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Diffs

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Dezzz17

RCTalk Rookie
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Location
Dryden,ON,Canada
RC Driving Style
  1. Bashing
Can someone please tell me what 29 tooth and 9 tooth Bevel gears are out of as i had bought the complete diff off ebay and pretty sure they were for the savage xl.The ones that broke are 43 tooth and 13 tooth,my truck is a savage xl. if i can use it,do i have to change the other one also.Thanks
 
The 29/9 are the HPI bullet proof savage gears:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXYDN6&P=7

The 43/13 are the "pre bulletproof" gears and you can find them in either machined form or cast form. The machined ones started showing up when the savage-x was made. The bullet proof ones don't come in anything in stock form I don't think. They are an upgrade for all savage trucks.

You will need to replace both front/rear diff gears if you have the 29/9 as the ratio isn't exactly the same as it is for the 43/13 and this will cause axles to snap on you and will be unnecessarily hard on the diffs themselves.

Ratio's:
43/13 = 3.3076923076923076923076923076923
29/9 = 3.2222222222222222222222222222222

So, the 29/9 will spin a tick faster than the 43/13 with the same input speeds.
 
No problem. Make sure you shim them properly. Strong gears still require good alignment or they will break too.

I run alloy cases and cups with the X/XL machined gears and they have been holding up just fine. I've changed bearings once in 3 gallons of run time with an LRP28S3 in my rig. Had a bearing grenade on me in the rear diff on one of the outdrives. I caught it right away and didn't do any damage to the gears. Now I keep a close eye on them.

I run 50K oil in the diffs and typical axle grease on the ring/pinion.
 
Just wondering if it is worth going on Ebay to buy these Savage Flux diffs, I mean are the cases the same? Or is it only the gears? I can probably rebuild a diff and shim it properly... Both my diffs went on me but I only replaced the rear with the flux diff, so I removed the front drive shaft for now... I can't believe how expensive diffs are lol I installed the Losi Mach427 motor and the first day it popped my rear diff lol, then I replaced that one and the front one went. So I'm only 2wd and only my rear brakes work for now.
 
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