Chumley

I'm looking into replacing the motor mounts on my '72 (350) because I suspect the ones on there now are not correct, as the motor sits about 3/4" lower than it should. (Someone cut out the bottom of the fan shroud so the fan would clear.) Question#1: would the tranny mount be affected and have to be changed also? #2: Are the mounts just a direct bolt-in, and what is easiest way to go about this? Thanks, Chumley

74 Omega

wasn't this covered?
https://classicoldsmobile.com/forums...50-engine.html

Chumley

I guess I was looking for a more specific answer to these questions than the one I had posted previously. I just wondered if the geometry would be thrown off if I had the correct motor mounts but incorrect tranny mount. To tell you the truth, I can only assume that the existing mounts are incorrect since I have the fan clearance problem. Rather than try to find a smaller fan, I would rather make it "correct" than mickeymouse it any further. Chumley

joe_padavano

I've heard this a lot, but if the engine were really 3/4" too low, the oil pan would be sitting on the crossmember. There's only about 3/4" of clearance normally. If you can fit a finger between the oil pan and the crossmember, the engine is at normal height. More likely, the trans crossmember is off somehow. My 70 W-30 had been improperly jacked by a previous owner under the open section of the frame rail. This caused the lower leg of the C-channel to be bent upwards, which in turn raised the trans crossmember, causing the nose of the engine to pitch downward. When aligned correctly, the fan should be centered in the shroud.

Chumley

That makes total sense to me Joe, although I haven't crawled under there to check it out it would not surprise me if that is what happened on this car as well. If that's the case, could the cross member be bent back without compromising the strength of the metal? Would this explain why the driveshaft spline seems to stick out of the tailpiece on the tranny more than looks normal? (rear seal also leaks a bit, although this could be due to age of car) Chumley

joe_padavano

The frame and crossmember are mild steel, not heat treated, so they can be re-bent with no ill effects. Of course, this is easier said than done. I ended up using a very large adjustable wrench over the lower leg of the frame rail and a piece of pipe over the handle of the wrench.

Chumley

Is there a difference in a '72 and '73 TH350 that might cause a proper fit problem? I'm assuming the tranny is a '73, possibly from the same car as the replacement engine. ( '73 Omega) My parts interchange book says a '73 TH350 will fit a '72 Cutlass, so now I'm confused. I crawled under there and doesn't look like anything is bent, although there seems to be space for the tranny to drop another 1"or so where the mount is. Looking at the tranny pan from the side, it looks to be higher off the ground toward the rear than in the front. (see picture) I got a number that was stamped on the tailpiece :6260036. There was another number toward the front I didn't get. The mounting pad seems fairly thick, maybe about 1" or so (rubber part) Is that about right? Maybe I'll just drive the car without the shroud until the weather warms up. Chumley