LS1 Brent

How come you don't see as much people rebuilding their own automatic transmission. I hear of people doing heads/cam etc... swaps by themself so why not their transmission? I myself am considering having someone rebuild my transmission, but it costs so damn much and I would have to save my money for a long time. Is it really that hard to rebuild your trans.??? thanx.
-Brent

jimmyblue

iTrader: (11)

I did my TH350 once. It needed a few specialty tools
(which I home-made) and took me several nights of
work. It came out all right, I put probably another
30Kmiles on it before I junked the van. But I just
did clutch packs & seals basically - not the same as
a more through rebuild; more like a "freshening-up".
I don't have the gauges or the other stuff you need
to check line pressures, etc. even on old-school
trannies.

Then I think the 4L60E is a lot fussier, wimpier, more
complicated and highly stressed than the old TH350.
So if I needed a fresh trans I think I'd just buy one
good-to-go (with a warranty and a reputation for
honoring it) instead of trying to save one that's gone.

LS1 Brent

The thing is, my car is getting up there in the miles and I don't want to spend $1500 on a rebuild because evryone says it will just do the same thing and go out again and I don't want to get a TH400 or a TH350 because I need my overdrive for the highway. Anyone have any suggestions??? Any help would be greatly appriciated.

James B.

iTrader: (1)

I tore down and rebuilt my 4L80-E myself in my garage. This is a trans I found on EBay. I used a LevelTen PTS rebuild kit and installed a TransGo shift kit. It took a while, I didn't rush it. I took each obstacle I encountered one step at a time. I had an ATSG Techtran Manual and a full-color GM Technician's Guide (big centerfolds, very sexy). There were a lot of thing that would have been easier with the proper tools but just about everything could be improvised. I also have the 4L60-E ATSG manual and can tell from looking at it there are a lot more tasks that are impossible without the specialized tools. With the 80 the only thing I could not do was get the input shaft teflon rings on.

With the tools, some time, and some patience there's no reason why any mechanically inclided person could not do this themself.
Lot's of parts. I just took it one sub-assembly at a time. No big deal at all.

After getting it reinstalled and the fuild topped off, it's hard to describe the feeling when you first get in, drop it into reverse, and it tugs against the brake pedal. Pulse rate soars, months of work and hundreds of dollars on the line, then you pull out onto the street, set it to "D" and take off. Your mind starts counting as you gain speed, Second, Third, Overdrive, and then the converter locks right on cue. It's a great feeling of accomplishment that I recommend to anyone willing to try it.

LS1 Brent

Wow, just looking at it looks tough.

James B.

iTrader: (1)

One of the methods I used to help me get through was to take pictures of nearly every part as they came out. The ATSG manual has every part identified with an associated 3-digit number. I labeled my pictures with the ATSG numbers. There are hundreds of parts and this made it easy to keep track of them.

This is one of the assembly diagrams for the 80:
Diagram

This is my index of pictures for the 80:
Index

The manuals show you and tell you how stuff comes apart and goes back together and which tool you need if applicable. Great experience...

LS1 Brent

Looks like a job i wouldnt know how to do. Can anyone help me decide what i should do? $1500 for a rebuild is too much and i will not pay that much and the TH350's and 400's do not have an overdrive, which i need. Any suggestions?

john kilgore

if you want to run a 400 just get a truck trans as new as possible. remove the pan and if it is clean, change the filter and run it. make sure you hook up the electric passing gear even if it's just a switch you can turn on when you punch it. these trans' are very tough. good luck

taqwache

if you have never rebuilt a tranny before then dont start on a 4L60E. the main reason that most people dont rebuild there own trannys is mainly due to the lack of information about it. it is not really hard at all, in matter of fact it is easyier then a motor in my opinion but all the small parts scare people. i rebuild them myself but i went to school for it and i am also the kind of person that can accept the fact that i might just screw it up and have to take it apart again. also i love saving the money. just call a couple of tranny shops and find out how cheap a kit is. then you will really not want to spend any where near $1500 on a new one.

kevinc

I rebuilt a couple transmissions in Mechanic School. One was a TH350 and TH400. Both of them were really burned out and beaten badly. After rebuild they were both bolted to the transmission dyno and they were both flawless. I equate it to baking a cake. If you can read and understand step by step instructions, you can rebuild a transmission. Just take your time and check your tolerances.

Kevin C