New Tranny

[BluHoe96]

So, at 110k my original transmission took a dump! Against my own instincts I did a pan drop to replace the original pan with an extra deep pan with a drain plug. To make things a bit worse I got sold my the Monster Transmissions sales rep to get Synthetic Tranny fluid. Great stuff! BAD for an unmaintained, 15 yr. old 4L60E! Changed the pan at 96k and 14k miles later DONE!

I started from the tranny hanging up in second, then progressively hanging up in 1st and second. Finally, while driving on the NJ Tpke. on the way to work, lost OD, pulled over to reset check engine light, tried to get going again and lost ALL FORWARD GEARS! SUX! After a long morning and getting towed back to Queens, NY I had Bobby at K&B Transmissions (great shop in Floral Park and they know the 4l60e very well!) tear the case apart.

After tearing it up they found that my rear planetary gear got chewed up and snapped off of the mainshaft. Also had bad band discoloration and the clutch packs and steels were pretty glazed. Other than the planetary pretty much expected wear for an old tranny not regularly maintained.

My moral of the story, if the transmission was not regularly maintained DO NOT change with synthetic fluid. If you are changing the pan then just ad normal dexron III fluid. I am pretty sure my seals and accumulators stopped sealing properly and I was losing fluid pressure causing the slip which just got progressively worse.

Had the trans rebuilt with a 4L70E 3-4 clutchpak, pinless accumulators for 1-2 and forward gears, corvette servo, and all new seals and hard parts. Never experienced the truck run this good! Part throttle shifts are smooth and quick, no more laziness. OD won't kick in till 47 mph whereas before my OD kicked in all the time and downshifted out of it more often. Full throttle shifts are firm.

Guess the question now is, what route should I go with for software? I guess BB is the best? Would like to step up power a bit and firm up shift points a bit more with tuning. In what way can I improve shifting electronically? I know I spent a lot on my truck, but I really love it and cannot find a more mechanically sound truck here in NY for the amount I have put in to this truck.

Carnage:


Rainy pic of her:

 

[AtomicHoe094]

Good stuff! How much did the rebuild cost ya? Yea Blackbear can help you out on the trans. They can bump up the trans pressure in the lines for even quicker shifting. Then you can also get the revlimiter changed and all the other fun stuff. Id suggest getting an in person tune just because of what youve changed to the trans already. This way he can control the line pressure while your driving around instead of sending pcms back and fourth

 

[retorq]

Hate to tell ya but the fluid had nothing to do with your rear planetary blowing up ... it's a common issue on 4L60s. Lucas trans additive would have fixed the leaking seal issues ...

 

[SeriousSide97]

how much did it cost

 

[arctic388]

I totally agree with the fluid changing. since my trans went bad in my Tahoe i have been doing a lot of research and a recurring them i saw was after a flush with higher miles it did more bad than good. i have a 99 mountaineer with 228K (got it with 32K in 2000) and i have never dropped the pan. i did a 14 qt flush around 100K with motorcraft fluid. i have a 99 Malibu with 190K (got it with 36K in 2000) and did drop the pan once around 110K. just used Valvoline if i remember correctly. I bought the Schaeffers Syn trans fluid with my Monster transmission so i will always run Synthetic in it but wouldn't switch to Syn in one that didn't already run it.

 

[BluHoe96]

The reason why I figure the fluid was the culprit is because of my pressure loss I was experiencing before my tranny just flat out stopped working. When the planetary gave way I wasn't in a huge upgrade or even flooring my truck. My truck doesn't even experience much hard take offs to begin with since I am so stingy with gas. In retrospec though I should have asked Bobby if he could add the reinforced sunshell so that this would not happen again.

After all was said and done including the new radiator and all the labor I got hit over the head for $2800. Definitely was a bit much and more than I wanted to spend! With my new job though I had zero time to just drop the tranny myself as well as the rad. I needed her running asap. He picked it up for me in NJ at my job, took it all the way to Long Island Friday, and had her up and running on wed. night. Not a bad turn around at all.

 

[bigfeet]

It was the fluid change. Same thing happens with differential fluid changes in Corvettes.