Trap door for 1989 FXR

[1340evo]

Hi Again.. my quest to get this machine right is ongoing. I've found the trap door bearing bores to be a mess from when last the bearings were changed, so i've go a new one to fit.
looks the same except the shifter folk shaft hole has a thread in it? any ideas as the cast one I'm replacing just has a bore where the shaft slides in? any thoughts??

[1340evo]

Ha.. just realised, it does not use the hole in the trap door for location anyway, its clearance as it locates in the gearbox body... so not a problem...
But still wondering why this one has a thread??.. what I may do is turn up a small part to fit in the c/bore and take the end of the shaft for extra support?

[xlfan]

It is not a stock trap door. My guess is that it is a counterbored and threaded hole for an allen head bolt, to prevent shifter shaft from sliding out, and position the allen head below the gasket surface.

It will act as a possibility to get shifter shaft out, without disassembly of trap door.

[Dan89flstc]

The picture is showing the outside of the trap door.

The opening for the shifter shaft must be the same inside diameter all the way through the trap door.

The threads make no sense...

Find a good trap door from a `99 or later 5 speed, it will use the bigger trap door bearings.

[1340evo]

you can get the shaft out anyway without taking the trap door off.. the hole in a standard trap door is bigger than the shaft so with long nose pliers you can pull them out by just removing the outer cover if you need to....
I think it could be to hold the shaft in but whats wrong with the original set up... having put the outer cover on, the shaft is trapped and can't move anyway... kind of fixing something that isnt broke?... its strange why they have done it~

[xlfan]

Do you know what aftermarket transmission your trap door originated from?

[turboprop]

My guess is that someone created a 'Fix' to a problem that didnt need fixing. The shift fork shaft is indexed by a threaded plug on the primary drive side of the trans case. That plug is typically adjusted/set after the end cover has been installed. I bet that someone made this door with the threaded hole with the idea that the end play could be adjusted from the right side without having to remove the inner primary. Or maybe not.

[1340evo]

I think its a Jim's trap door. looking on-line they appear to have the thread as well but I can't see a threaded shaft to go with it?

As you say, its sorted by the far side so fixing a problem that don't exist? Even if this shaft floated a bit would it matter?