dhirocz

Just spent this past sunday with a buddy pulling my pan. Last year I lost 3-4 and immediately limped home in manual 2nd. We found no residue in the pan like I was expecting...the pressure switch was plugged up. Long story short, 3-4 is still out.

Ive always been an avid diy guy and while im familiar with automatics Im hardly a rebuilder. Since I caught myself intentionally avoiding automatics because I dont feel I have rebuilders around me I can trust, I figured its time to dive into one.

So Ive got a '95 C4, one blown 4L60E and a desire to build this thing. Ive even spent time looking into teardown and rebuild procedures and troubleshooting procedures to identify and correct the failure (I hate having to do things twice).

What Im confused about is the parts really. Since Im not familiar with the theory behind its operation (teaching theory seems to be a dying concept nowadays), it makes it hard to make decisions for a guy like me. I know Ill be running a fairly mild mannered 383 LT4, and want a trans that doesnt shift super hard all the time (unless it's needed). So the question is, is there a parts list of proven builds out there that are a match for a mild engine that wont break the bank?

confab

Yeah, several people here have a preferred recipe for the street. IHBD and Arbee have posted theirs previously.

I like a complete freshen up and as far as hop up parts for a street car - Wide Kevlar 2/4, (because they're super hard) hard shell, Sonnax wide bushing for the rear sun, Sonnax pinless accumulators, larger boost and you can use the 5 pinion rear planet if you feel it is necessary along with enlarging the feed holes in the separator plate. The Sonnax replacement for the checkball capsule in the servo housing, and I like the Alto Red and thin steels for the 3/4. The large forward sprag, if your trans doesn't have it already. I disable the converter mod valve and block it off, but some people don't like that.

There are higher stalling factory options for the converter in most cases also that won't break your checkbook, and it really should get a new converter anyway.

You can literally spend as much as you want here, the sky is the limit.. But the above is good on the street, peppy and it won't bankrupt you.

Kevova

You need a manual for the 4l60e, transmission sites normally have info or FSM.. Transmission parts and service sites would be a better source as they provide info to transmission specialists. Codes? 4l60e defaults to 3rd. Do you have 1st? There were some concerns with shift solenoids(2). Normally they both are changed if one fails. The PCM controls shift and how hard it hits. It will be a combination of how transmission is built. All the typical mods on non electrical and the PCM programming. The OEM programming has " torque management" which reduces power for a split second ar the shift. The intent is reduce clutch/ band damage during apply. If torque management is turned off it should very firm.

dhirocz

I was thinking of a wide band and replacing the drum, a smartshell, sonnax performance kit, adding some extra clutches to the 3-4 clutch pack at a minimum. No question, its getting a new converter, just a little more stall than stock (2000/2200ish).

Right now I havent bought any parts yet...Im trying to develop a list as part of the plan. Id rather hear from guys who have done it though.

No codes or abnormal transmission behavior (other than the loss of 3-4) it still will shift into 3rd in D (and neutral out). I do plan on changing all electrical components while Im in there.

Car is pretty much as virgin as it could get so Im sure the PCM is tuned as delivered from GM.

confab

No torque management in 95, or certainly none that I am aware of.

The 4L60/E instantly smokes the 3/4 if you lose pressure anywhere.

What will happen is it will go forward fine. Back up fine. Everything is fine. 1-2 shift is fine. 2-3 flares and if you can get it going fast enough to jump 3rd, 4th flares also.

Those are the classic symptoms of a burned 3/4.

The on/off solenoids usually outlast the car.. You may want to change the EPC solenoid as it is PWM, but other than that you can just re-ring them and leave them alone if they are working.

Edited to add: Leave the load release springs in place in the 3/4 drum.. They didn't cause the failure and actually help prevent them. The ATSG "fix" which involves removing them and running the clearance way up is wrong and shouldn't be heeded, ever.

dhirocz

I wasnt planning on doing that.

I am contemplating using this transmission Ive got under my bench as a core. Its a camaro LT1 transmission, also a 95, and the best I can tell should work fine if I change the extension housing and output shaft. Ive also considered putting it into the car (shortening the shaft 3/4") but considering the last time this trans ran was 13 years ago, its not sitting well with me. Id hate to do all that work and end right back where I started.

Then theres the T56 Ive got hanging around...

Ive got the itch to build an automatic. The hell with it, lol

confab

I prefer the auto, actually.. It's what i have in mine and I don't want a stick shift.

Do a good job on it and I think you'll be more than happy with it.

May as well build the one in the car now, because it has to come out and apart anyway.

