transmission

Hi everybody MERRY CHRISTMAS !!! for Christmas my dad got my transmission rebuilt (4l60e) in my 97 Z71 it has the 350 motor....he paid a guy to take it out and the shop bench built it and then the guy put it back in....problem is the transmission slips when it shifts from 2nd to 3rd its only in between the shift once it gets in 3rd it doesnt do it anymore and it kinda seems like it does a bit when it kicks down from OD into 3rd...any idea whats causing this.....also the guy that pulled it and put it back in didnt undo the passengers side exhaust and the pipe cracked all the way around and broke off right at the flange where it fits onto the donut gasket can a new flange be welded on ?? i crawled under the truck everything was installed correctly (i used to put these things in all day long) the reason why i didnt do this one is because i had to work (13 1/2 hrs everyday)

Long hours suck, I know how it feels. I put in a few long weeks to catch up for the Christmas season so I could take Monday off. Hope your days get better.

When I rebuild a 700R4/4L60E I use what's called a "Z-pack" option in my rebuild kit. The factory 3rd gear pack has 7 clutch discs (I think), and the Z kit allows for 9 or 10 to give it better holding/shifting and less chance of burning up under a load. 3rd gear pack is the weak link. If there's too much gap between the clutch plates, it will cause the engine to rev up between 2/3 shifts. Shimming the gap between the backing plate and the retaining ring is very important.
If the 3rd gear accumulator has a weak spring in it, it too could cause a funny shift. I do a lot of performance work on trucks and Camaros, when I build up a 700R4, I usually make metal spacers for the 2nd and 3rd gear accumulators. It stiffens up the shifts w/o having to buy an expensive shift kit. There's a lot more tricks I've learned over the years and I could post a lengthy reply, but I won't.
Have the guy pull the pan and check the 3rd accumulator spring. If you can flex it w/your bare hands, I'd say it's too weak. If he rebuilds them on a regular basis and has a box of spare parts, find a stiffer spring or stack a bunch of big washers in it's place.

I have repaird several broken pipe flanges, seems to only happen on the right side. I have a pipe machine, so I can make a new flange and weld it to the old pipe w/o any hassle.

There's never an easy fix w/tranny probs. and it's never fun to fix a problem twice. I hope the tranny doesn't have to come back out.

Post back on what happens.

thanks for the reply i got the exhaust out this morning and i am going to try and find an exhaust shop or any welder that can fix it for me....as for the transmission the guy builds lots of transmissions but i think this may have been his first 4l60e but i'm not sure...i will ask him about the spring in the accumulator i hope it dont have to come back out but if it does atleast it has a year warranty....when i worked at a tranny shop not too long ago (i pulled them and put them back in) the guy that rebuilt them used a "reprogramming kit"...i think it was a shift kit he said it gave them more of a firm shift so it wouldnt have time to slip during a shift...have you ever heard of this kind of kit ???

I can't count how many 700R4s I have rebuilt/hopped up over the years.
I have used expensive/fancy/racing shift kits that were high-priced and time consuming. Getting them fine tuned was almost impossible.
There's a compnay called Trans-Go that produces some really nice/cheap shift kits. They have what's called a shift kit Jr. that I like using. It's simple, works great and doesn't require fine tuning (at least for me). I have used so many, I can usually get them right the first time. A lot of changes that I make aren't in the directions, just stuff I've come up w/over the years.
Go to transgo.com and look for a 4L60E-Jr. kit. You might want to get one for your tranny, since the pan/valve body will have to come off anyway.

ok thanks for all the great info i really appreciate it !!!!

I hope it all works out.

as of yesterday (morning) it shifted perfect when cold nice crisp shifts and it does pretty good when warm too..just a lazy shift every now and then...i think it just needs a shift kit i'm going to put the transgo 4l60e Jr. shift kit in it that you was telling me about (if the guy will still warrany it)...its weird because i thought it was the 3rd gear clutches had too much clearance but now its like it went away ?? maybe it just had to get broke in ?? maybe a valve in the valvebody was trying to stick who knows...its weird how it just kinda went away though....

Cool.
I'm glad it got better.