I have some ugly half shafts back there, could that be it? Just really hoping I didn't somehow bust my rear diff. Back of the car just vibrates like an out of balance washing machine. i'm not moving more than one or two, but the vibration feels like it should be going 70

Sounds more like drive shaft to me.  It spins way faster than the wheels.

Sounds more like drive shaft to me.  It spins way faster than the wheels.

Was in fwd during this.

Drive line

The driveshaft spins anytime the rear tires are rolling.

 

Have had a few go bad on the BRAT's I've had. Easy replacement.

What Tom wrote.

Tru 'dat.  Driveline U-joints.     Just heard the same sound from EA82.   Diagnosed my boy's car in 5 seconds.

EA81 u-joints are easy to replace.

 

EA82 u-joints are a Royal Pain In The Arse to do........

I did my research and, yes, ea82 ujoints will be a challenge.    I am considering a driveline shop in Portland ... but there's no fun in that.   

  My boy's car was easy.   Remove rear driveshaft.   Pull rear driveshaft from $100 parts car (she keeps giving, and giving and giving).  Install new old driveshaft.

  But now, I want a replacement spare for my '85 ea82 wagon.   So I gotta fix the broken one.   Thanks, Dad !!!

Tom, can I buy any ujoint for the ea82 ... or is it a special ujoint for replacing staked oem's?

This happened to my gl recently. I took the drive shaft out and the front u joint was very stiff. I used a ton of pb blaster and worked out all the dirt, the whole time rotating the joint through its movements. A bunch of mud and dry dirt came out of the joint. It steadily got more and more loose and eventually it felt fine. Put it back in the car, shaking gone.

This happened to my gl recently. I took the drive shaft out and the front u joint was very stiff. I used a ton of pb blaster and worked out all the dirt, the whole time rotating the joint through its movements. A bunch of mud and dry dirt came out of the joint. It steadily got more and more loose and eventually it felt fine. Put it back in the car, shaking gone.

This is exactly what it would seem like. Lots of dirt lots of mud, very few washes.  Will any ol u joint work? Got some out in the old garage from back when we had a beat up f150

These u-joints are specific too nissans and subarus of the era.

Got the EA82 u-joints thru AutoZone. 2-0430DL is the part number.

 

edited to add p/n

Edited June 26, 201510 yr by TomRhere

Advance has a couple of options for the 87 Brat, reasonable prices.  Autozone is showing a greasable Duralast for ~$7.