MTFCA Forum

I am trying to determine if the bushing at the end of my steering shaft needs to be replaced. I made measurements of the inside of the bushing and on the shaft.

Bushing measurements: 0.757, 0.766, 0.754, 0,760 (ave. 0.759)

Shaft measurements: 0.750, 0.746, 0.745, 0.744, 0.745 (ave. 0.746)

0.013 difference.

Photos attached. Forgot to take one of the shaft.

Need opinions!

I'd re-bush it while it's out. Shaft is probably OK.

I found my shaft was worn under size, so a new bushing was not going to work. I had to turn the shaft down slightly, and make a new bushing with undersized inside diameter to match the new, smaller shaft diameter. Getting the freeplay out of this shaft/bush was one important step in tightening the whole steering system, top to bottom. What a difference!

Um . . .? .125" = 1/8"

In the immortal words of Rick Perry, "Ooops!"
That 0 does make a difference, doesn't it? I will edit.

You can take some off the shaft, but machining it back to round may lead to shortening of the taper, and compromising the fit of the Pittman arm
Allan from down under.

I assume the shaft's original diameter was .750. If that's correct, the shaft wear is minimal. I'd install new bushings, and ream, if necessary, to the correct clearance. The shaft may not be evenly worn, so be sure the rebushed piece will slide over it before final assembly. Be sure any grease holes line up correctly. Be sure the shaft taper and keyway are in good condition and that the pitman is aslo in good condition to achieve a tight fit. Once you have driven the car a few dozen miles, all nuts & bolts will need to be checked for tightness. I'd want to go over the entire car after a few dozen running miles, checking everything for fit and tightness, just as Ford recommended doing on a new Ford car.

I assume the .750 shaft dimension that you recorded was taken from the unworn area between the pitman arm and the steering bracket. If you do nothing but replace the bushings, you'll end up reaming them to maybe .752 to allow them to pass over the .750 section of the shaft. Once past, your new bushings will be situated over the worn area measuring .744/.746. You'll then have .006/.008 clearance. Not a whole bunch better than what you began with.

I would machine the shaft down to a consistent .744 diameter, then size the new bushings to .745/.746.

In view of the comments, I measured the shaft in the 1" length between the pitman arm and the bushing area. I also measured the shaft in the 2" length above the bushing. I remeasured the bushing and the shaft under it. See the attached photo.

The six shaft measurements in the 1" length are 0.750-0.749-0.748-0.751-0.752-0.751 (ave. 0.750)

The six shaft measurements in the 1 1/4" bushing length are 0.744-0.742-0.743-0.748-0.746-0.746 (ave. 0.744)

I made measurements in the 2" length above the bushing but forgot to write them down. They were about 0.750.

The three ID measurements of the bushing are 0.758-0.756-0.758 (ave. 0.757)

(1) ). The existing clearance is 0.013 (0.757 minus 0.744).

(2) It appears the shaft has worn 0.006 (0.750 minus 0.744).

(3) Replacement bushings are 7/8 x 3/4 x 1 1/4. I assume the original bushing was that size and was reamed to an ID of
0.751/0.752 or more. Is that a reasonable assumption?

(4) It appears the bushing has worn .005/0.006 (assuming that the original ID was 0.751/0.752).

(5) The ID of a new bushing would need to be at least 0.752 to get bracket into position on the shaft as is. Therefore,
the resulting clearance would be 0.008 (0.752 minus 0.744), not much of an improvement. This the point Jerry
made!!!

In Summary: I am not capable of machining the shaft or removing and installing a new bushing. Obviously, I could take the items to a machine shop and have it done, and I will do that if it is really necessary.

If the shaft, in the 1'' length and bushing area, is machined to 0.742 is there a bushing available that can be reamed to accommodate the shaft?

The question I have is: If I live with the existing condition, how will it affect the steering?

I am replacing the pitman arm.

