Running the car with the rear in the air?

[Zithlord]

I am refurbishing some deep six rims. To ease the wet sanding/polishing job I have jacked up the rear of the car and put two supports under the torsion bars. My plan was to put the rim I am working on, on the rear of the car, and then put it in first or second gear. While the wheel is spinning I will do the sanding and polishing. Can this damage any mechanicals/engine tranny etc?

Thanks
John

[nick-moss]

You cannot be serious! Why risk loosing your fingers for the sake of a few Krone? Get them chemically stripped by a professional.

[Zithlord]

I am serious Nick, in first gear and the throttle at idle the wheel is spinning quite slow and there is no risk loosing fingers. I was more worried about the mechanicals. The rims are already stripped, this job I am doing is the polishing bit.

Thanks for your concern anyway !

John

[JohnT]

Does the car have a no-spin?

Otherwise when you apply pressure to the wheel won't the power go to the opposite one? If you block the opposite wheel, then the wheel you are polishing will turn twice as fast (that is the nature of differentials).

johnt

[CurtEgerer]

I've heard of at least one other (unnamed ) individual who has used this method. I'm told it works well ...... Myself, I like to keep the rubber on the ground as often as possible.

[Zithlord]

I have now returned from my garage and it worked very well. The pressure of the sandpaper and polish cloth is no so great that the wheel stops spinning because of the diff. It saves me a lot of time. These rims had some pretty bad and deep scratches and now their gone. I used 200, 400, 600, 800, 1000 and polish. I used wd40 to sand "wet"

I do have a "metal working machine" not sure what it’s called in English, but it spins and you can use cutters to from the part. Sadly enough the rims was a little bit too wide to fit in the machine, that’s why I came up with the "using the car" idea.

John

[LeafGreen]

This isn't so crazy (at least to me). I remember about 20 yrs ago there was a special brake lathe that was used on a certain model Honda that turns the rotors right on the car. Silly to think Honda rotors are that hard to get off, anyway... Regarding your concern, it should be no big deal as long as you don't go too fast. The thing that kills spider gears is the one legged burnout - and we've all done that a time or two on dad's wagon without any immediate damage to the rear end. Heck, Porsche made tractors, why not a lathe?

I happened to find one here: http://www.drivewerks.com/catalog/sh...CAT263_pg9.htm

[911pcars]

"I remember about 20 yrs ago there was a special brake lathe that was used on a certain model Honda that turns the rotors right on the car. Silly to think Honda rotors are that hard to get off, anyway..."

Alex,
Honda Civic. I forget what year (in the 80s), but I created some training materials for them using the car-mount rotor grinder you mentioned. It was so long ago, the state-of-the-art training medium at the time was filmstrip and cassette tape. It wasn't that they couldn't or didn't want to remove the rotors. It was to minimize any rotor runout that would cause pedal pulsations. If the rotors remained on the car, the brake lathe would grind the rotor sides parallel despite manufacturing variations. Honda received customer feedback regarding pedal vibration/pulsation and this was their solution.

Sherwood