99 deville power train

[denman]

Does anyone know about the 4t80e transaxle i am building a custom car using the above power train what I need is the offset distance from the crankshaft centerline to the transaxle output shaft centerline( vertical distance and horizontal distance) that is

Please advise

regards

Dennis

[Cadillac Jim]

First, check the coolant for combustion by-products and perform all the maintenance you would do on an old used car, including servicing the transmission. The drivetrain is bulletproof, including the transmission.

The rolling diameter of the OEM tires is 26.6 inches. Get close to that with your car and you can use the VSS and PCM for the speedometer.

[Cadillac Jim]

I've looked at the 1997 factory shop manual and also the 1997 transmission rebuild manual and there are lots of diagrams but no appropriate cross-sections or side views that are dimensioned. It's not as much as you might think because the transmission axis is at an angle behind the engine. I suggest that you use any running 1993-1999 Cadillac, and take half the rolling diameter of the tire as the wheel axis above ground, and measure both the half-shaft height difference and the center point of the damper wheel on the front of the engine and find it that way. This will get you as close as you need to be for chassis and body specifications.

If you are using the suspension too, and keep the suspension geometry (loading, or at least wheel position), all you may need is the damper wheel center point.

Be sure and get the tire make and model, and check the tire manufacturer's spec for rolling raidius. That will get you any differences between the tires in use and the OEM tires from 17 years ago.

[denman]

Thanks for the response I see where you are going with this and your answer is valid I was hoping some one might just have a trans axle just sitting around and could just put a tape measure to the trans and give me just the two measurements I need... I am at the point where I am making drawings for this install trying to plot it out..

Thanks

Dennis

[Cadillac Jim]

The problem of making measurements on a transmission out of the car is that the transmission is actually behind the engine, not under it. The angle between the crankshaft centerline and the transmission/axle centerline is about 20 degrees from horizontal. So, the vertical distance is very much a function of the angle that the transmission is measured at. You could put the oil pan on a level or some such but the resulting measurement would have about the same accuracy as finding a car somewhere and measuring the height of the damper wheel. Then, there's the fact that you have two CV joints and a front axle that is not in general perfectly horizontal.