OK everyone, finally dropped the tranny on my 94 Z... took out the servo and there was a lot of sludge, but heres the question, im looking to spend a max of 350 on the rebuilt total, heres the master rebuild kit i was looking at http://www.bulkpart.com/cgi-bin/miva...y_Code=4L60Erk , then i was going to get the corvette servo assembly, a stronger band, and the heavy duty sungear shell... do you think i should get a transgo performance shift kit too? if i did then i would be up to $300 area, well if you could look at that rebuild kit and tell me what you think of the quality of the parts or if someone could giv me some ideas for the best 350 to spend on a 4l60e, excluding the torque convertor, i already have plans for that, thanks guys!

 

Your 4L60E already has a Corvette servo. ALL LT1/LS1 F-Body 700's/4L60E's already have them. Unfortunately, there are alot of "suckers" out there that don't know this.

A Trans-Go shift kit will tear your transmission up...Even in the unlikely event that a beginner can build a 4L60E. These transmissions are very contrary, and it takes someone that knows what they're doing to build on and make it last.

I'm not trying to "rain on your parade", but I've been building transmissions for 14 years. I put well over $350 worth of parts in mine (at my cost!). I've seen waaaaaay too many people try to rebuild a 700/4L60E on their own. I get alot of them in boxes after the owner realizes what he's got himself into. There's also alot of "hidden" modifications that these things need.

Also remember...When your transmission goes, it'll more than likely take the converter with it...That's alot of money to spend on an experiment.

Frank
All-Trans Transmissions

 

TTT on this one..........

thanks for the help so far, but anyways my car will be having a max of 375 horsepower, with a 2000 area stall torque convertor, so what upgrades for the tranny would be good? also what special tools are required when rebuilding the 4l60e, i have torque wrenches, dial indicator, stuff like that, but i mean there is some special tools in the ASTG service manual, some of them dont look like there nessesary exactly, but anyways, if a home mechanic has rebuilt one of these probly would know some tricks and such, please let me know, thanks guys!

 

You'll need a foot press, or hand press to compress the spring packs in the input drum, Reverse housing, and the low/rev piston in the case.

Clutch clearance is imperative in the 3-4's...You'll also need to throw away the "load release" springs. I also use Kolene steels and Raybestos "blue" frictions in my 3-4's. (5) .079" steels, and (7) frictions. BTW, I have almost $100 (my cost) in the 3-4 clutches and steels!

An Alto "Wide" 2-4 band with RED lining is advisable...DON'T get Kevlar!

If you use a wide band (or any band!) you'll need to make sure the rev. housing is perfectly flat. If it's dished at all, the band will only make contact on the outer edges. The drums can be machined, but then you'll need a longer servo apply pin. A new housing runs around $100+ from GM. The heat from a burnt 2-4 band is what causes the housing to dish.

I use a Fairbanks Billet 2nd servo in all my race transmissions, but you can get away with the stock 'Vette servo, if you don't want to spend the money. A Sonnax "Super Hold" 4th servo is a good idea no matter what 2nd servo you go with.
...Just as a referance of how the Fairbanks, and Sonnax servos work with the Red lined band...I just took mine back apart to put a 4L65E sun shell/front support in it...After 3 years in the 12 second zone, I reused the band because it looked like brand new! This was after using 4th gear in the quarter mile last year.

You'll NEED a Sonnax or Art Carr pump slide spring!!!! They keep pressure up at high RPMs.

Did I mention you'll NEED an Art Carr or Sonnax slide spring? DON'T skimp on this one!

Throw the Trans-Go kit in the dumpster! I take these things apart all the time right after a Trans-Go kit is installed! They always take the 2-4 band and the 3-4 clutches out.

Sonnax .490" boost valve

If you use the stock servo, block the 1-2 accumulator, and leave the 2nd gear ball out.

Block the 4th accumulator

Put a hardened sun shell in it!

Drill the shift holes

Put a C-6 ring gear snap ring in the rear ring gear

Use either a Precision Ind. or Toledo paper and rubber set... A trans-Tec kit will work if you can't find anything else.

Put a Fitz-All orfice plug in the rev. housing piston, and use (2) early, and (2) late frictions...Early frictions are .010" thicker and help take up clearance.

Put (3) 700/4L60Eand (2) TH 350 frictions in the low/rev.

Use a late 700 "double cage" input sprag. The "French" 4L60E sprags are prone to "rolling". Again!...Don't overlook this step! Make sure you get it back in the right direction!

Use either Raybestos or Borg-Warner "tan" frictions in everything except the 3-4's.

Take up unit endplay with selective washer under input drum.

Check the low/rev sprag really well.

If any steels have hot spots of any kind, throw them away and get new ones!...I still can't believe how many idiots I see whiz wheeling steels.

Check the pump really good..No scratches that are deep enough to grab a fingernail.

Check both planetaries for wobble in the pinion gears, as well as the internal thrust bearings for the sun gears.

Check BOTH sun gears for pitting

Turn the screw on the EPC solenoid 1/2 turn clockwise.

Put a new PSM (pressure switch manifold) on it. A small amount of debris will make them fail.

Check all bushings and mating surfaces for wear. The front ring gear support (reaction hub) is notorious for wearing where the rear sun gear rides on it.

You'll need to make sure you don't have a low/rev piston with the 1825 numbers on it. The last 4 digits need to be 5550!

Take the ball out of the capsule in the case for the low/rev. piston

Drill a .035" bleed orfice in the low/rev. piston between the 2
outer seals.

Check all splines for wear, especially the pump stator.

Check the teflon rings on the input shaft. They're notorious for the bushings in the stator support going bad and causing the rings to eat into the pump stator itself. If this happens, you'll need a new input shaft and stator. It'll tear up the input shaft so bad that you won't get a teflon ring back in it.

Ok...What will ll this get you? I built Dirks (RACINLT1's) transmission. For 2 years the car ran 11.2-11.0 with his 4L60E. 1.51 60 ft. times on the spray. It took alot of abuse before it shattered the rear ring gear. This isn't a normal failure on a 4L60E, though.

It's Sunday night...I've built a "cyber transmission" tonight, now I've gotta go to work and do it all again tomorrow...for real...LOL

If I think of anything else, I'll modify the post.

Frank

Seriously, though...This is not an easy transmission to build and get right. I know people who have been building them for many many years that still can't get them right.