Hi Everyone;

Vehicle details in sig. Drivetrain is the 3.8 V6 with 4 speed auto (OD)
My mother-in-law gave this car to my youngest son. It has been sitting for 4 or 5 years, but seems to be in good operating condition other than the tranny. We replaced the battery and brought it home via a 3 hour highway drive with no issues, and it even seemed to give us pretty good fuel economy. The transmission problem is as follows. When starting out from a dead stop the car makes a very unpleasant shuddering/grinding sound, but once it is going more that a few mph it seems to run and shift fine. It seems load related, as you can avoid it by being VERY gentle with the gas, and it is worse going uphill. Also, if you manually shift it into 1st then move it into Drive after it gets going, it is fine. This is a bit baffling to me, and I was hoping someone might be able to point us in the right direction.

If you manually start out in 1st gear it does not do it? Can you pin point the area of the noise?

Correct. If I manually start in 1st then shift to D or OD after it gets moving it is fine.

Hard to be precise on the area of noise, but it seems to be from low in front of the driver. There is also a lot of vibration/shuddering.

I've got the ATSG manual for the 4T60E which is likely what you have in that car.
I don't have the time right now but you want to look at what is and is not applied for D1 manual and auto and see if you can find the culprit.

@Admin What is the limit to file size? I had a manual and it was less than 6 Megs and didn't attach.
I think you have a sticky valve and might try adding a bottle of trans fix.

That would be extremely helpful. No huge rush, as he still needs to pass his test. I don't want to put too much time and money into this car until I have some idea of how big a problem this is.

It is my understanding that this car has the 440T4 which is the same as the 4T60. Not sure how the E differs if at all....

Thanks for your help!

Roger

Well that would be an awesome easy fix! Any recommended products? I've seen a number of people on here having success with the Lucas product...

Lucas or BG products are good.
The valve for a manual shift is not the same as for auto. E just means it'* electronically controlled. It that valve does not open and close correctly it will cause shudder.

Excellent! I know I can get the Lucas locally, so we will give that a shot! Thank you so much!

Wait, I haven't seen the part where the fluid level has been checked while the transmission is at operating temperature and in Park with the engine idling.

Also, how many miles are on this car?