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2001 sudden Transmission issue


68ragtop
09-26-2010, 03:19 PM
My mother has a 2001 GP 3800 with 90K miles. The trans is suddenly growling, or grinding when it is in 1st & second gears, no noise in 3 & 4th. Oddly it makes this same noise when it is in park, but goes away as soon as it is in gear, but then comes make once it start rolling. Especally bad if I keep it in 1st gear, bring it up to 25 mph & then lift the accelorator. The drag on the transmision slowing the car back down, is very noisy.

Any thoughts. It aboviosly needs to be pulled, but is it repairable, or time for a new transmission?

Blue Bowtie
09-26-2010, 03:57 PM
As long as the repairs are done soon (or you park the car until it is repaired) the damage will be minimized. It sounds repairable, and you will likely find a worn reverse reaction drum and broken or missing thrust washer behind the second clutch - That drum is locked to the input shaft in both the 3 & 4 ranges so it won't make noise.

68ragtop
09-26-2010, 06:51 PM
The other strange thing is With the car parked & idling, if I push on the car, rock it back & forth against the parking lock, it will make the same noise in each direction. Weird.

68ragtop
09-27-2010, 03:58 PM
I just called a local transmision shop, & he claims that if the transmision makes noise under load in first & 2nd, It should not be making any noise when in park. This car does, & it changes when I rock the car back & forth against the parking pin. Also goes away as soon as it is in gear, but not moving.

He thought it could be the starter, but I highly doubt that. Way to solid of a groan to be a gear agains the flywheel.

Blue Bowtie
09-28-2010, 01:11 AM
Remind your transmission shop that the car has a 4T65E, and that on that transmission the input clutch and solenoids A and B are ENGAGED when the selector is in Park.

My money is still on the thrust washer behind the second clutch drum which is spinning while in Park, and the reverse reaction shell being worn/damaged. Then again, I'm no expert.

68ragtop
09-28-2010, 05:41 AM
Does it make any sense to have just those parts removed & inspected? I am guesing the transmission has to be pulled out of the car for this? For the $600 the shop wants for R&R, I think I am going to do that part myself.

Thanks again for your input & advise

Blue Bowtie
09-29-2010, 11:24 PM
The transmission has to be removed to access the reverse input and second clutches, and to remove the reverse shell. This is about as far as you can go with the trans in the vehicle:

http://www.wwdsltd.com/files/4T60SideCoverRemoved.jpg

At that point, you could remove the valve body, channel plate, chain and sprockets, and the clutches and drums, but I'd put a lot of money on never being able to install all of that in alignment again. It's a challenge sometimes just to get the clutch plates and drive fingers to align when assembling them vertically on the bench, and the input drum assembly is a crap shoot even with the factory installation tool. Setting the end play would be impossible unless you did it in space with zero gravity.

In short, it needs to be pulled. A rebuild kit with clutches, seals, gaskets, and sundries is only about $125.00 and the shell is about $30.00. The last one I did had less than $375 in parts with all new wear parts, thrust washers, chain, two bands, and reverse shell, including the filter and the oil.

tblake
09-30-2010, 08:54 AM
Remind your transmission shop that the car has a 4T65E, and that on that transmission the input clutch and solenoids A and B are ENGAGED when the selector is in Park.

My money is still on the thrust washer behind the second clutch drum which is spinning while in Park, and the reverse reaction shell being worn/damaged. Then again, I'm no expert.

Haha good one.

About all I can add is I've only had one of these type of trans's apart, and that was a 4t60e and not a 4t65e, so I don't know much. What I do know was even with it on the bench it was no fun to rebuild.

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