After i drive my truck 4 a little while I start to get a little jerking when I come to a stop and turn left slow or if I pull a trailer I get the same thing. Could it just b the cluthes in the limited slip or bearings.

 

Mine did that very thing,turned out to be a broken spider gear..

 

get some rear fluid, and some friction modifier additive from Ford, drop the cover and have a look see, if nothing broken fill and add additive, and start lookin for some parts. The lim slip clutches would really only show up on turns, the comming to a stop and straight take off would concern me.

 

I used Royal Purple for this. It has the friction modifier in it. I didn't need to ad any more.

 

I've just noiticed it when I turn.

 

You could have two problems. Not enough friction modifier and driveshaft slip joint needs lubing.

See these links for more info.

Sterling 10.5 Gear Lube Change

Slip Joint Regreasing

 

Our excursion was doing pretty much the same thing, growling almost grinding sound when turning with a trailer. I changed the fluid and added some slip additive, and all is good. What was suprising was with 238,000 miles and I know it's the original oil it was clean as could be.

 

Robin, do you have a link to rebuilding or replaceing the rear diff. My boy wants to change gear ratio's in his SD from 3:73 to 4:33 or 56. He's got 35 tires and tows very heavy toy hauler. Plus he's a 6.0. He's also 4x4 so we have to do both. I never did one before but it dosen't look hard. Thanks,

Chet

 

Sorry Chet, no links or write-ups. There have been some threads. Hopefully someone else will chime in.

You can try other Super Duty sections. Gassers have the same diffs.

 

Thanks Robin had to check. You're so good at most of these, just knowing where they're at. Chet

 

This is John Wood's fix for the slip joint. Just drilled, tapped, inserted zerk and a couple of shots of grease. 15 minutes at most.

 

I asked the same question awhile ago heres the links I was given https://www.ford-trucks.com/forums/9...r-manuals.html

 

Ive been kicking around the idea of doing this, my question to you guys is go you need to have the drive shaft rebalanced or does the grease fitting counteract the weight change?

 

Thanks for the information. I'll have to study it more to see if it helps.

Chet