Rear axle woes

[lukecp]

Well, my 12 bolt rear in my '72 C10 started howling pretty bad the other day. I was on the highway, and i noticed a whining noise coming from the rear of the truck. I drove the rest of the way home, parked the truck, and forgot about it. I drove it again, and it was still there. So i topped off the rear axle, and it was about half a quart of gear oil low (leaks through the pinion seal farily bad). It quieted it down a little bit, but the howling is still there.

I am really sure it is the rear axle. If i stick my head out the window, i can clearly hear it coming from the rear of the truck. The noise is there regradless of what speed the truck is going. If i put the truck in neutral and coast, it is still there. If i put the truck in a different gear, the noise has the same tone, although it is hard to hear it over the exhaust. It is also there on all road types (asphalt, concrete, gravel). It seems the worst when i am slowing down, but it is proably because i can then hear it over my loud exhaust.

So, any guesses on how long i can keep driving the truck before i need a new rear? This one has at least 200k miles on it, enought to wear out 2 350's and put 30k on another. I know it won't be too big of a deal to change over to a junkyard unit, but i really don't want my rear crapping out on me on a dark night. The truck is my only mode of transportaion, and i use it to drive home from college about every other weekend, so i need to keep driving it until at least Christmas time, when i will have the time to swap in another rear, or look for a cheap econobox to putt me around.

[fast71]

sounds like the outer pinion bearing is shot . you should be able to have that fixed

[Longhorn Man]

<---hmmmm...I wonder why your rear end is shot? (I had to...I get this all the time too)

[lukecp]

Lol longhorn....i do alot of that

Well, if the outer pinion bearing is shot, about how much would it cost to get that fixed? Since i should be able to find a junkyard rear pretty cheap.....and then i could upgrade to 3.73 gears if i wanted too.....
I really don't want to throw very much money into the truck right now. It may just get parked for a while if i can find a cheap econbox beater to putt me around in.....

[jhwkns]

Lucas.. Are you sure it's not a universal joint?

[Nova_Cobra64]

If I have anything to say at all, don't ever expect something in the rear end to be an easy fix until it's all apart. My crown and pinion swap ended up being a complete job. The carrier was shot and the spiders were toast, so I put a posi in. Apparently, one wheel burnouts will cause extra wear on the carrier. I'm not sure exactly how it happens, but thats what a couple different journeymen mechanics told me.

[lukecp]

Originally posted by jhwkns
Lucas.. Are you sure it's not a universal joint?

Pretty sure.....the U-joints are new as of May. The yolk on the rear had what seemed like alot of play on it last time i yanked the driveshaft...

I have done several hard 1-wheel burnouts, but not too many latley. Proably one 1 or 2 a month....mostly because i dont' want to fry my new tires too bad
Before i got new tires though, i laid 5 or 10 1-wheel marks that were about 50 yards long each....

If it is the rear, i think i will go ahead and put in a 3.73 geared rearend, and just live with it on the highway for a few months until i can find/afford a cheap econobox, and then slowly turn the truck into the hot rod i want it to be...

[lukecp]

Well, a little update.

I changed the fluid today (was reccomended by a member on another board). The fluid had lots of little very fine metal particals in it....and was pretty dark. The gearset looked to be in fine condition though.

So, i filled it up with 85w140 and called it good. Still howls though.

Think i will have any problems putting 80 miles at 60-65mph on it? I'm going home tomorrow evening or on Wendsday.

[71-longbed]

i had my rear diff. looked at by a mechanic a few months ago .... he said the gear were in fine shape ... he said there were a couple shims in the wrong place and he added other shims to get it set to zero ... only cost me couple hours of labor ...and no parts .... seems to make alot less noise now.... it could be the case with yours as well ... on the other hand i've never done a burn out either .....

i'd have a professional inspect it ...just to be sure ... being stranded on the side of the road isnt fun

[lukecp]

I may look into that Mitch...if there is a confident shop in my area that handles rears.....one thing i hate about living in a rual area is stuff like that.

