Steering not right

[red57]

OK, next installment. Today I tried two other used rocker shafts with no real change. There are minor differences in the various combinations of shafts and arms but nothing near the change I need.
A couple of pics - these are hard to measure so I tried to take exactly the same pic of 2 shafts & arms - first is new shaft and 2nd is old shaft.

I started looking more closely at the splines on the replacement shaft and was surprised at how crudely the removed splines were done. Here are comparison pics, first the old shaft and then the new one.


Marginal workmanship and it almost looks like they missed the one they wanted to remove - got part of two. That got me curious so I counted the spline teeth on the shaft and there are 36 teeth - with one removed every 90* to 'key' the pitman arm so it can't be installed wrong. So 36 teeth equals 10* per tooth and I can say for sure that none of my shafts or arms are one full tooth different.

​

So I tried to check just how much change I needed to get the rocker centered in the box and the arms pointed the right direction (centered). To do that I placed the head of my protractor against the shock tower and sighted on the pitman arm. The first shot is with the rocker centered and the 2nd is with the arms centered evenly and, interestingly enough the difference is about 10*.


So, not sure what I'm going to do but it seems possible that I might be able to carefully grind away a second spline adjacent to the ones they removed and achieve a 10* rotation of the arm in relation to the shaft??? Otherwise I don't know what other options I have since no individual parts/components seem to be wrong but the assembly just isn't right. :confusion: I even spent some time going back and checking the basics - the shock towers and the steering box & idler mounts are in the right place and the box as well as the suspension bits all fit like they are supposed to, the frame is straight and true.....

Thoughts?
Dave

 

[steveg]

Dave,
At least you've got an old one to experiment with grinding away a spline.

The new one is sure crude and the old one bunged up.

What a conundrum that the parts individually check out but they bolt together incorrectly! This argues the problem is somewhere else.


Edit:
Would like compare photos with same arm on both rocker shafts - would show any difference in splines.

Extra credit: different arms on same (new) rocker shaft. Ditto old rocker shaft.

 

[vette]

This might sound stupid but try putting the bent original pitman arm on the shaft. See what it does to the geometry.
And Steve's point about things seem to indicate the problem is somewhere else has a lot of merit. Could it be that the main shaft in the steering box is not where it belongs although I think this was mentioned earlier.

 

[red57]

This might sound stupid but try putting the bent original pitman arm on the shaft. See what it does to the geometry.
And Steve's point about things seem to indicate the problem is somewhere else has a lot of merit. Could it be that the main shaft in the steering box is not where it belongs although I think this was mentioned earlier.

Believe me, at this point there is no such thing as a stupid sounding idea (unless it's me for not being able to figure this out). Unfortunately I can't put the bent one the way it is because it's so twisted I can't get the rod ends into their holes when it's mounted. However, I guess I could grab the acetylene wrench and straighten it up some and try fitting it to see what it looks like. May do that tomorrow as well as trying for some more pictures that Steve suggested.

I agree with both you and Steve that there is a reason and I just haven't been able to understand it yet - something else, but what? It's getting to be embarrassing - it's probably so simple, I'm gonna want to shoot myself when I finally see it. When I talked about grinding splines off to achieve a 10* rotation of the arm on the rocker shaft - it really goes against the grain for me to alter something just to make it work when I know there has to be an explanation. I mean, there are entirely too many of these on the road and, other than Bob Claffie's comments earlier in this thread, I've never heard of anyone with this situation.

Which is what's keeping me from grinding splines for now. That and the fact that when I installed the old rocker the pitman arm was in virtually the same position meaning the new rocker seem very close to the same as the old one, certainly not 10* different (it's also what's keeping me from dropping another $350+freight on another new one). Round and round we go, chasing my tail.....

To answer your last questions, yes I do think the main shaft is in the correct position inside the steering box. I installed new balls and it shimmed to the correct bearing preload without any excessive/unusual stack of shims. Visually everything looks the same as it did 25 years ago when I rebuilt it the last time (BTW, I had no odd issues then and the box performed flawlessly for 20 years until the wreck).

Again, thanks

Dave

 

[steveg]

Dave,
It should be possible to clamp the bent arm together with the new one such that the splines align. Then you can observe the alignment of the square stops on either side.

