Strange transmission / T-case problem, wheels hard to turn after warming up

[psiaddict]

This is actually my first technical question here on the board; I hope you all can help me out.

I searched around, but I could not find anything… I remember reading something about a similar problem awhile back but I could not find it again…

Here is the history:

Okay, I just got my car running again. I just installed a new (used) motor, new (used) transmission, I had to swap the output shaft on the tranny since it was a 22 spline and the T-case was a 23 spline. New ACT 2600 clutch / RRE flywheel. OEM throw-out bearing.

I had the car warmed up and was checking for leaks, everything looks good. I turn the car around in the driveway few times and everything seems good, after a little clutch pedal adjustment, I am ready to drive the car over to the car wash and clean it up. This is when I found the strange problem.

I started out of the driveway but noticed that even though I was on slope, in neutral, I let off the brakes and the car would not roll. I backed up, jacked the car up on stands, all four wheels off the ground and put it in 1st gear, let it go for a few minutes and the put it neutral, now when I try to turn the wheels manually, they will not turn, it is like the brakes are on. I turn off the car for 5 min or so, the wheels begin to turn freely again.

So, it seems like the wheels stop spinning when something heats up, either the Transaxle or the differential…maybe it is something as easy as the brakes dragging but the car was not doing it before the engine/clutch/transaxle were replaced…

Anyone have any ideas?

 

[eclipsh]

Is the t-case yours or one you just got? You may want to check it for damage. a seized bearing on the output could cause that. I had it happen to me. If you don't get any better suggestions you may want to split off the neck on the t-case and take a look at the bearing and nut.

 

[babyviper]

i had this happen to me when i put a trans in with the wrong final drive gear. We had ordered a trans off ebay turns out it was a evo trans and the gearing is diffrent. we swap the final gear with the correct one.

 

[Colt4G63 also]

Do you have an open front diff, and does it affect all wheels equally?

I was about to type in that you had two different final drive gears, but then I read that you lifted all four wheels off the ground and still had the issue. I would definitely start pinpointing where the resistance is coming from; pull the transfer case again if you have to.

 

[psiaddict]

Is the t-case yours or one you just got? You may want to check it for damage. a seized bearing on the output could cause that. I had it happen to me. If you don't get any better suggestions you may want to split off the neck on the t-case and take a look at the bearing and nut.

Transfer Case is my original one, it was working fine before the Motor/Tranny swap, it just sat the trunk of the car while I was gathering the parts I needed… I just topped off the fluid when I re-installed it.

i had this happen to me when i put a trans in with the wrong final drive gear. We had ordered a trans off ebay turns out it was a evo trans and the gearing is diffrent. we swap the final gear with the correct one.

I don’t really know the source of the transmission, it was supposed to be a set with the motor, but when I went to put the motor and transaxle together, I figured out that the motor was actually out of a car with a Automatic trans. (Crank had a bushing still and the starter hole on the Spacer Plate was wrong) so they could not have been from the same car.

I wonder if there are any numbers I can look up to see what the trans. originally belonged to?

Do you have an open front diff, and does it affect all wheels equally?

I was about to type in that you had two different final drive gears, but then I read that you lifted all four wheels off the ground and still had the issue. I would definitely start pinpointing where the resistance is coming from; pull the transfer case again if you have to.

Yes since they were all off the ground, they should have just turned at different speeds… After thinking about if more, it seems like it has to be a problem with the Transmission and probably the VC inside… it seems to lock up when warm.

I may try pulling the transfer case off and testing again just to eliminate the front and rear Differentials. But I am pretty sure it is related to the VC.

I wonder if I could have done something wrong when I swapped the 22 sline output shaft for the 23 spline one?

 

[eclipsh]

Did you install the check ball and retainer clip properly? There isn't much to screw up. The only other possible issues during that procedure would be the wave spring and synchro for reverse not going in correctly.

I am stumped on what this could be. I don't think a bad VC unit could cause this since a failure should just mean it stops locking up or at worst permanently locks and acts like a spool. My bet is that you'll be pulling that tranny back out of the car.

 

[psiaddict]

Okay, well I figured it out… almost

After having a little more time this afternoon to look at the car, I have figured out that it is not the Trans or Differentials at all, I am very relieved, although still a little unclear on the reason for what it IS doing…

I had the car back up on stands (all wheels off the ground) I checked to make sure the wheels spun freely by hand, I put it in neutral and started the motor, in the time that it took me to step back to the drivers side wheel, the wheel was now almost locked again… I tested the rear wheels and they would turn but with more resistance, so, it looked like it was not heat related after all, but just starting the motor caused the problem.

I turned off the car and tested the wheels about every few minutes and after about 5-10 min, they stared to turn again and spun normally after about 15 min or so.

But since the fronts were harder to turn than the rear, I thought that is where the problem was, not the diffs. So I repeated the sequence with similar results (it took longer for the wheels to lock this time) but when they did, I suspected that it may be the brakes grabbing even though the pedal has free play. So I pulled both front wheels and sure enough the rotor was tight on the passenger’s side. I pulled the caliper off the pads and rotors and the hub now spun freely!

I could not figure out why this phenomenon happens when the engine is started but at least I know that the trans is not bad… I will look at it more tomorrow and see if I can figure out why one single caliper in the system is pressurizing…

 

[Colt4G63 also]

That's nuts. Does it have ABS? I can't see any reason a non-ABS car would be able to pressurize one caliper just by starting the engine.

 

[psiaddict]

That's nuts. Does it have ABS? I can't see any reason a non-ABS car would be able to pressurize one caliper just by starting the engine.

No ABS...

Okay, I have the problem fixed! But it was still a strange symptom to have.

Looking at the car this evening, I was able to duplicate the symptoms repeatedly:

1) Jack up the front of the car (both wheels)
2) Roll either wheels normally
3) Start the engine in neutral
4) Both front wheel would lock up almost immediately, you could still MAKE them turn but with a LOT of force.

After scratching my head for awhile and even filming the process for posterity, I got the idea to pull the vac source from the brake booster… when I did and started the car, the brakes no longer locked up! (I capped the manifold of course)

I now suspected the booster itself to be bad somehow, but after doing all the checks for the Booster in the FSM, it appeared to be good.

While doing these checks I noticed that the brake pedal free travel was very short so the pedal was too high. When I went to adjust the pedal, the locking nut was loose…I adjusted the rod about 4 turns in to get the pedal set up correctly and that is when it hit me that that could be the root cause of the whole problem.

I started up the car with the booster hooked back up and the wheels still spun freely!

After thinking it through, I think that the brake pedal rod must have come loose at some point (I had not touched it for over a year) then slowly rotated out over time and finally been right at the edge of activating the brakes, then when the engine is started, the vacuum assist is enough to pull the brake pedal slightly and cause brake caliper to slightly clamp down.

It may be that the RF brake is the first to respond to pressure, maybe even dragging a bit so that it why this caliper clamps down first?

Adjusting the pedal rod back to the correct position keeps the brake from being activated and allows the car to operate normally.

Anyway, Thanks for the help and suggestion it is now resolved, I am happy to be able to move on to phase 2… E3B16G and E85!