[Fot] clutch question

[fubog1]

 Yes that stack-up wear can add up.Having changed many hundreds of these clutches over the last 50 years, aside from hydraulic issues and normal wear and crappy aftermarket release bearings, the most common problem that I see is the broken clutch fork bolt.It shears and then the fork rotates on the shaft a bit and wedges itself tight, and then requires extra pushrod travel to compensate.When all is fitted, the external release arm is pretty much vertical, if it's trailing aft a noticeable amount, the bolt is likely sheared.Glen


 
 
-----Original Message-----
From: van.mulders.marcel--- via Fot <fot at autox.team.net>
To: Robert Lang <robertlangtr6 at yahoo.com>
Cc: fot <fot at autox.team.net>
Sent: Mon, Jun 3, 2019 2:49 am
Subject: Re: [Fot] clutch question

The TR6 has a reputed problem : the wear in the parts that are operating the clutch can add up in a considerable loss of travel of that  cylinder : suspension of the clutch pedal(shaft/hole), pedal to MC push rod, slave cylinder push rod to cross shaft, cross shaft to gearbox case.Marcel
Van: "fot" <fot at autox.team.net>
Aan: "fot" <fot at autox.team.net>
Verzonden: Zaterdag 1 juni 2019 23:24:23
Onderwerp: Re: [Fot] clutch question

Hi,
I have a bum c/r tranny, so I figured I'd swap in a stock box just to run while I figure out the problem with the c/r box. Due to the differences with the input shaft, I had to switch to from the 21 spline clutch disk to the stock 10 spline disk. I have done this a couple of times in the past due to "pesky layshaft thrust washers" Both clutch disks measure to within .010 thickness. I bolt everything up and verify via the clutch cross shaft approx. 1/2 inch of travel, which is normal. In neutral, the output flange spins freely. If I try to put the tranny in any gear and push the clutch pedal to the floor and try to spin the output flange by hand, it's locked. The clutch is not releasing.
I've measured everything a few times looking for anything that looks amiss and so for, nothing seems to be an indication of why the clutch won't release. 

Just to be sure that things are free in the bellhousing, I used a pipe on the cross shaft arm and slowly applied pressure and the clutch DOES release so the indication is that I either have mechanical sloppyness or insufficient hydraulic linear motion. I verified that the pivots have no slop and none of the pivot holes are egged out. I did find the pin to the pivot arm was slightly worn, so I threw in a 5/16 bolt to take up slack there, but that was to no avail.
In the process, I have tried switching in two different transmissions and several combinations of clutch disks and pressure plates and to this point the clutch will not release when using the clutch pedal but will release as described above when using a pipe on the pivot arm.
I plan to re-install the original gear box (and the proper clutch disk) at some point just to see if the problem is resolved but I have no idea if that will work or not. I guess I just have to try and see. But to be honest, doing around 8 transmission swaps in 12 hours is fairly physical not to mention the challenge due to the roll cage. But that's just me being a wimp. ;-) I mean, I could have used that time to actually FIX the C/R transmission - right?

All this is more or less a long way of asking - are there any documented measurements for things like the "finger height of the pressure plate measured to the clutch disk" or the height measure from the rear engine plate interface to the clutch fork pin? I bolted several PP's to a spare flywheel and came up with "around 1 inch" when the PP is bolted down, but that doesn't tell me anything like how far the fingers have to depress to open the clutch up. As I mentioned earlier, 1/2" of lever motion usually is adequate, so think that part of the system is correct.
In any case, I'm confused and puzzled by this case not to mention slightly bummed because I had to miss some lapping at Lime Rock because the car isn't in a running state right now. I thought about pinging "Click and Clack" and posing this as a "puzzlah", but decided not to. I also know that the solution should be obvious, but to this point is alluding me. So I need a kick in the right direction.
TIA,Bob Lang339-927-4489

_______________________________________________
fot at autox.team.net

http://www.fot-racing.com

Donate: http://www.team.net/donate.html
Archive: http://autox.team.net/archive http://www.team.net/pipermail/fot
Unsubscribe/Manage: http://autox.team.net/mailman/options/fot/van.mulders.marcel@telenet.be
_______________________________________________
fot at autox.team.net

http://www.fot-racing.com

Donate: http://www.team.net/donate.html
Archive: http://autox.team.net/archive http://www.team.net/pipermail/fot
Unsubscribe/Manage: http://autox.team.net/mailman/options/fot/fubog1@aol.com


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/fot/attachments/20190603/b378eed4/attachment-0001.htm>