it all up to your preference and pocket book.

Jack

 

[Chuck]

I checked the stroke on my 3/4" master cylinder: 1.25 inches. The HRB calls for a minimum of 1" stroke to produce .5" at the HRB. But the range of travel for the HRB is up to .890". Thus with the master cylinder stroke available, it should be well within the range of the HRB and thus there should not be any problem with blowing an O ring.

Hope I got the math right. If so, a pedal stop would not be of any value in this configuration.

 

[Jack Houpe]

I checked the stroke on my 3/4" master cylinder: 1.25 inches. The HRB calls for a minimum of 1" stroke to produce .5" at the HRB. But the range of travel for the HRB is up to .890". Thus with the master cylinder stroke available, it should be well within the range of the HRB and thus there should not be any problem with blowing an O ring.

Hope I got the math right. If so, a pedal stop would not be of any value in this configuration.

Chuck is your car an SPF?

 

[Ron McCall]

Chuck is your car an SPF?

Jack,

His car is a RCR.

 

[Markus]

Chuck, I have a 3/4" master. The point is that you don't need a lot of travel for disengaging the clutch. My problem was that I was not blowing the O-ring > I overtraveled the clutch cover plate which plastically deformed the diaphragm springs on the cover plate which made the hydraulik release bearing wobble which cocked the piston in the hydraulik release bearing which made the hydraulik release bearing leak and to figure that out I had to take the whole sh:lipsrsealed: appart twice.

So just install a clutch pedal stop. Besides the issue above you will save tons of time shifting because you only make the travel needed...... saves you tons of time in the quarter mile :thumbsup:

P.S. Thanks again to all the forum members which helped me chasing down my issue:2thumbsup:

Markus: What size master cylinder were you using that caused the over travel? 3/4"?

I checked the stroke on my 3/4" master cylinder: 1.25 inches. The HRB calls for a minimum of 1" stroke to produce .5" at the HRB. But the range of travel for the HRB is up to .890". Thus with the master cylinder stroke available, it should be well within the range of the HRB and thus there should not be any problem with blowing an O ring.

Hope I got the math right. If so, a pedal stop would not be of any value in this configuration.

 

[Chuck]

Thanks Markus. That makes sense. Got the concept now.

 

[Chuck]

Been doing a little home work and got some numbers that may be helpful to anyone doing the same project.

Part number for the internal hydralic bearing spacer, 1.330", McLeod #1428. Summit Racing price: $53.99.

Part number for the throw out bearing for an external slave cylinder, 2.225", McLeod #16525. Summit Racing price: $151.69. (That is a pricey piece!!)

So I got all the info and and most of the parts to go either internal or external. Now which way to go . . . . . . dang, I hate making decisions.

 

[Jack Houpe]

There is so much going on in the engine area of my MK1, I was happy to hide something. Once again its up to your preference.

 

[Lance]

I was proposing to use an internal release bearing for my ZF / AP twin plate clutch / custom flywheel because I like the set up and don't have the external lever for the actuating spindle of the gearbox. In view of the discussion and opinions above, I'm having a rethink about the internal option.

Does anyone know where I can buy an actuating lever? All help appreciated.

Lance