Overdrive your sawback

[Jeepiac]

A few people have requested more info on my overdrive mod using R1 gears. I've been running this mod for over two years now without a single issue, so I think it's been tested and really needs posted. Through some digging in the ol' computer I found some pictures of the first overdrive mod I did. Poor quality, but gets the point across.

First step is to enlarge the diameter of the recess that the pinion sets in. Don't make it deeper! It's a grind and test fit type of procedure. Not rocket science. Mount the R1 pinion on the Sawback input shaft. Shaft will have end play,(see arrow) but this will not affect anything and can be taken care of with a shim between the outer pinion bearing and drive shaft. Once pinion is on shaft, place into housing. Now to mount the diff gear. Once again I grind, test fit and grind a little more till the axles will slide into the gear and the mesh feels right. Smooth and easy to turn, but as little free play as possible. Red arrow is side that will need material removed. Blue arrow is showing a small gap that will be between gear and bearing. Gap is nothing to worry about. This is not a huge gear change, but does make a noticeable improvement and is cheap and easy to do
I think that pretty much covers it. If I left anything out, yell at me and I'll fix it

[spoo76]

Sweet, I've wondered if anyone had done the opposite of the supermoturd mod. Underdrive for the R1... Finally

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[Jeepiac]

Originally Posted by spoo76

Sweet, I've wondered if anyone had done the opposite of the supermoturd mod. Underdrive for the R1... Finally - RCCrawler

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After doing this to my R1 axles the wheels started turning. If it wasn't for seeing this thread I'd probably never done my mod.

[JatoTheRipper]

Thanks for posting this!

[soze]

Thanks for posting!

[Jeepiac]

Y'all are welcome. Glad I can finally give back to the R/C community and do something that will benefit the Gmade crowd

[Tinrabbit]

I did the same for mine and it definitely helps in steering and quite honestly makes my Sawback my preferred rig to drive on the trails. Honcho now gets lonely at home lol

[OSRC]

Did this mod at the same time I modded my R1. Came out great - thanks for the write-up!!

I'll add a few things:

A large flat cutter like this worked perfect for enlarging the housing. Take your time for sure...


I found it super helpful to mark the flats on the axle....that way I at least knew I was in the ballpark when getting the axles back together.


I didn't like the play in the input gear, so I worked on it a bit. The stock shaft has an e-clip recess already on it that fits between the bearings, so I stole an E-clip from my Tamiya parts box. From there, I just stacked 5mm Traxxas washers behind and in front of the pinion until I got it in the ballpark. Got about 4 behind and 2 up front. Solid as a rock!


I hate getting the axles back together and finding a random bearing...whoops!


Great mod and VERY easy to do. Mush less of a pain then the R1 mod. Highly recommended if your a Sawback or Komodo owner.

Thanks again Jeepiac for the write up!

[kongluc]

So whats the ring and pinion tooth count now then?

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[JatoTheRipper]

Originally Posted by kongluc

So whats the ring and pinion tooth count now then?

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Stock Sawback (GS01) is 32T/14T. 2.29 ratio
Stock R1 is 32T/17T. 1.88 ratio

[kongluc]

Originally Posted by JatoTheRipper

Stock Sawback (GS01) is 32T/14T. 2.29 ratio
Stock R1 is 32T/17T. 1.88 ratio

Thanks!

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[Jeepiac]

OSRC, nice work, and glad you found my mod useful. Might have to start sending my housings to you to have them done

[OSRC]

Got one more of my own to do! My spring-under Sawback (The Roobicon) needs all the help it can get.