If you have a specific question, need any help or get stuck, do a thread or PM me. I own a transmission shop, so I've seen a lot of the 4L60E. IHBD and Arbee know them backwards and forwards also, and they'll steer you right.

Good luck.

auburn2

I am a manual fan, but I have rebuilt 2 4l60Es so I am very familiar with it. It is a great transmission in my opinion. When it comes to electronically controlled transmissions it is my favorite and can be built to withstand any street engine.

The weakest point and only unknown is the 3-4 clutches. That is the only part of the trans that many people have an issue with. The reasons for failure are not well understood (see sonnax below). You will get a lot of different opinions on this. I had a car (03 suburban) with a 4l60e that had a 3-4 clutch fail in 2012 at 150k miles on a stock trans. That was my first rebuild. I have put another 60k on it since then and it is still going good. I think I blindly used Borg-warner 3-4 clutches and no return springs, but you will find all kinds of contradictory advice on this. Sonnax wrote an article about 2 years ago where they go through the 3-4 clutch problem in depth. You can find it online. I haven't really read it because I haven't done a trans since then but think they actually understand the problem now. You can find it online.

After the 3-4 clutches it is a solid trans, easily able to handle a 383. You say you don't want it to shift "super hard". I don't like that either, but one guys "super hard" is another guys "super soft". Compare it to stock - do you want stock shifts? I personally like it firmer than stock (but obviously not super hard only an idiot would want super hard :-)

If you want stock shifts I would get a basic rebuild kit and a trans go correction kit. I think the correction kit is called SK or something like that. If you want firmer shifts I would get a trans go HD 2 shift kit.

As far as theory autos are easy. I will give you basic theory for all autos here: At a basic level there are one or more planetary gears (look this up on the internet for a visual). A plantery gear has a sun gear, planet gears, ring gear and transmission case (the case never rotates). If all of them freewheel it is neutral. You can lock one of them, so it does not rotate and you generate a certain gear ratio. Lock a different gear set and it is a different ratio. Lock all three gears and it is direct - 1:1, they all rotate together. In an auto trans one set is locked to the input and one to the output.

The way they lock up is through a series of clutches. If you understand how a manual works imagine a clutch plate and a flywheel. Then shrink these down so they are a lot smaller and stack them one after another. Your flywheel is called a "steel". Then stack them one after another steel-clutch-steel-clutch-steel-clutch etc. and your clutch acts on both the steel in fron and behind it (double sided). Now tie the steels to one part of the planetary and the clutches to another. Normal operation they slip. Just like in a manual, you have the clutch in and the clutch turns with the trans input, the flywheel with the crank. In this case the steels turn with one part of the planetary, say the ring gear, the clutches with another, say the transmission case.

Now you have what is called a piston, this is like the pressure plate in the a manual car except it is normally disengaged. It is resting against the last steel in the steel-clutch array discussed above, much like the pressure plate is up against the clutch disk in a manual. Now when the trans shifts into a certain gear the presses the cluthches and steels together with enough force so the do not slip. It uses hydraulic pressure to do this. Since they don't slip that locks two parts of the together (in this example the planets and the case). The output could be the ring gear loclke to the output shaft by another set of clutches. Since the planets are locked they act as an ideler gear and the ratio between the sun and the ring determines the gear ratio.

I have not discussedc the torque converter here. I assume you understand how that works.

ErrrrCar205

It sounds like you're interested in doing a rebuild one way or the other, so this may be a moot point. But in terms of getting going in the short term, could you just replace the pressure switch? I lost 3-4 last year on my '96 and was terrified that the 3-4 clutch was gone and that I'd need to get it rebuilt less than three months after buying the car. Fortunately we have a reputable transmission shop in my town and they were able to easily put in a new pressure switch, and it was good as new. The part cost about $45 with the shop mark-up, if IIRC. And although I didn't watch what they did, they made it sound like they just had to drop the pan and swap one part for another. If that's the case maybe replacing the switch might be easy and cheap enough to do in the short term so you can still drive it while you figure out the long term game plan?

I don't have near as much knowledge as the other people in this thread, though, so I may have this all bass-ackwards.

dhirocz

I thought that switch was just to tell the pcm what gear the trans was in? Its still shifting into third (or trying anyway).

I didnt notice an abundance of clutch material in the pan, though it did smell slightly burnt. Was more brown than black.

drcook

There is also a table in the PCM/ECM module that can be accessed to firm up the shifts. B&M makes a switch that you wire in that will access it. I read that it was an option in Firebirds at one point of time. I can access the table via the Jet Tuner software that I have.

