Couple of questions

They were saying earlier that the sudden change in rpms is what really hurts the tranny. but wouldnt a stall help a lot because it would always stay above 4500rpms depending on your stall

What is the pump spring they were talking in the tranny and where can you get a better one?

Last one. Is 6000 rpms really that much of a difference from 6600rpms. is there really that much more heat made from those six hundred rpms?

 

when it's the max, it's the max.

say you're strong enough to benchpress 250 lbs. you can only do it once. so you get cocky one day, you have no spotter, and try to benchpress 265 lbs. you wind up dropping the weight on your chest and you can't get it up. you're in serious pain. your muscles are tearing, your bones hurt and you're frantically trying to keep the weight from crushing your chest.

but it was only another 15 lbs! well, when all you can benchpress is 250 lbs, 265 lbs is impossible. revving a 4L60E a mere 600 rpms over its max is like dropping a 265 lb weight on your chest.

 

The spring mentioned is the pressure regulator spring which pushes on the pressure regulator valve, both are in a bore in the pump.

Stiffer spring = higher line pressure

 

mine lasted 7 months! with 60k onit with that kit

 

Does this spring come with aftermarket shift kit? If not where can you get this spring?

 

Shift kits include it.

 

LOTS of good theories in here. can you mix type F in with III without issue?

 

If you use Type F you get firmer shifts, because type F has different friction surface properties than Dex III or Dex VI.

Some people say you can't mix, but there are drag racers who use Type F with no problems, I don't think it hurts ($0.02); I suppose you can tailor by blending...

 

I have several 4L60E's going over 7,000 rpm at WOT, some with shift points of 7,200 rpm, up to 7,600 rpm. There is a minor modification to the input drum that should be done to prevent the WOT from not happening. This is not mandatory, but just in case. The 3-4 clutch area under the apply piston has a checkball in a capsule, that once in awhile does not seat, due to centrifugal force. We block the capsule using epoxy, and then drill a .035" hole on the outside edge under the apply piston. This will prevent any residual oil from centrifugally applying the 3-4 apply piston at high rpm. With these modifications, I have not seen any problems. There are other things that I do also, but this can only help the 2-3 WOT shift.

 

I have some food for thought ..

I've built and run many lifted trucks with much larger than stock tires. A few weak points in the drivetrain tend expose themselves in auto trucks ... axles and transmissions. If the gears were not swapped the motor turns a lower RPM (speed relative). In looking at these trans failures, excessive heat (burnt fluid) is what we see. Small transmissions don't like to tow heavy loads (for very long) either, hence the 4L80E and Allison trans. Without fail, folks with newly lifted trucks with big tires are often disappointed with the power loss (remember, no gear swap!) ... this doesn't keep them from trying to go light to light ... lol The trans just can't handle the excessive load brought on by the larger tires. Before the tire slip was the weak link, now it's the trans. .. if the axle don't break first (wheel hop is the major killer of an axle though).

I believe axles break for the same reason transmissions break .. torque. In a auto trans., all that friction (holding the engine torque and cars traction) causes clutches to work excessively.

As for a stock 4L60E ... I say; the better your traction and the more torque you make, the shorter your trans will last .. assuming you do your fair share of street launches.

I think RPM, as a factor, can be found in a few cicumstances .. but I believe torque and traction will be the common denominator.

Just my .02

 

I'd venture to say excessive heat will kill a transmission before excessive RPM's.

 

Hmmm, after reading all this I'm glad I went with a stroker motor.... Right now I'm putting down 400rwhp and 465rwtq. The hp peaks at 5000rpm with the torque peaking at only 3500rpm. My tuner had lowered my shift points just a bit since the torque kicks in so early. I only have a mild 218/218 cam with the stock p/p heads and all the bolt-ons. I'm still running my stock 4L60 and it has over 109K miles on it.

 

That's not a lot of airflow for a stroker motor. I'd definetely bump that cam up by at least 15-20 degrees of duration and you will see huge power increases and a pretty big difference at the track with the right tuning.

Hell 218 isn't even close to what most people put in the stock cube motor.

 

well my car has 86,000 miles...B&M "street" shift kit (1-2 shifts are MUCH firmer, and 2-3 shifts feel like 1-2 stock lol) done about 17,000 miles ago at least...and no problems... finished my rear mount turbo setup recently (5psi)+380rwhp/410rwtq and no problems whatsoever...Have been running it pretty hard for a month now and tranny still feels awesome...feels the same as it did 40,000 miles ago...so i duno ill let you guys know what happens when i up the boost and upgrade some other stuff KNOCK ON WOOD!!! =) .ps.- first thing out of my tuners mouth while on the dyno was that he doesnt touch shift points on auto cars, i didnt ask just played along and the car came out great and has a nice powerband= im totally happy how everythign came together, so screw shift points, dont need 'em any higher.... lol

 

If you aren't making power higher than of course you won't need it, but a lot of people do.

