MG T-ABC

Hi All
Can some one tell me the year of the VW bug they use the steering box to replace the steering box on the 1948 MG TC looking to replace the steering box on my TC6881
Thanks

I have a more general question about TC steering boxes. TC Bishop Cam steering is notoriously tricky, but if it is set up with EVERYTHING working properly, it seems to work well, without too much wandering.

I hear a lot about how wonderful VW steering boxes are as replacements, how everything is stronger and new, and that once switched over there is no reason to ever go back. But I have also been hearing that the VW box is slower, makes steering harder with more turns of the wheel, and that it is NOT generally a satisfactory swap.

Who's right? Thanks.

Tom Lange
MGT Repair

All folks are right,,as long as they are happy with their steering, I think.
If it aint broke, dont change it. But if you are not happy with your present set up, do what you feel/ think suits you and your steering abilities best!
If one is not able for what reason what ever, to repair or set up the BC box properly ( non Whitworth countries (f.i. Germany) and have easy acces to VW boxes en know- how around the corner, why not switch?
TC life has many options to keep them rolling and still be happy!
Dirk - 74! and 35 years messing about with MG's

I have Datsun steering in my car because it came with it already installed, but I have driven stock TCs also. I agree that the original steering is much more sporty, and Datsun / VW more truck-like. The VW is even worse than the Datsun is, with its even lower ratio. The plus side is that the car is easier to hold straight on the highway and takes less physical effort to navigate twisty roads. The downside is that is feels like a different car, more modern in a sense. One finger steering, literally. While the low ratio drives me crazy, I will admit that I greatly enjoy the peace of mind that comes with the stronger components. I've personally never heard of a Datsun or VW box failure.

A while back I tried to get a new custom steering box made using modern parts, but in the original ratio. The shop, who makes custom steering boxes, wasn't interested and never said why. But from what I learned, it could be done for the cost of the conversion kits.

@Steve,
The peace of mind you mentioned was one of the main reasons to do the VW box, but my BC Box is well tucked away, awaiting better, younger and mechanically sound and better drivers, to do it " their way" The original Box from 1946 will remain with my car, come rain hell or shine!
Dirk

My TC has the BC box which works reasonably well, now with the toe set to 1/2" approx. I have had the opportunity to drive a TC equipped with a VW box and it also drove very nicely. If the steering was a bit slower I really did not notice that it affected performance all that much. I think that a bit of decrease in steering effort offset any slower response.

I like the quick turning of the BC box, and find the whole "wander" thing to be greatly exaggerated, and I think the "increased safety" of a VW box is far overblown unless you are comparing a worn out BC box to something. BC box tends to give warning through puddles on the floor if something wrong with sector shaft or housing. For the cost of a VW conversion, you can rebuild/repair a BC box to like new function and add a Thomkins kit for easier initial adjustment. A "new" BC box won't last as long as a "new" VW or Marles box, but you can't get the quick TC steering any other way.

Most of the boxes used in the Brit cars of the time and up through the later 60's and in some cases early 70's were of the same design. TR, Healey, AC, Jag, Morgan etc. were virtually identical. I understand the Cam Gear box in my early Morgan Plus 8 is a corporate relative of the BC cam box. They all have some on center lost motion. As I mentioned on an earlier post, the condition of the front end and its adjustments affects how the car steers as much as the box. The car should not be wandering all over the road in the first place. If you have to constantly correct the steering there are other problems or adjustments that should be made. The VW box has less lost motion and because of that will make even a fairly sloppy car easier to control, but it really doesn't solve the problem that may exist with the front end.

One of the first thing I was taught at UM was never, never, never turn a pre TD car steering when the car is stationary. That was M type to TC. TD on had rack and pinion so no problem.

As long as the car is moving, no matter how slowly, it's OK to turn from lock to lock but never, never, never when stationary.

Got it

Agreed, but I believe that turning while stationary is only cautioned against for the BC boxes. This is due to the high ratio and therefore increased abuse of the peg. With Datsun or VW boxes, while on skinny TC tires, I don't believe there is a worry. But probably prudent to follow that practice anyway.

Steve, I meant on the BC box, we didn't have conversions in the 1960's

Tom,

I have 2 TC's, one with the Datsun conversion and one with the VW conversion. I've also driven TC's with the BC box so I feel like I can speak from experience.

Yes, a properly set-up BC box has a sporty feel on the road and a smaller turning radius but unless it's "properly" set-up it's a bitch to keep the car going straight down the street when there's even the slightest crown or uneveness and that's at 20mph...even worse at higher speeds. In parking lots it's like steering a Mack truck.

Both the Datsun and the VW mods feel more stable and, while maybe lacking a bit of the "sporty" feel of the BC box, both still feel sportier than the TD or TF steering. Both also allow you to maneuver at slow speeds easier than the BC box.

I like all three choices but for real world driving prefer either of the modern(?) boxes to the BC.

More info: http://mwthemachineshop.com/vwvsbc

Jim Buell article on TC front end an excellent reference, a copy can be found in the resources section (technical articles) on this site. And see an in depth series at ttypes.org/ttt2. here: http://ttypes.org/ttt2/?s=steering&submit=Search They discuss the VW etc conversions in a fair minded, comparative manner.

I attempted adjusting my TC's BC box several times before I gave up. I rebuilt the entire front end and then tried again with the BC box. No joy until a fellow TC'er came by and determined the original box had some (then) older reproduction parts causing the troubles. A more modern reproduction worm gear was located that actually had the straight -ahead "notch" built into the design. That notch (not really a notch, see ttypes.org articles) is critical for set up of the BC box, and for proper straight ahead steering. Not really sure where that good worm came from originally, as I got it from AS just before they were sold to the current owner, who seems more interested (hint hint) in selling the VW conversion kits than stocking good re-pop box parts. I should add it was no simple task replacing that worm. This site has an old (AutoCar) article on how it can be done.

I cannot imagine driving the car with anything but the correct steering box, but imagine so many out there have never actually driven a TB or TC with a "properly" set up BC box. What a shame. With all the VW boxes going in, it should mean more "bad" BC boxes available to tinker with until the right combination of re-pop parts are found to steer the few correct TC's around on the lawn.