Mitchell transmission

Lawrie

Lawrie

Well-known member
Would any one know why there are three roller bearing in the cluster shaft.2 long and one short, making up the three,
I see on my V8s there are only two bearings, one long and one short ,plus a spacer between.
I would ask Mitchell ,but Im assembling the transmission tomorrow, and with the time difference it takes a while to get a reply.
Lawrie
 
For a while, and perhaps still, a Model A recommendation has been to replace the center "spacer" with ANOTHER bearing. Offhand I can't tell you if it is a long bearing or a short one, but I think a long.

The theory is "better support" to the cluster. One might question "proper lubrication" but we're talking a gear/shaft that is normally nearly submerged in the oil.

I have at least one ****** done this way. It's now lost in the succession of trannies I've messed with so I can't tell you any long term ramifications to this - but for me nothing has surfaced.

Joe K
 
Lawrie said:
Would any one know why there are three roller bearing in the cluster shaft.2 long and one short, making up the three,
I see on my V8s there are only two bearings, one long and one short ,plus a spacer between.
I would ask Mitchell ,but Im assembling the transmission tomorrow, and with the time difference it takes a while to get a reply.
Lawrie
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Like Joe said, it's for better support. Most important, it is to tighten up the cluster so it doesn't "wobble", which leads to premature wear, especially on the teeth themselves.

I met Steve Mitchell's dad, and he was an absolute overkill genius! Steve is a chip off the ol' block. He believes in overkill for longevity. He is also one heck of a caring person.
 
Just be sure that all three bearings are structurally sound. A fellow told me that he had re-used an old bearing instead of the middle spacer and later noticed an odd noise coming from the transmission. The noise increased to the point where he dismantled the unit and found that the middle bearing had come apart and the bits were eating up the cluster.
 
The modern replacements are not manufactured like the original Hyatt bearings were. The old original Hyatt types lasted for a lot more miles than the crap available now. Perhaps stacking another one in there will help in that respect.
 
thanks ,
strange though, the V8s have a longer cluster and only two bearings,
in this trans the rollers came apart and chewed up the shaft,
I will fit three bearings,
Lawrie
 
Hello, originally 2 bearings for cost savings, adds up when building 4.8 million cars! Most people do use the extra bearing replacement for bushing on restorations .Also it is a shame than modern replacements aren’t as good as a 90 year old one , logic would be that with improved materials they would be better or equivalent, once again,cost savings.
 
It seems to be more of a modern redesign problem. Hyatt used the spiral wound steel tube as the load bearing element. This allowed them to get a deeper hardness than using a formed roller. Some rollers have the tiny spindle tips that wear out far sooner then the actual roller surfaces. The way Hyatt made them would be considered cheap compared to the modern replacements but Hyatt had the process down to a science for a rugged long lasting assembly. Ford hooked up with them in the model T era so they had a long running relationship. Once the need for that type of bearing went away, Hyatt became a part of history.
 
I remember a while back someone mentioned using a bronze bushing in place of these bearings. Is that even feasible? I have always used bronze bushings for the pilot bearing and this got me to thinking about this question.
 
Y-Blockhead said:
I remember a while back someone mentioned using a bronze bushing in place of these bearings. Is that even feasible? I have always used bronze bushings for the pilot bearing and this got me to thinking about this question.
Click to expand...

I once acquired a rebuilt Model A transmission that had a brass bushing pressed in as a spacer. The bushing was of the correct length and ID but it completely blocked the oil feed hole in the cluster so I drilled out a hole in it to allow in the lubricant.

The normal steel bushing is split lengthwise which allows oil to enter the cluster bore via the midsection hole.
 
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