madmax93

I have a savage 4.1 and I loss rear wheel drive, it still has front wheel drive. I took out the diff and turned it and it sounded and worked ok. I also checked the pin that hold the shaft on, which is fine. I'm thinking it might be the transmission. Is it possible
that the truck could lose only rear wheel drive if somthing is wrong with the tranny.

burnchassis3

1st off ,yes its possible. To check this lift your truck up ,and spin the spur gear so that the wheels turn...hold the back wheels and see if you can still turn the spur gear.
As you turn the spur ..look at the the drive line starting at the trans..see if the cup is spinning,then dogbone,then diff cup,diff,wheels etc.
or hold your spur ,and try to roll the truck backwards on the rear wheels see if you can tell where the problem is.
CS

savaged_dude

Are you sure that grub screw is there? In the the rear hub. It may still have the head there but the tail that locks it was sheared off.

megamaxx

could have rounded a wheel hex/rim

mazdab2600

the tranny in a savage has a solid output shaft.if any gear inside was bad you'd have no drive to front or rear.
most common problems for no drive to front or rear.
1 grub screw missing/broken
2 stripped/chipped teeth on diff crown or pinion.
3 worn support bearings on pinion or diff support
4 improper shimming of the diff
5 missing/broken wheel hex pins
6 stripped rim hex

-SomeGuy-

There are 2 grub screws that you need to look for that would cause this problem. One on the tranny and the other on the diff.

rican25

what about the drive shaft screw? just a shaft on one end and the other end has the threads topped off with an allen head set screw. could be what you guys are talking about, not sure.

madmax93

I removed both grub screws and they were in tact. When i start the truck up the large bevel gear on the diff rotates and the drive shaft does too with the wheels off the ground, but when I put the rear wheels on the ground the large gear does not turn but it looks like the drive shaft is turning. Could it be that the diff needs to be shimed as mazdab has said, and how do you shim the diff ? I'm stumped on this one. I think I might get a new diff off of e-bay and try that.

mazdab2600

i think your refering to the spur gear now. the large one on the tranny?

if it spins freely then your too lose on the nut/spring. tight till the spring compress's then back off 1/4 turn.

if its the diff gear(crown 43t & pinion 13t) start checking for a bad bearing allowing the diff to shift away from the pinion.


may want to check the pinion bearings as well.had one go bad as well and took abit to figure it out.
plus a few extra broken parts.