Differential whine?

[c2xejk]

In the continuing saga of my Spirit, I have installed the new clutch and transmission. The transmission is a used 543 that installed the OBX from the prior transmission. I used the ring gear from the transmission and shimmed it.

Now it has a whine once you get above about 20mph. I am not sure why. Issue in the junkyard transmission? Should have I used the ring gear that came with the transmission? Did I not get the shimming correct? ??? Any thoughts?

[4 l-bodies]

Differential carrier bearings get replaced? Sounds like preload maybe didn't get set correctly. Did you set it with dial indicator and inch pound torque wrench? This is supposed to be be without ring gear installed. Is whine there all the time at speed above 20 MPH? Does whine go away when you push in the clutch? Does whine get louder with speed? Intermediate shaft bearing could be bad too. Sort of hard to tell difference between intermediate shaft bearing and diff bearing whine, as they're both turning.
Todd

[c2xejk]

It varies some with load. Seems to go away when I push in the clutch.

I put fresh bearings on the OBX diff when I installed it (in the old trans). I did not put in new races. I did setup the preload with dial indicator (0.010" preload)

One thing I just realized, the old trans was a small spline trans and the new one was a large spline trans. They have different final drive ratios... concerned the ring gears are not compatible...

[4 l-bodies]

If the noise goes away when you push in the clutch pedal, it is more than likely input shaft bearings. You can further test by placing car in neutral engine running, and clutch engaged. At this point only the input shaft is turning in tranny. If you hear some bearing whine it will increase in volume when driven (when a load is put on it).

You didn't happen to check or set input shaft free play did you? Ring gear could be either 3.50 or 3.85 in 90-91. 92 and up was 3.77. I doubt you could have even bolted the differential in if the ring gear wasn't a match for the intermediate shafts pinion gear. I know all the auto ring and pinion and transfer shaft gear counts, but don't know the manual tranny R&P #'s.

If you still have the old broken tranny, check to see if ring & pinion mate okay. If they do, then your R&P in your replacement should be fine. Do you have tags from either tranny? FD is listed on the tag.
Todd

[c2xejk]

I will try the neutral test and report back

Input shaft had no play in it.

I will check the tag on original trans. The new trans was 3.77

Thanks