More freaking vibes with MAR just days away

[Kavic]

Working on some minor vibration issues since the new lift on my 95 D1. Went from OME HD to 3" RoverTym with isolators top and bottom, replaced radius and trailing arms and installed a new front DC driveshaft.

I primarily get vibration when I left off the gas. The u-joints on the rear shaft look good and seem tight, don't notice play in them.

When I pulled the rear shaft I noticed I could rotate the pinion flange about 1/8". Is that normal? Could this have anything to do with the vibes? I recently had major vibes with a bad wheel bearing and have replaced bearings and stub axle. Could that have caused any problems with my detroit/diff?

With the rear shaft off, should that brake drum be making a lot of noise i.e. metallic dragging sound and/or tinkling noise? The vibration when I let off that gas appears to be gone.

Any help would be appreciated.

 

[noee]

With the rear shaft off, be careful, the set screw will come loose and the drum will fall off. That could be causing some noise in there if the set screw is loose.

What is it when you let off and get vibes? Hell, when I get on it, I get vibers, when I let off, smooth as buttah. I think your pinion is moving, I'd re-check the rear link bolts, frame and axle casing.

 

[Nomar]

I kinda suspect the u-joints for your vibration.Some feel pretty good but when you change them out; vibration gone.
Not sure what your metallic sound is.

 

[Kavic]

Was planning to replace the u-joints while it's out just to eliminate the possibility. More concerned about the play in pinion flange, I'm not experienced with this stuff....

Figured I would change the spacer setup in the trailing arms while I'm at it. Everything is currently tight, just retorqued everything a week ago. Didn't check the screw in the drum to see if it was tight. I'll take a look at that too.

 

[sven]

Do you have RTE rear links adjusted where the pinion is parallel with the tcase? What kind of rear DS are you using?

 

[Nomar]

IIRC,my pinion flanges seemed to have at least that much "play" in them...

 

[Kavic]

Do you have RTE rear links adjusted where the pinion is parallel with the tcase? What kind of rear DS are you using?

I may not have the rear links adjusted properly. I believe I was told to start with the 1/2" spacer and then adjust pinion down from there. I don't recall hearing the pinion should be parallel to t-case. That certainly would have helped. I was planning to change the spacer's again tonight.

I've bought the AB driveshaft a couple years ago to get rid of the rotoflex.

 

[sven]

You definetely have to make it parallel. I used the thick spacer + the thin spacer + a M20 washer that I bought from hardware store to make it perfect. I used a Sears magnetic angle gauge to measure the angles.

 

[Randy]

I may not have the rear links adjusted properly. I believe I was told to start with the 1/2" spacer and then adjust pinion down from there. I don't recall hearing the pinion should be parallel to t-case. That certainly would have helped. I was planning to change the spacer's again tonight.

I've bought the AB driveshaft a couple years ago to get rid of the rotoflex.

Kavic, long time no see. Take note of who the guys are that offered help here....you'll see them around the smoker next week!

 

[barefoot]

vibes when you let off the gas is probably a loose yoke (aka driveshaft flanges) but it could be u-joints as well! unfortunatley, the only way to tell would be to put the shaft back in (with flange bolts as tight as you can get them) and see if it is still there!.

as far as the e-brake drum making noise....you prob dont have the the little allen screw in anymore or it is very loose! if it is missing all together then the brake cover works loose and parts will fall out...ask me how i know! i dont think one would fall off completely as it is a very positional piece (pita) to get off. you may also have noticed a clunking when hitting the brakes...??

as for the slack in the pinion. it seems to be normal! my old pumpkin had at least that much and the newerish one i put in had just a little bit less so i would assume normal wear. although i am sure it has some amount of responsibility for all the driveline slop these things seem to have!

 

[Kavic]

Kavic, long time no see. Take note of who the guys are that offered help here....you'll see them around the smoker next week!

Hey Randy, looking forward to seeing everyone. And hopefully they'll be seeing me. My truck has been out of service alot this summer for some reason...

 

[Kavic]

as far as the e-brake drum making noise....you prob dont have the the little allen screw in anymore or it is very loose! if it is missing all together then the brake cover works loose and parts will fall out...ask me how i know! i dont think one would fall off completely as it is a very positional piece (pita) to get off. you may also have noticed a clunking when hitting the brakes...??

I saw your posts last week...

 

[D Chapman]

Drive shaft if out of balance.

 

[Kavic]

You definetely have to make it parallel. I used the thick spacer + the thin spacer + a M20 washer that I bought from hardware store to make it perfect. I used a Sears magnetic angle gauge to measure the angles.

Didn't get to work on the disco tonight. Not sure where you measured the angles from but I just went out for a quick and attached to bottom brake drum directly below DS attachment location. 0 degrees. Attached to bottom of diff directly below shaft. 3 degrees. So I'm assuming the pinion needs to come down 3 more degrees.