Z71 diff

[Piotrowski102]

Hey, could anyone tell me what rear diff the 1997 z71's came from the factory with? im talking in terms of posi, limited slip or open? because my truck spun both tires till I blew up the rear end today and I want to know what to replace it with because I still want both of my tires to spin, no one wheel peels please haha. Anyway the guy at Partsource derected me to this:

http://http://www.jegs.com/p/Powertrax/745940/10002/-1/10151

Would that be the right one? Thanks

Heres some pictures for yas.

[chevyfreak2]

damn how long of a burnout was that

[69-350]

my 97 Z71 came with a semi-floating 14 bolt rear end, should be a 3.73 gear ratio, with Limited Slips front and rear. I believe all Z71s from 96 up should be this way.

I know all Z71's came with limited slips after a certain year, and I believe it was 96 or 95 when they started this.

Also, all Z71's, and likewise "heavy duty" half tons (which may just be Z71's) and light duty 3/4 tons, should all have the 9.5" ring gear semi floating 14 bolt. I know my 1997 Z71 does, my buddy's 1990 GMC six-lug 3/4 ton 2WD has it (yes, a six lug 3/4 ton).

However, I've noticed a friend's 95 Z71 has the 10 bolt, and another friend's 99-02 Z71 has a ten bolt. I'm not sure on what they did from 99 up. I haven't looked under a 96 yet.

Another thing, for front differentials, I believe all half tons have the same split-case 10 bolt 8.25" IFS differential. Which, on another note, nobody makes any posi or locker units for. I did a bunch of looking on Jegs and Summit, and there's a bunch of posi/locker units for the 9.25" IFS front diff, found in all 3/4 and 1 ton 4WD trucks.

But one thing I've got a question on, according to Summit, K1500s with the turbo diesel had the 9.25" front diff in them, but in a couple forums discussing putting the 3/4 ton diff in a 1/2 ton truck, people have said that the diesel half tons don't actually have the bigger differential. If anybody has a diesel half ton, maybe you know, or could find out which one they have?

Also, I don't think it's too hard to swap front diffs. the 3/4 tons have larger fins on the housing, and bigger mounts. Some slight modification of brackets and shaving of the fins on the diff are needed to be done, along with adapters to mount the 1/2ton CV shafts to the diff. However, from my understanding, to mount 3/4 ton CV shafts is much harder, because the 3/4 tons use a slightly different mounting position for the upper control arms, I believe.

On a side note, I'm not entirely sure if the GVW option code has anything to do with the bigger rear end. My truck has the C5S - 6600lb GVW rating, I think the heaviest you can get for a half ton, along with the heaviest duty brakes applicable in a half ton, 7700lb I think. I am thinkin my truck was a special order one, because of some of the options, and the fact that the first owner used it to pull a fifthwheel camper with it, and had installed 3/4 ton springs and the big block size (19"x34") radiator (which totally made me happy because I could bid on, and just won an auction for a Perma-Cool electric fan setup, woot!)

Hah, and at the end of my long spiel, I just noticed that your pan has ten bolts, right? If it is a ten bolt, the option of a 14 bolt may depend on your GVW, or whether your truck is a true Z71. The GVW option should begin with a C, and be followed by a number, then another letter. And the Z71 RPO code is Z71, fairly straightforward, huh? Hah, anyways, go look in your glovebox at your options sticker and let me know what the GVW code is, and if it's a real Z71. I might have been misinformed if yours is a true Z71 and has the ten bolt (unless somebody swapped rear ends before). And one more thing, do you know what size brakes that has? I believe ten bolts are 10" and 14 bolts are 11". If you go to a parts store and they ask if it's the heavy duty brakes or not, that's why.

Anyways, after writing practically a short novel, I hope you aren't too intimidated by all the reading, hah. I want to know what GVW option you have though. Hope this helps.

[Piotrowski102]

Ya I got the pod out and that let me find some things out. Its a 10 bolt with 8.5" ring rear and 30 spline axles. I went ahead and orderd that pod on the link wich I believe is a posi pod corect? I dont have a clue in hell were that code is supose to be on the sticker. I found a code that sais z71 though.

[69-350]

Not sure if that's the right one. It says install in open diffs only? If your rear end originally had a posi, it'll be on that sticker, should be G80, which is for POSITRACTION, LIMITED SLIP. I believe this is the code for the newer limited slip axles, that arent true posi's. G76 is for the positraction code, I think this means the old ones.

Look for the G80 then, and because it's very useful for decoding your RPO code sheet;

http://www.c2e.info/rpocodes/

As for the aftermarket carriers, I'm not sure. I don't know if the one you got will work. I'd look around on Summit and Jegs, see what you think.

[Piotrowski102]

I dont even know. The part source guy said its the one that fits in my truck so its the one I orderd. I dont even know if its the same one that I linked to because they order through ekeystone on somthing, I just remember that the one I orderd is made by lock right and its a posi.

[Piotrowski102]

Well I used your link and yes my truck is a true Z71 but for some reason there is no GVM raiting? the only codes that I have that sart with c are C49 and C60. And also my truck has a G80(or had lol)

[69-350]

Hmm, might be right then. You'll just have to wait and see I guess.

[Piotrowski102]

Ya dude, Thanks for the help

[69-350]

weird, you truck should have the gvw on there somewhere. Hope I helped you a little, hah. And you're welcome