Transmission Gear Lockouts

[bsculley]

Recently I had a problem with the transmission in my BN2 not shifting into reverse. The selector rod was locked tight.

After some research and removal of the side cover it looks like the problem is associated with the spring/ball bearing detents.

I did get the reverse selector rod to move after some fiddling, but I would like a more robust solution.

Does anyone have a diagram showing exactly how the lockout function of these detents works?

I would like to understand it before assuming it's fixed.

Thanks,
Bob

 

[Randy Forbes]

Not a diagram, but a few pictures...

 

[Randy Forbes]

 

[bsculley]

Thanks Randy. Much appreciated.

 

[Bob_Spidell]

re: "... interlocking balls prevent more than one(1) gear from being engaged at a time ..."

Or, as Magnus Karlsson rather pithily put it, if they're not installed properly it "... will cause the car to remain stationary ..."

This may or may not be relevant or of any consequence, but there is a rubber pad that goes in a recess in the bell housing to cushion these shafts and/or prevents the shafts from going too far forward. This part isn't supplied by any vendor that I know of; I used a piece of linoleum cut to shape last time I assembled a gearbox.

 

[AUSMHLY]

Randy, fantastic photos with descriptions!

Anyone, why are OEM reverse selector rod angled at the end? I purchased a new reverse selector rod, the end is cut straight.

Bob, a couple thoughts why gears lock out.

If the selector rod detents are worn on the side, and or top, the rods may have some wiggle room, not locking in place.

You might try placing a thin washer on top of the ball bearing(s), creating more spring force. Might help locking the shaft in place.
If not, new selector rods would be in order.

If I remember correctly, in one of Karrlsons videos, he deepens the detents on one or more of the shafts to help it lock in place better.

The rubber pad Bob Spidell references is available from British Car Specialists.

Good luck.

 

[bsculley]

Thanks all. Since it was working and stopped I hope there is nothing serious amiss. Cleaned everything and got it moving again. Hopefully it stays that way.
Bob

 

[AUSMHLY]

Did you remove the tranny? What did you clean?

 

[bsculley]

Hi all. I pulled off the side cover for access to the selector rods. I was able to free up the reverse selector with a gentle tap. I cleaned everything visible including the overdrive filter and put in new oil. Obviously, I was not able to access or clean the actual lockouts. I'm hoping some of the new oil finds its way there, Reverse works now, although a bit stiff. I'm hoping it will loosen up, but if not, nothing lost.