Any DIY 4t65E rebuild tips?
 

Anyone have any tips on rebuilding a 4t65E transmission (besides throw $1,300+ at someone to do it for you)?

I've bought the THM 4T65E - ATSG TECHNICAL MANUAL.

That's the first step 8)

Study that manual. That's the Bible in the transmission world.

I would also find another 4t65 in the junkyard somewhere, and tear it down. Not only does this give you an idea of what and how things go together, it will also give you a good source of parts in case you find you need to replace an item or two in the trans you plan to redo.

You don't NEED any special tools to do the job, but having them will help you out alot. The ATSG will tell you which ones you will need. Ebay will have some from time to time on the cheap.

Sound advise and Keep everything ultra clean. The cleanest shops around are the tranny rebuild area.

Wouldn't it be wiser to replace transmission parts with new ones instead of used junkyard parts?

Use new for the wear parts, clutches, bushings, bearings etc.
But used is ok for 3rd sprag, 4th clutch shaft, input shaft, diff etc.

Yup. The used transmission would more or less be for practice and forensics. The thing with transmissions is that one never knows exactly what parts need to be replaced until the dissection is complete. This is where having a spare, parts transmission comes in handy. Believe me, having one around is well worth the money spent.

That ATSG book should tell you exactly what years got certain upgrades, and whether or not they are backwards compatible with older models. I think I studied the ATSG for a good month or two before I even started turning the wrench on my rebuild. I think I may have spent a grand total of 500 bucks on my rebuild, parts and all...and that is including the spare transmission that gave up most if not all of its parts. In fact, the old transmission gave up only a few parts to make the "newer" one work...most notably, its case.

Be VERY liberal with the blue goo. It's a parts glue and assembly lube all in one. Works outstandingly well for holding check balls in place when assembling the valve body.

Look up Trannyman95 on grandprixforums.net

This is his website:
http://www.tripleedgeperformance.com...ssion_Info.php

Lots of good info there, and he sells the uprgrade parts and wear items.

Re: Any DIY 4t65E rebuild tips?
 

Ok, you have the manual. Read through it and understand what has to be done to get the sucker apart and back together.

Now, decide what has to be done..i.e. how is it broken, what's wrong with it, etc. (Is this for the no-TCC issue you were having? If so, find someone with a scan tool that shows live data..before opening up the transmission, your problem might not even be inside the case..like a bad torque converter.)

There's going to be some special tools involved, stuff that may not be in your toolchest. Also, you will need an engine stand of some sorts and some creativity in using it. There are part assembly sequences that are next to impossible without the transmission case oriented a certain way (So gravity is working with you instead of pulling parts out of place.) There are ready-made fixtures out there that grab the transmission case by the built-in lugs and let you spin it around. They may be a bit cost-prohibative for you as they are intended for professional shops.

Last...have a backup plan (i.e. a spare transmission at the ready) A lot of shops will not touch the sucker after you take it apart...some will gust grin at you...a few will tell you what you did wrong after they put it back together for you. :lol:

There's a couple of online places that can sell you the replacement parts..both a basic kit of materials they know you will need (frictions, seals, gaskets) plus the stuff you will inevitably find busted inside the case..even on a transmission that is still "working" there is usually some part showing damage (like one-way roller clutches, baskets, etc.)

It can be done successfully, but it is not for everyone. I just blew up the THM700R4 / 4L60 that I rebuilt 10 years ago...and I'm not going to try rebuilding it myself again...once was enough.

Oh..and get a digital camera (if you don't have one, beg borrow, or steal one) to photographs things BEFORE you take them apart...like figuring out which valve train goes in which bore of the valve-body. Piece of cake if you've looked at enough of them...or they all look alike if it's your first try.

The problem is actually no 4th gear.

I've an got an engine stand, hoist, digital calipers, large sockets to use as seal installers, multimeter, jack stands, 2 jacks, engine support fixture, digital camera, torque wrenches, T-gages, a set of OD & ID snap ring pliers, plus lots of wrench sets. Partial to SK.

Plus patience & experience.

Also I have a TH125 tranny sitting under a workbench. Any usable parts from that?
It's the great, great grandfather of the 4t65E. ;)

The only other thing I can suggest is make acquaintances with a local tranny shop to ask for advice etc. My last tranny (in Feb) guy was very open with people coming in off the street and asking all sorts of questions. I was stuck there for about 5 hours and there were 3 people that came in looking for info. He was a nice guy, only sold 1 pan gasket to 1 dude.

Good luck with the build and keep us posted.