Rear Diff question

[buRRp]

I have a 91 SF 14 bolt in the burb. I was trying to find out if it has a G80 or what it has in it. The RPO code decal in the glove box is wore off and can't be read. Is there another way to find this out without taking the cover off. One wheel spins when I try climbing anything also.

 

[HotRodPC]

No other way to tell Lee. The G80 Eaton Locking Diff aka Gov-Lok also spins the wheels in opposite direction like as if it were an open diff, instead of both wheels in the same direction like MOST lockers or limited slips. One way to know, would be to jack up one rear wheel on a floor jack. Then get in your truck, put it in gear and see if you can drive it on the floor jack about 4-6 feet up your driveway. If you can, then you likely have the G80. If not, and the wheel in the air just spins, then you most likely have an open diff or a G80 that is broken. I myself, would prefer not to have a G80. If you have an open diff, you can install a Lock Right Locker. The Lock Rights are not the strongest systems though. They can handle up to 350hp and max of 35in tire. If I was running 33in tire and 300hp, I'd feel better about the Lock Right.

Its an inexpensive system in comparison to other lockers, and it easy to install. If you have the full float rear end, you don't even have to jack it up or remove your tires to install the Lock Right. Just take off your axle bolts, slide the axles out about 6 inches on each axle. Take the rear cover off, remove the spider gears, put the Lock Right unit in the carrier in place of the spider gears. Cover back on, fill with gear oil, slide axles back in and done. Go raise hell !!! JMO

Or you could spend the big bucks and go with a Detroit Locker.

 

[HotRodPC]

Rocky Road is the cheapest place I know of to get the Lock Right. Its $290. Part # for the 14b Full Float 10.5 inch is #1955. I've even seen them on eBay new for $225 when someone decided they were going to run bigger tires, so they went another direction and took the loss before it had been installed.

http://www.rocky-road.com/lockright.html

 

[buRRp]

Thanks for the reply. The axle thats in there now is a semi float one. I have a lead on a full-float one so I am planning a swap once I get it. I was just trying to figure out what the one I have in there now is. I will check into that lock-right. Thanks for the link.

 

[buRRp]

I know I am not making that much power and will be running 33's maybe 35's.

 

[crazy4offroad]

If you have the full float rear end, you don't even have to jack it up or remove your tires to install the Lock Right. Just take off your axle bolts, slide the axles out about 6 inches on each axle. Take the rear cover off, remove the spider gears, put the Lock Right unit in the carrier in place of the spider gears. Cover back on, fill with gear oil, slide axles back in and done. Go raise hell !!! JMO

Cant do it this way on the full-floater 14-bolt, the carrier is a 2-piece split design, you'll have to remove the carrier, remove the ring gear from the carrier, and split the carrier housing to get the spiders, sides and spider cross out. Then you can put the locker in and reassemble. You might want to look into the Yukon Grizzly or Spartan brand slip-in style lockers too. Usually $50-$100 cheaper than the Richmond Lock-Right.

 

[HotRodPC]

Cant do it this way on the full-floater 14-bolt, the carrier is a 2-piece split design, you'll have to remove the carrier, remove the ring gear from the carrier, and split the carrier housing to get the spiders, sides and spider cross out. Then you can put the locker in and reassemble. You might want to look into the Yukon Grizzly or Spartan brand slip-in style lockers too. Usually $50-$100 cheaper than the Richmond Lock-Right.

Thanks for correcting me on that Curt. !!! So then I got it backwards with the 14b SF??? I'd just about be willing to bet an 14b is NOT a G80. Very very uncommono the SF has had G80. I don't know of a single one in the square body years and all the ones I dealt with were 4.10 gears.

 

[crazy4offroad]

The SF will be like 10/12 bolts, with the x-pin and c-clips. I'm willing to bet it's just an open diff and not a broke G80.

 

[HotRodPC]

The SF will be like 10/12 bolts, with the x-pin and c-clips. I'm willing to bet it's just an open diff and not a boke G80.

Yep. To date, I've never seen a SF with a G80 or locking diff, or lsd for that matter. All of them have been open and 4.10s from the factory. This is in the square body years of course. I know in the later body styles there are some G80's and other gear ratios.

 

[buRRp]

Thanks for the info guys.