Hi guys,
Sorry for this late response but I have just realised that for TC stuff, this might be THE site as other sites seem to concentrate mainly on TD and TF.
I would like to comment on two steering box issues.
Firstly the standard TC steering box. I have such in my road TC (since 1968) and my race TC (at 120 mph). In my opinion, the main weakness of the BC box is that the top plate (with three bolt holes) was originally not hardened. As a youngster, I quickly learnt that the sector shaft and top plate "pick-up" on each other. That is, they scratch each other severely, even if fully submerged in oil! An old MG expert, Tony Ohlmeyer, told me that the top plate of pre-war cars was hardened. He suggested that I make a new top plate for my TC and have it case hardened. I did that in both cars and now, whenever I take that plate off for inspection, it is polished metal and the sector shaft is not scoured. Tony also suggested a "flash" of hard chrome over the surface, because that is better for friction reduction. I must admit that I have not yet gone that extra step.
Secondly, The different gearing of other (Datsun/ VW) boxes. I believe that these steering boxes might make a TC more drivable in certain circumstances. Ordinary road use might beg that easier ratio. However, If you want to compete in a motorkhana, then the direct steering of the original box might be an advantage.
Doesn't matter really. As long as we enjoy driving these special cars in the manner we like most.
Cheers,
Bob Schapel
TC Steering
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Tom Lange, MGT Repair
- Posts: 310
- Joined: Mon Jan 07, 2013 10:14 am
Re: TC Steering
Did the original poster (whose name is not given) ever find a TC with a replacement boix to try?
Tom Lange
MGT Repair
Tom Lange
MGT Repair
Re: TC Steering
Bob, the original TC top plate was 0.175 inch thick, and was hard chromed on one side. Pretty hard steel. I have heard stories about how the plates can distort upwards from the pressures over time from the top of the sector shaft rubbing against the plate at center steer. Over adjustment (removing too many shims) probably contributes to the distortion problem. Simple solution people have found is to make a thicker plate, so it does not distort over time.
The original rub plate (top plate) I have on the shelf clearly shows an attempt to texture the surface before it was hard chromed. Light machining marks across the entire surface, running mostly 90 degrees to where the sector shaft will rub. The Moss replacement plate I got several years ago also clearly had intentional texture to it on the hard chromed side. Makes sense to me to have a slightly textured rub plate. Polishing the plate might work better on a 120 mph race car, but it seems counter productive on a street car. Too bad Moss ran out of those rub plates years ago and does not seem at all concerned with the keeping the most basic TC steering safety/maintenance item in stock. I think I paid around $10 seven years ago.
The original rub plate (top plate) I have on the shelf clearly shows an attempt to texture the surface before it was hard chromed. Light machining marks across the entire surface, running mostly 90 degrees to where the sector shaft will rub. The Moss replacement plate I got several years ago also clearly had intentional texture to it on the hard chromed side. Makes sense to me to have a slightly textured rub plate. Polishing the plate might work better on a 120 mph race car, but it seems counter productive on a street car. Too bad Moss ran out of those rub plates years ago and does not seem at all concerned with the keeping the most basic TC steering safety/maintenance item in stock. I think I paid around $10 seven years ago.
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frenchblatter
- Posts: 625
- Joined: Wed Apr 01, 2015 1:22 pm
- Location: Royston, South Yorkshire
- Contact:
Re: TC Steering
Have you ever heard "if it ain't broke, don't fix it"
Lynne & Norman Verona.
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Bob Schapel
- Posts: 20
- Joined: Wed Apr 13, 2016 6:07 pm
Re: TC Steering
Hi fellow TC drivers,
May I recommend case-hardening the Bishop Cam top plate (3 holes ... some diagrams call it a side plate). When I first started driving TCs 54 years ago, I found that every time I took the top plate off, the plate and the top face of the sector shaft showed signs of wear or "picking-up". This was despite always having the oil level right up there. An old local MG expert named Tony Ohlmeyer told me to have the top plate case hardened and added that the pre-war ones were originally hardened. He said to then have a flash of hard chrome put over it. I made a new plate because the old one was so thin, and had it hardened. I never got to do the hard chrome thing. I guess that would be to reduce friction and I think I should try it to test that theory one day! Now, when I occasionally take the plate off to crack test the sector shaft, the plate is polished but unworn. The box now never needs the constant adjustment it once demanded.
Sorry for this very late post. I have been using another site which is good for TD and TF. I have come to realise that this site looks better for issues regarding TC?
Bob Schapel
South Australia
May I recommend case-hardening the Bishop Cam top plate (3 holes ... some diagrams call it a side plate). When I first started driving TCs 54 years ago, I found that every time I took the top plate off, the plate and the top face of the sector shaft showed signs of wear or "picking-up". This was despite always having the oil level right up there. An old local MG expert named Tony Ohlmeyer told me to have the top plate case hardened and added that the pre-war ones were originally hardened. He said to then have a flash of hard chrome put over it. I made a new plate because the old one was so thin, and had it hardened. I never got to do the hard chrome thing. I guess that would be to reduce friction and I think I should try it to test that theory one day! Now, when I occasionally take the plate off to crack test the sector shaft, the plate is polished but unworn. The box now never needs the constant adjustment it once demanded.
Sorry for this very late post. I have been using another site which is good for TD and TF. I have come to realise that this site looks better for issues regarding TC?
Bob Schapel
South Australia
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Bob Schapel
- Posts: 20
- Joined: Wed Apr 13, 2016 6:07 pm
Re: TC Steering
Oops! Sorry, not yet used to this site so put up my second post thinking the first one had not gone through ... was just on a second page!
Thanks guys, I did not know the originals were hard chromed. Are you sure? I am happy to learn new things but I have never seen one hard chromed despite all the spares Dad accumulated in his shed in the 1960s. Could it have been a USA thing, either for cars sent there, or a common mod when USA owners saw the problem?
Bob Schapel
Thanks guys, I did not know the originals were hard chromed. Are you sure? I am happy to learn new things but I have never seen one hard chromed despite all the spares Dad accumulated in his shed in the 1960s. Could it have been a USA thing, either for cars sent there, or a common mod when USA owners saw the problem?
Bob Schapel
Re: TC Steering
It his not a big job to switch from one to the other so perhaps you could get a VW steering box and try it. I have the option of both but have opted for the VW box for a different reason; being lower geared and lighter, it should be easier on my painful hands. 