PDA

View Full Version : 14 bolt question


darkroad
05-09-2005, 14:07
I have a question about swapping gears in a 10.5 14 bolt rear end. I have a 1985 10.4 14 bolt rear end that is currently set up for 4:10 gears. I want to swap in under my 1990 suburban which has a 14 bolt 9.5 4:10 gearing. My question is can I swap 3:42 gears onto the 10.5 carrier that now has the 4:10 gears or do I need a new carrier? Also am I going to have to change my rear driveshaft to accomplish this swap. I really want to go to the full floating rear end for the added weight carrying capacity.


Thanks

darkroad
More Power
05-09-2005, 16:43
Contact Randy's Ring & Pinion (http://www.ringpinion.com) about the gear swap, but I'd bet you can put 3.42 gears on a differential carrier that had 4.10's.

Surprisingly, the bigger 10-1/2" full-floating rear axle will require a rear driveshaft about 1" longer than what the 9-1/2" semi-floater requires. The FF has a shorter pinion snout.

Some have made the swap to a FF from a SF, and didn't lengthen the driveshaft, but you've got less spline engagement that way. Your call... I'd get it lengthened...

MP
NH2112
05-09-2005, 17:37
Is gearing up to 3.42 in a truck that you plan on carrying more weight with a good idea? Perhaps 3.73 would be a better idea.
darkroad
05-09-2005, 18:04
Hi Main reason I like the 10.5 is that I already have one with about 5000 miles and a total bearing and seal rebuild kit already bought for it left over from a previous project. I would gain larger brakes and like the free floating axles. If I rebuild my 9.5 it got over 200k miles on it and is getting kind of loose so I figure a complete rebuild. Turbo is in the works and already have gear drive for cam and complete serpentine belt set up so I can upgrade cooling. Also have a low milage dana 60 front axle too in case I want to swap it out also. Too many projects and not enough time. Thanks for the reply


darkroad
jcomp
05-10-2005, 13:00
I believe that 4.10 and up (numerically lower) use a different carrier than 4.56 and down.

I also question the judgement of going to that high of a gear.
More Power
05-10-2005, 18:20
If heavy towing is done with 3.42's it'll be done in direct.

Lil Red has 3.42 gears, 31.7" diameter tires and a .75 OD. 80-mph is about 2000-rpm.

MP