Austin Healy BN1 transmission.

[John S Farrington]

Fellow Healy friends,
I am in mid restoration of a BN1 Healy and a very early model. I had the pleasure of getting it to run and having some experience driving it before tearing it apart for restoration. The transmission is the old three speed with a backwards shift pattern. The overdrive also did not work. In putting it back together, want to upgrade to a BN2 4 speed or equivalent. I would prefer to keep the mechanical clutch linkeage but would consider hydraulics if that is a good option. The purpose of this posting is to solicit advice on this issue. The goal is to have a good four speed overdrive transmission with a shift pattern that is more standard than the BN1. Cost consideration also is a factor but secondary to four speeds.
Best Regards, John Farrington.

 

[John Turney]

John,

Welcome to the Forum. As I understand it, both the BN1 and BN2 use the mechanical clutch linkage. The BN1 has the bell housing integral with the transmission and the BN2 uses a separate bell housing. The BN2 through BN7/BT7 use similar side-shift 4-speed transmissions, so getting a 4-speed transmission is relatively easy (for a 40 year old car). My guess is that the BN2 bell housing would be hard to come by. I don't know if the later bell housings will mate to a 100 engine.

Actually, the BN1 transmission is a 4-speed. 1st gear is blocked off because it's too low to be useful. That's why "1st" is in second position. On the 4-speeds, 1st is only marginally useful. On flat ground, most people start in 2nd anyway, so it may not be worth the effort. Have you driven a 4-speed Healey? Maybe someone with a 4-speed lives near you.

John, BN4

 

[Healey 100]

John:

I have a BN1 and have never considered changing the transmission. My "three speed" unit shifts beautifully and is very quiet in all gears, in marked contrast with the later Healey four speed units. And, as John T says, the BN1 transmission really is a four speed. I do use the unblocked stump puller first gear on mine occasionally for dealing with very slow traffic situations.

Consider that when you put a BN2 transmission in a BN1 you are hardly preserving the marque, you are confusing it. I can understand making the change if the original transmission has failed and you cannot find a replacement. But a good three speed in a BN1 is an important piece of history, this is part of the original Austin Healey. Besides, if a thief tries to steal your BN1, he probably won't be able to get it out of the driveway!

Good luck and good motoring,
Bill.

 

[catfood]

I'm with Bill on this one. The three speed box is probably the best form of anti theft device you are likely to get!

The only problem I have with it over this side of the pond is when the car goes in for its MOT (legally required annual safety check). If I use our local Rover dealership I have to leave a large notice pinned to the steering wheel to stop the mechanic from driving it into the wall (up until recently I had an unmarked gearnob on the stick)!

Stick to the 3 apeed if you can, apart from being original, it's also something to talk about at the local pub classic car meets