# 4 Gear, Crown Gear Tuning....



## Ralphthe3rd (Feb 24, 2011)

Well, I dunno if this has been brought up before ? But since Today was 4 Gear Tuning day at the Speedy Pit Shop, I had a few 4 Gear/Specialty Chassis opened up on the work bench.
First off, I'd like to mention, that I have worked on the Aurora Special Chassis Before, and that includes all three variants. BUT, this was the first time I opened up an Auto World 4 Gear, as I ONLY own one of them.
The Aurora work was needed, as I recently picked up a couple of used chassis, and they were in need of new crown gears among other things. Well, when I opened up the Auto World chassis, I thought I would see pretty much the same thing, as I assumed these were fairly close copies, sans the Neo Traction magnets.
ANYWAY, much to my surprise, while the Aurora cars use a 15 tooth Crown gear, I noticed the AW Car had a larger gear. FYI, I had previously ordered a couple of the AW crown gears just in case these Fubar'd up as easily as the original Aurora ones did. But I had never examined the AW gears I had received, and didn't notice the difference with the Aurora Crown... ie- THESE AW Gears are 18 Tooth ! And good news is, like the latest Ultra G T-Jets, these gears will swap over and mate perfectly with the Cluster Gear....and even tested this out, and slid an AW gear over a Tyco axle, to test the mesh on the Aurora Chassis, and it meshed Fine ! Sooo...what this means is, you can now easily alter the gearing on both chassis, ie- go lower ratio on the Aurora, and Higher ratio with the AW. BUT I must add, as is the nature of the 4 gear beast, you may want to add a shim to get a better mesh in either chassis, and forestall any future gear damage from poorly meshing gears....just a Head-UP ! 
Ok, that ends my .02¢ Tip for the day....


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## gonegonzo (Jan 18, 2006)

That's good information . I have several 4 gc's that need doctoring .

Thx
Gonzo


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## tjetcar (Jul 7, 2009)

I found that the t-jet gear works better then the 4 gear crown. The t-jet is just a little larger in diameter, some trim is needed though. It does mesh better.


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