The Ford Barn

Russ/40 · 10-29-2019, 03:02 PM

Hello, I have been working on the rear float a motor addition to my 39' transmission in my RPU. I have decided to stop for some advice. I was able to adapt the FAM rear cushion casting to the V8 clamshell by elongating the two side holes to match the 1/4" smaller measurement on the V8 clamshell. That has gone well. When I did so, the casting at the rear of the mount sits about 1/8" apove the crosmember. That takes me to the point where I have to raise the transmission to make room for the rubber cushion at the top of the FAM.

Thats where I lack the install instruction for how high do you jack the transmission for the cushion. I attempted to jack the assembly up. It did go up about 1/2" relatively easilly. At that point I was lifting the whole truck. I still have the stock rear motor mount, so I was concerned about cracking the flywheel housing.

Should I loosen the 4 rear mount bolts, raise the trans a little more or should I make the cushion to fit the existing gap between the crosmember and FAM, then drop the transmission to a resting position on the crosmember? If I do the latter, the rear cushion will be thinner than photos of other installations, which I dont think matters, as long as there is some tension there.

Your expert experience as well as any observations are welcomed.

10-29-2019, 03:02 PM	#1
Russ/40 Senior Member Join Date: May 2010 Location: Santee, California Posts: 3,505	Return to the Rear Float a Motor Thread Hello, I have been working on the rear float a motor addition to my 39' transmission in my RPU. I have decided to stop for some advice. I was able to adapt the FAM rear cushion casting to the V8 clamshell by elongating the two side holes to match the 1/4" smaller measurement on the V8 clamshell. That has gone well. When I did so, the casting at the rear of the mount sits about 1/8" apove the crosmember. That takes me to the point where I have to raise the transmission to make room for the rubber cushion at the top of the FAM. Thats where I lack the install instruction for how high do you jack the transmission for the cushion. I attempted to jack the assembly up. It did go up about 1/2" relatively easilly. At that point I was lifting the whole truck. I still have the stock rear motor mount, so I was concerned about cracking the flywheel housing. Should I loosen the 4 rear mount bolts, raise the trans a little more or should I make the cushion to fit the existing gap between the crosmember and FAM, then drop the transmission to a resting position on the crosmember? If I do the latter, the rear cushion will be thinner than photos of other installations, which I dont think matters, as long as there is some tension there. Your expert experience as well as any observations are welcomed.