rear axle swap
 

Sorry if im already asking a question that's been answered im on my phone

I have recently blew up my rear gu6 axle in my 2003 blazer. This is the 2nd one in 2 years, is there anyway of getting a bigger axle like out of a 1500 or so? I have 33s and the stock gears so im sure that isn't helping. :(

Thanks in advance

Why don't you find a ZR2 axle to swap in. They are an 8.5 I believe. Or the best way IMO would be to swap in an 8.8 out of an explorer and have the hubs redrilled to 5x4.75.

Would I have to change drive shafts or anything? Im just trying to get out of breaking axles so often.

You may have to change the rear u joint and possibly figure out the ebrake but those should be pretty simple to figure out since a ton of others have done it.

But the splines will line up? I took out my e brake cables anyway I just wanna get like an upgrade for the rear so a zr2 or ford explorer rear end. Im thinking ill do the zr2 swap so do I have to change shock mounts for that?

Yeah they are both "almost" bolt in axles. Keep in mind also the Z axle is 2"(I think some correct me if I'm wrong) wider so it will push your rear end out a bit. What do you have for a lift? If its still the IFS the Z axle will make your rear wheels even with the fronts.

I know El_Beautor and Okiedoak20 are both running Z axles you may want to hit them up for more info:)

Yea I have the ifs I wish I had a solid front axle cause the front chews through cvs and steering components.

So I have the gu6 3.42s I think that's what it is, what do I do in matching the front?
Or do I change the front gears also with these swaps?

I really appreciate the help!

The only difference was the rear u joint. It is different and I found a conversion u joint and problem solved, also had to change the u joint straps but if u pull the axle get the straps with it.will save a lot of time later. The rear wheel spacing is wider. Thats helps a lot with the front/rear width thing.

that is probably your problem.. to high of a gear for the size of the tires. 3.73's would be better and 4.11's better still. the problem with changing the rear end gear is that you have to change the front end as well. which basically doubles the cost of the job. if you find an axle which as 3.73's in it (i think most zr2 axles had them from the factory) then you would still have to buy the front end gears and have someone install everything unless you know how to do that.

What I did was, I found a jimmy with 3.73 gears and took both axles. Sold some parts got most my money back then had the carcass towed out
Got $300 for that, then installed both axles in my Envoy. Axles ended up being free but still had to do some work to get them

FYI, all ZR2's came with 3.73 gears. Mine was a very easy swap as far as the rear ZR2 axle goes. I didn't have to change anything with the U-joints on my swap. I just got the rear axle and front diff together from a ZR2, and swapped both in to replace my GU6 factory diff's. The rear axle I did alone in about an hour and a half in the driveway with hand tools.

The front diff is tricky to get out, but once you have it out it's not a big deal either. For me I went from a '96 front diff to a '99 so I also had to upgrade my front CV axles to match. The older style are not compatible with the newer diffs.

You will notice a little difference with the 3.73 gears, but if you're running 33's I'd suggest you at least consider 4.10's, especially if you're offroading. With my 32's I do wish I had a bit more low end torque.

Another question I have since mine is lifted do you think I gotta mess with the length of the drive shaft? Because my axle now is under my leafs. Would the 4.10s give me horrible gas mileage?

The ZR2 axle won't affect the length of the drive shaft. If it works on your current axle then you'll be fine. As for the mileage I'm betting it 4.10's would improve your economy. You have 3.42's now which are built for 235/70/15's (about 28" tall) but you have 33's. The 4.10 will get you close to a stock end drive ratio. Remember also that your 33's are a whole lot heavier than stock wheels & tires, so you're turning more mass. The lower gears will definitely help, especially around town, offroading, and accelerating. Even on the highway I think they'll help.

thank you everyone for all the help!

these are my plans
i found a 8.8 4.10L with discs the junkyard said he will sell it for 150
then the drive shaft yoke off the ford.

now for the front can i take my drive shaft off and drive it until i get the front gears changed to 4.10s?
also where should i get the gears for the front?

I was told that it is possible to remove the front
Driveshaft and still drive with out any leakage
Or problems. The transfer case is internally sealed so no fluid will come out.this is for the
3 button 233 and 4 button 236 transfer case.

Alright good I have the 3 button

I might just focus on the rear axle for now, so I can get it back on the road.

Thank you I just wanna make sure I can 4.10 gears for the front before I buy the axle

i dont know for sure. but it cant be hard to find out.

I believe as long as you don't engage the 4x4 you don't need to remove the front drive shaft, as it is disengaged until use. Someone correct me if I'm wrong though.

With the 231 transfer case that is defiantly true..
The 233 3 button transfer case im almost certain. But the 4 button 236 with the Auto button, the drive shaft turns all the time. So I would say search the forum a bit more, or someone else jump in and clear this matter up. I was under the idea that because the 236 transfer case has cluthes inside the front driveshaft will need to be removed

I would remove the front driveshaft just because then I'd be 100% sure that it won't harm anything and no chance of forgetting or accidentally engaging the 4x4.

i hate to bring this up, but i just thought of it. if i were to find a ZR2 rear axle that is the 8.5 and put it under my 98, will the ABS still work? if not, what do i need to do to keep that? (insurance issue)

It should, so long as you attach the brake lines. :icon_wink: The speed sensor for the rear is at the output of the transmission.

well that clears that up....i dont know why i thought that i had two in the back like i do in the front. i have known that there is only one speed sensor in the back, but i for some reason i thought it was on the axle and not the trans. thanks for clearing out the smell of my brain fart.

You're good man, that's what we're here for.

Well I got the axle. Painted it,put new wheel seals in it, cleaned the parking brakes even tho Im not hooking them up. I got the axle shafts out the only problem i have now is trying to find someone to put the new bolt pattern on the axle shaft. But I got my drive shaft converted over. Just not unbolting the stock axle until I have a complete axle to put right back in.

You could use those wheel spacer / adapters from ebay. Lots of members use them on here with no problems with them other than auto shops not wanting to touch them.

Machine shop. Bring in the axle shafts and rotors and have them re-drilled.

They didnt wanna drill them for safety reasons. Oh well I bought explorer rims I just gotta get the bolts and figure out what I have to do for brake lines.

Cowards! (machine shop) :D

Well I got the axle in and driving I had to a little more modifying, had to make my leaf spring plates bigger and the axle mount I had to get machined to the new axle radius. I'll put pictures on my profile, since im on my phone