Exactly what is wrong with the 4L60E transmissions?
 

I am thinking about buying a 98' Trans Am, immaculate inside and out with under 70k miles, however it is an automatic.

NO matter where I go, I hear people bashing the A4 and how they are unreliable and how they always slip.

I don't mind having an auto and building it, and by building it I mean add in a shift kit, put in a 3600-3800 stall, and just make it able to live.

A4s are more convenient for me, but less fun to drive. I heard of some people say that they floor their ls1 with an A4 and afterwards the transmission starts slipping.

I have dealt with slipping trannies before, and I honestly can't stand it. It is so annoying trying to drive with one.

My question is, if I buy this 98 Trans Am, and I drive it nicely would it last me a long time?

There will be times when I need to floor it. I don't want to do that and then have my tranny explode.

Are there any FAQS I can read to build the 4L60Es?

The 4L60E isn't that bad. There are a few things you need to do to them, but nothing too extreme to handle a decent amount of power. You need to upgrade the 2-4 servo and band, upgrade the reaction sun shell, and install the 5 gear planetary set, along with a wazoo valve body, and you'll be fine.

The 4L60E is not as weak as you have heard.

The condition of it depends on what (if any) maintenance the previous owner performed.

There are lots of us that beat on ours every day with no problems.

Then there are people who have them fail, and have to move up to built units.

Yup they are stronger than what people give em' credit for.

I had only a shift kit/cooler and 3500 stall, running mid 11's this past year and got about 52k on it. The car was making over 375hp the past few years and now probably over 420 all of last year, it's held up rather well between the track and spirited driving.

Just now it is starting to show problems (still not slipping), but hey I race it and make well over 100hp more than factory rated, it's expected at that point not to last forever. And I will be replacing it with another built 4L60E and adding another 100hp. :)

In stock trim the transmission should live just fine in the car... depending on how it has been maintained in the past as previously stated. The 4l60E has a bum rap because people upgrade their engines' power output with no consideration of the transmission... in many cases. But, our experience has shown that installing converter alone will cause premature failure... this is because a higher stall converter generates a significantly higher amount of shear internally which translates directly into heat and degrades the fluid and rubber seals rather quickly.

There are several "shift kits" on the market that address different components. What is needed to provide an extra level of durability is a "reprogramming kit" that is offered by Trans-go. Known as an HD-2 kit. In order to completely and properly install it the transmission should be dissasembled and reconditioned at the time the kit is installed. However, there are many upgrades in that kit that can be installed with the unit in the vehicle and will effectively improve the transmission as long as there are no significant engine mods that bring the torque level up considerably. If the power output is increased there are several other internal hard parts that need to be replaced, remember this transmission was designed with driveability in mind... not necessarily performance.

g

There is nothing wrong with th 4L60E that isnt wrong with any stock part thats abused
with out the proper updates and maintenence ,So many people put turbos and nos an spray etc on the car the upgrade the rear, they upgrade the suspension, they upgrade the tires and much more to make the drive line stronger but for some reason it seems the trans is forgotten and when it dies its called junk, Yet and I have said this several times in various threads all that power you make has to pass through it and that makes it part of the foundation of any build up, For normal driving live any part with the stock engine the stock 4l60e is fine, But no one should but they do expect the stock trans to survive when you add several hundred HP to the car without upgrading the transmission to, Any more than with a standard trans you can expect the stock clutch to stand up to doing that either , But I have noticed people do not seem to mind that upgrade.
Anyway as mentions about there are some upgrades you should do to the stock unit for mild performance use,(shift kit,cooler,proper service,) But if you plan on building the car you should step up to a built unit before you get to crazy with the mods,

For now, all I plan to do to the car is add full exhaust and put in some gears

Catback, long tube headers, and a CAI.

The gears I will be putting in are 3.42s to help me get that bang off the line.

I don't see myself camming my motor, turboing it, charging it or anything like that. It will be a college car and a DD, but I need it to be expecially reliable.

With all the mods listed above, what would I need to do to my transmission to ensure it will do me fine.

It will go the drag strip but maybe like....once or twice a year.

