1991 V2500 4l80e 1st Gear Issue

[trav2210]

I think either way I'm headed into this trans. Any input on which kits to buy. Should I go ahead and replace all pistons while I'm in there.

Also, I got put in a bind and had to tow with the Burb. Didn't want to, but like I said, no choice.

Reason I bring it up is because It did fine, working in the same "limp mode" I had described before. It shifted as needed missing only 1st gear, however, at the end of the trip we hit a few huge Florida hills (haha) and it decided when climbing uphill it needed to be in OD at 35 mph and just about WOT????

It would dive down into OD and not come out. I would let completely off the throttle, and it would coast. Back on the throttle and it goes from 2nd to 3rd to OD in no time flat over and over. This was after about 25 min of towing.

I will throw a new TPS in it in the morning just to ensure no issues there, but I thought this was another weird piece of the puzzle maybe...

 

[HotRodPC]

Do you by any chance have a reputable trans shop around you that might do a diagnosis on it, as in run it on the scanner to detect any codes. If you can find someone to do it for $69 or $89 and give you an evaluation or honest educated opinion, it might be worth it.

As far as replacing pistons, if you're talking about bonded pistons, Yes, for the few bucks they'd cost I'd do it. I just don't know for sure that a 4L80-E has bonded pistons though. If it doesn't, then NO, just replace the seals on the pistons and they should be good as brand new.

 

[trav2210]

I'll look around to see if I can get a decent quote around here. I've done it in the past with other issues to get a second opinion, and can usually speed up the troubleshooting.

Took a video today of the trans tunnel. You can hear a buzzing that changes frequency with engine RPM. Never heard this before out of a trans. I'll post it up and you guys can tell me what you think.

Thanks in advance!

 

[trav2210]

https://youtu.be/SsqI3Twj2GE

 

[trav2210]

https://youtu.be/sqU-swBFe60

 

[trav2210]

You can hear the Buzzing at idle and how if flixuates with engine rpm. I was hoping for a cheap electrical problem to fix this, but the Buzzing leads me to believe otherwise. Trans will more than likely be coming out tonight.

Any suggestions of what the Buzzing may be in the videos?

 

[yevgenievich]

I heard similar noise with 700r4 when it came apart internally from running low on fluid. Basically hard parts shattered (i thing sprag was cracked and couple of other things). It will likely be obvious

 

[HotRodPC]

You can hear the Buzzing at idle and how if flixuates with engine rpm. I was hoping for a cheap electrical problem to fix this, but the Buzzing leads me to believe otherwise. Trans will more than likely be coming out tonight.

Any suggestions of what the Buzzing may be in the videos?

4L80-E has a couple more solenoids than just A, B and TCC lock up. If it's buzzing, not screeching or whining, it could be one of the solenoids.

 

[trav2210]

Trans came out last night. Fluid isn't too burnt, however, considering that I just replaced it, it shouldn't be burnt at all.

I think it is because, I got a great deal on a travel trailer and had no option but to tow with a bad trans.

I just split the tcase and trans. Pulled off the converter and will be opening it up tonight.

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[trav2210]

Started dissembling last night... Here are the preliminary pics

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[HotRodPC]

Everything looks good EXCEPT that very last pic. Not sure if it's what I'm seeing, or if it's the angle of the pic, but even the color doesn't look well. Are those burnt and worn clutches in that last drum?

 

[trav2210]

Yeah, they are pretty black. Steels are scored as well. I went through the valve body last night, not finding anything wrong.

On another note, the VB filters were clean as can be. Not a piece of dirt in them. I wonder if this is a reman VB??

After 200k miles + I would have expected to see more crud

 

[trav2210]

Cant seem to find anything that would be causing the noise in the above videos. No loose parts or excessive wear.

What's the best way to test out the converter. Besides flushing, I'm assuming use the inputs shaft(s) to spin and listen for noise...

any suggestions?

 

[HotRodPC]

The only thing that I know of to buzz on these transmissions is the A, B or TCC lock up solenoids. If it's got 200,000 miles on it, chances are you simply wore out that clutch pack. As it got worn and loose and could not compress the pack tight enough, the clutches slipped and got hot which explains the discolored steels too. Or, could it have been that buzzing solenoid was stuck ON, and that's what caused that clutch pack to burn up? With that many miles, I think just for good measure, I'd replace the 3 solenoids, even the wiring harness if it's any kind of brittle whatsoever, and of course a new reman converter too.

 

[yevgenievich]

if it is original style harness/connector, it should be replaced anyway. And as hotrod pointed out, torque converter should be replaced during a rebuild. Especially high miles one with a clutch inside.