What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Rear Axle Issues

K

k5blazinredneck

Registered Member
Joined
Dec 22, 2011
Posts
99
Reaction score
0
Location
Rocky Mount NC
So i just purchased my second k5. Ive been trying to find a decent one ever since i sold my first one. i drove 3 1/2 hours away to get it and drove it back and it went great! the blazer cruised at 70-75 the whole way home and had zero issues! the guy had a new goodwrench 350 along with a new 700r4 tranny and 241 tcase put in in 2011. Well like i said. I had no issues with it! At least until i got home and decided to try a little burnout...burnout:D well it roasted the 35s like they werent even there. long story short. there is a LOUD clanking noise coming from the rear of the truck. It doesnt do it all the time. when im driving at highway speeds its fine.it mainly happens when turning from a stop. also when i punch the gas. Im thinking i may have broke the spider gear? not entirely sure if it has a g80 or not. I plan on pulling the cover off this saturday to find out for sure. Any way i can diagnose the problem without pulling the cover? i dont mind doing it but just want to know for sure. I think the noise is mainly coming from the drivers side. Maybe its just because im on the drivers side? Could it be the brakes? i was thinking maybe the back brakes came loose or something? I plan on swapping a 60/14ff swap under it eventually but who knows.
 
Pull the cover. Only way to know for sure.

I've broken spider gears, a cross shaft, and gear teeth. It sounded different each time. It's hard to diagnose noises on the web, but I'd see whats going on back there before you lose a c-clip and the axle slides out.

Like I said, I've broken 3 10 bolts with 35s. Two were on the street and one was in dirt (not even rocks). Some people say a 10 bolt is fine with 35s and mild use. I personally say go 1/2 ton as long as you can and then upgrade as soon as it breaks. It's not worth nursing a 10 bolt. I finally went 60/14 CUCV axles. Still with 35s.
 
k5blazinredneck said:
. It doesnt do it all the time. when im driving at highway speeds its fine.it mainly happens when turning from a stop. also when i punch the gas. Im thinking i may have broke the spider gear? not entirely sure if it has a g80 or not.


Kinda sounds like the characteristics that a Detroit Locker makes under the same circumstances.
Click to expand...
 
I bet you have a gov lock and it's broke. Sounds exactly like a truck I built a long time ago after a burnout noises. Be careful we drove this thing another 5 miles and everything came apart and locked the rear end up
 
We'll I found the problem. Busted the spider gears. So my question is. I don't think I can just replace the spider gears. Maybe I'm wrong.. But if I found another carrier with 3.73s like mine has could I just swap it in? Without doing anything else? I've never done any rear end work so idk..
 
If you've never done any rear end work, honestly, you're best bet is to either find someone to rebuild it for you, swap in another 10bolt rear or do that 60/14FF combo now. Setting up the gears takes special tools, time and experience. You could try to read up on it and get the experience, but if you need it running quickly, go the swap route.

The previous owner swapped in a 12 bolt in my 1988 Sub and when that thing ate the pinion bearing, I just went to a local yard and bought a complete 10 bolt for $75. I rolled the old one out and the new one in and it's been good to go for over a year now.
 
As long as no metal chunks went thru the ring and pinion and damaged them,you certainly can replace the spider gears--also make sure the side gears on the axle shaft ends are not damaged,and they are not sloppy where they ride on the diff case--if they are,then your probably better off getting a whole rear end used ..

If the diff has a magnet glued to the bottom of the case or the cover,chances are any shrapnel might have stuck to it,instead of getting circulated thru the gears and bearings,especially if it was not driven far after the failure..

Swapping carriers is a bit involved,you must put shims on each side of the carrier bearings to get the proper back lash and gear mesh,and its kind of tricky,if you never did one before..also you might need a "case spreader" to expand the diff housing to get the carrier in..personally I'd rather swap another "good used" rear end in,than mess around trying to set up the gears in the original one..
 
10 bolt right. Should have external carrier bearing shims.

Pull shafts, pull carrier, keep track of where everything goes, replace spiders, reinstall. The 10 out if it has factory shims will be 2 big cast iron shims. Mark the bearing caps. Make sure to torque the bearing caps. This will allow you to fully inspect for any damage
 
well i completely forgot that i had an extra 10 bolt from my old k5 with 3.73 gears and an open diff. so i went by and picked it up. i put it in yesterday but i want to go ahead and replace the rear hardline brake lines. anybody know what size the line/fittings are? i dont really want to buy the pre bent kit and i already have a cutting/flaring tool. so im just gonna make my own. the only thing i need is the size of the line from the tee fitting to the drums. thanks in advance!
 
The brake lines going to the wheel cylinders should be 3/16",they could have metric thread nut fittings depending on the year--most take the SAE 3/8x24 thread ones...the line coming from the front of the truck to the rear brake line is usually 1/4" on square bodies,newer trucks sometimes use 3/16" line to the rears (maybe due to disc brakes?)...

I've replaced so many brake lines on GM trucks from 87 down,I know just what length and size tubing to get--and which fittings on some of the lines at the master cylinder and proportioning valve are goofy GM factory ones that have one size thread on one end for the tubing,and a different one on the other,(I cut the old tubing off close to the fitting and use a 6 point socket to get them out with no damage,then get the old tubing out by drilling or a punch...saves paying for new ones,which aren't that expensive,but difficult to find sometimes..)...

I sometimes fix only one brake line,but on most of the trucks I had,all the lines had at least one rusty "iffy" looking spot,and I did not trust them--I usually just buy all the tubing to replace all the lines at once,its about 40-50 bucks for a roll of the green coated stuff,the newer nickel-copper terne brake line costs about 20 bucks more,but supposedly will outlast the rest of the vehicle...the cheap "ready made" lines rarely last 2-3 years here...rolls of it are thicker walled tubing,so its a bit tougher to flare,but it'll last longer..

I like to cut the old tubing out intact and copy the bends on the ground and flare all the fittings on it then,it sucks having to flare a piece "in place" under the truck...its a lot easier to hold the flaring tool die in a bench vise,than by hand under the truck..
 
You must log in or register to reply here.

Latest Posts

Top Bottom