I too have been researching rebuilding the 4L60E for my upcoming engine build. If you upgrade to the 5-pinion sprags, use original GM ones. I have read that some of the aftermarket ones fail. The parts for the 4L65 and 70 E transmissions retrofit back to the 60E.

If you do google searches, there are numerous articles on building the transmission for higher HP and Torque applications.

confab

dhirocz is correct.. Replacing the switch won't cure a flare in third.

It can keep a transmission from attempting the shift, however. But if it shifts and flares, the shift was attempted and couldn't complete. The problem is the 3/4 clutch.

As it is a hydraulic dead end, it is common to find debris loaded on the lenses of the PSI switch manifold. More debris in a failed unit.

ErrrrCar205

I see, my bad. I misread your original post and thought that it wasn't trying to get into 3rd at all and was just sitting in 2nd all day. My information (quite possibly incorrect) was that if the pressure switch is stuck/busted and doesn't pass any data, the pcm throws up its hands and puts it in 2nd for the duration, so when I misread your post I thought there might be an easier way out for you. Sorry about that!

arbee

General premise is correct but a couple of errors. The transmission case is not part of a planetary gearset as stated and you don't need to lock three components for direct, only two.

dhirocz

You nailed it. I got 2 shifts out of it before it went.

I have just enough holding power in third to maintain speed at 45 at most on flat ground. Not enough to accelerate even a tiny bit so I cant try 4th.

Shifts the same in D4 as D3. One, two, flare. Does not, at any time, start in second. First and second are fine.

Gibbles

I did the 700r4 in my 84, i used all "red" clutches with the coated steels throughout.
I also managed to squeeze 7 or 8 clutches in the 3-4, i also used the wide "red" 2-4 band.

I pretty much installed every upgrade part that sonnax makes, and one of the upgrades that added a reinforcement ring for the forward drum, also required me to upgrade to the later style bonded pistons.

I have had that transmission installed, and pulled apart so many times i lost cound during my learning curve.
I can now have that trans pulled and torn apart in under an hour.

I gave me lots of practice and i experimented with different clutch stack ups, and clearances...

I also did a shift kit, billet 4th servo, standard vette 2nd servo, and boosted pressures.

I found i now like a very loose tv cable setting that allows me to run in 4th gear @55mph...
And i shift manually 99% of the time.
That helps to keep the exhaust drone under control... lol

I also have a 3200rpm (IIRC) torque converter that toon some getting used to, but learned to absolutely love!

I also have aftermarket heads, intake, ecm, headers, and an oversized exhaust system...

My trans is a tad overbuilt, it shifts a little too hard at part throttle, but perfectly at wot, and nearly instant/fast shifts.
Shiting manually helps, and i have fun trying to time my down shifts to my blipping the throttle to prevent a tire chirp.
It helps to makes a daily 60mile commute much less boring.

Gibbles

Also, if your car did not come with the bonded pistons, upgrade to them.
The lip seal pistons are a pita...
The bonded type are super easy to deal with.

Gibbles

I am also going to rebuild the 4l60e in my s10, the PWM has been acting up (converter going in and out of lockup) and a transgo "fix" kit for the issue did next to nothing to resolve, odd part is i also installed a new valve body with the kit...
So I'm thinking it's inside the pump it self, or a major leak in the circut.

I also did a mild shift kit/adjustment of the fluid paths in the seperator plate, the old vette 2-4 servo i had left over, all new electronics and pressure manifold, and i got very little to no improvement..
It actually seemed to slow my shifts down a little...

I have lots of left over clutches and steels left over from my vette, so it's getting some upgrades... lol

Only downside is that the transmission in my S10 is much harder to pull than my vette..

carguy604

I don't mean to hijack this thread but I'm in need of a detailed drawing of a 4L60-E. Actually, what I really need is just a couple of good drawings that show all the parts that bolt to the exterior of the case. My donor 4L60-E (for another project that I'm currently working on) is missing a few parts and I need to determine the part names and part numbers of what's missing. Can anyone help me out with a couple of good detailed drawings with p/n's? I tried looking for this on the interweb but no luck. Any help would be appreciated.

confab

Download Auto Trans Catalog on the left.

https://www.wittrans.com/catalog



If that doesn't help you, post pics.

The numbering system is kind of a quasi-industry standard for transmission parts suppliers. And, the descriptions are there even if they don't honor that.

It's kinda confusing actually, because there aren't very many external parts on the 4L60E.