Rear End Angle??

[Snohog]

Was hoping someone out there has made a shim to correct the drive shaft angle of the read end after lowering. I am using 5" lowering coils and the angle of the trailing arms has chnged considerably. If anyone has the made this shim and has the diminsions it sure would be appreciated. What angle is the u-joint supposed to be at, I didnt check before taking apart.

[ante_up13]

Are you using a supertrack bar kit and shock relocators? I am attempting the same thing on my 69 c-10 this week and early classic sold me the new coils, shocks and a super track bar relocator kit that is supposed to keep everything in alignment...as far as I know...which isn't all that much

[Snohog]

I purchased from ECE also, its a good kit and keeps all the angles correct for shocks and the adjustable track bar keeps the truck straight, no cat walking. The trailing arms are bent where the axle housing bolts up. The angle of that bend changes when you raise the trailing arm to lower the stance. When I sat the rearend in place the differential was angled down from horizontal and I think it should be up from horizontal. I looked at a couple of trucks last night that were stock height and on both the rear end was angled up Im guessing about 5 degrees. It may not make a difference but I dont want to put it all together and have to take it back apart.

[Tx Firefighter]

Run it brother.

I've done both 4 inch and now 6 inch ECE rear lowering springs. No problem ever with vibrations, noise, or u-joint wear.

[trailmaster]

With A Single U-joint On Each End Of The Driveshaft, The Angles Should Be Equal To Avoid Vibration. In Other Words, The Trans Output And The Pinion Should Be Parallel. Sometimes Wierd Things Happen But That Is The Rule Of Thumb. Make Sure That The Joints Are In Good Condition. If The Driveshaft Has Ever Been Cut, Make Sure That The Joints Are Still "in Phase" (aligned) With Each Other. A Constant Velocity Joint (two Universal Joints) At One Or Both Ends Would Also Cure Vibration Problems. Older Cadillacs Used A Shaft Like This.

[Snohog]

I thought I remembered the tranny shaft and pinion shaft should be parallel. I guess I'll have to put the rear end together and wait till the rest of the drive train goes in to adjust. Or I may just do what trailmaster suggest, If it dont vibrate dont adjust. Thanks for the info.

[chevytruckfan]

Originally Posted by Snohog

Was hoping someone out there has made a shim to correct the drive shaft angle of the read end after lowering. What angle is the u-joint supposed to be at, I didnt check before taking apart.

Summit sells shims to help relocate your angle problems I saw them in a catalog I will get the part number when I get home. As far as the angle goes if you still have the trans in the truck put a angle finder with a magnetic base on the output tail shaft. Then set the pinion angle 180 degrees from that to cancel.

[Snohog]

I called Napa and then every truck aftermarket shop in Indy yesterday, everyone sells them for leaf spring lift set up but no one had them for coil spring trucks. I'll check summit over the web dont have a catelog. ChevyTruckFAn if you locate that part number pass it along I would sure appreciate.

[Tx Firefighter]

This is going to freak you out, but I put a thick fender washer between the trailing arms and axle pads on a truck one time.

Just put the u-bolt through the washer and sandwich it under the axle and above the arm. It acts as a shim that way. Tighten the hell out of the u-bolt and you're good. The truck in question had new saddles welded onto the rear axle and the guy put them on the wrong angle and had vibration. Two 3 cent fender washers and he was good to go.

[68LSS1]

shims

[1972C10]

3-5 degrees down.

I made me some washers out of 1/4 plate

[Snohog]

Problem solved, great site 68LSS1, the slip in shims are perfect. I can assemble everything wait till the tranny is in place and set everthing properly. Thanks for the info.