4L60E rebuild. What did I get myself into...? :P

It looks like I'm in for an adventure.
Having to fork over 3.5k for a shop to replace the transmission was just a bit too expensive
as this is not a showroom piece, its a bush beater and occasionally daily driver.
The other option is to buy a used one for $500-700 of questionable history and life expectancy and put it in myself.
That does not seem like a good choice as it is quite a work to get it in and out of the car.
So, I've pulled it out and looked at it and decided to give a rebuild a try.

I'm hoping for some guidance as I've never done this before.


There we go...
It looks like the transmission was swapped out sometime as I don't think this is the original.
Is there a way to tell the year just by looking at the case?







What is the 33 stands for?

I followed Transmission Bench guide to disassemble it.
I was able to get it disassembled into major components and it looks like there are no major components that are broken gauged etc.
It looks like I should be able to rebuild it whit a rebuild kit.

I've noticed a few things that I would need your opinion...
The input shaft supposed to have a seal that I couldn't find.

Could the missing seal disintegrated and cause the transmission to fail? Where could have it gone?

The output shaft bushing seem to be in very bad condition. Not a big deal as I was planning to do all the bushing regardless.
Video of output shaft.

The other bad thing is that everything is covered in burned clutch material, fluid looks like coffee , on the upside no metal shavings of any kind that I could see.


This is where I'm right now.

This is where I'm at right now.

I'm planing to clean all the internal parts whit mineral spirits, I think it should be safe for all parts including wiring harness and solenoids.
How about the case? I obviously don't have a parts washer, can I just use engine cleaner and pressure wash it? Would that be safe to use to wash out the interior as well?
What other parts that doesn't come in a rebuild kit should I replace?

I'm looking at rebuild kits and it's quite confusing. There is only one from rock auto for the 4l60e
https://www.rockauto.com/en/moreinfo.php?pk=292006&cc=1304952&pt=8512&jsn=16
would this be a good option to start whit and order the band and bushings extra?

How about this one? amazon link

None of them state what kind of gasket it will come whit, as I understand there are different separator plates out there and i have to match the tight gasket whit what I have.
This is what I have;




Does anyone have a suggestion for a rebuild kit that's better?
I see on amazon things like "stage2" "stage3" etc, do they mean anything or are just marketing lingo?

Thank you.

Check on transtar site. Have only bought parts, but might have kits. Replace the wiring harness just to elimate possible leak later time. Wash out inside and blow it out. Valve body should be checked for wear for best results

BC K1500 said:

I see on amazon things like "stage2" "stage3" etc, do they mean anything or are just marketing lingo?

Click to expand...

That's marketing lingo. If it means anything, it's because somebody assigned a meaning after everybody started using those terms. In my memory, it traces back to when Gran Turismo came out on the Playstation. All of the "upgrades" you could make to your cars were "Stage 1", "Stage 2", "Stage 3", or "Race". Stage 1 is typically a mild upgrade, Stage 2 is a serious upgrade, and Stage 3 is "almost race". It's very subjective.

Sonnax has pretty good customer service, and if you email them with your budget and goal for rebuilding your transmission, they will give you a parts list of recommendations.

I've been telling people to check out Oklahoma Transmission Supply. I have no relation other than they're local to me, but they beat everyone's prices when I was shopping for parts for my 700R4 rebuild. https://otsparts.com

yevgenievich said:

Check on transtar site. Have only bought parts, but might have kits. Replace the wiring harness just to elimate possible leak later time. Wash out inside and blow it out. Valve body should be checked for wear for best results

Click to expand...

Wouldn't just replacing the seal around the connector be enough? Replacing the whole harness seems to be a bit overkill?

Erik the Awful said:

That's marketing lingo. If it means anything, it's because somebody assigned a meaning after everybody started using those terms. In my memory, it traces back to when Gran Turismo came out on the Playstation. All of the "upgrades" you could make to your cars were "Stage 1", "Stage 2", "Stage 3", or "Race". Stage 1 is typically a mild upgrade, Stage 2 is a serious upgrade, and Stage 3 is "almost race". It's very subjective.

