Reatta Owners Journal

The following is a three part series of instructional videos that describe how to overhaul the  GM HydraMatic 440-T4 transmission used in the Buick Reatta. David Allen does an excellent job of leading you though the steps needed to rebuild the transmission in a clear and concise manner. These videos, published on Feb 13, 2014, would be very useful for the Reatta owner who wants to take a shot a rebuilding his own transmission.

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GM 440-T4 Overhaul Overview Written by: David Allen

In this series of videos, I am rebuilding a General Motors 440-T4 (also called 4T60) front wheel drive 4-speed automatic transmission. This transmission job was ORIGINALLY going to be an in-frame job, but due to the damage found, I had to remove the unit to change the torque converter.

There are 3 videos, each about 30 minutes. In the first video, I combine a slideshow of the teardown and sub-assembly overhaul with a video of valvebody checkout. Parts 2 and 3 are live video of me re-assembling the unit.

The books I used are the ATSG (Automatic Transmission Service Group) 'TECHTRAN' factory manuals. See HTTP://WWW.ATSG.BIZ for the books. The books are simply titled "THM 440 T4 / 4T60 Techtran" and "THM 440 T4 Update" and "...Upate Volume II" These books cover the various modifications the factory did in the 1984 to 1339 production run of this transmission. This is very important when you are buying a junkyard transmission to use for parts, as the books show compatibility and identification of the parts.

The parts for the job were ordered from Transtar. All the parts to renew this unit to like-new condition cost about $400. This includes the pump shaft and bearing, all seals/gaskets, the 2nd clutch plates, torque converter, bushing kit (from Transtar) as well as a junkyard transmission to get the pump.

This is dedicated to my fellow car club members at HTTP:// and HTTP:// who have often asked to see what's involved in a transmission job.

  • License: Standard YouTube License

GM 440-T4 Overhaul Video Part-1

GM 440-T4 Overhaul Video Part-2

GM 440-T4 Overhaul Video Part-3

Thanks to David Allen for producing these videos and to Reatta forum members for providing links to them.

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