TR2/3/3A yet another TR3 steering box question/hone?

So I have the shaft and bearings installed in the housing and the end float as small as I can measure -about .001". I installed a new peg in the drop arm, and pressed (with threaded rod) a new bushing into the bottom of the housing before replacing the lower seal. Before I pressed it in, I made sure I could force it onto the drop arm by hand -it was very tight while the old ones slipped on easy with a little slop.

Now I can't get the drop arm to go into the installed bushing. The old bushings were bi-metal (like a main bearing) with brass on the inside and steel on the outside. New ones are solid brass (or copper?). The old ones from 2 steering boxes had a side wall thickness between .058 and .061 depending where you measured. The new wall is .060 to .063. The shaft is .87 and I've been cleaning it up with extra fine emery cloth. Do I need to get a hone and open up the new bush? Where do I get one and what size? It seems like I could easily end up with more clearance than I started.

First of all, .001" is too much. You want either zero or a slight preload (negative). Take out a .010" shim and put in a couple of .004".

The book says to ream the bushing, although I didn't need to ream mine.

The intention was to ream to 7/8" (.875"), but that's a little big if your shaft is really only .870". Might be better to pick up an adjustable reamer and shoot for .872" or so.

I buy most of my machine tools from Enco
https://www.use-enco.com
but there are lots of other sources.

Here's an adjustable reamer that would do, or P/N 2987A17 from McMaster-Carr would probably work better.

Randall,
If I check the end float without the rubber bushing in the steering tube, I get about .001. When I install the rubber bushing, it centers the shaft (apparently the bearings at the other end are not exactly centered and the length of shaft exagerates it) and slightly preloads the bearings. When I try to measure the end float with the rubber bushing installed, I can measure none. The shaft rotates freely now, but if add remove more shims, it becomes harder to rotate.

Am I missing something?

Probably in that case, I would try to bend the tube slightly, so the bearings do line up with it.

Even if you don't do that, I would (did) still set the end float without the bushing. I think the actual end float is what is important, rather than what you measure with the rubber bushing holding the shaft out of alignment with the bearings. There is a lot of force when actually steering the car, so the worm is going to move if there is any float, even if the shaft/column have to bend to do it.

Come to think of it, though, that may be why the steering on TS13571L isn't as light as I got it on TS39781LO. It has the earlier solid column of course, and the shaft actually rubbed on the housing without the (felt) bushing installed. I probably should have tried to tweak it back into alignment, but was in a rush so I just stuffed the bushing in after setting the end float.

But it's still not bad at all; with some effort I can still parallel park with one hand. Just not as nice as I know it can be.

Thanks again Randall. I ordered an adjustable ream. I've looked through all three service manuals I have and can't find anywhere mentioning reaming this bushing, or the size. I did measure all 5 of the drop arms, and 4 are .870 while one is worn and rusted to a bit smaller -perhaps my $20 harbor freight caliper is not accurate?

The new rubber seal does say .875 on it, but I know better than try to measure it.

In any case, I should be able to ream the bush to fit properly, but wonder how much clearance should be allowed. The bush does have an oil groove, but I know nothing about what the clearances should be.

End float is at 0 without the rubber bushing. I have no idea how to bend the steering tube into alignment. I tried heating the base thinking it might be soldered, but had no luck.

The only place I get answers to questions is here, and I appreciate it.

Thanks all.

TexasKnucklehead said:

In any case, I should be able to ream the bush to fit properly, but wonder how much clearance should be allowed. The bush does have an oil groove, but I know nothing about what the clearances should be.

End float is at 0 without the rubber bushing. I have no idea how to bend the steering tube into alignment. I tried heating the base thinking it might be soldered, but had no luck.

The only place I get answers to questions is here, and I appreciate it.

Thanks all.

Click to expand...

I should think that .003 clearance would be close enough.

The tube is soldered into the cast base. I once removed a bent tube and replaced it with a tube I got from Charlie Vogelsong at Dillsburg Aeroplane Works. The O.D. was the same but I think the wall was a little thicker.

Full disclosure: A student did the actual soldering for me.

If y'all were closer, I've got a full set of adjustable reamers in a wooden case.

Well, I can't find where the book says to ream either; but I'm fairly certain I remember reading it somewhere ... was really surprised when mine didn't need to be reamed. That was the rule back then anyway; basically the hole in the casting isn't necessarily machined accurately at the factory, so the bush is made a little oversize and crushes as you pull it into place, then gets reamed to size afterwards. The soft brass is much easier to ream, and if you make a mistake it only ruins a cheap bush rather than an expensive casting.

I just checked a new bush from TRF, it's .870"; while a shaft from the parts bin was between .872 and .873 everywhere I checked. I can push the bush onto the shaft, but it opens the split in the bush.

But since you've got the adjustable reamer, just ream it to fit snugly. Tighter is better, as long as you can work the shaft into place by hand.

Hi Tex I went the cheap route and used a small brake hone. It takes a little time, but it is user friendly in those small areas.
Steve

TR3driver said:

I just checked a new bush from TRF, it's .870"; while a shaft from the parts bin was between .872 and .873 everywhere I checked. I can push the bush onto the shaft, but it opens the split in the bush.

Click to expand...

The bush from Moss does not have a split. That probably makes it a bit easier to ream. The ones I removed from boxes all had splits.

The reamer showed up yesterday. It really wants to bite into the soft metal and I took off a little more than I wanted to -but still barely enough to install the shaft by hand. Once dropped into place, it rotates easily with minimal play. I removed the seal before reaming, and ruined it, so now I'm waiting on another. The box is all set-up and I can feel the center/straight ahead position. If I did it again, I take slightly smaller steps while reaming. I'm sure my box is better than it was, but it could be better.

Almost another item crossed off the list. Thanks again.
Jer