'94 60-e shifting problem

[AWeb80]

I rebuilt the trans ~9k miles (3 years) ago.

It has been having shift problems from 1 to 2 for the past few days. EVERY other gear works perfect. even the down shift from 2 to 1 is perfect....just the upshift is delayed like a MOTHERFUCKER.

here is a quick vid...I was at...maybe...40% throttle at the most....should have shifted at 2500 RPM....then when it did shift at 4k, it rev'd up before going to second. If I get to 15mph or so, throw it into N, then back to drive it will fall in to second or third, whatever is normal for that speed/throttle input, and work fine. If I go WOT, it will bounce off the rev limiter about 15 times before it will shift.

It did this a few times before I left for Toledo this past weekend, now it's every time.

Leander helped me rebuild this ~9K miles ago....I was really hoping for a trouble free trans for a long time.

any ideas?

http://www.youtube.com/watch?v=ilTskQ3xeI4

[19Cutlass94]

Mine started doing the same exact thing before I swapped to a 5spd.

[AWeb80]

Just drove it again tonight.....the more I think about it, I wonder if the line going to the accumulator came off....or maybe the shim I have inside the 1-2 is blocking something...or a spring broke.... Every other shift is fine....just the 1-2 upshift is delayed.


Thoughts?

[3400-95-Modified]

Any of your theories could be a possibility... however I think if the accumulator lines cam off you'd have way more issues than that.

The one time I had really delayed 1-2 shifts it ended up being the valve body was clogged up with aluminum shavings since I snapped the diff roll pin and the center rod was rubbing the case spreading aluminum shavings throughout the trans... Ever since then I've run my EP LSD.

[AWeb80]

Ya, I figured it's something to do with the valve body. Should I try a flush at a shop and see if will come loose....or bit the bullet and pull the trans and tear into it again?

[3400-95-Modified]

drop the pan first and see what your fluid looks like... Mine was blatantly obvious when I saw the fluid on what the issue was... It was all metallic looking and VERY black.

And if it is that, its probably not something that will come loose... I replaced that VB with a new one since it was so bad... I couldn't get valves out to clean them they were so stuck.

[AWeb80]

I haven't had the drive to really look at this yet, but some on another forum thing it could be something with the Vacuum modulator......wouldn't that affect all gears not just the 1-2 though? Some say it only affects the 1-2.

[robertisaar]

vacuum modulator effects ALL shifts. IIRC, on the earlier 4T60Es it effected the TCC as well, but i think that function was taken over entirely by the TCC PWM solenoid for the ones equipped as such.

[gpse3400]

I'd lean towards the accumlulator as well.

[AWeb80]

Last Saturday I dropped the pan and did a fluid/filter change. Also dropped the accumulator and pulled it apart. The 1-2 piston looked slightly wedged in there. I pulled it out and there was some slight marring on the sidewall of the acc housing. I took some 2000 grit sand paper and smoothed it out. Reassembled everything, new dex 6 fluid and WIX filter.

NO change. 1-2 shift seemed to take even longer this time....a good 30 seconds. SO thanks to my 2nd gear start switch I've been putting around like that for about 100 miles


Well, I don't want to be presumptuous......but I think I have my 1-2 shift back!!!!!!!!!!!

Took the GP to work today and then to my softball game....on the way home I was getting REALLY irritated at this 2nd gear start BS....it's no fun not being able to play in first....

...so I get up to about 30mph or so and say F it, and just punch it, I Downshifts hard like normal and I get major tq steer, then hits 6k and upshifts perfectly....

Drove around in town for another 30 mins and the 1-2 shift has been working fine since.


What gives?

[3400-95-Modified]

She wanted to be abused... lol

Still could have some issues valve body wise but hopefully not. Running it up to 6k like that might have just cleared some passages if that's all the issue was too.

[AWeb80]

Ok, some more input on my findings from today.

I drove it ~40 miles this morning and it wouldn't shift to 2nd until it was warmish.

It was even more prevalent tonight...was about 45* when I started it up and drove for a while....took about 80 miles before it would, I'm guessing here, be warm enough to shift properly....?

It was hesitating all night and then all of a sudden it works like a charm the last 20 minutes I was cruising around.


Why would it take sooo long to finally work right.......? does it have something to do with heat and being warm?

[robertisaar]

there is some kind of a "thermostatic element" in the trans, but i have no idea what it does. perhaps that may or may not be the issue?

[3400-95-Modified]

I doubt that has anything to do with it... I'm guessing a shift valve is stuck in the bore, and when the VB warms up enough the clearance changes and the valve can now move freely.

[AWeb80]

Damn, I guess I'll just live with it till I really feel like taking it back out.