What to look for when buying used axles?

[adaml23]

Ok, so I figured I'd start another thread in this section instead of continuing my last one and just give an update on where I'm at.

So I'm in the early stages of rebuilding a truck and was planning on going with 3/4 ton 3.42 gears. But, through talking with some guys around my area, they highly suggested 3.73s. Also, I was planning on getting a FF axle but am pretty sure they don't come with 3.42 gears. So, I've changed gears (get it ) and have been looking for 3.73s and found a place that's got a bunch of different axles that I'm gonna have to go thru and hopefully find a set of them in 8 lug this weekend.

So my question is to all the axle gurus out there. What should I be looking at when I go this weekend? I know how to tell if they're 3.73s, 8 lug and FF rear and 10 bolt corp. front, but how do I know if they're any good? Leaks? How to tell if the brake hubs are any good? All that stuff. Thoughts?

Oh, yea one more thing: Sounds like they're gonna want ~$100 for the front axle and ~$150-175 for a 14b FF rear. These are good prices right?

 

[flyboy1100]

pull the covers and check the gears. should be able to either count teeth, see markings, and check condition.

price seems OK since you will probably be doing a full rebuild on it anyway

 

[adaml23]

Why do you say I will be doing a full rebuild? I'm going to try and check these out and find out if they're good enough NOT to have to do a rebuild on them (not right away at least). How do I find out if they're good enough to just plug right in to my truck?

 

[flyboy1100]

Why do you say I will be doing a full rebuild? I'm going to try and check these out and find out if they're good enough NOT to have to do a rebuild on them (not right away at least). How do I find out if they're good enough to just plug right in to my truck?

Tear them apart and inspect. Only way to know, especially if they have been sitting in a yard. Might get lucky, might not.
Can you get a 14FF with 3.73? Seems high to me

Axles in yards around me are cores only and more expensive. I ended up just rebuilding my 10bolt because i didn't have a place my truck could sit for weeks while i found time to convert.

 

[adaml23]

Tear them apart and inspect. Only way to know, especially if they have been sitting in a yard. Might get lucky, might not.
Can you get a 14FF with 3.73? Seems high to me

They're not coming out of a yard. They are from a lawn care company that used to scrap vehicles on the side (random, I know, but whatever). The lawn care service, at this point, just trying to get rid of their "junk". I do agree about getting lucky or not, but I think I got a better chance with these than with a junkyard set. Here's the picture I got off their website:

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Can you get a 14FF with 3.73? Seems high to me

Also, I'm not sure what you mean by this comment? I'm pretty sure you can get them in 3.73s, if that's what you mean. Thought that 3.73s were a pretty standard option after 1980-ish. Please correct me if I'm wrong or if that's not what you meant.

I've got a guy here in town that wants $400 for a set of axles. Front and rear are from different trucks though. Is that a better option?

 

[Don5]

If you are buying them used, ask if you can see inside. Check for numbers designating gear ratio. You might get lucky and find a LSD in there. I would take a 3/8 ratchet and a couple of sockets. I would not buy anything unless I can pull a cover and look at the ring gear and the ratio.

BTW- I never have heard of 3:42 being offered in 3/4 ton. Doesn't mean it didn't happen but just that I have never heard or seen one. Good luck in your search.

 

[adaml23]

First, thanks for your guys' help with this stuff... don't know where I'd be without it.

Second, what LSD options were there? Or what should I be looking for? Have any pics?

In doing some searching, I think I found a thread talking about this stuff but not quite sure if these are what I should be looking for:

http://www.gmsquarebody.com/forum/showthread.php?t=6100&highlight=limited+slip

Am I correct in saying the detroit eatons in posts #2 and #3 from HotrodPC are what your saying I'd be lucky to score? Are the G80 locking diffs worth grabbing over the open carriers?

Again thanks for all your guys' input here with the "new guy"

 

[flyboy1100]

G80? Probably not. Better off getting aftermarket if you want something reliable

 

[Jacknife]

Yes you can find 3:73 or 3:42 in 14 bolt FF. Amazed the hell out of me but actually came across a set of 3/4 ton rears the other day with 2:73 gears. Yes 14 bolt FF rear & Gm corp 10 bolt up front. I have heard of 2:73 in 1/2 ton 4x4 but the highest I had ever seen was a 3:08 in a 4x4 1/2 ton & 3:42 being the highest I ever seen in 3/4 ton until now.
Of course you need to make sure the front & rear are same gear ratio to start with. Look at spring perch ( where spring set on rear ) bad to rust out there where center bolt sits but can be repaired. Try to brake loose the oil fill plug I have ran into those really sieze up before. Look at Yoke on rears where u-joints go I have seen those damaged, wore out & egg shaped, or strap bolts broke off in them. Turn the yoke by hand back and forth to get a feel of how much slack is present in the gears. Front seal will most likely be leaking a little in used rears.
If all that appears acceptable remove cover. There will be rust above the oil level which is normal if been sitting very long & I am sure they have. Don't be to alarmed over a little surface rust, but you will have to decided what is acceptable & whats not. Inspect carefully should even have a flashlight & a few rags. Look for broke or chipped teeth on ring gear & pinion. If brakes are stuck it will be a bitch to rotate & get a good visual. Even if all checks out you may put it in & have a bad bearing or something.
Would be a great advantage to take someone alone with that is familar with rearends, and to even manually give a hand.
I usally plan on having to replace brakes, wheel cylinders, etc.
Deciding what gear ratio you want is determined by many factors. What you intended to do with this truck, what trans you have, what size tires you plan to run, what kind of rpms your comfortable with.
Good Luck, hope you find what you want,
Also pay attention that it is not 14 bolt for a daully cause they are not as wide.