Trans problem. Looking for suggestions.

[Zimmycobra]

Took my newly restored TR4A IRS out for a short test drive tonight for the first time. Up until tonight it has been fine pulling in and out of the garage and a couple of tests down my long driveway and back, the transmission seemed to be very good. As the time went by today and I finally went out of the driveway for the first time, getting into 1st & 2nd became harder and harder. Eventually it didn't want to go at all. It would go into gear, but it felt that I was pushing it very hard.

I am open for suggestions. The clutch releases lower to the floor than I would like but it does seem to disengage. 3rd and 4th seemed to be okay. Does this sound like a linkage external issue or is it an internal one. Maybe synchros?

Any suggestions would be welcome as well as repair suggestions. Thanks.

 

[mrv8q]

Clutch slave cylinder rebuilt? New hose?

 

[Geo Hahn]

I would start by doing a bleed of the clutch hydraulics. If there is air in there you will lose some movement and 1st and reverse are the gears that will become difficult first.

Could be several other things but a bleed takes minutes and could pleasantly surprise you.

 

[Zimmycobra]

Geo & Kevin:

Thanks for the replies. Here is a bit more data that sounds relevant. During the rebuild, I rebuilt the master and the slave cylinders for the clutch (original tubes and hose - blown out). When I tried them out after a year of sitting, the clutch did operate, but it engages/disengages close to the floor. (The push rod is connected to the middle hole as required) I learned that the internal spring in the slave should push the piston out to take up all of the push rod slack. Mine appeared to not be doing that. At this point there was no issue with getting into 1st or 2nd in the very limited driveway attempts (900 ft driveway - so some testing and shifting was possible). In the interest of quality and time, I decided to replace the slave with a new one. I did that the other night and re-bled using the Motive power bleeder that I have. I even tried to use the Moss Motors suggested sequence to be sure to get all of the air out of the system. No bubbles and no change. The engagement point appears to have not changed as I had hoped.

At this point, I did finally brave the real world and went for a short drive on real roads. The total drive was less than a mile or two, but the difficulty of getting into 1st & 2nd became worse and worse. As I entered my driveway I could not get into 2nd at all. In a dead stop, I could get it into 1st with a great deal of effort. There was no gear grinding, it was just physically hard to engage.

I am now contemplating whether the problem could be a less than perfect rebuild of the Master Cylinder. Could it be that I am not getting the full amount of fluid being transferred. Maybe some blow-by, if you will, in the master. I will also re-look at the pedal linkage to be sure that there isn't too much wear and slack in the pedal to lever connection.

Any thoughts, suggestions, questions????? I am all ears. Thanks.

 

[titanic]

If you can verify the clutch is disengaging, the difficult to shift problem probably isn't caused by the master cyl. One possible culprit lives in the parts under the shift lever. If the retainer plate (Moss 848-180) under the cap (Moss 848-170) becomes dry&gritty, the friction can make shifting very difficult. Try removing the boot, depress the spring loaded retainer, and squirting WD-40 or other cleaner in the area, followed by oil. This may or may not be the cause of the problem, but it is an easy suspect to eliminate. Berry

 

[tomshobby]

While traveling last summer I had a clutch failure in Provost, AB. The pedal kept going closer and closer to the floor before releasing and finally did not release at all. One of my cousins helped repair the slave and it worked long enough to go to a festival event called Bunnock in Maklin, SK. We got in the car after the games and the clutch was the same as when we started. Checked the slave again and it was fine. Turned out to be the master. Drove over to Calgary with no clutch and was able to borrow a used master from a friend with a TR250. That fixed the problem. We had more than 4,000 miles left to finish the rest of the trip and had no more problems. After we got home I installed a new master and have had no problems since. We were pulling a trailer so I was very happy it all worked out.

 

[DanB]

Did you have the transmission out of the car? If you did, did you inspect the forks and the bolt that holds it on the shaft? Those can get wear that contribute to the problem. Being a TR4a, does it have the adjustable clutch linkage going into the slave? You could try adjusting that out more to see if it helps. And move it to a higher hole.

