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Transmission question

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John_Mc

John_Mc

Jedi Knight
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Hi all. My 71 TR6 is difficult to shift into 1st gear generally and particularly so when I'm at a stop. It doesn't grind, it just doesn't feel like it wants to go in, like I'm hitting a wall. Also, I get a lot of grinding going into reverse. Is this a synchro issue, a clutch issue, or a transmission fluid issue, or something else entirely? Thanks in advance for your insight.
 
Clutch or pilot bearing issue, most likely clutch.

First place I'd look is for wear at the joint between the pedal and the MC pushrod. Badly worn thrust washers are another common problem with the TR6.
 
My TR4 acts the same way,have to double clutch at times(when cold) to get into first or second,after driven for awhile and everything warms up it shifts as it should.Can't figure it out.
 
In both cases -- wouldn't hurt to bleed the clutch hydraulics. Only takes a minute or two before you pursue other causes.

In particular your statement "have to double clutch at times" could be that you're just compressing some air enough to get more clutch action.
 
Couldn't this also be the dreaded clutch fork pin problem. I had the same symptoms on a TR4A years ago, and it was because the pin had partially sheared, moving it on the shaft. The result was not enough throw on the fork to disengage the clutch fully.
 
This may sound a little nuts....but try and shift from 2nd into first...and use the double clutch between the two. Just may work. Good luck. Gil NoCal
 
I'm thinking that since it has been 9 years and probably a good 35k miles at least since I last repaired the MC and slave cylinders, that might be a good place to start. I'm comparing vendors right now. Any experience with best replacement kits? Also, I noticed BPNW has a long-throw slave cylinder kit. Anybody use this to favorable effect?

And I'm sure this has been brought up before, but couldn't some improvement be made by adding spacers between the slave cylinder and the frame, or would this cause damage? It seems to me that there is some play in the clutch shaft lever and my simplistic thinking is that if the play were minimized then it would require less clutch pedal pressure to release the clutch. Do I err in my reasoning?
 
joejoecat said:
My TR4 acts the same way,have to double clutch at times(when cold) to get into first or second,after driven for awhile and everything warms up it shifts as it should.Can't figure it out.
Click to expand...
On a TR4, first place I'd look would be the slave cylinder adjustment.

Or from that description, it could be just really thick oil in the gearbox, possibly combined with worn synchro rings. If you're sure the problem is not hydraulic, I'd try some Redline MT-90 in the gearbox. It has a 75W (winter) rating, so it's not as thick when it's cold as regular 90 weight.
 
Unless the slave is visibly leaking, I'd leave it alone. Same for the MC, unless you have reason to believe it is leaking internally (not a common problem with these) or the internal spring is broken.

There is supposed to be a spring inside the slave, that holds the piston out against the pushrod and clutch lever. If yours is slack, then I'd suggest replacing the spring.

However, play at the joint between the pedal and the MC can definitely cause problems (as I mentioned above).
 
TR3driver said:
However, play at the joint between the pedal and the MC can definitely cause problems (as I mentioned above).
Click to expand...

I checked that but it seems okay. When I got the car 9 years ago there was no sleeve in there and there was a lot of play. Replacing that made a bigger difference than anything else that I did. I do notice slight fluid leakage around both the slave and master cylinders, but I don't know how much is significant. The levels inside don't seem to have dropped, so it can't be much that's leaking. I'll check the spring and see if that and cleaning/bleeding the system help.
 
Is it possible that the fluid is not leaving the car but moving around the washer? Seems to me there should be no fluid around either cylinder. The fact that first and reverse are affected suggests the beginning of failure of the system.

T.T.
 
the hole in the peddle where the pin goes could be elongated, I had to weld mine up and re drill, and yes you can put spacers between the slave cylinder to move it toward the rear, probably get some comments about me suggesting doing that, but its would be the same as making a new fork rod and longer or getting the one thats adjustable. I put one nut inbetween the plate and the slave, and it works fine, great peddle feel and release in a good spot, just make sure you still have some play and your release bearing is not putting pressure on the clutch. Second if you shift into second and go from second to reverse you should stop the reverse grinding, also give it a few seconds before you go from second to reverse, main reason the reverse gears getting chewed up. I put a new slave cylinder on and have no issue, I have a brand new MC but have not installed it yet.

Hondo
 
Hi John. You should not have fluid weeping from the Master cylinders as T.T. suggets. It could be as simple as needed new seals.
 
For me, that problem was caused by very worn crankshaft thrust washers. The whole clutch assembly was actually moving forward when the release bearing engaged the pressure plate thus reducing the actual amount of release.
 
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