TTi Gearbox.

Mike40M said:

My 5-speed XHD came with the same oil recommendation text. Except that it said "Motul Gear 300 Oil 75W90 GL-5, or Castrol Syntrax 75W90 GL-5". Nice with alternatives.
One thing disturbs me though. It's a bit bigger, so it don't fit in a Manx. Hits the lower frame tubes. Well, after milling it a bit, it fitted. Not happy with that it has longer lever travel from 4th to 5th than for the other gears.
Main problem though is that clutch rod travel is to long. Gives a very hard clutch if you use the original handlebars with levers welded to the bars.

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As I live in France now I use the Motul Gear 300!

mdt-son said:

Hello Ralph,
I have a 5 sp XHD gearbox on order with TTI. Can you please tell me what the bore seen at the casting where they have machined clearance for the selector drum is for? Is there a boss on the outside? The wall thichness is rather small for holding a bolt or another threaded item.

I am discussing with TTI how to integrate a neutral switch at their transmission. My order is for a Mk3 variant and I want to keep the neutral switch which is std fitment on the Mk3.

-Knut

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I guess you are referring to the hole half way along the front of the case, where the drum sits...well in truth it isn't for anything except cosmetics!

Bruce went to the trouble to make it look externally like an AMC box whcih of course has a rotating selector plate and external items that relate to it (two bolts and washers). The standard selector plate/quadrant is held in place from the outside, as is the quadrant wich uses the other hole you see nearer the inner cover and higher up.

The TTi has these but purely as cosmetics, that hole is where they mount the dummy hardware which has no operational function.

If that hole was modified to mount a neutral switch you would need to be able to mount a striker on the drum, or machine an indent into the drum, activated the switch in the neutral rotational position.

The only alternative solution comes to mind would be more like other drum change boxes that have an indent on the drum end. This would be on the drive side, with a switch fed in from the outside, just where the chain and clutch are flailing around!

mdt-son said:

Hello Ralph,
I have a 5 sp XHD gearbox on order with TTI. Can you please tell me what the bore seen at the casting where they have machined clearance for the selector drum is for? Is there a boss on the outside? The wall thichness is rather small for holding a bolt or another threaded item.

I am discussing with TTI how to integrate a neutral switch at their transmission. My order is for a Mk3 variant and I want to keep the neutral switch which is std fitment on the Mk3.

-Knut

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Like Steve says they are more for looks, plenty of thickness though.

Thanks for the input, Steve and Ralph.

I will have a look when the gearbox arrives if the selector drum allows a dowel striker to be fitted radially to the dummy bolt. Otherwise, I will design a neutral sensor to take a signal from the crossover shaft.

-Knut

If that cover plate had been put where it is on the AMC box, it would not be possible to spot a TTI gearbox at 100 metres distance. All that bullshit on the front of the box is just a waste of space, - it fools nobody.
I like the TTI gearbox, but I am not a purist. If we were going to be genuine about historic racing, we would not allow it to be used and we would all go backwards. Somewhere, a decision will have to be made about intent - what are we trying to achieve when we race old motorcycles ? For me, I have no interest at all in eligibility. I would race my Seeley 850 against modern air-cooled Ducatis, Guzzis and BMWs. and be happier doing it.

Same place as a Quaife Al.

storm42 said:

I do not know Bruce's reasons but this site doesn't seem to like it. Go down to this bit: TRANSMISSIONS: ALL MITSUBISHI, V160, AND AZ6:
www://jackstransmissions.com/blogs/pages/oil-recommendations

As for the XHD bit, again I don't know for sure but I would guess that all the gears are just that bit bigger and stronger, obvious really but without a standard one to compare with, just a guess.

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From Redline’s website below. The referenced article is about synchro transmissions. Since the Commando gearbox is not a synchro, what’s the concern?

• Not recommended for most synchro applications due to the product's extreme slipperiness

Chris said:

Same place as a Quaife Al.

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All I can remember about my mate's Quaife is it had a squirrel cage bolted to the cam plate spindle which was turned by a couple of spring loaded pawls. But you could not see it unless you looked between the box and the motor. That box would have been brought to Australia in the early 1960s. But he had two - 5 speeds in the 500 Manx and 6 speeds in the 350 - which he still owns. The 350 is a genuine works bike. But back in the old days, nobody really appreciated how good they were. Even a 350cc BSA Gold Star turned out 40 BHP. The 1958 AJS 7R was the fastest 350 single.

My 5sp XHD arrived today. It has the crossover shaft option for Mk3 as well as no K/S. Pictures enclosed as I believe this particular version hasn't been shown before. All TTI transmissions carry a serial number.







-Knut