MTFCA Forum

Are there notches on the backside of this 11 tooth pinion normal?

I assumed they were caused by a hyatt bearing that came apart, but I see one in the classified that has the notches also. Mine definitely had a little wear on the flat surface from the bearing, but if the notch is normal, maybe I'll just use it. It's in fair shape otherwise it seems.


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I think the ring gear is too close to the pinion and the pinion has been pulled forward toward the front of the car. Probably a spacer has been placed between the spool and the rear axle housing. The pinion is scraping something inside the housing and also running a bit tight. Note the wear on the edge of the teeth.
Norm

I don't know Norman, here is the one in the classifieds and you can clearly see the Ford script and it also has the notches instead of the bevel like most gears do.

I think this might be a running change at some point.

Yes, mine was rubbing on the back of what was left from the hyatt bearing, so my Ford script is gone, but its not worn to badly. My concern though was those notches where i thought the hyatt got into it. that might not be the case.

The early pinion gears where notched like that for the closed spool drive shaft, more clearance.

Thank you Joe Bell for a good solid answer. I knew some pinion gears had the notch, and some do not. Never knew when or why.

2 more designs.

Thank You all, this was very helpful.

Oddly enough the pinion was not on a closed spool housing, but the vehicle was such a mish mash of parts I am really not surprised. I just wanted to harvest the gear for another project, but when i saw the hyatt had come all apart, I grew concerned. The pinion was still tightened down on the shaft though, so that was good. I feel the taper is OK and the key way on the gear still looks good.

Thanks, Joe. I had never made that connection.

That pinion gear shows wear typical of the gear needing to be set further to the rear, i.e. deeper in mesh, and given more backlash. The wear on the toe end shows the lack of backlash, and that it is on the face indicates that the gear should be deeper in mesh.

Hope this helps.
Allan from down under.

Allan from down under.

Chad, ignore some of what I advised above. The wear is on the heel of the pinion, not the toe. This indicates that there was too much backlash, and the pinion needs to be set a little deeper in mesh. The whole assembly still needs to be shifted closer to the ring gear to shift the wear down somewhat off the face.

Sorry for the confusion.
Allan from down under.

I learned something today. I have not before seen an early gear. Good to know that notch is not from wear. I think what Allan posted above is good advice.

Bad or missing pinion spool bearing ??

Ring gear bolts are on the small end of the pinion. jb