Early F Engine Distributor Resurrection - Need to Enlarge Distributor Housing Bore to Accept New Toyota Upper Shaft Bushing

4Cruisers

Supporting Vendor
SILVER Star
Joined
Apr 2, 2015
Messages
6,959
I'm replacing the upper distributor shaft bushing on an early F engine distributor. The new Toyota bushing is 15.88mm OD, but the old bushing is 15.80mm OD. So I'm thinking the easiest way to go is to open up the hole in the distributor housing. It turns out that a 5/8 inch hole is exactly 15.875mm, or essentially 15.88mm. Seeing as how that's not very much metal at all to remove, I was thinking a new 5/8 inch drill bit will open the hole up nicely, and stay centered. But I've also read that a reamer can be used to slightly enlarge a drilled hole. What would be best? Any input would be appreciated.

I'd really like to figure this out so that I can resurrect the other six or seven early distributors in my inventory. I have at least 25 or 30 new Toyota distributor shaft bushings to work with, but they all have the same 15.88mm OD. From everything I've read, most of the early F engine distributors are sent to the trash heap due to worn upper shaft bushings. Excessive lateral play at the top of the distributor shaft leads to constantly varying dwell and highly inconsistent spark. Some of the early distributors are kept alive by installing Pertronix electronic ignition set-ups, which are more tolerant than points for distributors with excessive lateral play, but I'd prefer a solution that would allow for points.
 
Joined
Nov 25, 2014
Messages
757
Location
Western victoria Australia
I see no reason a drill bit won't work using a drill press. Loctite the new bush in?

If you want to keep the integrity of the dizzy intact you can machine the outside of the bush.
Find a bolt that fits snugly through the bush, tighten with a nut and put the bolt in a drill press.
Clamp a hss cutting tool to the drill press table, adjust the table and voila! poor mans milling machine.
Have done this with brass bushes a few times.
 
Last edited:

4Cruisers

Supporting Vendor
SILVER Star
Joined
Apr 2, 2015
Messages
6,959
I see no reason a drill bit won't work using a drill press. Loctite the new bush in?

If you want to keep the integrity of the dizzy intact you can machine the outside of the bush.
Find a bolt that fits snugly through the bush, tighten with a nut and put the bolt in a drill press.
Clamp a hss cutting tool to the drill press table, adjust the table and voila! poor mans milling machine.
Have done this with brass bushes a few times.
I pulled my 31/64 inch drill bit from the toolbox and wrapped it with a few layers of Scotch tape until the bushing was a pretty tight fit. I spun the drill using a some light passes with a course file, then a fine file, and followed that with some 220 grit sandpaper. I then made a final pass with a 320 grit sanding block to smooth out the surface. It's getting really close to the desired OD. As a test, I stuck it in the freezer while I finish my second cup of coffee. I'll pull it out in a while and measure it cold. If all looks good, I'll apply a small amount of Lucas Oil assembly lube and press it in using my HF 20-ton shop press.
 

4Cruisers

Supporting Vendor
SILVER Star
Joined
Apr 2, 2015
Messages
6,959
After I was sure the new upper bushing could be pressed in I had to modify it by drilling a 5/32 inch hole in the side - the 19100-60042 F engine distributor has the side oiler cup provision and the hole provides a passageway to the spiral oil groove in the shaft. I pressed the bearing in flush and test fit the distributor shaft, there is very little side-to-side play at the top of the shaft - a big improvement. While I have the shaft out I might as well replace the lower bushing also.
 

4Cruisers

Supporting Vendor
SILVER Star
Joined
Apr 2, 2015
Messages
6,959
I decided not to replace the lower bushing, it still looks good and has the same ID as the new bushings. Last night I started to reassemble the distributor, starting with the shaft/washers/gear, pressed in a new distributor gear pin, and mushroomed the ends of the pin. Even without any oil in the side oiler it spins nicely. I'll finish reassembly this morning and post some photos.
 

4Cruisers

Supporting Vendor
SILVER Star
Joined
Apr 2, 2015
Messages
6,959
Well, another refurbished distributor (early F engine Part Number 19100-60042) rolled off the assembly line. Here are some of the details:

- New Toyota upper shaft bushing, complete with hole for oil passageway from oiler cup to shaft (significantly reduced lateral play at top of shaft)

- Upgraded breaker plate to allow for the use of the later, easier-to-adjust points (same as the later non-US extra small cap distributors)

- New OEM vacuum advancer, with modified vacuum nipple to allow for the use of vacuum hose instead of copper tubing

- New OEM distributor cap, distributor cap clamps, rotor, points, condenser, and terminal

- New generic shaft O-ring

Here are some photos:

_60042-1.jpg


_60042-2.jpg


_60042-3.jpg


_60042-4.jpg


_60042-5.jpg
 

Dizzy

GOLD Star
Joined
Feb 5, 2018
Messages
2,210
Location
Santa Fe, New Mexico
As a former machinist, a high-speed-steel straight reamer is the way to go for precision, if you have one. A reamer has like six flutes, so the tool is located in the hole better than the drill's two. Drills are for the rapid removal of material, or really small holes. The square end of a reamer can be fitted to a tap wrench and allow easy wiggle to get the cutting tool on the same axis as the OEM hole.

Nice work, btw. Did you do it on a hand-drill, drill-press, or something else?

I like the idea of points, and with them, the coil on the F head - primitive, bold, don't mess with the F unless it has pushed a fatigued fan blade thru the fender or hood. It gives my 2F a slight sense of inadequacy with it's fender-mounted coil and igniter. The metal vac line is even sweeter.
 

4Cruisers

Supporting Vendor
SILVER Star
Joined
Apr 2, 2015
Messages
6,959
Nice work, btw. Did you do it on a hand-drill, drill-press, or something else?
Thanks. I ended up taking a little off the OD of the OEM oil impregnated bushing (with fine tooth files, by hand), didn't want to mess with the distributor housing after all.
 

4Cruisers

Supporting Vendor
SILVER Star
Joined
Apr 2, 2015
Messages
6,959
Another one rolled off the assembly line a few minutes ago, and will be going to a new MUD home soon. This one has also been upgraded to the later breaker plate for use with the 1/75 through 9/77 points and sports a slightly different vacuum advancer, but still in the earlier style. I was able to match the 19100-60042's advance curve almost exactly.

Early-F-1.jpg


Early-F-2.jpg


Early-F-3.jpg


Early-F-4.jpg


Advance Curves - Early F No. 1 versus 19100-60042.jpg
 

Users who are viewing this thread

Top Bottom