bug in the rebuilt?

[denisew]

I just got my truck w/rebuilt trans back from the shop. they changed out all the clutches, seals,gaskets,etc. did the sonnex valve update. this was because i brought it in with the SES on, and the hard 1-2 shift that we all know and hate. anyways, i have my truck back now. but when i take it for a ride on the expressway, or over 50mph, and then come to a stop, as i accelerate from 1st to 2nd, it feels as though it slips just before catching second. if you baby it, it won't do it. like on a side street. but out on the main street, where you move in and out of traffic, it happens. basically the hard 1-2 banging shift has been replaced by this 1-2 slipping shift. almost like it slips into nuetral just before 2nd. the tranny shop took it back without an argument to check it out. just wondering if this has happened to anyone else. they did not change any solenoids by the way, because at the time, they were all good. anything familiar to anyone?

[OverBoardProject]

Transmission shops make mistakes all, the time, and the good ones always fix it without any complaints.

Shoot, when I had the transmission rebuilt in my motorhome they somehow had the wrong gasket set installed. And this is considered to be the best transmission shop in the area.
I'll still go back there next time.

[denisew]

as of the end of business day, still no problem from shop's point of view. everything is checking out on their end. they cannot duplicate the slip. rescanned. everything is all good. anyone else have a clue?

[BlazerLT]

Originally Posted by denisew

as of the end of business day, still no problem from shop's point of view. everything is checking out on their end. they cannot duplicate the slip. rescanned. everything is all good. anyone else have a clue?

Go for a drive with them and show them it.

[denisew]

I think I might have to do that tomorrow morning. I had it doing it today when I dropped it off. The trouble is, when it cools down, it disappears. Very similar to the original problem, the harsh 1-2 shift. Now with the cooler temps in Nov. it takes longer to get it to do it. I guess I will have to get the truck, drive it around till it slips, then go kidnap my mechanic. If I let it sit in front of the shop for a few minutes, it seems to be long enough for it to cool down and go away. It's too weird. One problem has been exchanged for another. But both occur after the same types of trips with the truck.

[BlazerLT]

You might have a tranny cooler that needs to be flushed and cleaned.

But realistically, you need to get someone from the shop to go with you when it is warm.

It is the only way, and don't take no for an answer.

[denisew]

tranny cooler.....supposedly this was already done. but for sure i will drag the mechanic along for the ride tomorrow.

[trypodd]

my ex geirlfrend hade a 99 doge durango that did the exact same thingi never could figure the problum out. only hers had benn doing it sence she baught it. i would defenentl make the shop fix it.

[denisew]

well, the truck is not doing whatever it was doing, as bad as 2 days ago. Not sure if it's correcting itself, the tranny shop says that the short delay in shifts between 1-2 is the kickdown. I'm just going to drive it for a week or two, see what happens. It IS under warranty. For now I'm tired of driving around, wasting gas, trying to FORCE it to duplicate the problem. Tranny shop says everything checks out. I am showing no codes on my scanner. I guess I just have to wait for something to happen?

[OverBoardProject]

Why not just go about your life without even thinking about it until it happens.

A little less stressfull

[denisew]

That's what I'd like, only my husband is still shook up over putting out 1200. for the rebuild. He wants it running like new, and I guess he's right. But he's got his truck, I got mine, and I'll just drive it till it breaks. Then worry about it. Hopefully it's not in the middle of this winter, 20 below 0 with the kids in the truck, waitin on a tow truck.

[corning_d3]

$1200?!?!?! For a rebuild?!?! My god, did you get a jar of vaseline when you got the truck back? I buy rebuild kits for your rig all day for $200. I'm assuming you have the pain in the neck 4L60-E transmission. A freshly rebuilt transmission will slip somewhat until the friction material and clutches/drum wears in a bit. Also, is it possible that you've felt the harsh shift for so long that a normal Chevrolet soft shift has you worried. So many people complain about harsh shifting, that most car manufacturers intentionally slip clutches for smoother engagment. To quote my old instructor, "People want to be going down the road 60mph, and feel as if they never left their recliner". If you don't "hotrod" a harsh shifting transmission, it can outlast a softer shifting one because the clutches don't slip against each other as much, which reduces clutch/band wear. Also, you mentioned a shift valve replacement. When a transmission is made at the factory, the valves are "lapped" and matched for that valve body only. It may be possible that the valve in question may not fit the bore properly, allowing fluid to flow past the sealing area after the aluminum valvebody heats up, causing it to slip. I hope i've helped....my fingers hurt.....

[OverBoardProject]

corning, It's nice to have a transmission guy on the board.

I hope that you can look in from time to time, and help us unworthy ones out.

[corning_d3]

:-), thanks for the warmth!! I have a .......LOT........ of experience with that particular transmission!! I'm also a '99 Blazer 4X4 owner. I make my rounds..........

[rlith]

I agree with corning regarding this.... If you want to put a firmer shift into a freshly rebuilt trans like this, I would suggest adding a vette servo to the mix. This way you have a firmer shift and less wear and tear on it... My trans has been reworked to the point I can chirp it into 3rd @4000 rpm if I want...(on top of the vette servo I run a transpak and an electronic shift improver)