Bruce

Technically the bushing/shaft fit just should be reasonable, you sure don't want super-tight fit.

Most times the shaft area where it rides on the bushing isn't worn too deep, if you can visually see wear or can feel a step down, then a new shaft may be needed. From your photo, and measures, the shaft seems likely to be usable, just polish the area with a long strip of crocus cloth or fine sandpaper to get a smooth round surface.

The new bushing is somewhat oversize, and has to be reamed, even with a new shaft.

Doing the job isn't hard with a few tools, an expandable hand reamer is most useful to get the bushing bore sized for the shaft.

Here is my how-to replace that steering bracket bushing, published a few years ago.

https://nebula.wsimg.com/5f34330de4188d ... 31FDB20580

You can use strips of emery cloth to reduce the larger diameter areas of the shaft. Measure and mark the more worn down shaft areas and tape them off, or mark them with a magic marker. Then use the emery cloth strips to reduce the high spots, being careful to work all the way around the shaft to keep it as round as possible. Measure frequently to avoid taking off too much metal and to avoid getting the shaft out of round. Emery cloth strips can be cut to any width needed. You can buy an expansion reamer in the appropriate size range to ream the installed bushing to whatever size needed. You need a spec for what the final clearance ought to be. With care and patience, you can get the shaft to a uniform undersize and get an excellent finish. A good straight edge, such as the edge of a quality steel rule, laid along the length of the shaft can quickly show up the low and high spots to facilitate marking the low spots and checking the progress of your work as you reduce the high spots. Use the straightedge frequently all around the diameter of the shaft to check the progress and accuracy of your work.

TXGOAT2 wrote: ↑

Thu Oct 13, 2022 9:11 am

You can use strips of emery cloth to reduce the larger diameter areas of the shaft. Measure and mark the more worn down shaft areas and tape them off, or mark them with a magic marker. Then use the emery cloth strips to reduce the high spots, being careful to work all the way around the shaft to keep it as round as possible. Measure frequently to avoid taking off too much metal and to avoid getting the shaft out of round. Emery cloth strips can be cut to any width needed. You can buy an expansion reamer in the appropriate size range to ream the installed bushing to whatever size needed. You need a spec for what the final clearance ought to be. With care and patience, you can get the shaft to a uniform undersize and get an excellent finish. A good straight edge, such as the edge of a quality steel rule, laid along the length of the shaft can quickly show up the low and high spots to facilitate marking the low spots and checking the progress of your work as you reduce the high spots. Use the straightedge frequently all around the diameter of the shaft to check the progress and accuracy of your work.

Have you ever tried to remove .007/.008 from a 3/4" shaft with emery cloth?

"The six shaft measurements in the 1" length are: 0.750-0.749-0.748-0.751-0.752-0.751 "

I'd probably put the shaft or the whole column assembly on wood V-blocks and spin the shaft with the steering wheel, then carefully use a single-cut file on the highest spots, if necessary.

Why not just replace the bushing while it’s all apart…they’re not that expensive and easy to install. I wouldn’t over think that job

My experience was with a new bushing and new shaft (both purchased several years ago). The old bushing came out fairly easily and the new one went in just about as easy. It fit the shaft just fine--no reaming necessary.

Suppliers catalogs have a 7/8 x 3/4 bushing. Where can a bushing with a smaller ID be obtained?

Another approach involves cutting off the bottom 12 inches of the steering gear shaft and welding on a new piece. This requires 1) a first class welder, and 2) the ability to machine the bottom of the shaft.

I have done this on a couple of 5-to-1 steering gear shafts I wanted to save. In order to do this I needed a donor shaft to provide the new material to be welded on to the bottom of the shaft. I wanted to use the same material originally used on the shafts. The two parts were very deeply turned to a point, and the welder added quite a bit of steel when joining the two parts. The welder I used was a master. After all, a steering column shaft is a mission critical part, on which the driver’s life depends.

