Is there a way to tell if I have one? I decoded the VIN, and it didn't say either way, and I checked the RPO sticker against the list I have and also, not there.

 

Hi, who did your decode, on this site or compnine.com? My RPO code is GU6 AXLE, REAR, 3.42 RATIO. I read somewhere G80 is limited slip or locking. If my van had locking pretty sure it would show the GU6, plus G80, I think. Highly recommend compnine.com, best $5 you can spend. Nevermind, I remember now, compnine.com doesn't have your vin, you could easily drive to your nearest GM Dealer and get a VIN printout.

 

I used the decoder here.

 

It was ARTIE1
that told us about the G80 being the RPO code for Locking Diff
he also told us that the diff will have the tag attached..
I dont think you wana go out side to check diff tag .. lol

 

Mine is a GT4 = 3.73 Gear Ratio
I have no RPO for locking rear diff...
and I have not looked under the van for the Diff Tag.
I have been told that not all Locking Diff are listed in RPO's
which to me doesnt seem right...from a manufacturing stand point.

 

If you don't have one, you can get a detroit tru trac put in for a decent price. Better and stronger than a g80.

 

I couldn't remember if Artie had said that, and I didn't want to search your thread, Ron. That thing is almost 60 pages.

I had a little trouble getting out of my driveway in this dusting of snow (1.5"). Only one wheel was spinning. I thought if I had the locking diff, it needed repair. Thanks.

 

I understand STAN.... it is a long thread I would have never had thought it would have been
this long.... any ways... its full of alot of great information...so.. let me turn you onto an Item
that I have installed in 2 different trucks 1 being my very own Not the Truck I have now
and the other was my cousins.
this is a cheap way to get a locking diff... and it works splindedly ...... I have had great results.
and I pulled a Race Car every weekend for 2 summers to the track .
https://www.powertrax.com/product-in...action-system/

tells all about their product and then the page to select your vehicle.

https://www.powertrax.com/traction-systems-product/

when I bought them I went threw Summit Racing but I see that Jegs has them too
This is for the Dana 60 like what is in my Van
http://www.jegs.com/p/Powertrax/Powe...gin|0||P_SKU|0

 

https://www.4wheelparts.com/Drivetra...SAAEgK-s_D_BwE

here is what the price is on a detroit locker for our vans...
keep in mind if your not savy on how to install your will
need to pay labor plus some kind of install kit.
Trust me when I say this is no drop in you have to install yourRing gear
and if your gonna go that route you should install new bearings as well
The item I suggest is cheaper and you can install yourself in an afternoon
NO shimming no aligning no preload no mess.. lol
AND IT WORKS...

 

I am going to get this diff cover when I install my locker...

https://eastcoastgearsupply.com/i-21...r-arb-red.html

as you noticed its RED.. but look closely you will see it has
both fill and drain plugs.. NICE feature.