Well i went in to get an estimate fir my pinion bearing at a local shop today and they said i would need a new ring and pinion also because when the pinion bearing starts to get loose it destroys the gears. Is that true?
As far as if you will have to replace gears, it depends what happened to the gears when the bearing went out. They can throw a lot of metal out that will ruin gears.
You would not need new bearings but I would replace, especially if the pinion bearing was spitting out metal shavings. The shop will probably have to pull them off anyways when playing with shims for backlash.
The only way the R&P would be damaged is if the bearings are so bad the pinion has noticeable movement. At that point the gears would wear funny until something failed, or the pinion could get sucked into the carrier. If that happened at high speeds it would be catastrophic. At low speeds it would probably lock the gear set up and leave some nice teeth marks in the carrier, but leave the pinion undamaged.
It takes a lot to destroy a R&P. Some metal shavings certainly aren't going to do it. What metal shavings will do though is kill other bearings so it is wise to replace all bearings.
CU Boulder Aerospace Engineering
I had my bearings changed out in my rear diff when I got my jeep earlier this year and it ran me about $500 here in Pensacola. If you don't mind coming here there is a shop in town that normally charges $250 per axle for labor in regearing. Considering you're not doing that and just replacing the bearings it may be considerably cheaper as I think my bearings cost me about $100 and then your fluid. Change them all out while you're in there. It's like replacing a clutch... Change it all out since you have to drop the tranny anyway. Got my bearing kit at advance auto parts. The shop is called winged wheel garage and apparently does quality work.
2001 Jeep Wrangler Sahara Edition
4" Zone Suspension Lift Goodyear MTR 35s
Black Rock 909 D Rims
I6 4.0L 5 speed 3.73 gears
And more mods to come