TR2/3/3A TR3 Carb Throttle shaft

[fogdot]

I have ordered replacements for the throttle shafts and bushings in my carbs. The standard shaft measures 0.310. Will I have to ream the bushings? To what size?

 

[Tinkerman]

YES! They have to be reamed. I would suggest that, if you have the
Moss catalog for the TR2-4A you read the Carb tips section. Page 30 in the catalog I have. I highly recomend having a carb shop do it for you. Moss sells the reamer for $160 it would be worth having an SU shop do it for you. Very critical area for the carbs. jmho.

Tinkerman

 

[fogdot]

Thanks. One thing about these cars is that I am recognizing how far I can expand my abilities. This may be outside the envelope.

 

[TR3driver]

Here's how to do it yourself for about $20
https://www.chicagolandmgclub.com/driveline00/1001/jasw.html

(Wish I'd seen that article before I did my own, but they still came out OK. I drilled for the new bushings in an ordinary drill press, which was a lot harder. Still came out OK tho.)

 

[Tinkerman]

Sheesh, which I had read that first! I could have done that without any problem, saved time and money also.

 

[martx-5]

When I re-did mine, I found that all the wear was in the old shafts. The carb bodies themselves had virtually no wear. Check everything first with the new shafts. You may luck out like I did.

 

[NickMorgan]

That's a fantastic way of re-bushing the carburettors. I hope I can remember it if ever I have to do mine.

 

[Deleted member 451]

I have always thought that it would be better to have the bushings made of a very hard steel and the shaft made of bronze. All of the wear would be on the shaft and could be easily replaced. Is my thinking faulty?

 

[TR3driver]

I have always thought that it would be better to have the bushings made of a very hard steel and the shaft made of bronze. All of the wear would be on the shaft and could be easily replaced. Is my thinking faulty?

I dunno, but both personal experience and what the tribologists tell me says it doesn't always work that way, especially for an unlubricated joint. Having an Oilite bushing supply some lubrication seems like a better idea to me even if the shaft is relatively soft (tho it's harder than the bushing).

Of course, you could oil it yourself like the book says to do; but from what I've seen, most people don't.

Then too, the original setup with a brass shaft running in just a "pot metal" (zinc alloy) housing lasted me a long, long time. If the Oilite lasts another 200,000 miles, maybe that's good enough? They should be lots easier to do the second time anyway, since now you just pop the old bushings out and push in new ones.

If you really want to upgrade, find a pair of those roller bearings ...
https://www.ztherapy.com/products/SUReman.htm

 

[Moseso]

That's a fantastic way of re-bushing the carburettors. I hope I can remember it if ever I have to do mine.

Bookmark the link! I just did. I have a subfolder of the "TR3" folder in my browser bookmarks entitled "How-tos," for just that sort of fine page.

 

[Brosky]

The problem is that as we get older, we forget the subfolder even exists......