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Unsynchronized gearset?

2K views 9 replies 6 participants last post by  GM 
#1 ·
J. Eriksson, the gearbox guru from Sweden, said that he is building a special unsynchronized gearbox for og900. My question is, how do you change gears on such a box and is it easy to learn?

Couldn't find any info with search, I don't know if the unsynchronized sets are called something else... I have heard the word "dog-box" is it the same thing?

-John
 
#2 ·
Learn how to double de-clutch i.e match the engine speed to the gearbox speed. Not very practical for an everyday driver but often standard on race cars of old. Getting the gears to transfer more power is one thing but it's the casing that holds the gears together that seems to be the weak point on C900's
 
#3 ·
I'm guessing - but would it not be fair to say that the gearboxes aren't synchronised anyway? Only synchronised because there are numbered sets ( #6 #7 #8 ect... )

If you were to take different gears from different sets you would then have an non-synchronised gearbox.

To me it would seem that you should be able to build a gearbox using gears from different sets - and there wouldn't be any difference required for driving technique..? :roll:

There are some gaps in my technical knowledge though - so I'm open to correction. :cheesy:
 
#4 ·
Reverse has no synchro which causes the jolt if you put it straight in without engaging 1st or 3rd first. My synchro in 2nd is shot and I double declutch the whole time when changing down - if I don't there is the most godawful grinding noise. So if none of them had synchros I'm guessing they would all do that without double declutching.
 
#9 ·
How much wider can he make the gears? My 900, 87 5 sp has the slowest syncros I've ever driven. My acura snicks, snicks. The point is that by the slowness of the syncros, unless mine are really worn, i'd bet they were 1/4" wide if that. He's better off using high tensil steel and using rice syncros. :roll:
 
#10 ·
Yes, Jorgen will hopefully have the unsyncronized gears available in the next few months. The 4 speeds he builds are designed to accept the unsync gears & have a stronger case/pinion to resist flexing. He has been working on these gears for a while & hopefully soon they will be available.

Shifting from 1-2, 2-3 etc isn't where these gears act different it's the downshifting where like others state you have to match rpm's & do the double clutching. I have been driving my dad's 1963 austin healey around which has sincro's in 2+ but not a syncro in 1st, takes some time to get use to.

I forget the exact width of the new gears but around twice the width of the OEM gears
 
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