TR4/4A Has anyone used steel gear bushings in their TR4 transmission?

[TuffTR250]

Has anyone used the steel 1st, 2nd, and 3rd gear bushings in their TR4 or TR3 transmissions? This is versus the standard stock bronze gear bushings. Is there any advantage to steel? And are there any problem with using the steel bushings or do they take some kind of conversion, or a different main shaft? Thanks!
Regards,
Bob

 

[titanic]

AFIK, the only steel bushing available for the pre-CF12500 (and earlier) TR transmissions is 2nd gear one shown in the Moss catalog. The other steel bushings fitted to the late TR6 gear boxes would require the later mainshaft.
A few years ago, I bought an OD transmission that was seized. An autopsy revealed that it had the "up rated" 2nd gear steel bushing and it had welded itself to the mainshaft. I don't know the cause, but suspect that it was caused by low oil level. There was a similar incident reported on the 6pack forum. Since then, I have been suspicious of the 2nd gear steel bush used on the earlier trans.
Berry

 

[mikephillips]

one thing to keep in mind is that bronze is porous so will soak up some oil where steel won't. So if it runs low the bronze can be to a certain extent self lubricating where steel will friction heat more and as pointed out may weld itself to the shaft.

 

[titanic]

Mike-I was thinking along similar lines that the bronze bushings are more forgiving of a low oil level and marginal lubrication. However, I don't think that the bushings are porous, like "oil lite" material, which is made of sintered powder and used as cast.
OTOH, the steel bushings as fitted in the post CF12500 TR6 transmission don't seem to have a problem and are an improvement over the earlier design.
Berry