K30 CUCV ring and pinion swap.

[84 M1008]

Gentlemen, please excuse my ignorance, but I would like to know if I can put a 3.73 ring and pinion in this thing. I put a dually front axle in it last summer and it has a 3.73 gear set in it which is exactly what I wanted to lower the rpms for highway driving. Question is, will this carrier with the Detroit locker accept a 3.73 ring gear. I am confused as to what the carrier break is on this rear end. The CUCV's had the corporate rear in them if that makes a difference. Thanks.

 

[QBuff02]

the carrier in the axle if it is a true cucv with 4.56 gears will not work. The split on the carriers is 4.10 and down and 4.56 and up. If your truck happens to have 4.10's in it then you can put 3.73's in without much fuss. If it has 4.56's you'll need a different carrier. However, you can find gear sets with thicker ring gears or ring gear spacers to keep the lower gearing carrier but not every axle or manufacturer has them. You'll have to look and see what's available.

 

[84 M1008]

QBuff02, thanks for the response. It is a true CUCV. The front axle I took out of it had 4.10 gears in it, so somebody messed with it. The whole axle was totally trashed so I swapped it out for the dually axle. I'll have to pinch the rear cover off and find out what it has. If the rear has the 4.56 gears, that would explain why the front axle pinion bearing went south. Thanks for the info.

 

[nvrenuf]

The Detroit Locker from the CUCV carrier will transfer over to the new carrier for the 3.73’s.

 

[nvrenuf]

the carrier in the axle if it is a true cucv with 4.56 gears will not work. The split on the carriers is 4.10 and down and 4.56 and up. If your truck happens to have 4.10's in it then you can put 3.73's in without much fuss. If it has 4.56's you'll need a different carrier. However, you can find gear sets with thicker ring gears or ring gear spacers to keep the lower gearing carrier but not every axle or manufacturer has them. You'll have to look and see what's available.

Actually, I believe it’s the opposite for spacers. Since lower ratios have a smaller pinion the ring flange is closer to the pinion center line. A spacer would work for putting a (regular) 4.56 on a 4.10 carrier.