If with the splines aligned, the stops don't align, that would show the splines to be in a different place on the new one. Assuming the forgings are the same so the stops become a proxy for the arm as they're all forged the same way and the splines are added later. Whew, hope that's clear.

Wonder if it's possible both the rocker and new arm are a little out and the tolerance stack is causing the 10* out. If that's the case, IMO, you'd be justified in grinding a spline and just doing the repair - you'd know for sure what the problem was.

 

[steveg]

Dave,

Different approach, thought experiment:

If the steering box chassis mount surface is a little slanted outward at the bottom from the crash, that would cause the steering arm to rotate outward, causing the problem were seeing.

Maybe someone here could provide a c-to-c measurement between the bottom of the idler shaft and that of the steering rocker shaft.

If yours was, say, 1/8" long, maybe that would make the difference we're seeing.

 

[Bob_Spidell]

I'll throw a SWAG into the pot (please excuse if it's been mentioned, I re-read the whole thread and didn't see it, but there's a lot of words). From what I gather, you're basing the center of travel on the (in)famous 'tight spot' on the steering worm. Since you have only one rotation in one direction and two in the other--my BJ8 has a little over three turns lock-to-lock, so that seems about right--using the tight spot as center maybe the tight spot is not in the correct location (IOW, the worm's machined incorrectly)?

 

[vette]

A similar thought to Bob's is that your desire to have the box centered is not necessarily necessary.
I believe you said you centered the box at exactly the same turns right and left. Is that necessary?
I remember when I bought my Healey about 25 years ago, the box was not centered. I had less turns to the left than the right and it would not turn as sharply to the left as to the right. I drove it that way for about 2 seasons before i took the car apart to restore. If I remember right there is suppose to be stops on the steering linkage that keeps any steering box from turning all the way to the end of its worm. Would sacraficing a wee bit of peg movement on the worm be noticeable. Again I have never rebuilt a box don't even know if I am using the right terms. Hope you get the idea.
Also, just my position on this modifying thing. It is one thing to modify to achieve a new or novel result but to modify to achieve a stock result seems not good.

 

[Bob Claffie]

In the original crash could the "peg" have been displaced into a different grove on the worm? Grasping at straws here . Bob C

 

[Bob_Spidell]

... If I remember right there is suppose to be stops on the steering linkage that keeps any steering box from turning all the way to the end of its worm ...

There is some, er, 'discussion' going on with DWR regarding their 'uprated' steering box. One unhappy customer, don't recall if he's on this forum, installed his and noted resistance in one direction near full lock, and got a replacement from DWM, which also had the same tight spot. So, I checked the DWM box I have on the bench--still working up the courage and will to install it--and it too has the tight/rough spot. I contacted DWM and got a call from Jeremy Welch, who seemed a bit agitated--that may be his natural state --and hoping to nip the 'insurrection' in the bud he insisted that the stops on the steering linkages would indeed stop the box/wheel from encountering the tight spot. We shall see (someday).

I have to say I probably wouldn't install the 'replacement' rocker shaft shown in the photos of 3/28 if I could possibly avoid it. That shaft must have been machined on a Monday, and if you remove some metal from the splines you would weaken the shaft (though probably not dangerously so). I know you're kinda stuck, as it seems most of the other components of the steering box are available except the rocker shaft (even from DWM). You might try Tom Monaco at Tom's Import Toys or David Nock at BCS; one of them may have a better one on a shelf somewhere.

 

[red57]

Sorry, been in the shop all morning now I'll try to catch up with responses.

Steve, post #25, I straightened the bent arm enough to lay it on top of the others and compared the spline 'key' positions -they all seem very close to the same. A straight edge laid across the keys lines up with the center of the cross rod hole in all three (bent one is a bit off but I expected that). BTW, if by 'stops' you mean the lugs on the side, I don't think they are anything but places to hook a puller on for removal - nothing close by for them to hit. Anyway the 'clocking of the splines seems the same on all three arms.

