UAZ28SS

iTrader: (2)

Baby Barf Yellow...

Get that clunking fixed yet?

csxfbird

iTrader: (5)

Indeed I did. Swung by Precision Alignment & Brake, got the car up on the alignment rack, and tightened the hell out of the rear lower control arm bolts. Clunk-free now.

Now, I just have to figure out what's causing a vibration from 70-75 mph. I triple checked the pinion angle (driveshaft is at +1, torque arm is at -3, to make a true pinion of -2), the car's been aligned, the only things left are the tires and the driveshaft. And the car wasn't vibrating before the suspension install.

Sam Strano

iTrader: (41)

A change in ride height will result in a small change in pinion angle (usually nothing that matters). I don't follow if the TA was on before or not, but either way a specific vibration at a certain speed would indicate to me that you need to tweak your pinion angle just a touch...

Pinion angle is a pain in the ***, I hate it. Frankly I usually start with a stock measurement and work from there. When/if I get a vibration or shake, I back it back down a touch. There aren't any absolute numbers, maybe you have a u-joint that's a little sticky and so what is normally ok isn't on your car.

csxfbird

iTrader: (5)

The new adjustable torque arm went on at the same time your springs and the Konis went on...I don't suspect it being the poly transmission mount, as I did grind down the two nubs as well as added a small rubber gasket to the mounting plate. Would you recommend trying to increase or decrease the torque arm pinion angle? Or just play with it till it goes away? I'll try upping the pinion angle on the torque arm up from -3 to -2 to see if it makes a difference; I find that easier than replacing the tranny mount.

JamRWS6

Well stock is 0, so the closer you get to that the better IMO.

Sam Strano

iTrader: (41)

I'd agree, I'd say go less than more. It's usually a slight bind in a u-joint that causes it and the more angle you have the more the joints are like that.

csxfbird

iTrader: (5)

Gotcha. I'll start at 0, and work from there then. Back to the garage tonight, lol. Thank you gentlemen.

Sam Strano

iTrader: (41)

Let me know how it goes... It can't be way off. In fact I'd probably not go zero, just back it down a little and stop when the vibration quits (maintaing some negative pinion angle). Or go to zero, and start adding it back.... the former just seems quicker and easier to me somehow.

csxfbird

iTrader: (5)

Will do. I'll go with my original plan and go from -3 to -2, and then to -1 and 0 if the vibration doesn't go away. I'll probably get to it tomorrow evening.

csxfbird

iTrader: (5)

So I adjusted the torque arm so that it gave me a pinion angle of -2...took it on the freeway, vibration was still there. Then set it to -1...vibration was still there. I also noticed that the car vibrates pretty significantly at 90+ mph (enough to where my glovebox sounds like it wants to open up, lol). Should I go ahead and zero the torque arm, or does it sound like the problem is elsewhere?

JamRWS6

You are netting the driveshaft and rearend correct? Is it a constant vibration or only when you let off the gas? If it didn't change now at -1 i don't think thats the issue.

csxfbird

iTrader: (5)

What do you mean by "netting"? And the vibration is constant, it's still there when I'm on the gas.

AnimalSS

iTrader: (1)

I have the same problem. I just recently had an alignment and it's still there. So, you all think this is a pinion angle issue? I'm actually getting ready to order Sam's springs for mine as well. I already have the Konies (been on the car for about three years). I have those crappy DMS springs right now and my right rear bottoms out over the slightest dip in the road, especially if I have someone riding shotgun (and forget back seat passengers). So, the fender lip has been cutting into my tire. The tires are about ready to be replaced anyway so, I not worried about them but, I would like to solve the both those issues. Should I get the new springs installed before any pinion adjustments? And, would the addition of a panhard bar help out in the rear with the tire scrub? Honestly, my wheels are 17" x 9.5" with 285/45s so they they stick out far enough where the rear fender would make slight contact with the tire even sitting still if you could push down far enough. I was hoping that with the new springs installed and adjusting the rear Konies one or two notches up from "full soft" I would eliminate the tire scrub issue. Just wondering if the addition of a panhard bar would be additionally beneficial.

csxfbird

iTrader: (5)

Lowering the car will change the pinion angle slightly, like Sam said. I'd wait until after you install the springs before making any pinion angle adjustments (I assume you already have an adjustable torque arm?). And the purpose of a panhard bar is to center the rearend, which has a tendency to shift once a car is lowered, causing problems like you're having with tire/fender clearance. Are you having clearance issues on just one side, or both?

JamRWS6

Taking the angle of the driveshaft and netting (adding) that to what your getting from the TA bracket on the rearend to arrive at the pinion angle.

csxfbird

iTrader: (5)

Since I measured the driveshaft to be at +1, I initially set the torque arm to -3 to make a "true" pinion of -2, which I believe is what's recommended. Then I set to torque arm to -2 and -1 to create true pinions of -1 and 0, respectively. None have quelled the vibration problem.

I also noticed that the vibration seems to go away a bit when I'm off the gas pedal.

AnimalSS

iTrader: (1)

My clearance problem is just on the pass. rear. The rear end is pretty much dead center as far as I can see. I think mine is "mostly" contributed to a bad spring. When I first installed the DMS springs and Koni SAs, the pass. rear Koni busted soon after the install. But, it was a few months before I realized it. I would occasionally hear a 'tire scrub" over a dip in the road when I had a shotgun passenger… which was rare. That's why it took so long to realize what was going on. So, basically I was just riding on the spring for months. I'm sure that weakened that particular spring, which probably wasn't that great to begin with. When I got the replacement Koni, the "tire scrub" issue went away for a while but has gotten progressively worse over the last year or so. Now, it happens over nearly each and every road imperfection from 35mph - 80mph. I'm about to remove the DMS springs and put the stockers back on until I can get the Strano springs and what ever else I need.

As far as an adjustable torque arm, unless it's stock I don't I have one. I haven't installed anything like that. Do I need one of those as well?

csxfbird

iTrader: (5)

I'd take a tape measure and see what kind of clearance you have between the tire and lip of the quarter panel, see of they match up on both sides. I'd venture to say that they'll be of a bit, with less clearance on the side that's rubbing.

And to make any sort of pinion angle adjustments (which is what you originally asked about), you'll need an adjustable torque arm. The factory piece is non-adjustable.

AnimalSS

iTrader: (1)

On the Passenger side (the one that rubs) the clearance is only 1.25" and on the Driver side it's 2.5" and, I also noticed that the "bump stops" (the foam blocks bolted to the frame right above the axel) are all but disintegrated.

So, what's a good adjustable torque arm?

Sam Strano

iTrader: (41)

I'm partial to the UMI full length: http://www.stranoparts.com/partdetai...=106&ModelID=7

And if you want it off the transmission tailshaft, you can run the relocation bracket (this one is for a stick shift car): http://www.stranoparts.com/partdetai...=106&ModelID=7