Any ideas?

well you might consider the transgo hd2 kit set to moderate level and a good cooler ,

people bash the 4L60E because, frankly, they are total idiots. complete and total ignorant fools. there are people on this site that take a stock car with ~350 horsepower, throw on fulll exhaust, a stall and heads and a cam, throw down 500 rwhp and say "durr why did my 4L60E break? what a piece of junk!"

are you SERIOUS? NO TRANSMISSION should last in stock form when you add 100 horsepower to the car and up the shift points 1,000 rpms. the 4L60E is a fine transmission - one of the better transmissions out there. you can put a stock 4L60E behind nearly any motor of a production car out there and it'll hold up fine. try doing that, honda. take a honda automatic and put it behind an LS1. no honda automatic can take that abuse because they're pieces of shit.

the 4L60E is flawed, yes, but EVERY OEM piece of equipment is flawed somewhere if you look hard enough. people complain because their STOCK automatic can't hold heads and a cam shifting 1,000 rpm's over the stock shift points, and they're idiots for doing so. on a stock car, the 4L60E sees 150,000 miles all the time. on a lightly modded car (stall, cooler, headers, cold air, exhaust), it holds up great - and that's with ~50 horsepower added. it shows it weakness when you add a cam and up the shift points - effectively throwing 75 - 100 horsepower over stock power up 800 - 1,000 rpm's higher than it was ever meant to go. of course it's gonna break.

it's a fine transmission. just build it accordingly, just like any other automatic out there.

I know it's not a F body, but my brothers 94 S10 has 372,000 miles, only thing thats ever been done to the 4L60E was the 1st gear shift spring broke one time. Before 300,000 miles. The first service was done at 207,000 miles, when he got the truck. We service it all the time. But I can tell ya, he's ran that truck pretty damn hard since he's had it, and I never would have guessed 7 years ago when he got the truck the transmission would have lasted this long. Just red-line the engine through 1-2 gears. Don't know how it's lasted, especially with the 33" tired he put on. even to this daywith the 33" tires, he'll still sit there and line lock it. Simply amazing!!

One time at the track is all it takes. Ask me how I know. :cry:

Ok I'll bite... how do you know? :)

g

Funny guy. :judge: First pass, blown posi, rear carrier bearings, converter and transmission. I think I needed the !Driver mod.

well then maybe something is wrong with me because ive been through several(2 or 3) built 4L60E's and blown them all. 1 of which was/is a built to the sky, max strength tranny from a sponsor.
sure they are fine for a stock/bolt on car but if you want to make any serious power youll have to do something different.

it's not all about the parts that you put in them. the transmissions break because of lubrication problems. you have to drill feed holes and such. the strongest components you can get will break if they're overheating because no tranny fluid is getting to them. you have a max evil trans, which is just a 4L60E thrown together with better parts. you need to get a tranny from someone that understands the trans. for example, i hear the kevlar bands are junk. you want the red eagle hi-energy bands. you want ones that have lubrication maximized, too. there's more to building a trans than putting in better parts.

I like this post Choco, you're right on the money. I agree completely! :cheers:

The problem is with your choice of trans builder then. Go to a guy like Chuck over at FLT and you'll have a whole new understanding of what a 4L60E can be built like.

Lots of "built" 4L60Es are crap. I know, I've been there before I found a good builder. Not all builders are created equal. Also, you have to remember that with any sort of BIG power you're going to have to freshen the trans once in a while. No matter how much you build a 4L60E (or any other auto trans) it's not going to last 100K miles plus track passes every weekend with a 500+ rwhp car without some freshening every so often.

x2 I dont even need to add my opinion. :)

I love this post :jest: , I had first hand experience with a supposely "built" 4l60e that was to handle 450rwhp and it broke on me in bolt on form. I will say this the 4l60e is a great transmission from my research and the people who I deal with. performabuilt said it right and the others guys.....THE BUILDER HAS ALOT TO DO WITH IT, PLUS STRONG PARTS. dont just throw a stall in there and expect it to last. also your best bet would be to speak with CHUCK at FLT. Good luck.

the problem is in how it transfers torque from the flywheel to the driveshaft.it uses 1 planetary gearset in first gear verse two in all other gm rear wheel designs.this means all of the power is sent thru 1 planet and then to the output shaft.all others split it thru 2 gearsets to initiate first gear ratio.now,shifting to second gear the band and drum are not a problem but the transmission is in "overdrive"because the front planet still is operating in 3.06 reduction is overdriven by the rear planet.this stresses the reaction tube during engagement .shifting to third we reduce the front planets ratio to 1 to 1.this is done very efficiently mechanically thru the use of a clutch pack already spinning with the turbine shaft eliminating the problems assosiated with a heavy stationary direct drum grounded to a sun gear during a 2/3 shift,however the clutch pack capacity is limited.shifting to fourth we again use the overdriving of the direct driven front planet once again creating an output speed that is faster than input or overdrive.high power splits input shafts ,output shafts etc.the transmission is limited with billet parts to 750 foot pounds with a very loose converter imo.we build them but the ratio is inappropriate for most drag cars and anyone who claims otherwise simply does not understand the principles of operation of this unique automatic transmission.