MTFCA Forum

Hello! Once again I come to the MTFCA gurus for help.

We are having an odd problem with our T and would love some fresh thoughts.

The car:
- 1927 touring, with a 1923 engine.
- Fresh rebuild of rear axel and engine. Didn’t fully open up the transmission, but did install new kevlar bands, and the clutch discs were all cleaned and inspected. They looked fine. The clutch spring wasn’t replaced, but it’s plenty tight.
- Added both the oil slinger kit and the outside oil line kit.
- Added sure-stop brakes.
- Switched to a 9-tooth pinion gear.
- Maybe 100 miles on it since the rebuild. Till now it has run very well with no issues since the rebuild. It has always shifted smoothly from low to high.

The problem:
When the hand brake is straight up in neutral, the high speed clutch is grabbing when the clutch pedal is released. Not enough to fully engage high, but enough to stall the engine if you hit the brakes. HOWEVER, it only does this OCCASIONALLY. It’s fine more than not. Why?

Details:
- It doesn’t do this all the time. That’s the head scratcher.
- It just started this the last few trips out.
- The high clutch is not slipping when the car is in high.

What’s been checked:
- Confirmed proper 13/16” clearance between the drive plate and the fork shifter.
- Adjustment of the bands (they are fine)

So here’s how it goes. We use the T each night to make a delivery to our store. It’s 1/2 mile each way. All gravel road. 1000’ of that trip is our steep driveway (23% grade). We are going downhill heading to the store and uphill coming back. The T is started, backed out of the garage and to the milk house (50’ or so in reverse). The T idols there with the hand brake fully pulled back while we load up (only takes a couple minutes). Note that the T has a good free neutral and would sit there with the hand brake in neutral, but we engage the brake for safety. We run in low till we get to the bottom of the driveway, then shift to high on the now level road. Shift back to low before turning into our store parking lot. The T gets shut off at the store for 5-10 minutes while we unload. Start it back up, pull out of the parking lot in low, then shift back to high for the straight stretch. At the bottom of the drive shift back to low (including moving the hand brake to straight up). Stay in low the rest of the way home. Through all of this the T behaves and shifts perfectly. When we pull back into the garage, Ernie lets off the low pedal to coast the last few feet. Instead of going into neutral, as it should with the hand brake straight up, it tries to shift into high. It’s jerky like high is not fully engaged, but it’s enough to stall the engine if you hit the brake. If he turns the crank right away once it stalls without changing anything, the car does move forward (this is with the hand brake still in neutral position). Last night he went back maybe 15-20 minutes later, tried turning the crank again without having changed anything, and the car now didn’t move - it was properly in neutral. The car fired right up, shifted and ran perfectly (just went back and forward between reverse and low a few feet).

It did this exact thing 2 days in a row. Ernie adjusted the clutch fingers. They were just shy of 13/16” so he tightened them 1/2 turn. They are now exactly 13/16”. The next trip it was fine. But the time after that, it did it again. So twice in a row, then fine, then again.

What has us totally baffled is that it’s not doing this all the time. If something were out of adjustment, it seems like it would be causing a more consistent problem.

It’s always been after climbing our steep driveway. Whether that’s coincidence or not we’re still trying to figure out.

Even with the long, steep climb the car is not running hot. We wouldn’t even call it fully warmed up - the temp gauge barely makes it half way to the low end of the normal running temperature. Nothing on the transmission feels hot. If any of that matters.

It has an excellent free neutral. It doesn’t creep even when first started on a smooth cement garage floor.

It’s been 9 months of rebuilding and we just finally got this thing running again. We figured to rebuild the transmission eventually but wanted it running to enjoy this fall and without actually tearing it fully apart, the transmission really seemed in decent shape. We really, REALLY don’t want to have to pull the engine again. If it comes to that, we’ll go ahead and fully rebuild the transmission while it’s out. But we’re hoping we don’t have to at this time.

We were sent a link to this site, and triple checked all the adjustments it goes through:

https://modeltfordfix.com/adjusting-the ... nd-clutch/

We’re now at a loss. What could make it behave this way so inconsistently?



UPDATE SUNDAY AM OF NEW INFORMATION:
Made 2 runs yesterday after I posted. The first time at the top of the driveway, it tried to do the shift into high instead of neutral. Ernie pushed the low pedal back down to continue forward in low speed, then put the hand brake all the way forward so it could go into high, then popped the clutch all the way out then pushed right back forward into low. Having done so he pulled the hand brake back to neutral, let out the clutch pedal, and it properly went into neutral. It still had a proper neutral when he pulled into the shop. The transmission still didn't feel very hot and nothing was smoking or any such thing.

