Jato Transmission Gearing

[kshoulde35]

Is there anyway at all to change the gear ratios on a jato? Will Revo transmission gears fit inside of the jato?

 

[Snook Man]

Revo gears would not be a direct fit and it would take extensive modification to alter the internal gear ratio.
What are you trying to accomplish, Taller or Shorter gearing?

 

[kshoulde35]

I want my gear ratios internally closer to allow somewhat seamless shifting to keep the rpms in the power band... for 132 -165 ft drag races

 

[Snook Man]

A close ratio Jato tranny would take a lot of work, it could be done but not without a bunch of alterations/tools/parts unless you luck up and find gears that will drop in. You basically just need to reduce the size of the 2nd gear input and increase the size of the 2nd gear primary for a closer ratio (Incrementally + & - equally). (easier said than done) 1st gear would remain the same.
I would just adjust the cb/sg ratio to top out the engine rpm's in 2nd gear at the finish line.

 

[kshoulde35]

I've been searching everywhere for gears to fit but no luck

 

[Snook Man]

It will probably be tough to find a direct fit if ever. The 2nd gear input wouldnt be all that difficult, you could replace it with a simple pinion gear with a set screw to secure it to the shaft. The 2nd gear primary will be the most difficult to find/make since it has to house the 2nd gear clutch.

 

[kshoulde35]

Wait i was uninformed that the second gear had it's own clutch?

 

[Snook Man]

Yea, the primary clutch # 5590 that makes the shift change resides in the primary 2nd gear # 5585.

 

[kshoulde35]

ohhhh yessss yesss... i thar case couldn't i shave a tad bit off the clutch shoes to require higher rpms to fully engage second gear?

 

[Snook Man]

Its not a centrifugal friction clutch inside the transmission like the engine clutch is, its a centrifugal positive engagement clutch with a steel pawl that flips open at a certain rpm of the primary shaft and grabs the 2nd gear hub assembly. You can only adjust it to make the shift change occur earlier or later.

 

[kshoulde35]

okay so now to the modification of the engine clutch... leading edge is where those pads are set correct? what would i need to do to make them engage higher up the rpm range?

 

[Snook Man]

The engine clutch comes stock in the trailing edge configuration. Left pic.
Leading edge is the center pic.

Leading edge will engage a little quicker with more bite than trailing edge.

The clutch on the right is a MIP clutch and it can be setup in leading or trailing edge with an extra hole in the shoes to time the engagement for earlier or later.

If you want a good clutch look at the 10th scale BUKU Komposite clutch. A little expensive but a Very adjustable clutch and would be perfect for drag racing.

 

[kshoulde35]

thanks so much for all of your input and on the traxxas site they describe the jato tranny as a close ratio two speed tranny so a good clutch setup is the next key ingredient in getting power to the ground at the right time.

 

[Snook Man]

a good clutch setup is the next key ingredient in getting power to the ground at the right time.

Couldn’t have said it better myself.

I have tried them all and the Buku Komposite is the best clutch on the market atm IMO.
You adjust each shoe (very easily) individually to lay down the power just as you like.

 

[kshoulde35]

thanks so much for all of your input