~ 80K miles, 2003 LS1, automatic trans, coupe. Stock internals, some bolt-on mods, and a custom dyno tune...346 RWHP. The trans has not been serviced since new.

A while back, during full throttle launches, the engine began to bounce off the rev limiter predictably 2-3 times in the 1st to second gear shift and then shift into 2nd. Then 2nd to third, and 3rd to OD appeared normal. At part throttle acceleration, I noticed no issues in any of the shift points. As things do, it has progressed to more hits on the rev limiter at full throttle, and hanging in 1st gear on part throttle accelerations, and then by playing with the throttle, it will shift into 2nd, and then 2nd to 3rd and 3rd to OD appear normal.

Tuner I spoke with said that it sounds like low fluid or trans needs to be rebuilt/replaced. I checked for any codes, and found none. Also checked the fluid level. It didn't take more than a few ounces before fluid started running out the servicing plug hole. The fluid appeared to be dark, but I have to admit, I didn't get a good feel for any friction material debris and didn't notice much in the way of burnt smell. Probably need to take another look and get a better sniff test.

I checked with two "stealerships" and one wanted me to bring it in, but it seemed like they were just going to check for trouble codes and take it on a test drive, I'm guessing they would probably check fluid level too for about $115 (I don't want to waste the money if that is all they are going to do...and then tell me to replace the trans). Then they said it would take further disassembly, at a rate of $100 hour...but it would go towards a transmission replacement, when they got to the point that it was determined to be the best solution. Between the two, they want between $3500 and $4000 to replace the trans with a certified rebuilt unit with a 36 month warranty.

I was wondering if there is something else I should be looking for, before replacing the trans. Talked to a Vette shop, and they said that they would replace the trans for about $500...RPM Level IV trans for about $2000, plus higher stall converter cost. Sounds like a better deal than the dealer, except the better warranty for the stock GM parts. Thoughts?

 

The first thing I would do is have the trans serviced. Take it to a shop that knows how to service the C5 auto trans. That would be the cheapest thing to do first. While it is on the lift check for any leaks.

 

PLEASE explain to us EXACTLY how you checked the fluid level.

Im not trying to be a smart *** but,,,, GOBS of people here do it WRONG and damage their transmission...

Please be specific on the procedure you use..

Bill

 

Just to be clear...my trans issues occurred before I ever checked the fluid level. Followed service manual procedure...

- Put the car up on four ramps...to keep it level and get it high enough to work beneath.
- Ran the car at idle as long as it took to get the trans to the appropriate temperature range called out in the service manual...can recall exact numbers...96F to 122F I think.
- Cycled through all the gears, pausing at each gear and returned to Park
- with engine running...pulled the fill plug from the side of the trans. oil pan..no fluid flowed out
- added a few ounces of fresh fluid into fill plug hole until fluid flowed out the fill hole.
- reinstalled fill plug

 

WHEW! You did it the CORRECT WAY!

If you change the Torque Converter, you will need to RE-TUNE the PCM!

Have you thought about changing the fluid and the filter before going head deep in a different trans?

 

Thanks Robert.

I understand servicing is a whole lot cheaper than a new trans or rebuild if servicing would fix the issue...just want to be careful to not spend a bunch of money to service a trans if it's likely that the trans is failing...money that could be put towards the rebuild/replacement.

 

Thanks Bill.

Yes, considering that first. Certainly cheaper than new trans.

 

If it were me I'd try replacing the 1-2 shift solenoid. If you're game to dropping the tranny pan it isn't too bad of a job and you can replace the filter and fluid at the same time.

 

Wouldn't that have put out a code for the 1-2 solenoid? It will shift into second, just not when it should. If the 1-2 solenoid was bad, would it ever get out of first?

Already had the pan off and back on...changed the filter and what fluid that I could, without flushing it. Fluid didn't smell burnt, but was a very dark brownish color with a dark red tint to it. Fluid didn't seem to be overly gritty.

Unfortunately, the problem remains.

 

The solenoid can get some gunk in it such that when it is supposed to be allowing tranny fluid to be flowing through it can't flow as much as it needs to for a firm shift. If its coil resistance is correct and it sees pressure at the pressure switch corresponding to being in 2nd gear when it is supposed to be in 2nd gear then it won't set a code.

 

This part here makes me think you're going to be doing either a transmission rebuild or replacement. The brown color means there's a lot of wear taking place and likely that's the cause of your lazy shifts.