Post #26, I checked and the mounting surfaces for both the idler and the steering box are true vertical from the frame and I'm confident there is no incline to the side in either - think it would have to be pretty extreme to causes this much affect but was worth checking, thanks

Bob Spidell, post #27, I'm basing/locating the 'tight spot by three methods - feeling it by tightening the set screw a bit, centering by steering wheel turns, and visually with the box cover off. The worm is an original I have been using for 25 years and the tight spot has always been in the middle where it belongs so I believe it is correct. Here is a pic after finding the tight spot per above and then pulling the cover off. Thanks,


Vette, post #28, It may not be truly necessary to have it exactly centered but it does need to be much closer that it is now - I'm almost 7 years deep into this project and can't just put up with something I know is clearly wrong. To be clear, this is not just 'a wee bit of peg movement', this is 1/2 turn of the steering wheel. Also, because this is an original tapered worm, when 1/2 turn from the middle there is a lot of clearance (looseness) and if I tried to tighten (remove slop) then I would have a very tight spot 1/2 turn to the left - not good for the driving experience. I think you are right about stops, the ones I know of are on the bottom of the stub axles that hit bosses on the bottom of the king pins. Lastly, I agree, I am not comfortable modifying something just to accomplish a 'stock' set-up - shouldn't need to modify in that case. Thanks

Bob Claffie, post #29, no worries on that score, I completely rebuilt the box and the amount of clearance inside the lid would not allow it to jump a tooth. Thanks

Bob Spidell, post #30. I have no experience with the DWR 'uprated' box, know nothing about how well they work. I do suspect some 'marketing' is involved because one of my earlier careers in the '70s was as a machinist in a production job shop (remember those?) and I can tell you that making a constant worm would be much easier than making a tapered worm with a tight spot in the middle - remember these have to be milled and then heat treated and then ground and the set-ups involved would be challenging. My personal theory for the constant worm marketing is that no one has the skills anymore or is willing to invest in the tooling required to make the tapered worms. JMHO
I agree with your assessment of the 'new' shaft - I was never very pleased with it but when I bought it several years ago, it was the only new one I could find. I'm about to do another post with pictures of what I found this morning and will go into more detail. BTW, DWR, AHSpares, and SCParts all sell them now between $350 & 400 + freight - Moss even lists them for $600. Question is are they all made by the same shop somewhere or is there a quality difference?? Thanks

So, next installment soon (takes me longer to type these than it does to do the work)

Thanks again to all,
Dave

 

[red57]

Another round of observations. First another comparison between the steering box in the center of it's travel vs the steering arms in the center of their travel. I used a protractor to measure the angle referencing the front face of the shock towers. First is with the steering box centered (on the tight spot), idler arm is at 68* to frame, and pitman arm is at 90*. Second is with the wheels pointed straight ahead, idler and pitman both at 80*.


Next, Steveg had asked for more comparisons between the shafts & arms. Big thanks to Steve because these are quite illuminating. I knew there was some difernces but this forced me to get creative by making a cardboard piece I could mark on for deferent combinations. Blue ink is new shaft and purple ink is old shaft.
So, I'll start with the new shaft and arm #1 (the one I was planning to use) - first shot is box centered & 2nd shot is wheels straight ahead (arms centered)

Then, new shaft and arm #2 (another spare I have)

So, both arms worked about the same and here is where the steering wheel is to go straight.


Now, here it gets interesting, this is the same sequences but with the old shaft and the same two arms (remember, this shaft is twisted at the splines in the wrong direction to help me).
So old shaft and arm #1 -

- first shot is box centered & 2nd shot is wheels straight ahead (arms centered)​

The same but with arm #2

And finally, here is where the steering wheel is to go straight using the old shaft - it's not fixed but the tape marking center moved from about 5:30 to close to 4:00 so clearly going in the right direction.


So, I'm still not too sure exactly what to do - the old shaft clearly gives a better result and it is twisted where the arm attaches. If it wasn't twisted the results would be even better, not much but a bit. Having said that, I'm still at least 1/4 turn of the steering wheel from going straight when in the center of the travel. As I said somewhere else, in that situation with the stock worm, I would be forced to run the box on the loose side to avoid a bind/tight spot 1/4 turn to the left, not exactly optimum.

I think I will call SCParts tomorrow and see what their response is, if they can shed any light - bottom line is, as Bob Spidell pointed out, this shaft is kinda marginal anyway and considering it clearly is off some, I would like to have them replace it and hope that their QA/QC has improved. One of the problems is, as I said before, I bought it several years ago (haven't been able to find a receipt so don't know exactly when) and therefore am somewhat at their mercy.

Well, that's all I know right now. Observations welcome and thanks to all for reading this far and offering good helpful suggestions.

