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TR2/3/3A Clutch Adjustment

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Redoakboo

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I have a 57 TR-3 with a TR-4A transmission. I recently replaced the clutch as the pressure plate in mine came apart; no damage though. I have it back together, checked the adjustments at the master cylinder and slave cylinder. Both were .079 and .030. I started the car and it starts to grind when you put it in Reverse. It will drive in forward gears but not very smooth Is there an adjustment someplace I am missing? A Teck at Moss mentioned that there were three holes in the shift arm at the Slave Cylinder. Would the placement in these holes be my problem?

Richard Vinal
 
The lever coming out of the bell housing has 3 holes. The clutch slave rod should go to the middle hole. If it already is, then you may need to bleed the air out of the circuit.
 
Thanks John,

I put it back in the lower hole as that is where is was when I removed the gearbox. I definitely need to bleed the system as until I can get the piston back into the cylinder, I can't push it back far enough to attach the rod.

Dick
 
Redoakboo said:
...checked the adjustments at the master cylinder and slave cylinder. Both were .079 and .030...
Click to expand...

I am unsure what that means. I adjust the free movement of the slave rod but adjust nothing on the master. I do not what float/free play you would want at the slave since you possibly have an early TR3 slave and a later TR4A box -- but I think 'the specified play at the adjustment nut is 0.12 to .016 inches' is often cited as the norm.
 
.030" and .079" are the clearances specified for the early Lockheed hydraulics. But a 57 should have Girling hydraulics. IIRC the early Girling values are .010" and .100". But IMO, that isn't going to make this much difference.

Not being able to push the piston into the cylinder suggests a problem at the master cylinder or a clogged soft line. There is a valve inside the MC that should open when the pedal is released, which allows fluid to flow backwards into the reservoir. Although it does take some effort, you should be able to push the slave piston all the way in and dispel fluid back into the reservoir, even if there is air in the lines.

There is a tiny "wavy washer" type spring inside the MC that opens that valve during the last little bit of piston movement. If the spring is broken, or the piston hangs up for some reason, it may not open the valve.

All that assumes you have the slave return spring disconnected. It's really stiff, so I suggest getting the rod in place first and then hooking the spring up.

PS, putting the rod in the bottom hole will decrease clutch travel, not increase it.
 
Geo Hahn said:
I am unsure what that means. I adjust the free movement of the slave rod but adjust nothing on the master. I do not what float/free play you would want at the slave since you possibly have an early TR3 slave and a later TR4A box -- but I think 'the specified play at the adjustment nut is 0.12 to .016 inches' is often cited as the norm.
Click to expand...
The MC adjustment was deleted on later cars (probably from too many complaints).

Which gearbox shouldn't affect the freeplay. For example, I use a TR6 gearbox, TR4A clutch but still the freeplay adjustments for my TR3 hydraulics.
 
Yes something is not correct. I would replace the master with a new one, not a rebuild. The slave is a simple in construction, so I usually rebuild that, and purchase the master new because they get soooo problematic; plus I hate pulling them and putting them when something inside is not correct; the slave I rebuild in place. Can’t you open the bleeder on the slave and push the guts back in then hook up the spring? I do not like the factory spring and make my own that has less strength. Are you using a one inch slave and not a 7/8?
steve
 
Re-positioned the rod to the middle hole and bled the system. It seems to be shifting fine now, a little slow going into reserve, but no grinds.

Thanks Guys, for all your assistance

Dick
 
And thank you too. My wife has nerve damage from a back issue, and I have considered moving the rod to the bottom slot to reduce the clutch force for her. Now I know from your experience that it isn't a good option.
 
You might want to investigate the "wussy clutch" described in the Buckeye Triumphs clutch articles. The author tested several combinations of TR6 clutches, and found one with such low pedal effort that he dismissed it. But AFAIK it worked fine even behind the 2.5L 6 banger; should do OK with a TR2/3 motor. Lots more work than just moving the pushrod; you'll need to either get your flywheel redrilled or use a TR4A flywheel plus gear-drive starter (to fit in the early bellhousing). But, as they say, a happy wife is a happy life.

CJD said:
And thank you too. My wife has nerve damage from a back issue, and I have considered moving the rod to the bottom slot to reduce the clutch force for her. Now I know from your experience that it isn't a good option.
Click to expand...
 
Thanks Randall. I'll look into it. I know the technology is there, just need to figure out a direction.
 
Thanks Randall,

Your comments are always appreciated. New question, now that I have found out I have a transmission out of a TR-4A, it might be time to address the fluid? I think it currently has 30#. Moss recommends EP 90. What would you suggest? It does have Overdrive.
Dick
 
The 1 inch cylinders were not available a few years ago, so I tried a tr6, 7/8 slave cylinder and it took a lot more force to push it down. In addition, the manual suggests lifting up the shifter when going into reverse. I do not do that will my driver and it goes into reverse fine, but a few years ago on a tr3 I sold, lifting up the shifter seemed to help. Moreover, I knew a guy that owned a transmission rebuild shop and he would tell me that when a car does not go into reverse smoothly that is a clutch problem.
 
I use (and like) Redline's MT-90 in all my overdrives. Doesn't seem to make much difference to the OD, but makes a noticeable improvement in the main gearbox, IMO.
https://www.redlineoil.com/mt-90-75w90-gl-4-gear-oil
Kind of expensive, but prices vary so shop around a bit.

The TR3 shift mechanism is supposed to have a step that makes it difficult to move the shifter all the way to the right unless you lift up on the knob. The original knob even had "LIFT" inscribed on it. But by now, most of them are pretty badly worn (from people not lifting) so it doesn't take much to force it over the step without lifting. Later on, though, I believe it was modified to be more of a ramp. The TR4 owner's manual still says to lift; the 73 TR6 manual doesn't. (I didn't check the others.)
 
Randall,
I drained the gearbox but, only got about 1 pint of oil out of it? The manual says a TR-4A gearbox with overdrive take 3 1/2 pints?? Does the overdrive section have its own drain plug? I periodically check the oil with the dip stick on the top and it always shows oil? I was not going to use the side plug to put in the new oil, but sure would be easier through the dipstick hole. Your thoughts? If only 1 pt came out, where is that 3 1/2 pints going to go?

Dick
 
Yes, the OD has it's own drain plug, plus (on the later ones) magnets and a screen to clean.

No reason not to use the dipstick that I can see, in fact I made the swap myself (later gearboxes don't normally have a dipstick, it's only found on TR2 through early 3A). But you can check the plug if you want, to double-check the dipstick. Just make sure it's level, since being tilted either side-to-side or fore/aft will affect the oil level at both dipstick and plug.

I don't pay too much attention to absolute amount, since I'm usually starting with a partially full bottle anyway. But ISTR it takes most of a quart after draining both gearbox and OD.

If you have the later type drain plug with notches around the edge, I definitely recommend either building or buying a tool to engage more than one notch at a time. I've seen lots of people try to get them off with a hammer and drift (or similar), and the result is often a plug that leaks. Best to have a new gasket on hand too (or suitable O-ring per CJD). Sorry, I forget offhand who sells the tool commercially; here's a shot of the tools I made; with the best one (IMO) in the foreground and the previous version in the background. The old version worked well enough, but was awkward to use as it put your knuckles at risk between the bar and frame if it broke loose suddenly.

i0Ffy1U.jpg
 
I put 2 quarts...and that puts me in the upper middle of the dip stick. You will need to drain the OD.
 
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