Late 36 distributor rebuild - lower bushing

[sjaakslinger]

I'm rebuilding my late 36 distributor. I replaced the top bushing without issues, the rotor fits in fine. The lower bushing gives me headaches though. I pressed in a new one, the rotor didn't fit. Way too tight, although it test fitted well before installing the bushing.

I got 2 new ones to be sure. Installed 1, same issue, too tight, the rotor hardly goes in. Took the bushing out. The 3rd one I could slip into the housing by hand...so that's no good.

Any ideas here? Thanks.

Dennis

Verstuurd vanaf mijn SM-G781B met Tapatalk

[v8fordman]

Dennis, the simplest thing to do is to either take it to a machine shop that has a wrist pin fitting machine or you can buy a small flex hone at your local parts store. Some may suggest using sand paper rolled up, but I don’t recommend that because of the grit left behind. Either way, use your shaft to check your clearance through the entire process. I would do it for you, but you’re too far away.

[JM 35 Sedan]

Usually after a new bushing is pressed in place, the ID must be reamed or honed to size.

[Brian]

Aren't those bushes 'oilite bushes'? Oilite [sintered] bushes should not be reamed as that operation tends to smear the surface of said bush...at least that is my understanding.

[sjaakslinger]

Thanks all. I was also thinking it might need some honing or machining. Was hoping it would be a direct fit though.

Dennis

Verstuurd vanaf mijn SM-G781B met Tapatalk

[Terry,OH]

Sponsored Links (Register now to hide all advertisements)

The reamer used should pilot off the front bushing so the front and rear bushings are in alignment. I think Charlie Schwindler can do that.

[JM 35 Sedan]

Originally Posted by Brian

Aren't those bushes 'oilite bushes'? Oilite [sintered] bushes should not be reamed as that operation tends to smear the surface of said bush...at least that is my understanding.

This was taken from a tech article I just read....

Oilite bearings may be reamed provided a dead- sharp cutting tool is used. However, reaming does destroy porosity more than single point tooling. Honing and grinding are never recommended on Oilite bearings on any surface which will become the bearing surface.

[sjaakslinger]

Ok, thanks for the input. I'm in The Netherlands, experienced flathead rebuilders are rare here. I do visit the US a lot, so maybe I should have that bushing done there.

I was thinking a machine shop here might be able to work it out? Would that be an option...having it machined?

I ordered a 120 grit honing tool. So that would not be a good idea to use on the bushing?

The inner diameter is only a fraction too tight...

Dennis


Verstuurd vanaf mijn SM-G781B met Tapatalk

[deuce_roadster]

Often when pressing bushings into holes they take on a slight hour glass shape, especially thin bushings. A tool that has an inner part that fits inside snugly but turns, keeps the bushing from distorting and can prevent what you are seeing since it fit the shaft before pressing into the case.

[Brian]

Deuce roadster has the solution...make up a spigot ed tool with which to press the bush into place with. Impregnate the bush with oil beforehand....

[sjaakslinger]

Thanks all. I had it machined yesterday at a car restorer closeby...fits perfectly now.[emoji106]

Verstuurd vanaf mijn SM-G781B met Tapatalk

[JM 35 Sedan]

Originally Posted by sjaakslinger

Thanks all. I had it machined yesterday at a car restorer closeby...fits perfectly now.[emoji106]

Verstuurd vanaf mijn SM-G781B met Tapatalk

I'm glad to hear you have the bearing fit resolved. Keep us posted on the rest of your distributor rebuild. These early helmet style distributors can be built to give you many miles of trouble free service once you get them built with good quality components installed and set up correctly, and timing set properly. Good luck!

[Bored&Stroked]

I'm going to have to see if I can find a reamer for these procedures - anybody happen to know where to purchase one? I should just go mic the shaft to figure it out . . . buy hey, maybe somebody already has the info. LOL

I was thinking about the comment of a reamer that picked up the outer bushing. Then I pondered how one was going to get it through the rear bushing and into the outer bushing . . . and then ream the rear busing - without already having reamed the rear bushing to get through it. So, unless I had a reamer that I could expand (accurately) once inside the rear bushing, then it would be of no use to think about the front bushing as a guide. Anybody have some details to throw at me?

[deuce_roadster]

I think the diameter of the outer bushing where the shaft rides is much smaller than the one in the rear. You can measure a shaft you have out of a distributor.

[Bored&Stroked]

Originally Posted by deuce_roadster

I think the diameter of the outer bushing where the shaft rides is much smaller than the one in the rear. You can measure a shaft you have out of a distributor.

That is correct, but the reamer will never get to it until it reams out the big rear one - so I don't see how it can be used as a center . . . unless some special "adjust in place" reamer is used, or it "slides" down a centering/piloting shaft?

[sjaakslinger]

I'm making some progress on the distributor. Rebuilt the contact points plate. Took some effort to properly line up the contact points.

I didn't make good enough pictures of the weights. Are the 2 straight springs correct in this picture? So both springs on 1 side of the shaft?

Thanks.

Verstuurd vanaf mijn SM-G781B met Tapatalk

[38 coupe]

The springs are correct in your picture.
If you can find a shaft marked "11A" on the back it will have a better ignition advance curve than the "68" unit you currently have.

[38 coupe]

Originally Posted by Bored&Stroked

That is correct, but the reamer will never get to it until it reams out the big rear one - so I don't see how it can be used as a center . . . unless some special "adjust in place" reamer is used, or it "slides" down a centering/piloting shaft?

Thinking about this everything needs to center off the large bore in the back of the distributor housing (the aluminum casting). I think the two bushings could be reamed separately (I suspect that is what Ford did when making them new).

The advance housing (the iron part) centers in the large bore in the distributor aluminum casting. The bushing needs to be centered in the advance housing so a simple centering fixture with a straight reamer should work.

A second fixture that centers off the large bore in the distributor housing and fastens to the machined back surface could align a different reamer for the front bushing.

Thoughts?

[sjaakslinger]

Originally Posted by 38 coupe

The springs are correct in your picture.
If you can find a shaft marked "11A" on the back it will have a better ignition advance curve than the "68" unit you currently have.

Thanks. I will see if I can find one.

Verstuurd vanaf mijn SM-G781B met Tapatalk

[Bored&Stroked]

Originally Posted by 38 coupe

Thinking about this everything needs to center off the large bore in the back of the distributor housing (the aluminum casting). I think the two bushings could be reamed separately (I suspect that is what Ford did when making them new).

The advance housing (the iron part) centers in the large bore in the distributor aluminum casting. The bushing needs to be centered in the advance housing so a simple centering fixture with a straight reamer should work.

A second fixture that centers off the large bore in the distributor housing and fastens to the machined back surface could align a different reamer for the front bushing.

Thoughts?

One could make a little "bushing adapter" that "plugs into" the front bushing location and then has a much larger outer section with the ID of a straight reamer. Then a full-length, full-size reamer could be used to size the larger rear bushing. I think that is the approach I will take next - easy to setup on my lathe.