Dave
​

 

[vette]

Well Dave, Good Discovery. Clearly you don't yet have the optimal solution but I do want to mention that running the steering box not exactly on center may not be as bad as you think. But maybe it will. I did very tedious micro adjusting to get rid of the tight spot in my box. I understand your desire to have an excellent system. And I would be equally frustrated having put in as much work as you have to have it not come out at the best possible. As far as getting an exchange on the part or I should focus on an exchange to a quality one, I hope you can achieve that. We are at the mercy of poor Quality production methods and assurances and it is annoying. I have also been in a similar situation with some major components. I ordered a set of 3.54:1 rear gears some years back. I ordered them from a known suspect from across the pond that has also been mentioned in this thread. Those gears were terrible. I had them set up by a know expert in assembling rear gears and he said their is no way those gears were ever going to run quietly. I had bought them almost a year before I needed them during the restoration and had them on the shelf for many months. I went back to the supplier (across the pond) I even had the receipt and they would only say that they wanted the complete pumpkin sent to them for their inspection. Needless to say I wasn't going to send them my only and original pumkin to some far away land and hope to get it back. I asked them to send me another set of gears and they would not. So I said just forget it. I was out the money and had a lousy set of gears. Sometime later I came across another supplier who was selling one run of gears. I bought them. I had them set up by a different but equally qualified rear end man. They too were noisy but not as bad. I live with them to this day. My point is that where these things are getting manufactured is crap. And the retail seller is usually not to favorable to trade back and forth. We need better manufacturering in the LBC aftermarket and we all know were the bad stuff is coming from. Good Luck, I mean that for you.

 

[steveg]

Per Vette's comments about foreign suppliers, my own lessons:

1) the cost of return shipping to the UK (or AUS I suppose) is enough to kill returns. This makes me want to buy things that are either cheap or hard to screw up. Can't think of any of the latter category right now.

2) When I was a new owner I bought some things from C*pe - they were unresponsive when I had issues with fit and breakage. Lesson learned. Sales-oriented folks can become deaf when problems occur.

3) buying from Moss, Tom's, BCS or Healey Surgeons (for AHspares stuff) becomes an insurance policy since you can return it stateside for reasonable shipping costs. IMO this is worth the markup. I ordered a British mild steel muffler a couple of years ago from Surgeons and they specifically told me I could return it to them if there was a problem. Their markup becomes the insurance policy.

 

[DerekJ]

Don’t get hung up on the position of the steering wheel with the single spoke being straight up. I seem to remember that after I fitted a new rocker arm after a crash, and played around with the refitting, when the steering was correct the wheel was slightly off centre and I had to adjust it back to the spoke straight up position.

 

[vette]

Here's another stupid idea, but crazy enough that I myself, if in this situation might look into it. Would it be possible to hand file ( or with a power burr tool ) the grove in the worm to eliminate or reduce the tight spot? Goofy Huh.

 

[Bob_Spidell]

I've heard it mentioned--maybe here--that the worm is hardened (seems logical). Filing down the 'tight spot' would likely result in a 'very loose spot' in short order.

 

[Bob Claffie]

Another unlikely scenario, is it possible that the steering column itself has suffered a twist in the accident ?

 

[AHS3903]

Very interesting subject and discussion.
As others have pointed out the issue can be summarized to "The problem is the relationship of the arm on the rocker shaft to the position of the left road wheel" so lets discuss just that aspect.

I'm a little concerned that you may not be giving enough credence to your having adjusted the camber to -1/2° from the standard +1° .
If this has been achieved by moving the top of the king pin in, as opposed to moving the bottom out, that will, in of itself, change the relationship of the rocker shaft to the position of the left road wheel.
( It will make the left wheel turn out)
To correct this you will need to turn the steering wheel to the right to make the left wheel point straight ahead.
Turning the wheel to the right to make the wheel point straight ahead will move the peg off the "high point" of the worm.
Obviously you can still get the "toe" correct by shortening the center rod BUT the peg NOT BE be on the high point of the worm.
Although it is indeed possible that the replacement rocker shaft is incorrectly made for experimentation, I would be inclined to return the camber of the left wheel to +1° before doing anything else.
That'll be 5c please

 

[steveg]

...I would be inclined to return the camber of the left wheel to +1° before doing anything else.
...

Good point, Mike. Returning to a stock specs baseline always necessary for troubleshooting.