TR2/3/3A Steering box rebuild:

Hello,

since i am doing an apron off project, this winter, I'm wondering the best way to assess the steering box & decide if it needs a rebuild ( & how to do that too).
1: does this look like the original cover?
2: the box is filled with axle grease, is that best?
3: what's the best way to clear that stuff, to inspect the worm drive?

any help appreciated.

thx!

GP

That zerk is not original -- that would have been a fill plug and the lube used would have been gear oil.



I would be looking at whether it leaks (which may be why it got grease) and how much play it has after proper adjustment.

Geo, Thank you for your reply:

the steering has some considerable play. But it feels stiff at low speed.
No leaks though.

do you have an opinion on the Revington spring box top?

thx again.

best regards

Guy

The grease is a dead give-away, it needs to be rebuilt at least. The only point in using grease is when the box is so badly worn that it won't hold oil any more. Evidently, the zerk was added because it won't even hold grease now!

The "spring top" makes no sense to me, except as a cover-up for wear and/or misadjustment. The box is designed to have some play off to the side (not straight ahead); but it mostly doesn't matter because the front suspension is always trying to pull the wheels back to straight. The only exception is at very low speeds (eg parking) where the friction of the tires on the road keeps the suspension from centering. And when properly adjusted (and not worn), the box has no play in the straight-ahead position, which is the only time it really matters.

Also, there is a lot of upwards force on the peg in a hard turn. If the spring is strong enough to not be compressed by that force, then it is going to cause a lot of extra friction. And if the force is stronger, you are still going to have play that only shows up when you are trying to make a hard corner. Not exactly the time to have the steering develop a mind of it's own!

I've never installed one myself; but several people have come to me for help with their steering boxes after installing one. The results were awful, IMO, much worse than what I know is possible without the spring. My advice to them has always been to lose the top and do the adjustment carefully; every one has said it got better after doing that.

I've tried several approaches to adjustment; the one that works best for me is to hang a dial indicator on the end of the shaft (mounted to the outer column). Add a shim, then with the top adjustment backed off, observe the dial indicator while trying to move the shaft by moving the Pitman (aka drop) arm. The total indicator reading is how much shim you need to remove to get to exactly zero.



BTW, Enco almost always has an inexpensive dial indicator and magnetic base on sale for $25 or so. Definitely not the same quality as Starrett or Mitutoyo, but I've owned that one for many years now and it has served me well. Seems to be on sale for $20 at the moment. https://www.use-enco.com/CGI/INSRIT...MKANO=388&PMKBNO=3495&PMPAGE=44&PARTPG=INLMPI

Or you can get one from HF for about the same price, but in my opinion, Enco is just a little bit better even when buying the cheap "import" grade tools.

Once the end float is set to exactly zero; center the box (without hooking up the center link or steering wheel) and tighten the top adjustment just finger-tight while rocking the shaft back and forth with your fingers. The proper adjustment is when you can just barely feel the box bind as it goes through center. Lock the nut and check it again.

I use Valvoline full synthetic GL5 gear oil in the box, as it seems to cut down on friction.

I also converted to free-turning pivots instead of the "Silentblocs". Joe didn't offer the Delrin ones back then, so mine are brass & SS from BFE. If I ever do manage to wear them out, I'll use the Delrin ones. The brass & SS ones didn't fit just right out of the bag, I had to add a shim to one of them and relieve the other one. That was some 25 years ago though, so likely no longer true today (if BFE even still sells them). I also added grease zerks so they can be greased every other blue moon.

But I converted mostly because the Silentblocs I was getting back then never seemed to last more than a few years. I doubt the change made much difference to steering effort.

Tires do make a big difference, though. I recently replaced the (NLA) Potenzas with Kumho Ecstas and the difference was quite noticeable. It's now easy to parallel park with one hand, while before it was just doable.

Thanks Randall,

I'll focus on a rebuild.
You are correct. After closer inspection, I found where grease had seeped out below the box On to the drop arm assembly.
(not much, but it was there)

"The grease is a dead give-away, it needs to be rebuilt at least. The only point in using grease is when the box is so badly worn that it won't hold oil any more. Evidently, the zerk was added because it won't even hold grease now!"

Do you know of any good rebuild kits or service?
I read in some old threads about TRF doing rebuilds, but that was years ago.

i have zero experience with steering & not sure where to start.




thx again.

