If by light or heavy duty you are referring to gear ratio, then you have a gear ratio problem (there was an upgraded axle for 2008+ models, but I’m not thinking that is what you are referring to).
There are two gear ratios used – 2.94 is standard, and 3.36 is in the “Big Tow” package, “Off-Road” and on later models, the Pro4X. So, I’m thinking you probably had 3.36 gears. There should be a sticker on the side of the differential that shows gear ratio, to be sure.
Long story short, the gear ratio in the front and rear differential must be the same. If you had 3.36 gears, and put in a 2.94 replacement rear end, you won’t be able to use 4WD, since the front diff has a 3.36 ratio. If I’m right about the ratios, don’t try 4WD – something will break.
The electrical connectors suggest you had an e-locker diff in the original rear axle. If you have a switch on the dash to lock the rear diff, that’s what you had. I’m not positive, but if you had an e-lock rear diff originally, no hook up may also cause a fault, but I don't think so. I suggest making sure the ratios match before worrying about that.
Good luck!
There are two gear ratios used – 2.94 is standard, and 3.36 is in the “Big Tow” package, “Off-Road” and on later models, the Pro4X. So, I’m thinking you probably had 3.36 gears. There should be a sticker on the side of the differential that shows gear ratio, to be sure.
Long story short, the gear ratio in the front and rear differential must be the same. If you had 3.36 gears, and put in a 2.94 replacement rear end, you won’t be able to use 4WD, since the front diff has a 3.36 ratio. If I’m right about the ratios, don’t try 4WD – something will break.
The electrical connectors suggest you had an e-locker diff in the original rear axle. If you have a switch on the dash to lock the rear diff, that’s what you had. I’m not positive, but if you had an e-lock rear diff originally, no hook up may also cause a fault, but I don't think so. I suggest making sure the ratios match before worrying about that.
Good luck!
