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DavidAGO
05-16-2012, 10:50 AM
Hello All, I have been lurking for several months, learning much about TR6's and using the search feature, but a problem now that "search" cannot answer. My 1976 TR6 is slowly coming back to life. I have the hydraulics completely rebuilt, clutch and brakes working fine. Or at least as far as I can tell on jackstands. The effort to push in the clutch seemed high, but since the car was not running I did not worry about it much.
Now that I have the engine running and the car moving under it's own power the clutch pedal effort needs some attention. It is hard to push in, or at least much harder than on my MGB or any of my previous British cars. More importantly, the clutch seems to catch quickly, you cannot start off smoothly. The clutch seems to be either engaged or not, there is no real transition. Where do I start looking?

Thanks for any help

David

TR3driver
05-16-2012, 11:01 AM
A common complaint, so it seems. Here are a couple of relevant articles.
https://www.buckeyetriumphs.org/technical/clutch/StickyClutch/StickyClutch.htm

https://www.vtr.org/maintain/clutch-laycock.pdf

Unfortunately, it pretty much all requires removing the gearbox again.

DanB
05-16-2012, 11:02 AM
Hi David,

It sounds to me like the issue is probably your pressure plate. Assuming all the linkages are not binding in some way, that is really the only thing I can think of that would cause what you say. Did you put a new clutch in, and if you did is it a competition setup? On your transmission, the lever that connects to the slave cylinder may have 3 holes in it. Which hole are you using? You may be able to move it to the bottom hole to maximize your leverage.

Dan B
South Charleston, WV
66 TR4A IRS EFI
80 TR7 DHC

DavidAGO
05-16-2012, 05:17 PM
Dan, the lever from the slave cylinder is on the top-most hole, that is the one that was the straightest. I'll move it to the bottom hole and see if it makes a difference. After reading all the relevant articles that Randall cited, it appears I am doomed. But maybe not.

thanks all

David

hondo402000
05-16-2012, 06:36 PM
Hi David
welcome to the forum
I can only say work toward a solution from the least amount of effort to the most amount of effort
hydrolics
Pin hole in the shaft
grease the shaft if you have zirk fittings
at that point you will be pulling the transmission if its internal
like broken clutch fork pin, pressure plate or friction disc, throw out bearing
I cant imagine its internal to the tranny at this point


Have fun!

Hondo

HerronScott
05-16-2012, 07:19 PM
Welcome David,

I had similar issues when I rebuilt my TR4A back in the mid-80s and installed a Quinton Hazell clutch kit which must have used one of the aftermarket Borg&Beck pressure plates as it took an awful amount of pressure to apply the clutch.

It worked and although I didn't have any issues with it for the 6 years/75,000 miles that I drove the car, I wish I would have had the money to replace it (poor student!).

Scott

DanB
05-17-2012, 02:40 PM
The clutches on TRs are usually stiffer than a B anyway, and if the pressure plate is designed for racing it will be stiffer still. The extra pressure of the springs will take some getting used to. Try keeping your heel on the floor as you let the pedal out with the ball of your foot. That might help you ease it out as it engages. Moving to the bottom hole also helps more than you might think it would.

If there is wear in some of the components inside I suppose it could create a bind situation. Another less likely cause would be mismatched hydraulic cylinders. If someone replaced one of the cylinders with something from a different application or an aftermarket cylinder in a different size it would affect the operation. Assuming they are stock TR6 hydraulics, if you can't live with the clutch like it is you are going to have to pull the transmission.

Dan B
South Charleston, WV
66 TR4AIRS EFI
80 TR7 DHC

TR3driver
05-17-2012, 02:58 PM
The clutches on TRs are usually stiffer than a B anyway,

I'll disagree, although I've only driven a MGB once (once was enough). I have a TR6 clutch in my TR3 (along with the TR6 gearbox and alloy flywheel), and while it's not the lightest clutch I've ever driven (with Dad's Peugeot it was hard to tell if your foot was on the pedal or not), it is not unreasonably heavy either. Very comparable to all the other manual transmission cars I have owned, and lighter than my last Chevy. It should be lighter still in a later TR6, as they used a reduced bore in the clutch MC (less force but more travel).

As outlined in the articles I referenced above, the TRs with the really heavy clutches are because people are (unknowingly) fitting the wrong parts, or because the TOB carrier is binding on the front cover.

Also worth checking the pedal pivots. I don't recall the arrangement on a TR6 offhand, but on a TR3 it is quite possible for the pivot shaft to rust inside the pedal bushings and make them quite stiff; especially if there has been a leak at the MC.

Yet another possibility is that someone has fitted a larger bore MC or smaller bore slave cylinder. Along with the heavy clutch covers come problems with insufficient travel at the slave, and changing the bores will cover up that problem.

DanB
05-18-2012, 10:38 AM
I see we agree on everything else though.

Dan B

TR3driver
05-18-2012, 11:09 AM
True, I was only objecting to the idea that it "should" be heavy. Otherwise I was agreeing with you, with perhaps just a bit more explanation.

Nelson made an amusing comment in this article:
https://www.buckeyetriumphs.org/technical/clutch/ReliableClutch/ReliableClutch.htm

He used a popular substitute pressure plate with exceptionally low force, and decided he didn't like it because it was too soft! Sounds a lot like the Peugeot.

DavidAGO
05-21-2012, 02:16 PM
Thanks, moving to the bottom hole helped a lot! It is still not as smooth or light as the MGB clutch, but much more mangeable.

David


The clutches on TRs are usually stiffer than a B anyway, and if the pressure plate is designed for racing it will be stiffer still. The extra pressure of the springs will take some getting used to. Try keeping your heel on the floor as you let the pedal out with the ball of your foot. That might help you ease it out as it engages. Moving to the bottom hole also helps more than you might think it would.

If there is wear in some of the components inside I suppose it could create a bind situation. Another less likely cause would be mismatched hydraulic cylinders. If someone replaced one of the cylinders with something from a different application or an aftermarket cylinder in a different size it would affect the operation. Assuming they are stock TR6 hydraulics, if you can't live with the clutch like it is you are going to have to pull the transmission.

Dan B
South Charleston, WV
66 TR4AIRS EFI
80 TR7 DHC