just put in the new 9"-finally.

works great- it has traction loc and came from a ford p/u truck.

problem is that i feel a shift when letting off the throttle. it doesnt feel like torque and does not do this when the clutch is depressed. it almost feels like the insides of the center section are shifting. not violent, but enough to make you wonder what it would do in the wet--

thanks for any suggestions.

btw- wheels and lugs are tight, all underneath is bolted in tight.

 

Could you be a little more specific on what is happening? Do you hear any noise or clunking when the occurs? I'm thinking that maybe the leaf spring pins are smaller than the holes in the springs perches, so the rear end walks a little. Could that be whats going on?

 

If it feels like a 'clunk' when you let off the gas, then its too much backlash. It may not be as noticeable when you push in the clutch because the engine compression isn't making resistance like it does when you just let off the gas.

Check the backlash in 3 places around the ring gear and reset as needed.

Also, for good measure, check the rear U-joint. Sometimes that can be worn and give you a 'clunk' feel, but its not usually as pronounced as the backlash issue.

 

Tighten up the u-bolts that mount the rear end to the leaf springs. These really need to be tight or it will create the exact problem your having.

 

I was thinking the same thing.

 

Also check u joints.