I hope you mean u have a one inch lift in the front with springs, please tell me you dont really have blocks in the front. If you do, doesnt that scare the **** outta you, pardon my language on here but thats really dangerous even with one inch i would think thats bad. i hope they are the super long lift blocks, cause those are the only ones that belong in the front.

 

The gears should be fine. Especially if you didn't see any metal shavings in the oil when you drained it. You should look into getting a center pivot drop down bracket for the driveline's center bearing. That will correct your driveline angle.

 

If you can turn the tires in the opposite direction by hand, then yes, I would say that your clutch packs are bad. Here's a link on replacing the clutch packs on the sterling 10.25 rear: Sterling 10.25 Trac lock rebuild


I use 80W-90 gear oil and 1 tube of LS additive.

 

The one inch blocks on the front axle assemble are longer than the square axle housing, meaning the blocks protrude slightly both in front and behind the axle housing. They are in there solid.

I have a new u-joint in and the truck drives like before, no noise. My grabbing a hold of the drive line and shaking it wasn't a good test method, because it didn't show the u-joint being loose or starting to wear out. Only when the vibration got worse and it blew up did I find out the u-joint was bad. I was so focused on the ring and pinion. I should have taken the u-joint loose from the pinion flange and checked it that way.

I looked at a friend's stock F250, standard cab. So he has a single drive line. Mine's extended, to I have a two piece. The stock truck has a 2 inch block between the rear axle and springs. I'm assuming mine would be the same if it hadn't been modified. Mine have been replaced with the 3 to 3 1/2 inch wedge shaped blocks, so one inch lift. This time I stood back and looked, instead of being under the truck and too close. Of course a properly angled drive line to pinion setup would have a negative angle, the drive line coming down from the tranny and angled up to the pinion via the u-joint, the pumpkin more or less level. Mine is doing the opposite, a positive angle. The drive line comes down, but the angle to the pinion comes down even further. The front of the pumpkin is angle up way too high. I think this is what's causing me to eat up the pinion u-joint.

I think whoever installed the lift put the blocks in backwards. My next step is to turn the blocks around, which should angle the pumpkin back down in the front and see if that corrects my drive line to pinion angle.

Any other thoughts welcome. And if I'm wrong somewhere here, please let me know. Thanks

 

From what you are describing it doesn't sound right to me. It sounds like you are on the right track though.

Glad to hear it was just the U-joint.

Tim

 

Ya, I think you're on the right track. My dad has an 01 SD and I took the blocks off that and put the taller factory ones off of a 99 on it. They are definitely tapered and could only be installed one way. Sounds like that is your issue. Good luck

 

Update, for those still interested.

I finally loosened the u-bolts and turned the lifting blocks around. Set the springs back down on the axle and boy, what a difference. The drive line to pinion angle is now negative, like it's suppose to be, and the angle is 2 to 3 degrees. It looks like a stock set up now. I think I'm even feeling it drive better

So hopefully I won't be blowing up u-joints. Time will tell.

Thanks to all for the help.

 

Hey good deal, glad to hear it was an easy fix.

 

I'm glad you got it figured out. Not sure if anyone said this yet but the driveline angle split matters a whole lot more than the pinion angle alone. When I went to Ford and GM vibration analysis school they said to always shoot for 1/2 degree, no more no less difference between the front and rear. If they are zero they will make noise. Too much and it will make noise. I hate messing with U joints but rear ends are easy. You can shim the carrier bearing if you need to to get the split in tolerance. Also shim the rear axle if needed. You have to measure it by measuring the angle of the driveline on each side of the u joint. Then get the difference. Do that front and rear and look at the difference between front and rear. That is the angle split. go for half degree and they will stay in phase and be quiet.

Just more worthless info I like to throw out there.