4T60 Rebuild

[orange57]

Hello,

I'm about to venture into a rebuld for a 4T60 out of a 1989 GM. I know the transmission was used in the bonneville. has anyone rebuilt one of these, have any tips or advice?

Thanks,

matt

[BNaylor]

Technically that autotransaxle is a TH440-T4, GM RPO code ME9 and was found in many GM cars not just the Bonneville. See link below which may be helpful.

Click here

[orange57]

BNaylor,

thanks for the link. I know the trans has been used in many different vehicles. mine isn't in a bonneville, but it seemed this forum got more traffic, therefore i figured it may get a quicker answer.

I have the ATSG manual for the trans, which mentions several special tools, all J-XXXXXX. with out these tools is a rebuild going to be feasable? I picked up the Pro-King rebuild kit, which appears to have everything, i'm just wondering if i'm getting in over my head.

I'm fairly mechanically inclined, i do a majority of my own work, bu the trans still scares me. is a rebuild something a that can be done in your own garage?

[maxwedge]

I would not recommend a first timer doing this, the access, required tools and experience dictate a pro should do this. You will need a support to hold the engine in place, this job is virtually impossible without a lift, as the subframe and suspension have to come out, also working on your back is ugly with this type of removal. That is just the R and I sissue, this is one of the toughest transmissions to overhaul. You should also do a pressure test before removing the unit for daignostic purposes.

[tomj76]

I realize this is an extremely old thread, but I'd like to add a comment anyway.

I've never rebuilt an automatic transmission prior, but I just finished doing a 4T60 from my '90 Celebrity. The lack of J-xxxxx tools was not a problem other than one particular step, which is where the thickness of a washer is chosen to meet a spacing requirement. The measurement could be done without the factory tool, but the shop manual does not give dimensional data needed to do it. For my rebuild I chose to check the play in the stack after the cover was in place instead, but again I had to use good judgement without the tool.

I "held" the transmssion during the work by standing it on the passenger side output seal (after removing the speed sensor), and a floor jack with a piece of plywood under the "bell". There may be better holders available from a tool store, but this worked very well.

The reason I had to do this work was b/c the 1-2 Band broke. The rebuild work was not difficult, but it does require an attention to detail and a clean workspace. There are some special tools for assembly of the clutch pistions, but these can be avoided with two people working together.

The main difficulty I had was purchasing a good rebuild kit. I bought one from a brick & mortar store, but returned it for lack of I/O seals. Then I bought a second one from an on-line company after getting a list of all included parts. However it was also incomplete. No metal I/O seals or plastic ring seals were included. After several (three) kits, it was determined that these parts had been left out of the kit (i.e. manufacturing defect). The supplier was very helpful in attempting to get the right parts, but I've found they have a pattern of selling parts that don't fit the targeted application. If I did this again, I'd avoid both the supplier and the manufacturer.

I did this by removing the engine and transmission from the top, rather than try to drop the subframe.

That said, I finished the re-install and took it for a short test drive. So far, so good.