I'm looking to run an Eaton 1 ton rear in my K-10 I'm lifting this winter. I've been told they come with 4.88's, or 5.13's standard. My question is : Is this only with the 4wd versions, or did the 2wd trucks with these axles have the same gears? Any help wpuld be appreciated.

I got mt Eaton from a 64 3/4 ton Chevy 2wd. It had 4.56's and was open, but not anymore buzz, buzz, lincoln locked :D

I had one I sold a while ago that was 4.10, and occasionally you can find them in 3.90, but usually it is 4.56 and 5.13

The only difference in the 2wd and 4wd versions *should* be - the 2wd used coils and the 4wd used springs. 4.57 or 5.14's are the norm w/ 4.10's scarce. They sell aftermarket 3.90 and 4.10 gears.

most are the 4.56 but i have about 25 of them . if you are lucky you can find one with factory no-spin . my s-10 also has the buzz-buzz locker the highest gear was a 3.73 my 1972 k-20 came factory with that (that gear hard to find ) except in your eariy big-block trks they are good axles

Thanks for the help. I guess I will buy the 2 axles from my uncle then.

what size ring gear does an eaton have anyway?

12.25" ring gear

Randy's Ring and Pinion sells the 3.90 and 4.10 gears

....And it's 4.57 :p

A guy is selling a Detroit and 5.13 in the for sale section on this board for 300 bucks

Do most come with limited slips, or are they open?

Zero came with limited slips.

If you will re-read the above posts, you will see that most are open, and that very few came with the Detroit Locker

Sorry to offend thee, old wise one!

None taken.

Just read next time:p

The 1 ton eatons came with 10.5" ring gears. The 12.25" ring gear eatons came in C40s or 1.5 ton trucks. The 3/4 ton and 1 ton trucks used the same size ring gears but had different size brakes.

Originally posted by 70~K5
The 1 ton eatons came with 10.5" ring gears. The 12.25" ring gear eatons came in C40s or 1.5 ton trucks.

Never heard that before...score another f-up for Petersens 4Wheel:rolleyes:

Originally posted by reddwarf


Never heard that before...score another f-up for Petersens 4Wheel:rolleyes:

To back up what I wrote, I pulled out one of my Chevy Service Manuals. The 12.25" GM Corp. axle, what most here refer to as a Eaton is rated at 11,000 lbs weight capacity. The rear of a 1 ton truck is rated a 7,500 lbs per my '95 Dually C3500 data tag.

Originally posted by 70~K5


To back up what I wrote, I pulled out one of my Chevy Service Manuals. The 12.25" GM Corp. axle, what most here refer to as a Eaton is rated at 11,000 lbs weight capacity. The rear of a 1 ton truck is rated a 7,500 lbs per my '95 Dually C3500 data tag.

Mine is rated at 17,000 - it's got the pinion load bolt :D

Are the Eaton Rears Full Floaters? Are they tough? Dependable? Easy to rebuild?

Any info would be appreciated, I am thinking about buying a truck with one in it.

Originally posted by MYTZUK
Are the Eaton Rears Full Floaters? Are they tough? Dependable? Easy to rebuild?

Any info would be appreciated, I am thinking about buying a truck with one in it.

Yes they are FF. The are incredibly strong. The shafts are a hair larger in diameter than a 14 bolt. But locker selection sucks. If you can find a used detroit grab it - they aren't made anymore. You're only other option is to weld it up.

If you have a 10.5" ring gear Eaton you can use a DL for a 14B but you have to use the axle shafts from a 14B to as they're fine spline and the eaton uses coarse spline axles stock.

What is a good donor truck to look for Eatons under???

My Uncle has a heavy equipment scrap yard with tons of one ton plus service trucks by Chevy, GM, International, Dodge, and Ford....most are dually rears....a few are 4x4 and have huge T/C's with huge round front diff's...I've never really paid much attention to them....but this thread has me thinking now since 60's are to much and these could be cheap...

Thanks.

Look for a 3/4 ton 4x4 chevy from '62 to '72.