Converting 293 Gears To 342 In An 8 5 GM Differential

[@p9raceway759]

Great seeing you driving it. Setbacks. Scratch your head. Overcome. Pride of doing it yourself. Priceless.

[@tj484]

ya i tryed a 373 in my nova a little to low.was running 3000 at 55mph so went to a 342 just right.the 373 is a good quarter mile gear for sure

[@Danno74Z]

Hi Steve, I did a rear end gear change in my 8.5" and that turned ugly real fast. Initially I was going to check the right rear wheel bearing because it was making noise. Easy Right. Not so fast! I drained the oil (previous owner told me the diff was worked on) and need to removed the pinion cross shaft bolt. Put a wrench on it and it just loosened with little effort. Weird. whoever worked on the diff snapped that pin and just put it back!!!! I know the previous owner and he did not know that. I trust him. I tried everything to get that pin out. Even a tool designed to remove the broken pin. Nothing worked. Talk about being depressed. Called a couple of rear end shops and all said good luck! What a nightmare. I covered everything like an operation room and used a Dremel tool and cut out the pin that was stuck and totally destroyed the open differential that was in there. Replaced everything and went with an Eaton Posi and new ring and pinion. My God....Just to check a wheel bearing noise. Just have to laugh!

[@stevesgarage7644]

Wow! That is insane brother! I fear I may need to swap out my entire diff also. Gears still make noise so I may just drop in a 12 bolt and be done with it.

[@Danno74Z]

@@stevesgarage7644 Steve, When you replaced your ring and pinion did you replace all the bearings and races? Carrier bearings and the pinion bearings? Along with a new crush sleeve? That crush sleeve pre-load was ridiculous to achieve. 14-19 inch pounds. I had a 3' breaker bar with a section of pipe on it. Had to hit 300 foot pounds to crush the sleeve then measure. Not enough then try again still not enough try a third time went over!! Come on man give me a break. Luckily my install kit from Yukon came with 2 crush sleeves like they know your going to screw up. So I did it over again but still went over to 22 inch pounds. Forget it!! I back the big nut off ever so slightly and hit 15 in/lb. If that makes the bearings fail I'll buy something else! Really like you car man.

[@theshark2804]

This was with 5.5 bs right? I have to get a posi kit for my nova as well. The lips are already trimmed and i plan on running the same gears as you. This will be a tough one.

[@stevesgarage7644]

Yes, correct. 5.5" bs.

[@tj484]

the 373 is good if your going to use a 700r tans.nut for a th350 trans to low for the dayley driver.its a good qurter mile gear.and im rummimg a 275/60/15 tire

[@tj484]

ya a 8in wheel with a 5.5 backset will just work to get them tires under her

[@tj484]

theres a math formuly for fig out the gear and RPM RANGES

[@theshark2804]

@@tj484 im running a th400. I didnt have any plans for 373 gears.

[@stanmendoza7871]

Hey Steve haven't seen any post in a while hope all is well! Did you solve the tire fitment problem? You mentioned you might trim the fender lip for clearance. I'm having the same problem with my tire fitment and was thinking of trimming 1/8" to 3/16ths of fender lip instead of a smaller tire size.

[@stevesgarage7644]

Sorry, I missed the notification on this. Yes I did trim it some but not very much to make a huge difference. I had to put in some coilovers to raise it about a half inch and that helped a lot.

[@tj484]

TRYED TRIMMING MINE STILL RUBS

[@stevesgarage7644]

Just a thought. Check your leaf spring bushings and see if they're rotted. Mine were and it caused too much play side to side causing some rubbing as well.

[@tj484]

@@stevesgarage7644 ya there not to good