gear change

[oldmechanic]

does anyone know if a 3.42 ring gear can be used on a 4.10 carrier with no problems?
OM

[DmaxMaverick]

It depends on the axle and where you source the parts. GM 3.42 gears will not fit a GM 10.5" carrier (presuming that's what you intend). Randy's Ring and Pinion offers a kit to do that (the only one I know of), but I don't know if it requires the carrier. If you mean the GM 9.5" axle (2500LD/7200 GVWR, but not all of them), then you can use the GM 3.42 gear set for that axle. If you have a 3500, or 2500 (HD/8600 GVWR), then it's a 10.5", which was never optioned with gears higher than 3.73.

It's fairly confusing once you look into all the possible combinations, exclusions, and year to year changes.

[oldmechanic]

I have 1992 c2500 that the rpo shows to have gu6 3.42 axle I also have 93
gmc c2500 with a gt5 4.10 & a g80 limited slip & I want to put the 3.42 gear on the limited slip carrier
Thanks OM

[DmaxMaverick]

I don't think it will work. Your 92 with 3.42, is it a full floater? (it shouldn't be). It should be a 7200 GVWR, with the semi-floater (9.5", I think). They aren't interchangeable with the 10.5" full floater, regardless of the gear sets.

[Nebraska farm boy]

I have 1992 c2500 that the rpo shows to have gu6 3.42 axle I also have 93
gmc c2500 with a gt5 4.10 & a g80 limited slip & I want to put the 3.42 gear on the limited slip carrier
Thanks OM

Depending on which rear depends on what you can do. 3/4s can have the 10.5 or the 9.5. The 10.5 is also called the 14 bolt Full Floater. To identify this easy look under your hub cap. If you can see the center hub has a second set of 8 bolts on it, it is a full floater. A 9.5 will just have a hub like a 1/2 ton with no external hub. The split on a 10.5 is 4.10 and above so any other gear will fit with a lower ratio than 4.10. Not sure on the 9.5.

[oldmechanic]

they are both 10.5 full floaters

[Nebraska farm boy]

Then yes you can put a 3.42 on a 4.10 carrier.

[oldmechanic]

thanks for all the info,if I had explained what I wanted in the first post it would have saved time, thanks again