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TR2/3/3A TR3A Distributor Bushing...ID too small???

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houleyh

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I'm trying to put a brand new Brass bushing for the distributor (Moss #153-500 for 40480E Distr).

The shaft measure exactly 0.488" and the ID of the bushing does 0.486". It won't fit. Also the hole (oiling) is not on the new bushing???

Did anyone had this issue before? Do they need to be reamed up (to around 0.491"- 0.495")?

Please help me

Thanks

Yvan Houle
 
Obviously, that scenario will never work. Reaming is not a good option unless you can control the tolerances and the process very tightly.

Contact Jeff at Advanced Distributors for his advice. He knows these units better than anyone.

And yes, he'll help you even if you're not buying from him. He is a very good man.

https://www.advanceddistributors.com/

I suggest that you send him an email as soon as possible to get your answer quickly.

Good luck.
 
Aloha Yvan,

I agree with Paul. Jeff is very helpful. He recently rebuilt a distributor for me at what I consider a very reasonable price. He also is very prompt in answering his e-mail.
 
If you choose not to have the new bushings resized professionally you can do this yourself AFTER installation. Don't do it before because they will collapse a bit on installation. Also, if the shaft measures .488 aim for 0.490 for the fit. No more than about .002" of clearance would be OK on a new bushing that small. .495 would be way way way too big. HOWEVER, measure the shaft and bushing several times and make sure your measuring tools are accurate before deciding what size to ream these to. Measure twice, cut once.

By the nature of the process, reaming gives you a very tight tolerance. Don't use a drill bit for this, use a reamer. .490" is not an exact metric or inch size. However, you can go to https://www.mcmaster.com and use their search feature to look up "chucking reamers". You'll find a page where you can specify the exact size you need/want. When you ream the bushings, chuck the ream in your hand drill, lubricate it and the bushing with engine oil and run the reamer at VERY low speed steadily into and through the bushing. Reaming is done at a very low speed compared to drilling.
 
If you choose to take this course of action, make sure that your distributor housing is securely clamped in a vise. You do not want it to be moving while you are trying to ream out the bushing.

Also, use very liberal amounts of lube along with the SLOW speeds explained above.
 
Another alternative is to use adjustable reamers. With these, you take out a little at a time until the fit is just right. Since there are many bushings on our cars that require reaming after installation, having a set might be a worthwhile investment. They are available individually and run about $10 to $20 apiece depending on size. I have a set in a nice wooden box with lots of patina my father gave me that must be at least 70 years old.

BTW: The adjustable reamer size you would need would be 15/32"-17/32". Here's a site that has one for $13.20
 
I agree with Art. Adjustagle reamers are great. The way they work is by sliding the reamer knives along a taper by turning jam nuts. As the knives move up up the tapered shaft, the o.d. gets a little bit larger. You can get very precise and probably what the machine shop would use. Use LOTS of lube to avoid chatter and you will get a nice finished job and a tool for your toolbox.
 
The nice thing about adjustables is that you can slowly ream out more and more material in multiple passes and check the fit each time until you're satisfied. I've used them at work but have never been able to justify the expense of a set for home.

The site I listed above won't be cost competitive on the adjustable reamer you need. Instead, visit MSC industrial:
https://www1.mscdirect.com
and search for "adjustable reamer".
or
visit Grizzly.com ( https://www.grizzly.com/ ) and search for "adjustable reamer". They sell sets and the 7-pc set is a very reasonable $44
 
I hate to add this but the most of the "value" line of these reamers are ... made in India! Anyway, the one (from India) I used to ream my trunnion bushings was fine and did a perfect job. Just make sure that, as you start, you get it small enough to just polish the bushings and don't get too aggressive with the cuts. Take your time, oil, and it will be perfect.
 
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