Over the phone diagnosis shaking / hopping

[sope]

A friend of mine phoned me last night telling me that his 86 2500 with a C clip 14 bolt intermittantly shakes violently, usually around 40 MPH My first guesses were bad tire, siezed U joint or bad carrier bearings in the rear. He checked all those things and says they are OK. From his description of the carrier saying there are small clock like springs in it, it sounds to me like he has a Gov Lock. I have no experience with these. Is it possible it could be causing the problem? He says there is no visible problem inside the diff. Any other idea's. Like I said I have not seen it nor will I have time to have a look any time soon. I should add the shaking is not in the steering.

 

[dyeager535]

Gov-lock will *typically* only give you problems when turning, if they stay locked up you will get some wheel hop depending on turning speed and how sharp the corner is.

As fast as the carrier turns, were it the gov lock, I'd expect it to not be intermittent.

 

[sope]

Thanks for the reply. He just phoned me and it turnes out it was a bad U joint. The first thing I told him to check.