bug in the rebuilt?

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 basically the hard 1-2 banging shift has been replaced by this 1-2 slipping shift.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?

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.

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?

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.

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.

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.

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

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.

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?

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

A little less stressfull

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.

$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.....

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. :biggrin:

:-), 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..........

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)

$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.....

Well, I WAS starting to get over this, now I almost feel guilty for not being able to save $1200. Yes, it's the 4L60-E, and again, it's only an issue between 1&2, all others move moothly. If I drive like grandma, even 1&2 are smooth. It's only when I get on it, and I don't mean flooring it, just your average "pass this sunday driver when the light turns green" get on it. That's when it kinda "feels" like it slips, just for maybe 2 seconds, before it gets catches 2nd. (RPMs go up to around 3000.) It feels as though it is SLOWLY improving, as I drive it each day. Or like you said, I was too used to the old banging,harsh 1-2 shift. But I haven't been on any trips too much longer than 20 minutes. Maybe I'll take it out today for a longer, faster cruise.
A question about the valve body replacement...you think IF it was'nt done correctly, it'll show up before a 1 yr. warranty expires? And why I am feeling this slip, yet the it's not throwing any codes?

Well, I WAS starting to get over this, now I almost feel guilty for not being able to save $1200. Yes, it's the 4L60-E, and again, it's only an issue between 1&2, all others move moothly. If I drive like grandma, even 1&2 are smooth. It's only when I get on it, and I don't mean flooring it, just your average "pass this sunday driver when the light turns green" get on it. That's when it kinda "feels" like it slips, just for maybe 2 seconds, before it gets catches 2nd. (RPMs go up to around 3000.) It feels as though it is SLOWLY improving, as I drive it each day. Or like you said, I was too used to the old banging,harsh 1-2 shift. But I haven't been on any trips too much longer than 20 minutes. Maybe I'll take it out today for a longer, faster cruise.
A question about the valve body replacement...you think IF it was'nt done correctly, it'll show up before a 1 yr. warranty expires? And why I am feeling this slip, yet the it's not throwing any codes?

Is it still doing it?

Yes, it's still doing it, but it's getting better each time I take it for a ride. On the other hand, it's also getting colder outside, and it seems that it was worse when it was warm outside. So I'm not sure if it actually IS improving, or the colder weather has something to do with it. I haven't had time to go for a longer ride to really test it out. Any thoughts? Any and all are welcome.

The colder fluid will bring up the line pressure.

How long is the warranty for?

12,000--1 year.

Alight, see if the problems keeps getting better. You might have to wait till it gets warmer again for it to fail.

today the temps outside were near 60. warmer than the last few days. and of course, the problem was more obvious, as I feared it would be. what are you thinking it could be? is it gonna take till next summer for whatever it is to fail?

If it is that bad that you can notice it, I would take them out again before it gets colder and show them that this is not normal, if they bullshit you and say it is, get another shop to go for a drive with you even if you have to pay them 20-30 for their time.

Then you have something to go back the original shop with. But again, first try to get them to go out with you. If this slip is as noticeable as you are saying, don't have them make you think that it is. No codes coming up doesn't mean the transmission is fine.

the truck is going back in late this afternoon. they are going to drop the tranny again to check it out. it is going to be cold outside the rest of the week, so i do know if i'll really be able to tell if anything was fixed, assuming they find anything. i did find out the valve they replaced was the accumulator valve, and not the tcc. took it to a different shop, they said it definately was slipping, and to have the original shop check the servo. think any of this plays a part?

That's fair of the other shop.
So many act funny because you brought it to their compition.

Good Luck with it

yeah, well, i got him to go with me first before i told him about it being rebuilt and still being under warranty with the first shop. really, he didn't have to tell me anything, since there was no chance of him making a dime on a tranny still under warranty, but i guess the shops know of each other. maybe it was more of him helping the other shop owner,than me. who knows....but i'm greatful for any ideas toward a good ending for this whole ordeal.

