If anyone is around right now that can eyeball pinion angles, could you also confirm that my angle looks high? I left some of my tools an hour down the road and I don't have anything to measure with.
Eyeball my pinion angle please!
- Thread starter jeep_boss
- Start date
OP
Crap, I had uploaded the wrong picture. No worries though, I wound up making the drive to pick up my tools tonight. I measured it out and the new poly trans mount did in fact add a few degrees to my pinion angle. Ran into a snag getting my passenger side UCA out - the dipshit 4x4 shop that the previous owner had install the exhaust BLOCKED the forward bolt from coming out. I don't have enough play by removing the rear hanger bracket, I'll have to get creative to make room without breaking my exhaust :/
OP
I'm either overthinking this or confusing myself. When measuring pinion angle for a CV setup like mine, I'm ONLY measuring the angles on the axle pinion yoke and the shaft itself, correct? If so, the daylight reveals that they are both inline.
The only other things that had happened since this vibration started were:
The only other things that had happened since this vibration started were:
- Bad u-joint replaces at front of rear (pressed the new one in evenly)
- New trans and motor mounts
You're overthinking it.
This is where you should measure your angles:
The rear pinion should be 1-2 degrees LOWER than the driveshaft angle, otherwise you will experience vibrations. So if for example the driveshaft were 15 degrees, the pinion would be 13-14 degrees.
This is where you should measure your angles:
The rear pinion should be 1-2 degrees LOWER than the driveshaft angle, otherwise you will experience vibrations. So if for example the driveshaft were 15 degrees, the pinion would be 13-14 degrees.
Are the u-joint bearing caps centered in and properly seated down into the yokes? Not being seated down inside the nubs pointed to by the arrow will cause a hard to isolate vibration.
And there's no chance the pinion angle could be a tad above the driveshaft is there? Better the pinion angle be pointing a tad under that of the driveshaft angle than a tad above the driveshaft angle.
And here's a better point from which to measure the pinion angle from, it is precisely perpendicular to the pinion shaft. Rotating the angle finder as shown will directly indicate the pinion angle.
And there's no chance the pinion angle could be a tad above the driveshaft is there? Better the pinion angle be pointing a tad under that of the driveshaft angle than a tad above the driveshaft angle.
And here's a better point from which to measure the pinion angle from, it is precisely perpendicular to the pinion shaft. Rotating the angle finder as shown will directly indicate the pinion angle.
OP
Ok, I was doing it right then. I'm not sure how low I should go though, given my RE lift setup - there aren't really any components to it that would cause the flex that most people correct for with the lower angles. When I originally measured, it was 1 degree down, right now it is even, so if I can figure out the bolt removal problem (just started a new thread on it) then I'll drop it a bit and see what happens!
OP
Bearing caps are completely seated and flush. I bit th bullet and bought a good vise recently for jobs like this (Wilton 1755, a thing of beauty!).
To your second point, that is EXACTLY where I was getting confused - I wasn't sure if the transfer case yoke needed to be measured too.
OP
OP
OP
It started after my u-joint went out to lunch. It just seems amplified now with the poly mounts. It's no where near as bad as with a bad u-joint, but it's enough for me to worry about it doing damage over time!
Well yes, poly mounts suck, big time. I'd never run them again. But given that it wasn't always there, it has to be either the addition of the poly mounts, or the new u-joint you installed (which you might have installed improperly).
OP
I'm positive the u-joint is in there properly. When I swapped it out, I had also swapped trans mounts. The old one was t completely shot, but I know that it made everything sit a few mm's lower. I look to be dead even on angles, so I will have my work cut out today in getting that bolt out to adjust it!
OP
One last
NICE!!! I missed that photo of the spot on the back of the diff! Thank you so much for that!!!!
NICE!!! I missed that photo of the spot on the back of the diff! Thank you so much for that!!!!
Polyurethane transmission and motor mounts pass vibrations far more readily, rubber mounts are a better choice. Which is why car manufacturers always use rubber mounts.
OP
I'm not bothered by the additional "normal" vibrations. I look at them as a bonus for feeing abnormalities, such as what's going on with my rear DS. It wasn't as pronounced with rubber though - the initial swap I did was with an OE rubber mount.