Rear gear change

[eventhorizon66]

What's a reasonable price for a gear change (3.08 to 3.73), Auburn posi, bearings, installation/setup, etc?  I had reputable shop quote me $1150.  Assuming that the parts cost around $800 (approx. based on summit prices) that puts labor at $350 (for about 4 hours).

[VileZambonie]

If they do it correctly then that's on par. If they are reputable make sure they are reputable in setting up final drives. I usually charge about $350 in labor to set up a 10 or 12 bolt. For a friend I'd do a lot better though so you can save some coin if you buy the parts yourself and find someone who knows how to do it right and pay them on the side.

[eventhorizon66]

Thanks for the reply.  Unfortunately I don't know of anyone else, so I'll have to bite the bullet on this one.

[VileZambonie]

where do you live

[eventhorizon66]

The shop I'm referring to is Pyle Bros in Baytown.

[HAULIN IT]

Hey, My wife has family in Baytown. Went there to visit once, came home a week before the whole terrorist plane thing. I was in Texas about an hour & started seeing drag cars going down the highway, turned out Houston Raceway was about 10 minutes from where they live. I never got unpacked, went straight there. I have to agree, a few hundred labor is about right. Lorne

[eventhorizon66]

Another related question: I've heard that driveshaft vibrations sometimes rear their ugly head after a dramatic increase in rear gearing.  I realize this is kind of a "it depends" sort of situation, but what is the likelihood of me having to rebalance the driveshaft after the gear change?  What would be a reasonable price for this?

[HAULIN IT]

Really that sounds like a cop-out for a drone from improperly set-up gears. If the driveshaft was balanced true before the gear change, the only way I see something showing up that is truly in the balance of the shaft, would be that you have changed the "sweet spot" your now running at, say cruise speed, however that spot would have still been there if you had sped up the same RPM's your now going, understand? I think $30-$40 would do it. Maybe others will have a different thought, Lorne 

[eventhorizon66]

Thanks for the response HAULIN IT.  It never really made any sense to me, either, why a gear change could cause driveshaft vibrations.  Like you said it's not like the shaft is suddenly experiencing much higher rpms than it could have reached with with the old gears.  Maybe the people that have this problem always had a balance problem but the new lower gears just make the problem much more apparent as the engine revs free-er or the engines new "sweet spot" falls on the point where the vibrations occur (like you said).  At any rate I'm not gonna lose any sleep worrying about it, I just wanted to know if anyone has ever heard of this.  I just hope I didn't knock the driveshaft out of balance with all the times I've hit it with my head, LOL.