gearbox mounted compressor

[Jacques Reed]

Hello Harle,

Further to previous post: I believe your concern is leaking at the shaft where it goes into the bottom of the compressor.

If the shaft and/or bronze bushing are not worn, there should be little or no leakage into the compressor base. The viscosity of the transmission oil would also help to prevent leakage. The problem arises if either the shaft or bushing are worn and then transmission oil will certainly pass.

When manufactured, the clearance between the shaft and bushing would most likely be a precision running fit which allows for smooth rotation with minimum play between the bushing and shaft. If sloppiness between the shaft and bushing exists then it would require the bushing to be replaced and reamed to the correct size for the required fit. Most often it is the bushing that wears due to being the softer material. Ford distributors are a good example of this.

If your compressor has seen a lot of use then new bushings would be the way to go or just monitor for any leakage and then decide if the bushings need replacing.

I had a look at a picture of a Webster type transmission mounted compressor that I once had and it too lacked the fitting at the bottom. Wonder if the parts book is accurate?

Cheers,