Sonnax has pretty good customer service, and if you email them with your budget and goal for rebuilding your transmission, they will give you a parts list of recommendations.

I've been telling people to check out Oklahoma Transmission Supply. I have no relation other than they're local to me, but they beat everyone's prices when I was shopping for parts for my 700R4 rebuild. https://otsparts.com

Click to expand...

Thanks for clearing up the marketing lingo.

I'm in Canada, shipping stuff from US is fairly expensive, that's why I'm looking at amazon and rockauto.
I'll send them an email and see if https://otsparts.com would ship to Canada,
if not then I'm leaning towards this kit from rock auto. any thoughts?

BC K1500 said:

Wouldn't just replacing the seal around the connector be enough? Replacing the whole harness seems to be a bit overkill?

Click to expand...

Over time can start leaking around pins

teardown your transmission first and then order parts. I would order a complete kit from Dana @ Probuilt Automatics myself. You get what you pay for parts wise. Have you done any research on rebuilding a 4L60E or are you just going for it? There is a reason these shops charge $3500. Last unit I did was over $1500 (canadian) in just parts and that was without torque converter and also before covid! This is the time you can make yourself a killer unit, but there is more to it then just changing some clutches and new seals.

some tools that will be required:
dial indicator
feeler gauges
GOOD set of snapring pliers
specific bushing drivers
shop press and/or arbor press
lip seal installing tool (can make or buy)
seal installers and resizers for input and stator shaft (have seen DIY attempts make sure you buy extra seals)
tool to align pump
tool for low/reverse clutch pack
tool/fixture to disassemble input and reverse drum clutches

I would make friends with a transmission shop that can help you out. my first build trying to do stuff without proper tools was very frustrating. I eventually bought some basic stuff and over the years have bought more. Are you in the lower mainland?

^Agree'd with everything in his post.

And keep your timeframe in mind. Personally, I can do anything in my shop with enough time and motivation. Your motivation is saving money, are you still saving money after you buy all the special tools needed? Are those tools a 1-time use purchase (and be honest with yourself). Time, do you have a hard stop where you need to have it back together? If not, decide when it is getting to be to long of a project and bring it in to have somebody else finish it.

You've posted, asking for advice. Here's my advice. I hate to be a downer here, but a transmission is not the sort of component that an amateur should mess with. I group myself in here as an amateur too. I'm exceptionally good at figuring things out, and fixing just about anything. But there is just too much that I don't know -- routine experience, which good transmission shops have, which I don't have -- for me to EVER bother with touching a transmission. Some things you can save a few dollars on. Rebuilding your own transmission, with limited experience, is NOT one of those things. I find ~$3k a bargain in getting a reliable transmission. $500-700 for a used one might be a decent, cheap alternative. One little check ball out of place, one minor incorrect measurement, and all of your work, all of your parts, could be out the window, and you're right back at square one. You gotta do what you gotta do, but from one truck guy to another, I'd advise you to reconsider. (I recently had my transmission rebuilt, with a few upgrades and a shift kit. $3,400 out the door. I would do it again in a heartbeat.)

the thing with DIY transmission buildint is are you prepared for this to take weeks or even months? the first unit i did took me 3 months. i started with a bad core so i ended up having to get the pump machined, planetaries rebuilt, someone had swapped in an early input drum during a previous rebuild so i had to source one, i had no press or bushing drivers so i had to get the bushings installed at a shop which means packing up everything and taking it there, clutch clearances wernt right so i had to order different thicknesses to get clearance right. are you prepared to pull the valve body or the whole unit if things are not right? because if you're not and end up taking it to a shop the money spent was for nothing. most shops won't reuse parts even if they are "new" its not worth their time to R&R a unit again, they will sell you everything so they dont have comebacks. sure you can slap a unit together and put new seals and clutches in it and hope for the best, but this aint no th350 or 4l80e. the 4l60e has chronic problems that need to be corrected if you want any sort of longevity.