i am having a major problem getting my pinion set on my bmr UCA. i have the powerhouse 1 piece 4" driveshaft. the UCA was installed yesterday, and i stared getting gear whine, so i went back to the installer, and they adjusted it, and now if i hit bumps it sounds like the driveshaft is hitting the car. the UCA looks like its cranked all the way out, the punkin is kind of pointed up and the driveshaft is a little above it now. this does not look right to me, and its hitting the car. im going to go to a different shop tomorrow, but i wanted to know what is the correct procedure for setting it, so i make sure its done correct this time.

 

Not sure where the gear whine is coming from, but pinion angle has nothing to do with it.

The drive shaft and the pinion should be pointing down relative to each other ... generally the opposite of what you described. Depending on your ride height, pinion might be near horizontial ... providing the angle of incidence between the two is within specification. The specified angle is posted on the forum, but off the top of my head I do not remember. I suspect it should be on the order of a 2 -3 degrees, though but with the car loaded at rideheight.

Referring to one of my chassis books, the front-joint angle should be determined as well, expecially now that you have gone to a one piece drive shaft. The combined angle between front and rear should not exceed 7 degrees.

Had you not changed the UCA at all, likely the front angle would be higher and the rear lower than normal. If you only shoot for the rear setting, you might cut yourself short on the front (or total). With our linkage set up you could probably go to near zero on the rear (say 1 deg to be safe) ... as the rear squats under accelleration, the rear linkage will rotate the pinion down, increasing the angle the rear (front reduces).

Does that help at all?

 

i am at stock ride height, no plans for lowering. im guessing the whine is from the harder bushings. this does help, im going to see if i can find a place with a lift to fix it tomorrow.

 

Good luck. Ask questions. If you are at stock ride height, not sure why you installed an adjustable UCA. Lowers are not?

Keep in mind, the engine is angled down, the drive shaft angled down further, the pinion should be slightly pitched down relative to the drive shaft.

 

i bought the UCA, because the driveshaft i have is 4" and it has some minor scratches on it from slightly touching the body, powerhouse told me the pinion was prob off a little from factory. i also bought it to help stop the wheelhop. you wouldnt have a diagram or pic so i could see kind of how it should be angled and exactly where to measure the pitch?

 

The only clearance a 4" shaft has is with Saleen short shifter adapters... the rest is all rumors. We sell them all the time with no issues. Yes it will also rub if you pack 3 fat boys into the back and go over a speed bump at 10 miles per hour.

I think the pinion angle isn't set correctly. What kind of lowering mods you have?

 

no lowering mods! its from all the **** potholes here in nyc

 

One piece shaft will not solve wheel hop.

 

i bought the 1 piece shaft because its much lighter, and i also felt a big difference with it when i installed it last year.