Rear Axle Shaking bad

[arren]

I have a 94 b4000 4x4. I swapped in a 3L73 8.8 from a mid 90's ranger to upgrade from 3.27's and an open diff. Around the same time, I had replaced the transmission and transfer case as well as swapped in a one-piece driveline. The truck has a 4 inch lift, blocks in the rear. With that new axle in, I have a terrible shake. I won't even call it a vibration because it is so bad. My shifter moves back and forth, it's like driving on a washboard. Since this, I have rebuilt the transfer case, bearing and seal kit, had the driveline balanced, went to 33's and had them balanced. With the rear end on jackstands and running in gear, I can see and feel the driveline wobbling, so I swapped in another driveline only to have the same effect. I can see the passanger side brake drum is bent and can hear it scrape the brake shoe with every turn. The rear wheel bearings have minimal play in them, about the same for each side. I can't see the brake drum having that large of an effect, but it is next on my list as it needs to be replaced regardless. So, any ideas or direction would be greatly appreciated

Thanks in advance,
Arren

 

[RangerSVT]

Check your trans mount. Also, check your pinion for play (where the d-shaft bolts to your rear axle). BTW, I hope you re-geared the front as well...

SVT

 

[arren]

Will check the trans mount. the rear yoke is solid, could be bent tho i guess? not sure. I did regear the front with a lock rite no worries there!

 

[RangerSVT]

It's possible you have an axleshaft bent, causing both your vibration and oval-like brake drum...

SVT

 

[Sasquatch_Ryda]

Might be the axle flange bent and not the drum...

 

[arren]

I actually did think of that and replaced that shaft with the one from my old axle, sorry forgot to mention that. I figure it must be good as I didnt have the vibration with that old axle. Once the transmission mount and drum are checked out I will post results. Thanks for the help guys!

 

[Sasquatch_Ryda]

You could drop the rear shaft and go for a drive on the front. See if it changes.

 

[arren]

So I got another brake drum and put it on. No change so I jacked the truck up and both drums are rubbing the shoes now. With it running I put my ear to the diff cover and could hear an awful noise like something is broken in there. So, I pulled the cover to see what I could find. The carrier bearings had no play and neither did the pinion. The cross pin had a little bit of axial play so I pulled the retaining bolt and it had play inside the hole of the cross pin. I dont know if that's normal or not. The spider gears had a bit of backlash, again I dont know if that's normal or not. I also noticed my clutch pack(limited slip) is definitely worn out because I can spin the wheels separate without too much difficulty. Aside from that, the axle looked fine. Maybe theres something wrong that I can't see. I wasn't able to get another transmission mount yet, but it doesnt look like it's moving when the truck is up on jacks and running.

 

[arren]

Update: I ran the rear end on jacks with the drums off and found both axle shafts looked out of round at the flanges, not a lot but with a screwdriver planted next to it you can see and hear it hit with every rotation. i'm not sure if its out of specs or not but it could be normal as far as i know. theres also a tiny bit of up and down play at the wheel bearings, very minimal but its more than any junkyard axles ive checked have. I checked the rear shocks and they seem fine. I took the driveline out and ran it to see if the noise I'm hearing is coming from the t-case or transmission and there was no noise so its definitely in the rear end. Is there any thing else anyone can think of for me to check?

 

[legoms013]

No.

Nothing should be rotating out of round and there should be no play in the bearing up and down (or left and right). In and out movement of about 1/16" is normal.

Your shafts are bent, I'd get new ones.

Actually it sounds like the axle as a whole as a lot of wear on it. Rebuild it, rebuild another or build an expo 8.8 on the side. It is time to retire that axle in one form or another.

 

[arren]

I was afraid of this. Well I will post back once I am able to afford another axle. Thanks for all the help guys I appreciate it

 

[sixty9oz]

I have basically the same problem, but with the drums off, I can't see anything moving out of round or anthing, and that's putting a straight edge to it and feeling it also. With the drums (which are new), it looks like they are moving up and down a little, but very slightly. Bearings are new. With wheels and tires on, around 60+ on jack stands, it shakes like nobody's business. Replacing the drums helped a lot, but not completely. I'm not sure if it's the axle, shafts, or rims/tires. After a year or so of replacing every bushing/bearing, mount, brake, tires, tie rod end, ball joint, shock and a few other things, I've finally narrowed it down to the rear end, so I know how you feel. lol