The accumulator valve controls shift firmness. When you said valve in your first post, i assumed a spool valve in the valve body....My mistake

yeah, well, i got him to go with me first before i told him about it being rebuilt and still being under warranty with the first shop. really, he didn't have to tell me anything, since there was no chance of him making a dime on a tranny still under warranty, but i guess the shops know of each other. maybe it was more of him helping the other shop owner,than me. who knows....but i'm greatful for any ideas toward a good ending for this whole ordeal.

So now the oringinal guys are owning up to what they have to fix?

the original shop has my truck again as of 5 p.m. last night. they are dropping the tranny again. this time, they have their regular builder on staff. (he was on vacation when the original rebuild was done.) who knows if things were done correctly, but i'm hoping this guy just finds whatever is wrong. in the meantime, my remote start/alarm has gone on the blink. not sure if they had to mess with any wires from that when they were screwing around getting the trans in and out. never had a problem with it before, though. i can remote start it, but there is no sound for the alarm, and the door locks struggle just before they lock/unock. fuses are good. i really don't want to fix or move anything till this trans is right. i don't want to hear that any repair we did somehow affected the outcome of the tranny work, electrical-wise. what a mess....

I hope you are not paying for this.

Also, look into your battery being low or your alternator weak.

no, no, no...this is pretty much under "not yet repaired"- the warranty hasn't even "officially" started. they do not start it until you are completely sastisfied with the job. then they stamp-date your warranty.
the alternator was just replaced this april. i will check that again and the battery as soon as i get it back from the shop. it never ends!! we're expecting our first snow tonight,(chicago area) and here i am without my truck..

no, no, no...this is pretty much under "not yet repaired"- the warranty hasn't even "officially" started. they do not start it until you are completely sastisfied with the job. then they stamp-date your warranty.
the alternator was just replaced this april. i will check that again and the battery as soon as i get it back from the shop. it never ends!! we're expecting our first snow tonight,(chicago area) and here i am without my truck..

But your truck a two wheel drive right?

2wd blazer is a little easier to handle than my other, which is a 92 2wd s-10, with absloutely NO weight in the back end. also have an 88 k-10, cannot renew plates until it passes emissions, or it becomes elegible for antique license plates. now THAT'S the one i can't wait to get rollin...

2wd blazer is a little easier to handle than my other, which is a 92 2wd s-10, with absloutely NO weight in the back end. also have an 86 k-10, cannot renew plates until it passes emissions, or it becomes elegible for antique license plates. now THAT'S the one i can't wait to get rollin...

That is true, 2wd s10s are a nightware in the winter.

all is well with the tranny. they wound up replacing entire valve body, why? not sure. just glad it's back to normal.

did you have to pay for it?

did you have to pay for it?


nope...not a cent.

Sweeet, and it shifts fine now?

Glad to hear that they supported their own problems. Hope it runs well for a long time.

Sweeet, and it shifts fine now?

riddle me this....
the truck shifts sweet now, but in the meantime, my audio on the alarm went out (aftermarket-commander), the turn signal "noise" is going on and off, (actual lights work fine), and my husband had to move the truck out of the driveway this morning and he said he could barely keep it running. it started fine for me later in the day. all this in the week i've had it back from the tranny shop. they said they had to reprogram the computer when they rebuilt the trans. they were also screwing around with the solenoids in their search for the weird shifting, before they replaced the valve body. is it possible they crossed wires somewhere? is there any one section all these items would meet? maybe something got pinched somewhere? i had NO electrical problems 2 weeks ago.

I'm not sure whats causing your alarm and turn signal problems, but I will always let my customers know that when rebuilding an electric automatic, wierd things will happen for about 2 weeks, including the engine performing poorly. If it continues to run bad, pull the ground cable and let it reset.

I'm not sure whats causing your alarm and turn signal problems, but I will always let my customers know that when rebuilding an electric automatic, wierd things will happen for about 2 weeks, including the engine performing poorly. If it continues to run bad, pull the ground cable and let it reset.


just curious, why does that happen?

Wierd things can happen when you disconnect the battery on a newer vehicle. It has to re-learn it's idle, fuel mixtures, re-learn how you drive and adapt to how you drive. Basically, your engine and transmission have to re-adapt to how you drive. And it takes a month or more in some cases.