And he probably won't touch the shift points because they can be tough to get right. Maybe he just doesn't know the tricks so he doesn't touch them at all to avoid the hassle.

 

haha! the evidence continues to mount in my favor! RPM's = 4L60E's serial killer, not power

 

my 4L60E gave out when it i was only making 398 to the wheels with stock shift points

 

what mods did you have done to see that 398 rwhp? were you cammin'

 

This is gonna be pretty long, but as this is Choco's thread I'm sure he'll be ready to respond accordingly.

I’ve owned 5 different 4L60E transmissions across 3 different cars, ranging from a heavyweight, cammed, stalled Trans Am to a lighter weight stock Camaro. In addition, I’ve been involved in other A4 LS1 car build-ups within my club. Here is what I’ve learned:

IMO, there is no one single factor that is worse for a 4L60E trans than HEAT. Now, that’s not to say that other things don’t contribute as well, but heat is #1. Here is my “hit list” of 4L60E killers, in no particular order:

- Excessive heat, especially when racing (over 200* is not desirable, 210*+ is bad)

- Excessive power through the shifts (like deleting all Torque Management, or spraying N2O through the shifts).

- Excessive overall power/torque production of the motor.

- Excessive weight (even worse for the trucks, but also hurts the heavier F-bodies like a fully loaded Trans Am ‘vert, or a Trans Am with 200 additional pounds of stereo stuff and insulation).

- Manually downshifting under full load (WOT). Many trans builders agree that manually downshifting from OD to 3rd, under little to no throttle input, before going WOT is better than flooring it in OD and making the trans handle the downshift from a TC-locked OD all the way to 1st or 2nd gear (depending on speed) under full engine power. By putting it in 3rd pre-WOT, the trans will be doing a 3-1 or 3-2 downshift under WOT rather than 4-1 or 4-2. However, something like manually downshifting to 1st from an OD state at the same moment as going WOT is not good.

- Excessive RPMs (regularly shifting over 6200rpm).

- Improper line pressure (either too high or too low).

Any of these alone is not good, and any combination can get real nasty real quick. However, unless you push the trans to an extreme in any one of these categories, chances are that none of these will lead to a failure your first time out... with the exception of excessive heat.

I know it’s been posted above that 6000rpm is the max operational limit of the 4L60E, but I believe that up to 6200rpm would be safe, assuming you are still at near-stock weight and power levels, as the stock rev limiter will allow that to occur. GM left that 200rpm window for a reason, because certain conditions can cause the shift points to occur higher than the 6000rpm preset. Stock shift points are set to 6000rpm for the 1-2 and 2-3 shift, however as anyone who has run logs of stock 4L60E WOT shifts knows, the actual shifting RPM can range from slightly under 6k to over 6k. Traction, tires (PSI differences or even just different brands within the factory size can both cause slightly different diameters), uphill vs downhill traval, etc. can all cause the shift points to raise or lower to a small degree. I have tested and seen this happen first hand. I think it reasonable to assume that if 6200rpm was significantly dangerous for the trans at stock power levels, GM would have set the limiter to 6000 for the A4 cars and shift points to 5800.

I think the furthest that I’ve personally seen a stock 4L60E pushed was in a Procharged ’02 WS6. This was one of our club project cars a few years back. The car had a stock trans, running an ATI P1SC kit with a vig3200 stall + B&M cooler and otherwise stock.

The car saw 90% track usage. The stock trans was being shifted at no higher than 61xx RPM, and it lasted probably a few dozen track passes plus 5000 street miles before the next round of mods. Then, we tossed an H/C package at it, plus a smaller pulley and some dyno tuning. At that point the car was being shifted at 68-6900rpm, and still at stock weight. The trans died right away, as did quite a few “built” 4L60Es (very bad trans builder) till we got a good one.

However, it’s impossible for me to say what the primary factor was in the death of those transmissions. Many harmful conditions existed, from heat (as high as 240* even with a cooler), to A LOT of power (580rwhp), to heavy weight (lots of stuff added for the blower kit, plus the full stock weight of a Trans Am and a 200+ pound driver), to removal of TM, to high rpm shifts. Simply put, it was a recipe for disaster.

Overall, my point is that heat is still by far the most harmful factor. And once you get past the heat, there are other things that can be just as harmful as high rpms. It’s all about which factor you push the hardest as to what will be the primary reason for failure. Is shifting your stock 4L60E at 6600rpm bad? Very likely. But don’t think you’ll be safe spraying a 150 shot through the shifts so long as you keep the shift points stock.

 

Here's all the proof you need. My buddy's got an '01 z28 with an STS kit at 8lbs. It puts 473hp and 478 tq to the wheels and he's got a stock 4l60e with a shift kit that he still shifts at 6k. He doesn't drive it like a grandma either. Surprises the hell out of me.