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TR2/3/3A Dang! Clutch slipping in 5th

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PeterK

PeterK

Yoda
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Noticed the revs increasing going up a hill in 5th so I babied it home for 10 miles. Looks like I might have oiled the disc but I haven't put it up on the lift yet to investigate. Clutch fluid is at top so It could be the front seal on the W58 or the rear on the engine (hope it's not!)

Yup - revs increase, MPH does not. I guess that was my last ride this season.
 
Still running the stock flywheel and clutch? If so the flywheel is drilled so a tranny leak will go through the flywheel and miss the clutch. Might want to check the clutch adjustment. If the adjustment is good it’ll have to come apart.
 
I ordered a couple of front seals and front cover gaskets to replace when I pull the (W58 Toyota) gearbox. Flywheel is TR4A as is clutch cover (pressure plate). It is adjusted so it disengages high off the floor (for speed shifting) but if I take it apart, I'll spin the (McLeod hydraulic) t/o in a couple of turns to put the a little engagement a bit lower. There is plenty of free play at the top but I hope I'm wrong and it does turn out to be adjustment related. Not really hard to r&r and will give access to install a modern starter while I'm at it.

Still moving cars around so I can get it on the lift and see what's up. I rebuilt the clutch master this spring and no leaks or loss of DOT4 fluid.

Thanks for the help John!
 
Not likely IMO that it's oil on the clutch faces. Oil will certainly make them act up (usually chatter or "binary clutch"), but not just start slipping under load, at least not for long. If it does slip under load, the friction surfaces quickly get quite hot, hot enough to burn off any oil.

More likely adjustment or wear, IMO. Not that it matters, you'll want to replace that seal anyway, if it's been leaking; and probably the friction plate too.
 
It sounds like the adjustment is a definite possibility. Remember, as the disc face wears, the clutch fingers lift and the adjustment tightens. In other words, any clearance you had has reduced over time and use. Since you have it set for a high pedal for speed shifts, any wear will result in the clutch never fully engaging. An adjustment may fix the issue!
 
First thing I checked was the pedal return spring. It's good. Then tested freeplay using my hand to depress the clutch and it felt normal, hasn't changed but calls out to be verified regardless. The one thing about hydraulic t/o bearings that I don't love - got to remove the gearbox to set the free play. So I ordered seal and gasket kit to install while I'm in there just in case the seal that I installed with the W58 has failed or I damaged it. It should all become apparent once it's out. After I mow my field.
 
Aaah, not the stock linkages. Then there isn't much you can do without "digging in". The likely issues are:

1) throw out assembly pressing on the clutch. (bleeding is all you could try without pulling the tranny. The MC may be holding pressure in the line)
2) Clutch diaphragm weak.
3) Worn out or contaminated clutch disc.

I'm afraid after the bleeding, the tranny has to come out for the rest.
 
Still on hold waiting for Kubota parts to fix my 3-point hitch. Tractor is in my shop so the 3A is patiently waiting for it's turn for it's mechanic (me).

First thing I'll attack on the 3A is the m/c rod adjustment (after reading Randall's solution to dragging TR6 brakes) and bleeding since the only thing changed this year was the clutch m/c. Stay tuned.
 
If the MC rod was adjusted too tight, it can maintain pressure in the line, even after the pedal is released. I’ll cross my finger that is the issue!?!
 
I adjusted the M/C rod yesterday, clutch still works fine, but the rod WAS too tight. Test drive I punched the accel in each gear, all tight except once in 5th same uphill as before, the revs increased with the speedo but one time it felt like an automatic downshifting down then back up for a second. Due to the amount of oil on my drip pans, I still suspect an oiled disc due to the leaks. I've got my tractor fixed so I can put the 3A up on the lift and look closer with my endoscope - so I won't take it apart until I confirm my suspicions, and check the gearbox fluid level.

BTW yesterday my town had Maine Cabin Masters (DIY network) here for our fall festival so I took the time to drop in with a few classics for a mini car show from the locals. Runs like a top!
 
You say 5th gear. Are you running an electric overdrive. Could a sudden downshift be an electrical problem. After all, it is a Triumph!
 
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I doubt that it is oil from the main seal. I have the toyota trans in my TR3. As many times i have tried to stop the main seal leak, it still leaks.........
Even with a main seal leak I have no problem with slippage. My thinking adjust first, then maybe the shims at the T/O bearing.
 
The Triumph flywheel is designed to expel any oil leakage from the tranny to the front of the flywheel...away from the clutch assembly. It has drilling’s through the wheel to accomplish that feat. If you have another style flywheel, it may not have the drilling’s. So clutch disc contamination should only be an issue if you are running a non-Triumph flywheel.
 
Thanks John. I just have to get to it; I have too many pre-winter chores to do right now. I can still drive it OK, just not too far and avoid uphills in 5th. Otherwise perfect. Thanks again. I'll keep this updated, uh after the garlic is planted...
 
2020 update sort of. Spring test drive, no work done since 2019, and all 4 gears would punch when I hit the gas hard, i.e. no slip. Tried 5th and it seems OK on the flat, and previous 5th gear slippage was up a long hill which I didn't try.

So back up on the lift, pulled the inspection cover, and all is still nice and clean in the bell housing like I just installed it. I tightened up the sump bolts while there for a couple of drippy looking bolt heads. Cleaned up road draft oil. Checked W58 level and it was nearly a quart low - took almost a full pull of fluid in my vacuum pump. Valvoline synthetic 75W90. So at this point I'm doubting anything is out of sorts with the hydraulic t/o or setting, thought so but had to verify.

That brings me to the last change point before I noticed slipping. Just rebuilt clutch master cyl, might have bollixed setting the push rod and had it too tight, and it was hard to bleed properly with one person and my Motive pressure bleeder doesn't quite fit the reservoir so it leaks a little pressure. Pump it up, quickly duck under and hit the bleeder before I lose pressure - funny really! Could the spring in the m/c be broken? I might just rebuild another spare to have ready regardless.

So my solution/answer is no answer, just an update. If I get someone to assist bleeding, I'll try it again. But for now, I feel safe staying close to home at watching for slippage. Maybe it was the gearbox low fluid?

Well that's the update so as it is.

Pete
 
Glad it's doing ok. I've always used gravity bleeding when working alone. Just place a clear tube on the bleeder and crack it enough to see fluid and let it run into a can. Then just sit back and add fluid to the MC when needed. It works with every car I have ever owned, so long as the MC is primed. It even works with my new cars with traction control and anti-skid systems in between, when doing the brake side. When I am flushing the system to change the fluid completely, I will pump the pedal to speed things along. The clear tube prevents sucking air back into the system between pumps.
 
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