GM 8.5" 10 Bolt Rebuild / Knowledge, Opinions, and Advice Requested

[Scott Vincent]

As I've mentioned in a few posts already, I am rebuilding a 14 Bolt axle that will go in the rear of my 1974 K20, and a 8.5" 10 bolt that will go in the rear. I wanted some different perspectives on a few things.

I am NOT a rock-crawler, and nor do I intend to be with this truck. This will be my utility vehicle, a truck that will be used as such. it will not be my daily driver. However, I am sure I will take it off-road. Moving through these axles, I would like to keep from going broke, but also keeping in mind that if I build it well the first time, it will be better off. So here's a few questions I'm looking for different viewpoints on.

1. Lockers - Do I honestly need a locker, or lockers? Will I truly benefit that greatly from dropping $1300ish on an air locker, which seems to be the logical route if I'm going to do it. Or can I continue forward as planned, reusing the existing axles and differentials?

2. Axle Shafts - Are chromoly axles really any use to me if I'm not crawling? The expense doesn't seem worth it. Current plan is to reuse the shafts in both axles. Preliminary examination did not show any concerning signs.

3. Rear Axle Disc Brake Conversion - The idea of this looked great, until I looked at the kits. How beneficial are these to do? Some perspectives from guys who have done it would be great.

Every component I've removed such as the knuckles, steering arm, hubs, etc, have been muriatic soaked and neutralized, primed and painted to clean them up, remove rust, and protect them. Not going overboard with cleaning and painting since there is no intention for this to be a show truck, but taking measures to help get things in as good a shape as I can.

Also, I'm going to look through this site later to see if there are any posts on this, but my 14 bolt is a nasty mess. Any direction on best practices for cleaning or tips are welcome.

As always, thanks in advance.

 

[Curt]

Ok.First,you can do this!I picked up a few cheap tools from H.F..Seal and race driver set,6 ton press,dial indicator and magnetic base,and caliper.

I already had very nice torque wrench.You Will need various pieces of scrap plpe,1”-2”.

Anyway-1.I would go with a No Spin locker (Detroit)in the rear.It fits inside the carrier and is a breeze to install.Plus it’s pretty much bulletproof.I’d leave the front diff open for steering,plus you’d save some money,and the 8.5 will hold up better.

2-14 bolt stock axle shafts are crazy strong.Probably not an issue with tires smaller than 38’s.However,the front axle is a different animal all together.It could be very beneficial to upgrade the shafts.Especially the stubs and hubs.Right now you’re at a 19 spline outer/stub.However,being a “unlocked”axle will help as will staying off the throttle.Plius upgrading the front shafts/hubs will be $$$.

3-I have a disc brake conversion and love it.However,more $$$.My truck stops extremely well and balanced.Upgrade you could do later…?

As far as tips and tricks,YouTube.Yukon took some time to answer a few of my questions.

I think I posted some stuff on here as well,but not much.I can give you some vendors I used,if you want.

Be patient and take your time.You got it!

 

[Curt]

Oh,I used gas to wash my axle housings out with what’s called a wash down gun or binks gun with about a 100 psi of air to it.I don’t recommend because a lot of reasons,however,it works amazingly.Many many cans of brake cleaner and elbow grease will have the same effect.

 

[Scott Vincent]

Sweet! So far I'm on the right track then. I've just about got the 10 bolt for the front done and buttoned up. I'm just waiting on a few parts to finalize it. I mainly went in to both of them to inspect and change the wear items like ball joints, bearings, races, seals. I got these axles along with the K20 I bought which already had axles, but the rear is welded and the front is some toothpick 10 bolt.

Nice to hear about the 14 bolt since I'm running 37's right now. And the front as well since I was hoping to just put it back together in stock form with all wear items changed out.

That brake upgrade is a big decision I have to make. Believe it or not, I've never worked on drum brakes myself, but always heard they are a p.i.t.a.. Disc brakes I know all too well. but that money...phew.

I think I'm just afraid to put it all back together and find out down the road that I would have been better putting something different in these axles. But, sometimes that's just a part of it.

Thanks for the reply Curt!

 

[Scott Vincent]

I totally forgot to ask this one though. Is it ABSOLUTELY necessary to replace ALL steering arm fastening parts? Studs, conical washers, and nuts?

 

[Nonstop]

I would have to agree with Curt on all of it EXCEPT the rear disc set up. I lost my parking brake and was not overly impressed with it. I converted back to drums and was much happier. It stopped well with the disc brakes after I converted to hydroboost, but was not worth the time or effort to me to convert to rear discs.

Oh, and rear drums are not that hard. You will only have to do them once and you should be fine for MANY MANY years.

 

[Curt]

I would replace anything that looks worn.Especially fasteners that steer your truck.

And yes,you can lose your emergency brake.Some kits allow some type,or you could go with the following….if you have a NP205