 

[Geo Hahn]

...I learned that the internal spring in the slave should push the piston out to take up all of the push rod slack. Mine appeared to not be doing that...

Should there even be a spring inside the slave? I thought yours would have an external spring -- number 59 in this listing: Moss Clutch Page

That is how TR3s & TR4s work but I am not totally conversant with 4As.

Of course there is always the 'dreaded broken clutch fork pin' but several possibilities to consider before that.

 

[KVH]

If you are experiencing a very low disengagement and engagement, something is wrong right there. That needs to be fixed first.

Remember to read the manual carefully on the slave rebuild. You should have an internal spring, piston and seal, and that's about it. Do exactly what they say about turning the push rod to take up all slack, adjust the nut to 0.10 (or whatever) and rotate back to the nut. Then be sure you bleed the hydraulics at the slave.

Once you get the hydraulics fixed, assuming you don't have a clutch taper pin problem, or a bad clutch, itself, I'd suspect the shift lever. In my 4A I got stuck in my own driveway. Luckily. The little anti-rattle plunger slipped out the the shifter would not maneuver in the shift fork slots. Everything just seemed locked up; I couldn't get into any gear. Imagine the head of the shift lever trying to move into position, but no matter where it goes, a little steel anti-rattle shift plunger (roller)--Moss part 848-150--is getting in the way. It's like trying to get to the milk with two old ladies and their shopping carts blocking each side of the aisle.

The fix was hassle: remove the dash saddle, carpet, plinth and center bracket. That very well could be your problem. Of course you could have defective shift fork plungers. When I found the anti-rattle shift plunger it was all scored up from being jammed from all directions.

If your problem is first/second, but not third/fourth, that may mean that the ball bearing detent or plunger on the fork (either may be installed) is bad. I find that unlikely, but I guess maybe. If your problem is all four gears, then maybe that anti-rattle shift plunger (and not the fork detent) is in the way.

Good luck. If it's nothing above, I'd consider the clutch or fork pin.

PS Did you already rebuild the top cover? Did you set the detent resistance? That can be set using a tool that measures force, like a simple fish scale.

 

[Zimmycobra]

KVH:

Thank for all of the suggestions. After this past weekend, I am leaning heavily to your analysis or something similar in the shifter mechanism. As far as the clutch goes, I replaced the slave with a new one and it may have helped a bit. Next effort in that area will be a new master cylinder and SS hose. For now it seems okay but will check more, once I get back on the road for testing.

Now for the shifter issue. What I noticed this weekend leads me to believe it is the mechanical shifter assembly. No problem with 3rd & 4th or reverse. You know how you lift to go into reverse. Well I noticed that if I left a bit going to 1st & 2nd and go hard to the left, it will shift into 1st & 2nd very nicely and smoothly. It seems that somehow the 1st/2nd shifter has some play in it and is sitting too high or out of whack (a technical term). If I stay in the 1st/2nd orientation, it will shift smoothly either way. When I leave this alignment and then go back I have the same problem. It is therefore some sort of mechanical binding or misalignment.

As you have pointed out, it is most likely an easy fix, once I get to it. At least I haven't done carpeting yet, so it is just removing the dash support and tunnel cover to get to the gear shift assembly and cover. A bunch of work to get to a hopefully small problem.

I will keep you all updated. Thanks for the support and help.

 

[Zimmycobra]

KVH:

You hit it right on the head on two counts. First, your analysis of my shifter woes was dead on. The anti-rattle plunger had dislodged and was just loose in the shifter channel. It was blocking the 1\2 shifter and causing trouble. Cleaned everything, re-installed with new grease and all is back to working fine. Thank you.

Oh yea, you were also right about small problem, easy fix, huge hassle getting to it! Taking the whole dash support out, removing the new polypropylene tunnel cover (which involves removing the hand brake handle and e-brake tunnel cover as well) and then reassembly. What a hassle. No issues - just time. Still - glad it was an easy fix and didn't have to take trans apart.

Thanks again to all of you on the forum for your help and advice. Always good to hear from others with similar issues and their suggestions for a cure. I appreciate it.