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Posted by Joe Johnson.   [PICTURE: SAME | NEW | HELP]


Engineer on team #47, Chief Delphi, from Pontiac Central High School and Delphi Automotive Systems.

Posted on 4/2/2000 7:51 PM MST


In Reply to: Re: EXACT Same problem seen on the mystery machine posted by Travis Covington on 4/2/2000 11:32 AM MST:



Have you actually backdriven the wheels on the two sides to get a feel for whether or not something is causing a hang up on the bad side?

Backdrive effort is a pretty good method to judge efficiency of gear trains.

Also, have you tried switching the left and right side wiring so that you can judge if this is an electrical or a mechanical problem?

This is not a fool proof method. As it turned out on the Mystery Machine they had multiple problems that caused us to be confused by this technique --- actually, this is probably worth going over --

Like you, they had one wheel (the left side) that would not go under load. We found that it was tripping the breaker. When we switched the wires from side to side, the right side would not go under load.

As it turns out, ,they had binds in BOTH sides of their drivetrain (bad bevel gear bearing design, I hate bevel gears ;-).

Anyway, we were prevented from finding it because
1) they had not removed the no-backdrive pins from the transmissions and
2) they had a bad electrical connection on the motor that did NOT trip the fuse.

The bad connect caused high resistance that kept the RIGHT side from tripping the fuse. We kept looking for trouble in the wiring on the LEFT side (replacing the whole side piece by piece and then entirely). It really took a lot to discover that there were several problems causing the strange behavior.

I'll try to stop by the pits in FL to see if you have fixed the problem. I am sure that you will have more help than you can really use, but I will stop by just in case.

Good luck.

Joe J.