1990's 3800 FWD transmission Questions:

[SBRMD]

1. Which trans came with in NA 3800 in a 1997 LeSabre? Final Drive ratio (w/out gran touring susp)?

2. Obviously, a beefier 4T65E came in the 1997 Riv w/ the SC3800; does it have the same ratios as the trans asked about above? Final drive ratio?

3. Granted, the LeSabre trans isn't as heavy duty, but...could one easily transplant the standard '97 LeSabre trans into to Riv?

Thanks to all in advance for any/all info.

Steve in Mpls.

[tim63riv]

Steve,

Don't go there! Either fix the transmission in the Riviera or get the proper used one! The LeSabre likely has the 4T60-E and the Riviera has the 4T65-E. The electronics on the transmissions are significantly different as is the vehicle wiring harness. There is a metal tag on the rear passenger side of the transmission toward the firewall that has a three digit alpha code on it. That is the transmission you need.

Tim

[Larry Schramm]

The other way that you can tell what transmission came in the car is to look at the RPO codes usually in the trunk, door jam, glove box. The white sticker is about the size of a 3"x5" card with a bunch of three digit numbers. Find the transmission 3 digit number and look it up on this list.

http://www.marshu.com/images-website/car/gm-firebird-camaro-rpo-car-door-manufacturer-codes/gm-firebird-camaro-GM-RPO-car-codes.pdf

You will know exactly how your car was built. It also lists all of the other variables to the basic car/vehicle.

[tim63riv]

Larry,

That is a good point for determining which transmission is in the car, (4T60-E or 4T65-E) but the model number is the only way to determine the correct transmission for the application. These transmissions have both drive to driven sprocket gear ratios and final drive ratios that can vary. That is why the model number is critical.

Easiest way to tell the transmissions apart visually is by the vacuum modulator, which is at the driver side front of the transmission, facing toward the radiator, 4T60-E has one, the 4T65-E does not. Also, the 4T60-E has the wiring harness connector facing forward toward the radiator, the 4T65-E has the wiring harness connector facing toward the left front tire.

Get the right model number for your application or you'll have issues like shift timing and feel, TCC engagement and gear ratio incompatablity codes.

Tim

[SBRMD]

Thanks guys, that feedback is extremely helpful.

Tim, I heard essentially the same things you've said from a transmission tech today. Sounds like a bad idea. Darn! Trans in the outgoing LeSabre is well-rebuilt, thought maybe some value could be preserved.

The Riv's trans hasn't really done anything particularly bad yet. It's shifts occasionally cylce into a bang-into-gear feel, but usually are smooth. It also seems to slip momentarily from tip-in. Nothing to do yet... But the LeSabre goes bye-bye soon, hence the questions.

Edited March 10, 2010 by SBRMD
typos! (see edit history)

[Guest wildcat465]

Steve, talked to your bro last night, sorry to hear about the LeSabre engine. Looking forward to seeing you soon.

[SBRMD]

Hey Paul!

Well, turns out the engine issue seems to be just the harmonic balancer and the crank sensor, which apparently was knocked out by the balancer when it came loose. So, a reasonably inexpensive repair. I think we will be fixing it, and then up for sale.

Since no possibility of vulturizing the trans, I'll have to see what happens w/ the Riv.

Sure appreciated seeing you and Donna 1/24/10. I'll make it a point to find some time soon, gotta catch up.

-Steve.