Okay, so you’re ready to reassemble the forward/coast clutch support. Remove the three oil seal rings, discard the cooler return seal from the support assembly and put in a new cooler return seal using the socket wrench. Now replace the oil seal rings, lubricating the support. Put in the low roller clutch assembly and turn the cage of the low roller clutch as far as it can go, resting it on the face of the outer race surface.
Unfortunately, something’s not right. What went wrong?
Well, if it this were our operation, we’d get out our phone, do some clicking and open up our copy of the GM 4T80-E Transaxle Rebuild Repair Manual on MINI CD. We’d review the process for the Forward/Coast Clutch Support Assembly to see where we got off track. And right there before us are the basic steps, each numbered and referencing a detailed graph.
It seems we forgot to check for wear or damage. A redo does indeed show what we thought was a pristine oil seal ring was water damaged, disrupting everything.
Back to work.
We think having one of ATSG’s manuals in PDF format on your personal device is a great idea. The MINI CD gives you the info of the print version, all the graphs, charts, tables and instructions, but lets you access it through clicks and swipes on a computer, phone or tablet. It’s a great way to manage working on the 4T80-E and sharing information quickly.
The General Motors 4T80-E transmission can be found in at least the following makes and models and there are likely newer models too (check your owner's manual or identification plate):
- 1994–2005 Cadillac Deville
- 1993-2002 Cadillac Eldorado
- 1993-2004 Cadillac Seville
- 2006-2011 Cadillac DTS
- 1995-2003 Oldsmobile Aurora
- 2004–2005 Pontiac Bonneville
- 2006-2011 Buick Lucerne
Subject: GM 4T80-E Transmission rebuild instructions on PDF - 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011. | ATSG THM 4T80-E CD