Greetings All-

Just picked up a '90 F350 2wd to replace my used-up van... nice shape, but has two issues that I have valiantly tried to cure but have come up short: The driveline vibrates badly -- the center support bearing was bad, and replacing it helped a lot, but it's still there at around 70 mph and up. The Haynes manual doesn't include info about the bushing at the back of the trans; could this be bad? The tires may be the culprit, but if so it'd be the most out-of-balance dually ever.

Related to that is trans fluid is leaking out the back of the trans as well, but not through the seal; instead it's coming out through the shaft and into the forward U-joint. Should there be a plug at the end of the splined shaft that slips in the trans? I'd guess this plug would have to be almost 2 inches in diameter.

Lastly, I replaced the pwr steering box (it was binding severely). It's all good except there's now huge play in the wheel. The paper that came w/ the new box said "don't adjust". The linkage that follows looks good, and while a friend moved the wheel, we verified that the play seems to be in the box. Should I adjust it anyway? Am I missing something?

Anyway, many thanks for any input.

Dave in Delaware

 

Hi Dave,
Check your driveshaft end yokes to see if they are line up with each other. Sometimes on a two piece driveshaft when the yoke is slid off the spline it is not always put back in the same place when reassembled. This is called " being out of phase". Also another thing to look at is the angle of the pinion shaft on the rear axle and the angle of the transmission u-joint. Both of these angles must be equal to each other or vibrations will result.As to the oil leak coming from the universal yoke, this may very well be true. I would check it out. Leverett Fernald

 

97 f150 4x4 4.6v8 auto.
I would have the driveshaft "balanced".
It cost me very little to have this done and I have no more vibrations.