1984 K5 Blazer-ChromeMoly Axle Upgrade Question...

I've been plowing snow for 10 years with a 1984 K5 Blazer 6.2 diesel. I'm tired of breaking the axle shaft where it goes through the spindle-hub. So of course I Googled it, and all kinds of stuff comes up. What are the recommendations that you guys have for me?

And a recent noisy U-joint had me pull my rear drive shaft, and the axle yolk and shaft is worn. I was able to push the U-joint caps in with zero effort, and one of them even fell out. I tried to weld them last time, but the welds just cracked. So I'll need a new rear drive shaft and a differential yoke. The truck has a 2 inch lift block in back to support the 1500 lb of rock salt I keep for ballast. In the front I added three leaf springs. It sits nice and level even with the 7.5' Fisher plow

I know the way to go is a 14 bolt full floater and a Dana 60, but that's a whole song and dance, plus I have a full-time transfer case converted to take a 700 R4, but that's a big big job. I just want to be able to beat on the truck a little bit more than I am now.

My plow truck , (for 16 years) ,was a 78 square , short bed with a 4 inch lift and 33's with a western blade with a dana 44 up front and a 12 bolt out back , 203 case , part time converted and I had little or no trouble with breakage.

That being said , a yoke and a new rear driveshaft ain't no big deal , but what are you breaking on the front end? The axle joint or the stub shaft itself ?

Your front end should be a 10 bolt and they are just as tuff as a 44. The only problem I had was when I was on it hard pushing snow and grab traction somewhere , instantly , I have popped the axle joint , which in turn take's out the axle's most of the time. This happened a few times with precision brand axle joints and then I switched to spicer x axle joints and didn't have any trouble's after that.

I wheel my 77 blazer I have now hard and I know my weak point is that axle joint with 38 inch rubber and I have only broken one and it was not a spicer x axle joint , but now both of them are , no trouble so far.

They do make chromoly shafts and high dollar axle joints but I have not used them so far, but I have thought about it. They say though the high dollar axle joint's are not for highway use and sometimes I am driving at 55 mph in 4 hi on snowy roads so that has held me back on the deal.

So broken axle joint , (which trashes the axle's) or the axle shaft itself ?

I run 33 snow tires, and I've broken the joint where it wraps around the U-joint. I think once I broke a universal joint. I've never broken the shaft itself, and my rear drive shaft and yoke are worn. LMC offers the yolk for $150. Seems a little rich, I'm sure I can find one in the junkyard down-south for a lot less, as long as I bring an impact with a strong battery and the correct size socket

Do you have a driveshaft shop near you ? 150 for a yoke is bank , a driveshaft shop or wrecking yard or maybe a parts store would be way cheaper. I just stick with spicer stuff because I believe that they are stronger and maybe a driveshaft shop or parts store can usually can order spicer stuff for you or maybe go online to order spicer .

I myself have not broken the ear's on an axle shaft itself but when the joint pop's it has alway's taken out the ear's with it.

I would try spicer stuff . Before that I would check the steering , there is stop's on the back side of the knuckles and if they are broke off and your steering is a bit out of adjustment you may be turning to far for the axle and or joint to handle which would cause breakage , (just a thought).

I don't mean to insult you UGLY but perhaps you're breaking joints from your driving style. You can not put much torque on an open U joint. That means, when your wheels are turned one way or the other, your joint is at it's weakest. You have to be gentle on the happy pedal when turning. The extra weight of the snowplow is likened to big grippy tires, making the situation even worse.

Plowing obviously is the worst thing you can do to a truck. When you get stuck and the plow is over the bank and you got ice underneath the truck and yada yada yada, it's just easier to push on that brake-parts-pedal

Shiftpro brings up a very good point- axle ujoints are weaker the more the front wheels are turned. But typically with plowing your front wheels are probably pretty straight when pushing snow into the berm.

I researched chromoly axle shafts a few months ago and ended up buying some made by a company called Ten Factory. Yukon makes some also and they were my second choice.

Also what axle ujoints are you using? The standard replacement for many many years was the 297x. Now Dana/Spicer makes a 760x. A bit better for about the same price.

http://www.fourwheeler.com/product-reviews/131-0212-5-760x-spicer-u-joint-jeeps/

There are also CTM joints and RCV (CV joints) for a lot of money. The CTM ones do not have needle bearings- instead rely on grease and brass bushings. Need to be re-greased all the time.

TenFactory came up in my search, along with so many other names!

I have some 760's, but the issue is my shaft holes are worn. Interestingly, a friend bot an '87 K10 that really belonged in the junkyard. But he's rebuilding it at my shop. All new brakelines, pads, rotors, hoses, calipers etc. One of his front axles, or maybe both, I don't recall had the original joints. They had a little bit of wear, and after I used my 20 ton press to bust them out, I installed MOOG Mexico joints. A couple of his cap holes were larger than the cap. The original joints were badly rusted in, I had to cut a couple to get them out. I gave him a good used axle.

I don't understand how the holes were enlarged so perfectly, but they were. I even tryed a few different ujoints, same result.

Some of the nice things about the chromoly shafts are that they don't neck down as much as the stock ones near the splines. That is one weak point. The other weak point is like you just pointed out- the ears around the ujoint stretch out and get weak. The ears will then either rip off or not control the ujoint and the ujoint breaks. The aftermarket chromoly ones have some extra material around this area to make them stronger.

Then they are usually recessed on the inside for use of full circle clips instead of c clips. Full clips are better:

https://wayalife.com/showthread.php/3345-Front-Axle-Shafts-C-Clips-vs-Full-Circle-Clips

That hub and rotor seen in the one picture, that's not from the Chevy is it?

It actually is, but... when you're attaching these tiny thumbnails, everything looks the same. It's from a 1995 Suburban 2500 4x4, 6.5 diesel that I have in my shop.

CORVAIRWILD said:

It actually is, but... when you're attaching these tiny thumbnails, everything looks the same. It's from a 1995 Suburban 2500 4x4, 6.5 diesel that I have in my shop.

Click to expand...

Ahh ok, that makes much more sense. I saw the unit bearing and was thinking there was some Dodge crossbreeding going on.

Getting a little off topic, that 1995 Suburban is a customers, and I've been doing a lot of work to it, but because most of the vehicles I work on are my own, I haven't been keeping track of the hours. So I've got to create a bill for it, and I have no idea how many hours I put into it except it's alot.

I changed the upper and lower control arm bushings, lower ball joint, (the upper was good). Sway bar link of course, and the rotor, caliper and outer tie rod. I have to change the rotor and maybe a bushing or two on the other side, and both ball joints. But I don't know if I have the time, and I just had a work-related injury that's slowing me down for a few days. So is there a place to look for flat rate for the work that I've done?

I also changed the dash bulbs, every single one was burned out. Next it'll need oil cooler lines, I'm going to get those from Leroy Diesel Service.