Summary of the differential parts.

[RobertDonkers]

The generation numbers are assigned by me in order of when they were released.
From what I can see there was some overlap with the X having the 21 pinion and ring gear. The XL also had a change the flux set at some point.
Difference between the Gen2 and Gen3?
I also see there was an option that was released by HPI in 2018?
Does anyone have some thoughts in here? I left the HR spiral cut and any other after third party brands out.

Gen 3
Flux hp/XL:
Pinion and ring gear: 102692 (29/9)
Spider gears: 86032

Gen 2
Savage X 4.6/XL
Pinion and ring gear: 105551 (29/9)
Spider gears: 87193

Gen 1
Savage 21/Savage X SS kit
Pinion and ring gear: 86030/86031 (43/13)
Spider gears: 86032

 

[RobertDonkers]

The one on the left I believe his first generation and the middle one is the second generation. I just picked up the third one off of eBay with the packaging on the right. The diff case is different with the one on the right. Anyone know about what the one on the right is?

 

[Biddie_fiddler]

Can't say I've ever seen the middle diff case in my savages... I've owned 3, a savage 21, and 2 savage x 4.6, and a savage xl k5.9. Every single one had the diff on the right. Just different gears. The 4.6 had the "bulletproof" versions.

Where'd you get the middle one from??

 

[RobertDonkers]

A pair came in a savage I bought. They looked new.
I found this on the hpi site for the bulletproof diffs:


For more speed and absolutely the last word in durability for your nitro or electric Savage monster truck, there is no need to look any further than this Machined Bulletproof Diff Bevel Gear Set!

Featuring a truly monstrous gear ratio of 29/9 (stock is 43/13), this bevel gear set will outlast the rest of the truck AND give you extra speed for those big-air burly moments every Savage owner loves to see!

Fits all Savage monster truck models. This gear set is now the standard diff gear for the Savage Flux HP!

The Machined Bulletproof Diff Bevel Gear 29T/9T Set is the latest and strongest version of the Savage monster truck bevel gears. It is stronger than these previous bevel gear options:
I
#102246 - MACHINED SUPER HEAVY DUTY BEVEL GEAR 43T / 13T SET

#86922 - MACHINED HEAVY DUTY BEVEL GEAR 43T / 13T SET

#86030 - BEVEL GEAR 43 TOOTH (1M) & #86031 - BEVEL GEAR 13 TOOTH (1M)

NOTE: Because of the altered gear ratio, plus the larger gear and tooth size, your Savage monster truck should have these fitted front and rear

 

[TwistedToys]

Wow. Great info.. that just proves how long I been out of this hobby... I just assumed all the diffs (and ratios) were the same. Thanks for the right up!

 

[olds97_lss]

The difference in what you labled as Gen 2 vs Gen 3 of the BP gears was the ring gear. One is sintered (compressed metal powder) then machined, whereas the other is machined out of solid steel.

They had similar in the previous non-bp diffs as well. Sintered vs machined before the BP's came out.

I've had all the variations I think including version 1 which was sintered non-bp, plastic cup with only 2 spiders in it... good times. lol!

 

[RobertDonkers]

I found this good video as a follow up to my post.

 

[rc4me.US]

The one on the left I believe his first generation and the middle one is the second generation. I just picked up the third one off of eBay with the packaging on the right. The diff case is different with the one on the right. Anyone know about what the one on the right is?

The 3rd one is made by Rovan (Name changed to Rofun recently).

 

[RobertDonkers]

Thanks for pointing that out, so I must have purchased a Rovan or RoFun differential based on the labelling and black teeth. Is that stuff any good? It doesn't look as good as the HPI gear in the photos. I am guessing the HPI stuff is king here. Just purchased the rest of the bulletproof 29/19 setup of HPI parts to finish a slider. Almost, it needs a body and a pair of big bores. Still not deciding on a fllux or another nitro yet.

It would be good to hear or see something from HPI.

 

[Jabbo]

I´m currently in a middle of upgrading diffs. Is the HPI 102692 (29/9) strongest you can get from the market or are there any better aftermarket options?

Thanks,

 

[Biddie_fiddler]

I´m currently in a middle of upgrading diffs. Is the HPI 102692 (29/9) strongest you can get from the market or are there any better aftermarket options?

Thanks,

Best you can get from HPI yes, couple aftermarket options but they're on par with HPI's stuff. I had a set of spiral cut gears from hot bodies, but they never really fit right for me and ended up blowing the bearing around the diff pinion gear. Ended up going back to the HPI ones (the ones you've listed) and added a center diff trans to take the load of the diffs. Haven't blown one since and run 6s quite often ?