SCCR box synchro gone maybe?
Turbo Mini Forums

Bit annoyed with myself really, got a SCCR box on my Kad 16 valve engine and ive had it running 2 months with not much useage and the synchro feels like its gone on 2nd gear. Theres a bad crunching on the downshifts from 3rd to 2nd.

Does this sound like a synchro issue?

The clutch was dragging a bit on a track day i went on at curbourough but i wasnt really pushing hard and i took it home when i couldnt get it into gear, i didnt fight it.

Could it have been the clutch dragging that caused it? It cant be power surely? im about 150bhp but thats not on the limit of a synchro box is it, dog box would be a bit overkill

When i built the box up i used the original synchros out the donor box and they all looked spot on.

Looks like the engine is coming back out

Thanks for any help

Matt W

Sounds like synchros. Mine is doing the same in 3rd, and from other threads I think mine could of been due to some clutch drag.

As you know only one way to find out!

I could be wrong, but im sure revs would kill the syncros more than power, and any clutch drag is making the sycros work harder, as they are slowing/speeding up the flywheel up aswell as the gears.

Edited by matty on 28th Nov, 2011.

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1/4mile in 13.2sec @ 111 terminal on 15psi

Did you change down into second very often on the track? Ive cracked quite a few baulk rings doing that.
You say they looked spot on but did you sit the baulk rings on the cones to check them?

I seriously doubt it!

I checked them on the cones, and they were fine. I was changing down into 2nd quite a bit infact it was probably nearly all 3rd to 2nd changes.

The cluth drag is the only thing I could think of, I bled the system out again and it was a lot better and driven it a bit since and then I heard the crunching, it's alright when going slowly

Matt W

where is the clutch biting point?

the damage may have been done, due to the clutch drag as the gents above have stated.............. you know what to do, its not the end of the world though.......... chin up and steady away

Near the bottom, the clutch feels nice now.

Matt W

bite point needs to be higher imo,

Thanks for the info guys... Either way it's got to come out. Gutted

Matt W

It could be worse, ive got 2 boxes to do 3 if you include the spare!

Hope you get it sorted.

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1/4mile in 13.2sec @ 111 terminal on 15psi

We did the same thing to the van's box. Looks like the baulk ring has given up on ours. Yet to take it apart and see what's up.

Its something I dont need to worry about anymore

Edited by paul wiginton on 28th Nov, 2011.

I seriously doubt it!

Yes you dirty dogger! Lol

If something is worth doing, it's worth doing half of.

learn to heal and toe

Edited by fastcarl on 28th Nov, 2011.

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foot and mouth?

Cheers guys,

Ill get some pics up when ive got the box out.

Out of interest does anyone use a dog box in there mini for road use? is it a bit 'savage'

Matt W

I use the Swiftune box, its no more difficult to drive than a standard box - easier infact, you dont have to use the clutch, I dont even use it on downshift

I seriously doubt it!

Do you use any kind of shift cut whilst on the track Paul? I was thinking of wiring something up to my shifter for my dog box but if its not needed it will save ALOT of hassle!

Edited by matty on 28th Nov, 2011.

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1/4mile in 13.2sec @ 111 terminal on 15psi

Ive seen the swiftune gearsets, i believe there made by quaife. Look a very nice piece of kit and they can certainly take some hammer.

Been to MED this morning and i reckon i can get a good price on one of his sets, its just whether i want a dog box or not.

Matt W

One important piece of information missing is the manufacturer of the gearset.

A friend has a Mini Sport ST ratio gearset and it has never had much synchro on 2nd - something that MSpt admitted isn't uncommon and suggested he return the gears for replacement.

Metric is for people who can't do fractions.

There not from Minisport

Matt W

I seriously doubt it!

I know the do some sort of shift cut for motorbike engined kit cars, they use a pressure sensor in the gear change rod which senses when your *leaning* on the gear change and cuts the ignition for a pre determined period some actually allow you to put a different period for the change in different gears.

Also some do the same on the way down and blip the throttle by means of a solenoid i think.

I think there called flatshifters or tricker shifters, they may only work on sequential boxes though because the upshift means that your pulling the gear change rod in one direction (or pushing) for each up or down change, whereas obviously your doing both and going across with a mini box so i cant see how youd get it to work.

Might be worth a look for your box though Matty

Matt W