30th t/a

iTrader: (51)

I have 12 bolt Moser rearend in my Ws6. This rearend was rebuilt back in 2016. I have put 4000 miles on it and have no issues with at all.
I have 3.73s and want to change to 3.90s.
Here are my questions:

1. Can I reuse the bearings that are currently pressed onto the carrier since they only have 4k miles on them ?

2. I found a used 3.90 ring and pinion. Looks to be in great shape for $200. Would it be fine to swap it in or spend $485 on a new ring and pinion?

Thanks

FirstYrLS1Z

iTrader: (4)

1) If the bearings look 'perfect', no pitting,however slight, on the rollers or races, OK. I've re-used used carrier bearings with no issues
2) setting up a used gear set is no different than setting up a new set, pattern,pattern,pattern. A used set, since it has already a wear in pattern, could end up with some noise. I set up used sets for maximum centered contact pattern for the best widest pattern. The used 4.56 set I picked up at Canfield swap meet for my Z is still going strong/fine after 17 years. Initially there was some noise on 'coast' but steadily decreased with time as it established its' own wear in pattern.

SteveC

IF the 3.90 used gears are in good shape use them, send them out first to be "Cryod", it should not cost more than $100 (now adays) to do this. JMHO (don't kill the messenger)

wannafbody

iTrader: (2)

For the cost of gears, $250 or so, I wouldn't risk a used set unless your budget is really tight.

LilJayV10

iTrader: (39)

Where are you buying gears at for $250 and for what rearend?

I bought a set of Motive's for my 7.5 earlier this year and they were like $450.

wannafbody

iTrader: (2)

https://www.summitracing.com/parts/sum-741204

I wasn't aware the name brand gears had gone up that much in price. Motives were $354 and I'd avoid them. I had two sets howl in my Mustang 8.8 rear end.

2QWK4RU 06 GOAT

iTrader: (1)

Carrier bearings are fine should you be using same carrier and the preload was set correctly on the first go around.

Used gears are not for newbie installers who have limited experience and shims available on hand. In the end, they can be installled and work fine or with some minor annoyances. Assuming the pattern shows decent enough.

Good luck.