short gears and tall tires ?

[85_IDI_4x4]

i have read that running gears shorter than 4.10 or tires taller than 35" can cause pinion failure in the 10.25. I know some guys on here have done one or both of the above and wonder how there pinions are holding up.
I have a project i slowly am building and plan on running at least 4.10 gears and tires in the 38" to 44" range. It is an offroad only toy so cruising speed does not matter. Only getting through mud and down trails and up hills. It is a 6.9 with a t19 and sterling 10.25 axles. Dont know what tcase, only that its a BW. Any suggestions on what gears would be a good choice would be appreciated.

 

[91dirtydiesel]

My 10.25 is out of a 97 and it is 410. My truck isn't very fast off the line but I have decent power/mileage with my 38.5s. No problems with the pinion, but I would like to run 4.88 or bigger gears. Since your offroad then u should probably go bigger then 410 with that tire size

 

[blown84]

^^^agreed. 4.56s would be your best bet with that combo.

 

[MUDKICKR]

i have a sterling 10.25 rear axle setup with 4.56 gears and its also a factory posi. when the gears where installed it was completely rebuilt with all new bearings and clutches. also have a set of 4.56 gears for a frt dana 50 if your interested in them. i ran the gears with a set of 37s and a zf5 and i think they were great for towing and driving.

 

[snaponprofile]

How do 4.10's do with 33 inch tires?

 

[Brianedwardss]

How do 4.10's do with 33 inch tires?

Great combo, especially on a truck with overdrive

 

[snaponprofile]

Nice, I will soon have some alcoas w/ 33 tires.

 

[gonecrazyi]

I've got 385/85/16s on mine. A little slow on take off but oncethe Turbo spools she takes right off.

 

[snaponprofile]

I've got 385/85/16s on mine. A little slow on take off but oncethe Turbo spools she takes right off.

ZF5 or auto?

 

[gonecrazyi]

Zf . The auto may actually be a bit quicker than the 5 speed.

 

[snaponprofile]

Oh, I am swapping out my auto for a ZF5.

 

[Dieselcrawler]

For wheeling I LOVE my 4.10 gears and 40 inch rubber. Low range is great, crawls good. Never had issues with pinions

 

[gonecrazyi]

You'll be fine. I plan to find a 460 5 speed. I like the gear splits better.

 

[85_IDI_4x4]

alrighty guess ill be going with either 4.56 or 4.88. Randys r&p has good price on the not quiet kind lol im not sure what kind of locker yet, either a detriot or a lsd without clutches.
To make it confusing it will be running 2 sterling axles, one front and one rear. Its going to be articulated in the middle and have a boom and winch off the back half to pull stuff out with. Found a guy in farmshow who did something similar only his was a field sprayer

 

[jam0o0]

i've got 38"s and 5.13 gears in my bronco. it doesn't have pinion problems

i've got 4.10's and 32's on my IDI. it's got 270k with no problems.