Bishop Steering Box

[Rob Reilly]

If there is a thread for strange things DPOs have done to these cars, this one would be in it.
Restoring the Bishop steering box, I find the drop arm was loose. Not only loose, but welded to the vertical shaft. But the weld was broken all around. The clamping bolt was too long, and they had put on a spacer nut and extra washers, but didn't tighten them, so it was still loose. All because the bolt was 1/2" too long. Couldn't they find a shorter bolt?
I ground off the weld and got the drop arm off. I was careful not to grind away the alignment mark on the shaft. Now I see an alignment mark on the top of the drop arm, which I would expect to find on the bottom. Was the drop arm on upside down?
At least the box is in good condition, no need for more shims or the Tompkins modification.
It is stamped 2 37 in three places, which I suppose is the date it was made. The car was made in May 1937.
The box is full of grease. The T Midget Instruction Book says remove the filler cap and fill with gear oil, no grease. But it has an ENOTS oiler fitting, not a cap. Blower and Autobooks manuals say to put SAE 140 Extreme Pressure gear oil in it. What is the current thinking on that, all agree?

[Steve Simmons]

Wow, that's scary. My concern now is what the welding might have done to the metallurgy. At this point I might consider at least a new pitman arm.

The oil I'm using now is Redline Heavy Shockproof. It is claimed to cover the 75W-250 range. Full disclosure, I haven't yet put it in a bishop box, only Datsun which ordinarily takes 90W. Redline is good at answering tech questions though, and could confirm that it's appropriate for the BC box. I'll have to do this soon, as I have two BC boxes that will be put into service soon.

[jagman2]

my preference is to use Penrite steering box lube. i use it in my XK-120, P1 Rolls and my TC.
works very well, especially if you have any oil seepage.

[Duncan M]

Proper way around for the arm to be installed is so that when everything is installed on the car, the arms bend is downwards.
Bolt/nut that is for tightening the arm to the (vertical) sector shaft should have holes for a split pin to ensure it stays tight, and also the sector shaft should have a groove where the bolt fits to lock the arm in place if somehow the arm bolt does get loose.

Grease probably installed so it would not leak out, like the gear oil. The oil seal for the box is where the sector shaft exits the box at the bottom. When the sector shaft "bushing" gets worn, the shaft movement becomes uneven, causing the seal to distort and leak. Another instance of the car telling you when maintenance is required. Packing grease in there is always discouraged, and is probably partly responsible for destroying the worm's ball bearings. The other reason for destroying the ball bearings would be improper adjustment of the front (bearing pinch) plate shims.

[Ray White]

I do not wish to be controversial but....

https://mwthemachineshop.com/vw-vs-bc-steering

[Rob Reilly]

Thanks for all the comments.
We don't have Redline and Penrite here, I presume they are SAE 140 viscosity, but we have Pennzoil and Valvoline SAE 140 EP, so I used Pennzoil.

The DPO welding job was very poor, almost no penetration, and the heat affected zone was only about 1/32" of an inch on the bottom end of the vertical shaft, i.e. he didn't do much damage, and it cleaned up fine, so I'm not worried about it.

Other than that, the steering box is in great condition.

I'm 99% sure the drop arm was on upside down. This looks right. The alignment marks on the bottom line up.

Please ignore the angle of the steering column and steering rod; the steering column is laying on the brake pedal and the axle has no load on it.

One last question: the steering rod and tie rod both have a left hand thread on one end. Is there a standard orientation convention? Should they both be on the left hand side of the car? One was and one wasn't when the car came to me.

[Steve Simmons]

Every time I've ever put a tie rod onto a car, I've thought about that. I don't think the factory would have even considered taking the time to make sure they put them all on the same way. In reality it makes zero difference since you don't adjust them independently. So I think they just grabbed one off the shelf and stuck it on the car. I have zero data to back that up though, other than the fact that most manufacturing lines were under tight scrutiny for frivolous expense.

[Rob Reilly]

Call me obsessive compulsive if you like, but I put them both on the left hand side.

[Duncan M]

Rob, sure looks like a TC drop arm. I guess the TA drop arm does not have a taper fit for the drag link ball stud, like the TC?

If that was a pic of a TC BC box and drop arm, I would say you definitely got the drop arm on upside down. Curious the TA would be opposite. Of course the drag link that connects to a TC drag ball is the oddball of the 4 link ends. Also the only ball with a tapered fit below the nut.
https://ttypes.org/keeping-it-on-the-st ... ng-part-5/

https://ttypes.org/tc-steering-understa ... ssemblies/

[dezwartj]

I am using John Deere "Corn oil" in my steering box. It is a very runny grease that is thick enough to not leak out of anywhere and runny enough to act like an heavy duty oil. An excellent invention from John Deere.

[Rob Reilly]

This better? I propped the steering wheel end up on a stick at what I guessed is about the right height.
The TA has straight shanks on all 4 ball pins. Also flats so you can get a wrench on them. All are in great condition, no wear. The tie rod and steering rod are solid bars, not hollow.

[Duncan M]

Rob, you could put it in an Earth orbit and it would still look like it was upside down, when compared to a TC box and arm. So you are inferring that the hole in the small end is NOT a taper cut?

[Steve Simmons]

Regarding the welding, it seems you were lucky that the previous owner was such a poor welder! I think I agree that there probably wasn't enough heat to do any real damage.

That said, it's a good idea to periodically get the arm crack tested for safety on any TABC car.

[Rob Reilly]

Right, the hole in the Pitman arm is straight, not tapered.
I stripped all the paint off before and checked for cracks, none found.

I can see this steering can be put together several ways, and I did not find a reliable old picture showing how the factory did it. Also it is unwise to trust the way I found it, as the DPO apparently fooled with it, also having nothing to guide him.

The steering rod should not have a large vertical component to the force it exerts on the left hand steering knuckle. It should be nearly parallel to the tie rod in the straight ahead condition. That can be achieved with the pitman arm on either way, since the ball pin is also reversible.

There is one other factor to be considered. Which way should the grease nipple be, up or down? It was down as found. The other three are up, can't be put in the other way because the tie rod would interfere with the leaf springs.
Up, the grease will leak out. Down, road dirt and rain and snow will get in. They should have had rubber gaiters on them, like most ball joints, but they didn't. A short length of bicycle inner tube would be better than nothing.

[Duncan M]

Looking at Andy King site and others, it would appear a new arm is interchangeable with the TC, except the small end hole can be done without the taper for TA/TB purists.

Once the engine is in, and wheels on the ground, you will likely find the TC orientation of the arm (shown in first photo in post above) is correct, with the drag link hanging below the nut, like in second photo. Same as a TC.

[Rob Reilly]

Well, I tried it with the drop arm angled down and the drag link steering rod below the drop arm, grease nipple and ball joint down. Nope, no good, not going to work, it interfered with the right hand spring and dragged on the left hand spring.

drop arm angled down, ball joint below

So thinking about it overnight, I think it's better to have the grease nipple and ball joint up so as to keep road dirt out of the ball joint. So I'm going with drop arm angled down, ball joint above it.

drop arm angled down, ball joint above

So the alignment mark on the drop arm is on the top where it can't be seen. I wonder if this is another example of using Morris parts.
Perhaps there was an alignment mark on the bottom of the drop arm once upon a time, but there is none now.
I have 4 T-series restoration books, 3 manuals and 9 other MG books and am amazed and disappointed not to find a picture of this. There seems to be a real lack of information about the TA, compared to the TC. I suppose it's even worse with some of the pre-TA models.