btw, i do have a weeping rear pinion seal but cant feel any play in the flange. And i cant feel any play in the wheel bearings but ive read that sometimes they will make noise/vibrate even if you cant feel any play.

 

No, you can not pinch off the brake hose, the brake hose is a super hard rubber on the inside (has to be, to with stand the pressures created by power brake booster). If you pinch the hose, you will collapse/damage the inner portion of the hose, and in turn will create a situation where fluid will travel one direction, under pressure...but not release the pressure when foot is removed from brake pedal. This is another reason why you should never drop the caliper while the hose is still connected, this will also damage the inner rubber portion of the hose.

The proper way to remove the cup, is to remove the hose, drain fluid, then blow air into the capiler with compressed air, forcing the cup outward. Be sure to have an old brake pad or block of wood in the area where the cup will be moving into as it comes out. They can really pop out quickly, and you can get hurt if you're not careful.


Just passing along this info, even though you have already determined that the brakes are okay.

Brian.

 

Thanks for the info, will sock it away for future reference!

This problem is really starting to irritate me. Never thought it would be this hard to locate such an issue.

 

Anyone have a recommendation for a rear shaft u-joint? Gonna pull the rear shaft tonight and go for a test drive. Might as well change the u-joint while it's out again.

 

Removed rear shaft to install new u joint. Went for a drive without the shaft and vibration was still present.

Running out of options

 

I take it the vibration is NOT correlated to engine speed, i.e. you don't think it's engine vibration.

Usually if it's correlated to road speed it's tires or drivetrain, more likely tires.

You're saying it can't be the tires, driveshafts or brakes. So it has to be the transmission, transfer box, diffs or something in the axles.

Did you run it without the front shaft, assuming you can lock the diffs?

I know you said you got new tires, but you didn't notice any difference at all? That seems strange to me.

 

I would go back to this phenomena.....check the rear bearings, look for any metal shavings in your running gear?

 

Engine rpm doesn't effect it. Transmission gear doesn't seem to affect it, whether in 3rd 4th or neutral.

It is worse under slight loading, like minimal throttle up shallow inclines. And it is less noticeable under heavy acceleration.

While the rear shaft was out, I yanked on the pinion flange and it didn't move at all, but when rotated it fell very notchy. Like the gear teeth might be grooved.

I'm wondering if possibly both driveshafts had worn components. So when I removed the front shaft, the vibration was still present, but now that the rear shaft is sorted the front shaft is still not right. Might pull the front shaft out again tonight and see what happens.

 

No metal in the 3rd members?

 

Checking diff fluid is next on my list. Changed fluids in both front and rear awhile back and the rear didn't have much in it due to weeping pinion seal. I've never had a worn differential vibrate at low speeds before though, I would find that odd.