105 Gearbox Question

[njh1964]

Apologies for what may be a dumb question, but do all 105 gearboxes require the gear shift to be pushed down/in to shift into reverse, or is this just an early or late gearbox feature?

Regards,


Nick

[AikenDrum105]

Just the early ones - you can fit a push down lever to a later gearbox with the automatic 5th/reverse lockout though - Mine is setup that way.  Pushing it down doesn't do anything - but it looks right    

[njh1964]

Hi Scott,

Do you happen to know if a later model shift assembly can be bolted straight onto a gearbox which originally came with a pushdown shift assembly?

I'm trying to make up one good gearbox from about two and a half spare gearboxes, one of which has the pushdown shift but is also missing the actual pushdown shift lever.

Regards,


Nick

[AikenDrum105]

I might have a spare push-down if you need one - they're getting a bit thin on the ground, that's for sure. (and they can be buggers to get apart if you do have one that needs restored..)

You can fit a late lever without the pushdown to an early box - but I'm not 100% sure if you can replace the push-down interlock in the neck of the box with the auto-lockout interlock from a later box to match it. worst case you could remove the lockout completely - and just give the teeth a clean now and again going from 5th to 4th

It's pretty easy to take the vents off the turret of the gearbox and remove the lever joint - swap it and the interlock plate with the spring over and see how it goes...  the vents have shim rings that centralise the lever joint in the gate - you might have to muck around with these to get it smoothly returning to the middle 3rd/4th area of the gate,  and not bind against the 5th/reverse interlock....

Good fun:)


Cheers,

[njh1964]

Hi Scott,

What I was getting at may be best described in the below diagram. Assuming part "A" is a gearbox which originally came with a pushdown shift version of part "B", could you just replace the pushdown shift version of part "B" with a later model (ie non-pushdown shift) version part of "B"?

In other words, can you graft a later model shift tower and housing onto an earlier model gearbox?

Thanks for your help on this.

Regards,


Nick

[AikenDrum105]

Oh...

I'm not sure   I have a niggly thought about the size of bearing(s) in the back of the tower being different - and/or that they may be shimmed to a clearance during assembly of the split case / turret... - but that may all be based in fantasy

Vin Sharp would be the first person I'd personally think of to ask that question.

If this just to get the later lever / lockout I'm pretty sure it will be easier to migrate the upper part of the mechanism in the turret  - But if you need to make a full gearbox out of differing series parts that might be a measure as you go process

Sorry if that's not particularly helpful  

Cheers,