TR3driver said:

...The "spring top" makes no sense to me...

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For some years I used the top with the spring loaded pin but then the pin jammed in the hollow shaft and it failed to work. It came from a well-known U.S. crafter of engineered TR products but his reply was 'I do not do those anymore'. I have since returned to a solid pin (though the cover was modified by him so I had to fashion my own version of a stud & lock nut).

GTP1960 said:

...i have zero experience with steering & not sure where to start...

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That pretty much describes every task I have done on the TRs prior to doing it for the first time. I proceed regardless and (so far) they still run and I have all my fingers.

I think Randall's narrative has given you much of what you need.

BTW - In addition to tires making a difference (as noted above) you may also find that tire pressure is a factor.

I could echo the words of Randal and George, but I know they nailed it. I followed their advice and can only add one thing. When you try to feel the tight spot in the center of the worm, be sure to first remove the bushing from the other end of the shaft. On mine, the worm was not exactly pressed onto the shaft centered, which causes the other end to sort of wobble when rotated and was giving a false sensation of where the tight spot should be. If you go to macys garage website you can find a great write up on all the steps to rebuild a steering box.

Mine works great, doesn't wonder and I might be able to parallel park with one hand, but try not to. It's full of synthetic oil and doesn't leak. Get a new bushing, seal, gasket and jump in there.

TRF apparently does still offer a rebuild service. Take the original part number and add an 'R' to the end, eg 506962R for the LHS version of the "split column" box. But be sure to be sitting down when you see the price! The "RCU" price code (Rebuild Customer Unit) indicates that you send them your old box to rebuild.

If you can find a copy of their old "TR2 & TR3 Glovebox Companion", it has a pretty good article on doing the rebuild yourself. But, there are a few things that I've done differently.

If you think you even might reuse the worm gear (which was NLA when I did my first rebuild), it makes sense to me to get it out of harm's way, or at least not put any force on it (through the peg) while disassembling the box. Might not always be true, but I was able to remove the worm before undoing the big nut on the drop arm, on both solid and split columns. It's a bit fiddly as the British say, you have to kind of unscrew the worm past both the peg and the edge of the opening, but it came out for me.

The TRF article talks about using a slide hammer puller to remove the bushing. Mark Macy points out that you can slip a flat washer in through the opening to the side but then talks about using a hydraulic press to remove the bushing. I used the washer, but stacked up some threaded rod & nuts for an ad-hoc puller, which worked perfectly for me and pulled out the bearing and seal at the same time.

I suggest buying a Pitman arm puller ("Pitman arm" being American for "drop arm") that fits. I didn't have one the first time and made do with a big 2-arm gear puller, by making some side plates for it that locked the arms in the right position. (Otherwise, they just slide off.) But the experience convinced me to buy a Pitman puller the next time, and the puller worked much better. The opening on the one I got was just a bit too small, so I had to grind it larger, but it worked great otherwise. In both cases, though, I had to tighten the forcing screw until I thought something was likely to break, and then whack it with a BFH to pop the arm loose. Best to leave the nut loose on the shaft, so it and the arm don't go flying when the joint pops apart.

Let me know if you decide to do it yourself and can't find the TRF article. It's in my stack of things to scan, but I could do it sooner rather than later if needed.

PS, when I did that first rebuild on my previous TR3A, my worm gear was pretty badly worn and showed lots of damage (probably from trying to overtighten the top adjustment). But I went ahead and reused it anyway, as there didn't seem to be any other choice. The wear in the gear meant it didn't get tight on-center, but rather had two tight spots off to each side. So it always had a little play while driving. But still, my overall reaction was "Why didn't I do this much sooner!" The improvement in steering was truly remarkable even with the worn out worm. And the play didn't seem too objectionable to me, as I was already accustomed to having to gently wiggle the wheel back and forth to keep a straight line on the freeway

Not as elegant as a scan, but here is a quick & dirty snapshot of those pages in the Glovebox Companion.

You may have to enlarge a bit and go squinty-eyed but I think it is (barely) legible.

Hey thx guys!

this is one of those deals that I didn't see coming,
and am getting my brain around it, bit-by-bit.

