Alright, I have a nasty vibration that seems like a U-joint, but it's not. Maybe have a bad one now due to the issue, but I didn't when I first checked. And the problem is only getting worse.

I have a 95 short bed 4x4 mazda5od.
3/4ton overload springs from the junkyard were installed by the previous owner, I do not thing they are the correct springs, but I love the ride height in the rear.

My rear end is out of an 88, my 95's 8.8 basically came appart. I posted about it before.

I need to figure out if there can be other things i should check along with my pinion here.

It is the only thing I can come up with for being wrong.
What other things are there I can check?!
I plan to pull the diff cover, and check in there, but I'm positive my ring and pinion are not missing teeth.
I had a break lock up on my recently, due to a frozen Parking Break cable. This drug for an extended trip unknowingly. Could my clutch pack have froze up, and really screwed things up also?
Truck wants to act like a posi, or not. It wont make up its mind.

The truck was only vibrateing at 65-78ish, now its 25-58ish and 65-78ish.
I can drive 60, and it seems like everything is in harmonic ballance I suppose.
I have virtually no power in 5th gear on the road, and horribal gas mileage.

Breaks are new all around, and are not dragging now.
clutch is brand new. Its not clutch.

I got no out of the ordinary codes except some wierd right bank code for the engine. The vibration is certianly from the rear however.

Just one problem after another on this truck.

 

Okay, Superbowl is over.

Back to alternate man time. Which means. TRUCKs.

 

When I got my truck it had a vibration at a certain speed, 55-60. Drove it like that quite a while. Finally replaced u joints, and the vibration moved to 65ish. Finally took driveshaft to a drivline shop to be balanced. Was bent. Had almost .050 runout, think acceptable is about .007. Made new shaft, and vibration went to 70ish. Few months later, pinion seal started leaking, and pinion started clunking when take off from stop. Replaced seal and front pinion bearing. No clunk, and no vibration, unless it is above 75. I ain't driving BUFF faster than 75 to look for the vibration.
I believe the bent drive shaft ruined the pinion bearing, seal, and the ujoints. There was no visible damage to the shaft. The shop was going to balance the shaft while I waited, and charge something like $25, but checked runout first and stopped right away. Took a couple days to get the tubing, and a couple hours to make the new shaft. Cost around $125.
Hope this helps. Frank

 

Very helpfull.

Thank you.

 

Simple stuff first. check the tires. make sure they're in balance. while you've got the rear tires off, check the back brakes. You're e-brake was just out of whack recently. maybe the brakes are dragging out back.....well, after thought..you'd probably notice dragging brakes all the time, not just at certain speeds. tires are off, wouldn't hurt to check them.

 

If you're worried about the pinion, just see if there is any play between the pinion flange and housing. It should be zero due to the bearing preload. Any play at all (you might try using a dial indicator) would explain your noises.

Dave

 

I think my bearing preload is gone. Unsure.

When i took the flange off i wiggled the pinion, and it moved more then i'd have liked it too.
However the rear end was on the ground, so the differential woudln't have spun.

I think my pinion is climbing the ring gear. If you stop, and put on the ebrake, it will pop back into its normal position.
Going to have to adjust the backlash on it once i get the bearings changed.

low92flareside.
I can't remember if i wrote above, but i've checked all that stuff already.
Its too outa wack to be a tire imballance.
I can feel it through the shifter, and the transfercase shifter.

i found a place to check my driveshaft in saginaw. I guess they are the best around here.
Once i get this rear end in line, and new Ujoints in, I'm going to have them check it for trueness, and ballance.

 

Before you go and spend too much money on this project, keep in mind that you can bring that axle to a junkyard and get a replacement with lower miles for realy cheap. I'm talking under $40 if you give them your exsisting axle. All that would involve would be possibly re-doing brakes and removing e-brakes and brake lines. Alot cheaper then dealing with pinions and possibly axle bearings.

 

Everything is fine, just need to replace bearings.

Ubolts will be 30 dollars too.
And i just got all my breaks working fine, i dont want to screw with them.

about 45 dollars in parts and a days worth of time to change the bearings, is much faster then removeing and redoing a whole axle all together.