Hey guys, the owners manual for my 94 S15 jimmy mentioned something about a factory locking rear diff. My truck didn't come equipped with that but I was wondering if I would be able to pull a locker from a salvaged blazer/jimmy. So here are my questions...
Are the locking diff trucks hard to find?
Is it possible to create your own switch for the locker?
Is it worth it/are they dependable?
And how can I identify a truck with the locker?

Thanks!

 

Your options are to put a G80 unit in it from a later S10/Blazer or you can purchase one of these to put in it.

http://www.summitracing.com/parts/PWT-1931-LR/

There are plenty of threads on this subject.

 

Or just weld it shut, but this way tends to break on the road.

 

Inside the glove compartment you will a sticker there, look for the three letter code of G80. This is the factory locking differential unit. They are not that hard to install. Just remember the bolts on the ring gear are left-handed. If not you will have lots of trouble taking them off! LOL

 

These are not LOCKERs. It is a "Locking Differential". Meaning it drives like an open diff, but if excess spin is detected at one wheel, it will clutch up like a posi. At low tire rpms, it says locked for better low end power and easier take off, etc.

G80 Gov-Lock. Look into it, it is an interesting design. If your's come with it (there are a TON of GM vehicles that did) then if you do not feel it (i.e. spinning one wheel at take off) then it could be broken as it is operated by weights and clutches and anything designed to "lock up" when spinning, will take considerable wear an tear over the years depending on driving habits

 

Oh gotcha, well a limited slip is better than an open diff IMO. I checked the RPOs for my truck like 96blazernut suggested and I don't have the G80 option. Is the RPO code same for every car that would come with it? (like 1st and 2nd gen s-series trucks, tahoes, suburbans, etc.) And would a G80 diff from another GM car fit in my S15? My local junkyard has a ton of 1st and 2nd gen s-series trucks so I'm sure one of them is bound to have what I want. And are the RPO codes in the same spots for the 1st and 2nd gen cars (in the glovebox)?


Oh and one more thing... are they durable? Would I have to worry about a junk yard diff being bad? Thanks guys!

Would this diff work in my truck?
http://cgi.ebay.com/ebaymotors/10-Bo...item4cec186f25

 

I got mine from a 98 Blazer. I would stick with the second gen trucks. I'm sure that there is a interchange list for them somewhere.

Mine has been very durable. I haven't beat it much yet but thats to come next summer.

 

Oh ok, but both of your trucks are the 2nd gen models (in 94, they introduced the new pickups but the SUVs like my jimmy remained the same until 95). So my question is if it would fit into my 1st gen, but I'm assuming it will. And I found this neat vid on youtube about g80s... http://www.youtube.com/watch?v=p8nAbg5suFw

 

It should just drop right in.

 

These axles have earned the nick name gov-bomb, sine they are know to blow up inside.
THAT BEING SAID: most people breaking them are guys building streetable racers that want the benifits of a locker without the drive/ride problems of a full time locker...

If you are going to yank one, images will be your best friend. look for rebuild, regearing, and salvage how to's. these things have anumber of moving parts. the more that moves, the more that can break. look at the images for every identified problem, that way when you are at the JY, you can crack it open and take a peak before it's in the garge and you get screwed.

I would say it's better than an open diff (no sh*t right) and better for a daily driver than just fusing (welding) the gears of another axle since you will run into problems with the other compenents being too weak.

the Gov-Lock rears have been around since like '75 or so, maybe a bit earlier. you should have NO trouble finding one. just make sure the teeth and spline counts are right. you will not have fun with a 30 spline if you have a 28 etc.

Also if you want a JY locker you would have to be extremely lucky. either crack the right diff and score, or find one of the like 4 vehicles offered with an OEM locker (like Dodge Powerwagon) gl with that though