Texasknuckle , I looked up the Macy's article and called them about a rebuild.( Thx)
i'll compare it to the TRF article and see what I can make of it.(thx Geo & Randall)

i understand what Randall meant about "better sit down": because Macy's rebuild sticker shocker is approx. $1000.-$1200, not including shipping. However I may bite the bullet and have them do it, (big IF) I can manage to get the drop arm off. (Thx for Pittman puller tips, Randall.) And free up the steering box.
(BTW: the workshop manual says "use a suitable lever to remove the drop arm from the center tie rod".....not sure what thats referring to)

didn't have any trouble with the stator tube or wiring though.

best regards

Jake49 said:

Don't have access to a press or don't want to buy a reamer? Send your disassembled steering box and rocker shaft here and we'll install the rocker shaft bushing and ream to size for you.
​

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Funny thing about that; I didn't have to ream either time. The new bushing was sized exactly right (which was actually a bit of a disappointment as I was planning to ream undersize to match the wear in the shaft).

If you do need to ream, you can pick up a cheap "chucking" fixed reamer for well under $50 @ Enco. I forget the size offhand, but it is a standard fraction of an inch (maybe 5/8"), not some funny decimal or metric size. The required clearance is built into the shaft. Stay away from the "adjustable" reamers IMO, especially the cheap ones. It's just way too hard to use them, and too easy to make a mistake that ruins your other work. BTDT, reamer went in the trash along with the ruined bushing.

As a side comment, a friend of mine actually added another bushing to the bore above the original bushing, so the shaft gets more support. He had to open up the bore for the bushing, so it's not a trivial job, but I believe it will significantly extend the life of the rebuild and might even help reduce steering effort a bit. There is a lot of force trying to twist the shaft off-center, and I believe much of the reason so many TR3s steer so hard is because wear in that bushing is allowing the shaft to twist, which causes the peg to bind in the worm. The extra bushing should help resist the twist.

I believe Mark's web site is also mistaken about the availability of parts. TRF has the bearings and races listed; they don't like to sell the bare worm gear but will install a new worm gear on your shaft for you (for about $300). Moss sells the bare worm if you would rather do it yourself. (667-375 for LHD). But for $40 more, there might be something to be said for letting TRF install it for you.

I can't promise anything (don't know how busy he is now, or how willing to take work from out of state), but you might try contacting Bob Jasper in Bellflower, CA. He might be willing to do a rebuild on a time & materials basis rather than fixed price, which may or may not actually save some money. Bob is a long time TR3A owner, does all his own work, and wins awards at almost every show he attends. Since he retired from his "day job", he moonlights as a TR mechanic. Last time I asked, though, he was backed up for months, so don't expect overnight service. You can find his contact info at https://trsc1977.com/Page_3_Contact_Info.html You can also find Steve Hedke on that page, who does much the same thing (and was likewise backed up for months last time I asked).

GTP1960 said:

(BTW: the workshop manual says "use a suitable lever to remove the drop arm from the center tie rod".....not sure what thats referring to)

Click to expand...

The center tie rod is the link that runs between the drop arm and the idler arm. The tie rod ends attach to it, and it carries the Silentblocs that engage with the drop arm and idler arm. So, what they are talking about is prying between the drop arm and center tie rod, to break the tapered joint between the Silentbloc pin and the drop arm. You can buy a "pickle fork" tool designed for similar tasks, or just use one of those great big screwdrivers that never gets used for actually turning screws.

However, I've never had much luck with that approach. Usually, the rubber in the Silentbloc is already broken, and when I start prying, the top plate on the pin pops off and leaves the pin in the arm. I've had much better luck using a VW style tie rod separator, like the one shown here


PS, if you are going to pay someone to rebuild the box for you, just ship them the whole thing with the drop arm still in place.

Thx Jake49,

i'm reevaluating my options.
out of pan & into the fire.

GP

You will need a good arm puller, but they will come off. I would suggest once the nut is broken loose (that is if you use an impact gun on the nut) to just loosen the nut with the gun and turn the nut off by hand with a wrench so you do not stretch the threads. I used a wheel cylinder brake hone and reamed out the bushing. They just need a little.

GTP1960 said:

(one more question: how do you reconnect the drop arm to the center linkage?)

Click to expand...

With the Silentblocs, it is important to have the drop arm in the "straight ahead" position while making that connection. But with the free turning replacements, it doesn't matter. Then one approach is to use a plain nut at first to tighten the taper. Once it's locked, remove the plain nut and install the (new) nyloc.

I'm going to go with the delrin free turning replacements, as I tore up the silentbloc separating it, anyway.