Sorry for stupid

[Burn]

Was doing some reading on gears and axles, I know the H3 has 4.56. I'm running 285's want to run 315's thought I might have to rear gear to get the RPM's back right. My stupid question is do the front and rear need to be geared the same (4.56/4.56) or can you have (4.56/4.88 or 5.13). I don't think the front will take anything larger than 4.56. Or can I just run the larger tires and reset the ecu to accommodate.
thanks

 

[f5moab]

Yes, you have to have the same gears in front and rear axles. And I do believe 4.56 is the max in the front. And it is not a dumb question if you ask first. Dumb is asking how to repair the axle(s) after the fact.:giggle:

 

[Burn]

Yeah, maybe I should just go with some new 285's but man I love the way the 315's look, filling in that space. Thanks

 

[alrock]

315s work fine without regearing; many people run with them. I believe the performance dropoff is more noticeable for those that have shoehorned 37s onto their H3s.

You can always compromise and run 305/70-16, essentially a wider 33"

 

[08H3]

315's w/ PCM tune will get you back really close to stock performance.

 

[LagunaH1]

You will notice a change in off the line acceleration and your gas mileage will change, but that's just part of the "cost" of bigger tires. You will, of course, also gain some amount of capability off road.

 

[mkmcgreg]

Does the adventure and base models have different gearing to compensate for the different size tires from the factory?
I ask because I have a base with 33"s and wonder if I can regear it up to an adventure package and gain some performance back

 

[jakesz28]

If it has the 5.3L it has 4.10 gears. If it is the 3.5 or 3.7L you have 4.56 gears.

 

[amrg]

the 5.3L can be regeared to 4.56 I believe. Although no one seems to have done it.

 

[08H3]

the 5.3L can be regeared to 4.56 I believe. Although no one seems to have done it.

That's correct. There is no difference between the Alpha and 5 cyl diffs other than the material. I have an Alpha carrier in mine with the 4.56 gears.

*By "carrier" I mean the pumpkin. GM actually defines the carrier differently.

 

[alrock]

And no, there's no difference in diff gearing between Adventure (33") and base (32")

 

[Burn]

Thanks everyone, lot of good people on this board.

 

[4speedfunk]

I think Kflips re-geared his Alpha to 4.56.