After welding, the shaft was turned back down to the nominal diameter (0.750). After trimming to length, the taper and the thread were turned on a lathe. Then the key way was cut using a woodruff key cutter in a mill. Finally, a cotter pin hole was drilled in the threaded portion of the remanufactured shaft.

This was a lot of work, but it solves the problem of wear between the shaft and the bushing.

Respectfully Submitted,

Trent Boggess

Goodness! Such carrying on for a purchasable part! This isn't a supercharged Duesenberg after all!

1. Replace the shaft with a new one, replace the bushing
2. Flame spray the shaft, turn to size, replace the bushing
3. Turn down the shaft to eliminate wear, replace bushing, ream to fit

pick one depending on how important original parts are to you and the depth of either your pockets or the breadth of your professional acquaintances

it just isn't that big of a deal!

BLB27 wrote: ↑

Thu Oct 13, 2022 8:53 pm

Suppliers catalogs have a 7/8 x 3/4 bushing. Where can a bushing with a smaller ID be obtained?

From McMaster-Carr... https://www.mcmaster.com/bushings/multi ... earings-8/

Get a 7/8" x 5/8" bushing and enlarge the hole as needed, in a lathe. If you want to go that route...

If I live the existing condition, how will it affect the steering?

BLB27 wrote: ↑

Fri Oct 14, 2022 2:17 pm

If I live the existing condition, how will it affect the steering?

Difficult to say. Depends a lot on the condition of everything else in the steering system. If all else is pretty near perfect, it may be okay with only new bushings. Steering issues are seldom caused by just 1 thing being worn. It's usually the cumulative effect of wear in every component from the steering wheel to the wheel bearings. After that, add in possible alignment issues. I'm not trying to make this excessively complicated. It really isn't. It's taking shortcuts that adds unnecessarily to the level of complication when things don't work right.

I just went down this road and chose to replace the bushing, the steering shaft and gears with new made 5-1, the pitman arm, and the tie rod ball. Not the cheapest way, but it revolutionized the steering in my 22. Honestly, by disassembling things you have already invested quite a bit of your time and energy. It would be a shame to put things back together less than perfect, especially because the parts are available and steering is important. Just my two cents.

Morgan

it is more than your opinion. Model T steering exists in only two states: worn out and increasingly hazardous, or refurbished back to new. Any compromise to your repair choices would have left your car in the "increasingly hazardous" realm. It really is sad the number of owners, (and I feel it is the majority) who say "who cares...it's an old car".

Good for you and the choices you made.

Scott_Conger wrote: ↑

Tue Oct 18, 2022 5:55 pm

Morgan

it is more than your opinion. Model T steering exists in only two states: worn out and increasingly hazardous, or refurbished back to new. Any compromise to your repair choices would have left your car in the "increasingly hazardous" realm. It really is sad the number of owners, (and I feel it is the majority) who say "who cares...it's an old car".

Good for you and the choices you made.

Morgan & Scott:
Couldn't agree more. That's why almost every one of my T's, past and present have had bushings, bolts and the yokes rebuilt. Tomorrow I'm taking the torpedoes front axle to Jack Putnam to get the yokes repaired via the "Steven's tools". Did the entire front end 2 years ago on the Fordor, including that cussed steering bushing. Glad I did. Tight and confident steering!

Many people may not realize how nicely a Model T with the chassis and tires in good condition and proper adjustment can ride and handle.

TXGOAT2 wrote: ↑

Tue Oct 18, 2022 6:11 pm

Many people may not realize how nicely a Model T with the chassis and tires in good condition and proper adjustment can ride and handle.

So true!

I decided to replace the steering shaft. The condition at the end of the shaft is more than I wanted to deal with. The items at the head of the shaft appear to be in good condition, as shown in the attached photos, and could have been reused.

The last photo shows the new shaft, gears, bottom bracket with new bushing, and new pitman arm.