Bench-mount holding fixture that clamps a GM TH350, TH400, 200-4R, 700R4, or 4L80E case by its factory lugs so you can tear it down and spin it 360 degrees hands-free.
Pulling a 4L80E out of a Silverado 2500, a Sierra 3500 or an Express van and getting ready to tear it down on the bench? A heavy-duty four-speed with the converter out still weighs well over a hundred pounds, and trying to pull the pump, the drums and the center support while the case rocks on a bench is how parts get dropped and gasket surfaces get gouged. This J-8763-B style holding fixture clamps the case by its own bolt lugs, bolts to your bench with the included base, and swings a full 360 degrees so you can work on the valve body side, the front or the rear with the case held still.
The J-8763-B is the fixture number GM service procedures call for on its rear-drive automatics. The case hangs from the fixture arms, and two tightening handles let you rotate it and lock it at any angle. That matters on a 4L80E because the teardown changes direction several times: valve body and solenoids come off the bottom with the case upside down, the pump and the overdrive section come out the front with the case standing up, and the center support and rear geartrain come out the same way. A lifting ring is built in for getting the case on and off. The center post is threaded M16 x 2.0, so a longer bolt can be fitted for a deeper case, and many shops weld the base to an engine stand to roll the whole unit around the shop.
Do the diagnosis before you pull the unit. Many 4L80E complaints are electrical or pressure related and can be fixed with the transmission in the truck, so read our 4L80E common problems and fixes guide and check line pressure first. For vans, 4L80E Express van common problems covers the heat and speed sensor issues that look like internal failure. Transmission Digest's article on a 4L80-E with no Reverse makes the same point: separate hydraulic, electrical and mechanical causes before you commit to a teardown. Once the unit is out, the fixture makes the air checks and inspection much easier.
The listing names a long list of GM cases: 180C (3L30), 200, 200C, 200-4R, 250, 250-C, TH350, 350-C, 375, TH400 (3L80), 425, 475 (3L80-HD), 700-R4, 4L60, 4L60E and 4L80E, and builders also run the Ford AOD on it. One honest note for 4L80E owners: some application charts list the 4L80E with an optional adapter, and some builders report needing to slot or trim a leg so the bolt holes line up with a 4L80E case. Hold the fixture up to your case lugs before you hang the transmission and do not force a bolt that is not straight. Parts for the rest of the job are on our 4L80E parts page.
| Fits | GM 180C/3L30, 200, 200-4R, TH350, TH400/3L80, 375, 425, 475, 700R4, 4L60E, 4L80E |
| Mount | Bolts to bench with included base; case mounts by factory lugs |
| Rotation | 360 degree swing, dual tightening handles lock at any angle |
| Center post thread | M16 x 2.0 |
| Weight | 13.2 lb |
| Dimensions | 21.06 x 13.98 x 4.33 in |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
The listing includes the 4L80E, but some application charts show it with an optional adapter and some builders slot a leg to align the holes. Check the fixture against your case lugs before mounting.
Many shops weld the base to an engine stand to get rotation and mobility. The fixture itself bolts to a bench with the included base.
M16 x 2.0. You can fit a longer bolt if a deeper case needs more reach.
About 13.2 lb, and the box measures roughly 21 x 14 x 4.3 inches.
Yes. The fitment list covers the 4L60E, 700-R4, TH350, TH400 and several older GM cases.
