Bigwavedave

My trans is 6 mo old on a rebuild. Last one lasted 17 years (original) - had to rebuild for worn clutches. Car is essentially stock (91 with 5.7L). Had to take it back in due to lack of forward drive. Car was driving on freeway at 70mph, then dropped to 3rd gear. Once I stopped it stopped. Only had reverse.
Shop showed me the planetary gear with the top lip (spline?) broken off like a ring from a gatorade bottle. Also showed signs of being burnt.
They claim this can only happen from abuse.

Not sure how as a 20year old I can get a tranny to last 17 years, but at 40 I can only get it to last 6 months? It has less than 2Kmiles on the rebuild. Wouldn't this car need to be at the strip daily to get this damage this fast?

Plus, they already had to repair it once:
I had to take it back in at 3 months for high revs/shifting issue (shifting at 4K rpms hard in each gear). They said they had to replace a spring?

Anyway, researching this it sounds like the planetary would wear over time (worn gears) and not snap (especially on a stock set-up - I bought the car new). Also see heat/overheating/lack of lubrication can cause failure.

My questions:
(1) This car sees daily driver use (no abuse, spinning tires, etc. - I am the only driver). What would need to happen to make the thing snap? They claim it was new.
(2) Could the spring issue have caused low pressure/cooling, and cooked the gear? Did the hard high rev shifting it caused stress the gear?
(3) What other things should I look at/question?

nickhil2003

maybe the shop didnt exactly replace it with a brand new part?

Bigwavedave

I don't have much faith in them, since they accused me out the gate of drag racing. I just need enough "proof" to get them to fix it under warranty (right), and continue the warranty. I figured 3 years would show a good rebuild from bad. Didn't expect them to reneg after 6 months.

Bigwavedave

I think I really have just one main question:

What is the function of the spring that was replaced, and what kind of damage could it have caused?

junkcltr

iTrader: (1)

Are you sure you broke a planetary gear or just the sun shell?
If it was the planetary, then how bad is the play on the gears. Maybe worn out endplay caused it?