ok, i just bought a 99 Lesabre and its a great car. But one problem that has just arose was that under hard acceleration the car will shudder into gear. As far as i know this car has the 4T65-E, these are the reliable transmissions or am i mislead? I would like some input on what you guys may think that the problem is. Am i going to be spending a butt load of money or is it something minor that can be fixed without me selling my soul?

Thanks again

First thing you will want to check is your trans mounts. Not sure if yours is the same as the bonnevilles. But this happened to me and at least 1 other member. A bolt falls out of the front left trans mount and when that happens the car will shutter bad on the shift. Here'* what to look for.

I checked the mount this morning and it fully intacted and the bolt is snug. I'm thinking that it might be a clutch inside the transmission itself, and this is what my mechanic is suggesting the problem is as well. I just don't understand the car shifted fine the day that i got it and it ran like a champ, now this is happening. Are there any other suggestions you may have on what it might be?

Check your other trans mounts just to make sure. You will need to go under the car to do that. Jack up the front of the car and see if there'* any play in the wheels while you turn it.

OK, I checked all mounts and they all check out fine. I let the gentleman that just did the clutch on my Mustang take it out for a drive and see if he can tell what the problem is. He came back and told me that from 1st to 2nd was slipping to engage. Thats exactly what i thought, and for him to rebuild the tranny it would roughly be about $1200!!!! After nearly having a heart attack i drove the car home. I drove it pretty hard to see what it would do, and my results were a bit puzzling. Under hard acceleration and with the pedal to the floor from first to second is pretty rough, now if you let up on the gas shortly before it goes into second it shifts like a dream, no slipping what so ever. What is this pointing to? What can it be? Is the tranny on the road to breaking down or is this something minor?

Sounds like low pressure. Try changing the fluid and filter. That may fix the problem.

if changing the fluid doesnt work, then i coukd sell you an extra tranny i have, it came off a 98 regal with 90k miles on it and worked fine before i took it out. id sell for 700 if interested.

Mine does the same thing, I know the fluid needs to be changed soon so that could be the issue, but I am having them do an overhaul at the same time beacuse I need this tranny to last me for awhile

My suggestion to you guys is to try a shift kit and when you pull the pan, add one bottle of the Lucas stop slip trans goop.

I haven't added the **** kit yet (I'm lazy about driving the mile to Home Depot for the parts), but that Prelude this morning was looking at the Regal a bit funny as I took him out.

Before you have someone tear into your trans you may want to get a line psi test done. A qualified treans tech should have gaues and a scanner to do this. I would also take it to Autozone and get is scanned for codes. I think they will do that for free.
I know these transmissions have issues with the psi control solenoid being whacky. After that I would drop the pan and see whats in it. If you have an excessive amount of material than you will need a rebuild