Ernie went over all the linkage adjustments again. He went ahead and turned the cam bolt over as several had suggested. There is no side play so it doesn't seem possible it's slipping off the cam. He adjusted the linkage to allow almost no play in the pedal, then adjusted the cam bolt to compress the transmission spring as far as possible - almost like the low pedal was all the way down. It's as far back as possible even in low, so there should be no chance for friction to build in the clutch plates. With things adjusted this way, the point that it engaged in high was with the hand lever forward of neutral about 3". When we came back after this trip, it did go into neutral and stop, but still didn't seem quite right. If the hand lever moved forward no more than 1" it started to engage high and creep forward. Ernie shut if off then immediately tried to crank it. It wanted to creep just a little and the crank turned hard compared to usual. Ernie pulled the floorboards, glanced at the linkage to make sure nothing was rubbing, and started the car. In those few minutes, everything seemed back to normal. The car started fine, cranked much easier than it had a few minutes before, and the hand brake had to again travel the 3" distance to start to engage high. Low and reverse again felt normal to move the car back and forth a bit.

We are grasping at straws. It currently has Shell-Rotella T5 10W-30 oil in it a "Synthetic Blend Heavy Duty Diesel Engine Oil". Any chance it just doesn't like that oil? Problems definitely started after we changed the oil the first time, although not immediately so. Maybe a week or 2?

Looking back, there was a morning Ernie backed the T out of the shop and down the milk house and pulled the hand brake fully back to lock the brake while it idled. We loaded the milk then went to engage the hand brake to neutral so he could get in from the driver's side. This is what we always do. But this time, the car started to move forward. He tried 2 or 3 times to move the hand brake to neutral, and it kept engaging every time, lugging the engine down to the point of stalling. We think maybe it did stall it out the final try. At that point, smoke came out from around the transmission. We made our delivery in a different vehicle. When we got back, Ernie adjusted the linkage (nothing with the clutch fingers) and the T started fine and pulled back into the shop. Before we took it out again Ernie went ahead and screwed the clutch fingers in a half a turn. Since we were still coming off a rebuild, we didn't think much about it at first. That was Monday the 5th. We made a second run on Monday that was fine, and then our Tuesday run is the beginning of the issues I posted above. I apologize, I should have thought to mention this incident to begin with, as typing it out now it seems important somehow.




Thank you all!

~Katie

If you’re really lucky, the least expensive possibility, and the first place to look is at the cam on the hand lever cross shaft. Possibly, your cross shaft has a little slop in it side-to-side and sometimes the cam engages the adjustment bolt on the clutch lever properly, and other times the shaft moves over and the adjustment bolt falls off the side of the cam causing your issue. Side-to-side slop in the cross shaft may be due to a slight bent frame rail. OR, maybe there isn’t any slop and the cam is bent left or right a little and the adjustment screw rides the edge and just falls off the edge occasionally.

Anything else I can think of is probably an internal transmission problem.

Through “lets off the low pedal Instead of going into neutral, as it should with the hand brake straight up, it tries to shift into high. It’s jerky like high is not fully engaged, “

That may be clue the low pedal clevis is hanging up, causing the clutch lever to be engaged. Check interfere e with bendix cover, or something.

A good fix sometimes for the clutch lever adj bolt that glides on the cross shaft cam is to reverse the bolt, put the hex head on the cam, after grinding it to a semi dome shape. Better than the tiny bolt shaft riding there, can’t easily fall off the cam and put you in direct high .

I have 2 26's and with both of them, the actual neutral is with the parking brake slightly forward of straight up.
It is possible that the bolt on the clutch lever at the side of the transmission is slightly out of adjustment and needs to be tightened against the cam a little bit. or it could be that the cam on the cross shaft is slightly out of alignment with the bolt. Some things if they are very slightly out of alignment can shift either with uphill or downhill orientation or with expansion due to temperature. I don't think you have a problem inside the transmission or with the clevis adjustment if everything works with the lever forward and using only the pedal for shifting. So focus on the position of the cam and bolt and also the adjustment. Some T people have found that adjustment works better by turning the bolt upside down with the head against the cam. That will give you a wider point of contact with the cam.
Norm

I'd look carefully to see if the cam is getting loose on the brake cross shaft. It would be a good idea to check all lever to shaft fits.

Utah shift is hanging up or cam the controls it

Adam wrote: ↑

Sat Sep 11, 2021 11:21 am

Anything else I can think of is probably an internal transmission problem.

We studied the cam again and can't find any side-to-side slop in it. Nor does it ride close enough to the edge anywhere in its travel to fall off the side.

Does it sound likely to you that it's internal? Would you share what you think internally it might be?

We still don't have any guesses ourselves what it could really be internally, but are starting to lean more that way since we simply cannot see anything wrong with the linkage, nor manage to adjust it in any way to correct the problem.

~Katie

Clutch discs hanging up on drum lugs?

Make certain that the clutch cam is securely locked to the brake cross shaft. It must turn with the shaft.

jab35 wrote: ↑

Sun Sep 12, 2021 10:00 pm

Clutch discs hanging up on drum lugs?

This is it! While I wish it was as easier fix, I suppose at least it is fixable. Ernie says in hind sight those lugs were somewhat chewed up but he thought they were good enough to work. Clearly not. He took the clutch fingers clear out so all we had was low, and the car runs with no issues. So that is definitely the problem. Sadly we still have an original drum, so we'll have to order a new drum plus the new lugs for it. And then decide how much else to replace while the transmission is out of the car.

Thank you everyone for your help!

~Katie