XH Motorcycles Forum

Motorcycle Resource Forums => Technical Resource Discussion => Topic started by: Berlin Bob on January 10, 2016, 02:58:36 PM

Title: Tranny bushing material
Post by: Berlin Bob on January 10, 2016, 02:58:36 PM
What is the bushing material for the trannys ....931 ,952,932  bronze ???...i was getting inputs that vary ....what is everybody using ?????   and what is best ?
Title: Re: Tranny bushing material
Post by: Donkey Hotey on January 10, 2016, 04:00:26 PM
I used 936 because it seemed like the absolute best compromise for machinabiity and bearing strength.

Enco sells 932 hollow bearing stock. I believe it's the same, with a little less lead in the alloy. I paid extra for the supposed machinability of the 936 but, it cut easily, with a gorgeous finish. I wouldn't hesitate to try the 932. Enco was also cheaper than McMaster.

What you don't want is a sintered bronze, AKA oilite. Sintered bronze is porous. It's a good choice for applications where they don't have much lubrication (shifter mount). That porosity makes the bearing weaker and more prone to wear.

I have to add: the transmission I did has less than a thousand miles on it since the rebush. I may not know what I'm talking about and it may be headed for disaster. It's also a lot work and expense to get everything true, centered and bored to precise size. If I had to charge for the hours it took, it would be much, much cheaper to let Jamie and Marty do it.
(http://www.ehforums.com/ehwebsite/forums/index.php?action=dlattach;topic=866.0;attach=259;image)

(http://www.ehforums.com/ehwebsite/forums/index.php?action=dlattach;topic=866.0;attach=261;image)
Title: Re: Tranny bushing material
Post by: Berlin Bob on January 10, 2016, 06:15:56 PM
Thank yee Greg ...that helps ....fyi  i did order the 932
Title: Re: Tranny bushing material
Post by: Donkey Hotey on January 11, 2016, 01:07:49 AM
Are you doing the machine work? Ordering the replacement circlips from Atlantic?

The chuck I used is an 8" set-tru. I was able to clamp each gear in, then adjust the chuck with a dial indicator to get the gear absolutely centered and on-axis. That involved some tapping on the face of each gear to make sure the face ran true in the chuck, before adjusting for radial runout.

It was also a lot of wrangling to get good inside dimensions on the bushings as they were getting close to final size. I used telescoping gauges. Inside micrometers would have been better.

The target clearance was 0.0015-0.0020". They all ended up within that range but, it took time and lots of careful measurements and cuts.