I think the pinon bearing is shot....i can get a new (used) rear for $125...not sure what ratio though....and put it in myself...but it is a pretty big job.

I proably should't try to drive it home but i will anyway. I may regret it though...but who knows. I will throw my bike in the back for backup transportation

[71-longbed]

good call with bringing your bike along .... i've been told by guys that 12 bolts can go a long long time after they start howling .... if your easy on it (aka no more burn outs or heavy launches) ...im pretty sure it will gte you home alright ... let us know how it goes

[lukecp]

Burnouts or heavy launches? Where would you get that idea

[lukecp]

I got home a few hours ago....the truck made the trip without a hitch. The noise didn't change any....and it feels about the same.
I decided to go ahead and pick up another rear (due to the large amount of fine metal particels that were in my gear oil). Should have one tomorrow or sometime this week.

Any tips for putting in the new rear? Looks like a pretty simple job....i will go ahead and rebuild the brakes on the new rear too. I think i will get one with 3.07 gears, even as much as i want 3.73's. I drive the truck on the highway 90% of the time....so i need to be pretty smart about my gear selection. It dosen't look like an OD tranny or a econobox will be in my budget anytime soon also.

Oh well

[stelth2002]

I ve loooked for a 3.07 rear for a while. I finailly gave up and now have a lead on a cast overdrive tranny I wish you luck as im in the college pinch too.

[71-longbed]

im glad you didnt have to use your bike ..... i stopped riding mine for fun a few months ago ....let use know how the rear shoppin goes ....peace

[Beefcake]

I've done the bike thing a lot.... sucks. Specially when its winter and nobody expects some idiot to be on a bike in the middle of a snowy night. I got tired of wipping out on ice patches.... so now I have 3 trucks.

[rambler]

Mine is/was doing the same thing, it is probably the pinion bearing as it did leak around the front seal and one long trip, it got real hot and almost locked up.. finally got a parts truck from teeitup and now swapping rears for it.. I think short trips are OK as long as you keep adding fluid,, but of course it also leaks out.. if you can wait a little bit.. till I get mine back on the road,, I live in KC, but travel to your area usually bi-weekly to work my Dad's farm.. (he's getting older) maybe you can check with teeitup and see what he has in rear ends.. and I'll pick it up for gas money,, either meet you at st. robert,, or maybe even have my brother (he lives in Rolla) drop it off there...

[lukecp]

Thanks alot for the offer Rambler, but i was lucky enough to find one today

I go back to Rolla for college around the 10th of January....let me know next time you are town and maybe we can meet up and talk trucks for awhile

[rambler]

No Problem, glad you found one.. Your around my old stomping grounds.. My folks actually live in Plato,, if you know where that is,, Houston MO , was the big "city" to me back then.... I'll give you a yell around then,, and we can definelty talk trucks,,, talk my brother in dumping his S-10 for a real 67-72!

[lukecp]

Yeah, i know where Plato is....population 74 i think. Right on the headwaters of the Roubidox (sp?) creek. I spent alot of time in Texas county putting up gypsy moth traps the summer before last for my job. Had alot of fun too.
Willow Springs is my home....and Rolla has become my other home now, lol.
Hope to see ya around sometime

[highboy_04]

what rear did you end up getting? what gears and all

[lukecp]

Highboy, today i drug home another 3.07 geared 12-bolt without posi. As much as i hate 3.07 gears, i drive the truck on the highway almost all the time and i need the extra gas mileage.
I already started cleaning it up....tommorow moring i will give it a fresh coat of gloss black paint and start pulling out the old one....maybe i can get it done in one day

[highboy_04]

no posi, that sucks. atleast you found a new one. hope all goes well.

[jorgensensc]

After reading this I should be concerned!! I've been driving my howling rear end for about 6 months nonstop everyday!!!! Heck, I just drove it from Cali to Texas at 80-85 MPH the whole way. I had no idea they would lock up because of this!! I guess I should quit doing burnouts ( I average about 2 a week). Of course ignorance is bliss, and now that I know about this my rear will go out