1959 engine mounts replacement - with V8 motor in?

[Ramto171]

Hello!

I am from Western Europe and new in the forum, drive an 1959 Cadillac 2-door coupe in good running shape since mid of last year. The car is lot of fun, but its disturbing me that at 50 mph / 80 km/h at 3rd gear (high) i get a rumbling sound for up to ca. 62 mph. If I shift back to 3dr gear (low), the same sound comes already at ca. 35 mph. Thats why I think not the prop shaft but the engine itselve should cause that. The rubber at the gearbox mount look fresh and the gearbox was overhauled some years ago by professionals (said the pre-owner).
But the engine mounts show already lot of small cracks in the rubber, and I fear they are worn. Want to replace them, but WITHOUT lifting the engine / gearbox out of the car, which is a lot of work. Eg by supporting / lift up the complete engine / gearbox unit ca. 2-3 inches or so from underneath (car is on the car lift of course). One Gearbox lifter at the gearbox, one under the engine > change first the RH, later the LH engine mount step by step.
Is this possible - has this anyone of you done already - or definitively must the engine go out or be lifted a little bit with an engine crane from above. I am not sure: Will i get enought space to get out the motor mounts with engine stays in and what to be dismantled min. to avoid damages.

Surely one of you tried or has DONE already the exchange of the 2 engine mounts with engine remaining installed and can give us good advise.  Thanks for our kind help.

Best regards, Otmar

[The Tassie Devil(le)]

G'day Otmar,

Congratulations on your ride.

The Engine Mounts can be replaced by raising the engine, even without undoing the gearbox mounting.

But, you need to loosten the fan shroud if the car has Air Conditioning, so that as you jack the engine up at the front, you don't hit the fan blades on said shroud.

If you intend to lift the front of the engine up high, then it is a good idea to remove the Distributor Cap so it doesn't have any chance of hitting the firewall.

Bruce.

[Ramto171]

Hello Bruce!

Thanks for the helpful info, my car has non AC. I am happy to hear the motor can stay in and I can "fish out" the  motor mounts just by lifting the engine up at the front by a gearbox lifter from unterneath.  Must the propshaft be disconnected when I lift up the engine at the front 2-3 inches. Especially left side of engine mounts area looks not to have much space for the fingers.

Kind regards, Otmar

[The Tassie Devil(le)]

I don't think you have to go that high, but with a non-A/C car, you might have to remove the top radiator hose as it is possibly too short to stretch that far.   You don't want to spring the top of the radiator.

One way of raising the engine without damaging the sump is to use an overhead hoist (engine crane) or something similar and lift it from above.   This will give you better access from underneath to wiggle things out.

Bruce.

[fishnjim]

Be prepared for a fight.   I replaced the ones on my '58 (same block) with the motor out and it's not easy bolt (3) access and it wasn't easy getting the mounts loose of the frame.   It might be better access using a lift than working from the ground.   
Usually worn/broken mounts will cause the motor to lift/move, rather than make noise.   So it might be something else.   Start the car and put in gear with the hood(bonnet) up and have someone watch the motor/mounts for movement from the side/clear as you slowly raise the throttle with brakes one.   It only torques one way, one side goes down, one goes up.   If it doesn't raise, the mounts are good.       

[steve hachen]

Hello Otmar,
Are you sure it’s not your carrier bearing? 1959 Cadillac’s have a two piece drive shaft or propeller shaft with the carrier bearing in the middle. Group number is 2.0910, part number is 567 2771 with the support bracket that is vulcanized rubber; the bearing part number is 940 778. There are number of shims the go below the bracket that are used to make the drive shaft straight from front to rear. If you are missing some shims, or maybe that bracket had been replaced in the past and all weren’t reinstalled that could be your issue. If the drive shaft isn’t straight you will have a vibration. The group number for the shims is 2.0962, the part number for the shims is 147 2817, AR, as required, but that might not be of much help to you.
Good Luck, Steve