Well i orderd some new gears for my truck and come to find out i have the 10.5" rear (after i tore it all apart of course)

Every website i found swore i had the 9.5" so i like a fool trusted them.

Now i have not tore into my front end yet so i was hoping you guys could help me with an easy way to identify the front end on my truck.

I have the gearing for an 8.25" IFS so i hope to god that is the one i have.


Thanks in advance,

If you have the 10.5 rear you will have the 9.25 front.

Thanks.

Guess i learned a lesson.

Yep, you will have the 9.25" front. I am suprised that the websites would say you had the 9.5 Rear diff. As a 3/4 ton Suburban with a diesel, I'd have automatically thought that you had the 10.5 rear diff.

Do tell;

Ordered gears from who? Where? I really want to get away from my 4:10's. I never tow anything. Which ratio did you choose?

Thank you.

If you never tow a 3.42 is plenty of gear. May want to even consider a 3.08 or so.

I talked with Bill from Heath's at length about this and he claimed that TIRES have the biggest impact on fuel mileage. Big Monster mudders with horrible rolling resistance being bad, stock ones with good rolling resistance being good. I plan on doing some testing with tall skinny ones, once i wear this set out.

I had originally wanted to go with 3.42's but he basically talked me out of them saying it would down shift like crazy if i ever went over hills and such. He said 3.73 was the correct ratio, which puts the engine at about 2000 RPM, with stock tires. This 2000 RPM, he said, was the 6.5's sweet spot. Being a mechanic myself i had thought that lower RPM = Less fuel = better mileage. We also talked about how lower (meaning smaller numerically) gears effect take off speed as well, that being they make you take off like a grandpa even at full throttle.

I don't plan on doing any towing so i may go with the 3.42's now, I'm still torn.


As for gears, i got mine from a place in Cali called Progear. They are an after market shop that sold me some used OEM ones at a VERY reasonable price. Nice part about OEM gears is they claim you don't need to re shim the rear end.

Any thoughts?

Nice part about OEM gears is they claim you don't need to re shim the rear end.
Any thoughts?

Maybe just me - But I'd check the lash anyway.
They're used gears and may have some wear.

OTOH - I'm fairly sure that even new OEM gears may need some adjustment (?) There are a lot of possible variables (due to tolerances) in something the size of a rear end.
PLEASE correct me if I'm wrong... Not sure if I've ever put in new OEM gears. Usually junkyard parts for me. OOPS - Salvage Yards these days;)