Savage flux 9t bevel gear

Nadboo

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52
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Sitka, Ak
Does anybody know what diff/bevel gear sets if any would replace the bulletproof diff bevel gear, the 9t gear. I can’t find hpi parts and I’m hoping by some miracle I can use a diff (high hopes) from another manufacturer.
I took my flux out to entertain a kid (6yr old) a few weeks ago. After bombing around the yard a while, I stopped in front of a 2 inch step in the path and proceeded to do a back flip. I was amazed as it jumped 3 feet in the air and did a full back flip and landed on the wheels. But that’s where the fun stopped. I destroyed the teeth on the 9t bevel gear in the rear.
I discovered the problem yesterday when I took it all apart and have been scouring the web for a replacement part to no avail. I have the older type gears that came in the savage X but if the power does this to bulletproof ones I really don’t want to waste my time with weaker parts. I hope it’s not time to shelf the flux.
Any help or advice would be greatly appreciated.
 

olds97_lss

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rc4me.us sells replacements. I don't think they are HPI parts, but they look good.
https://rc4me.us/product/hpi102692b/

Oh, it's on backorder.

I have a running search on ebay for the BP gears, I saw a couple sets of the pinion/sintered ring gear show up a day or so ago. Setup an active search there and buy one when it pops up.
 

twhit17

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5
I too need to know where to get another 9 tooth gear or if there is another brand of ring and pinions that fit !
 

Nadboo

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Sitka, Ak
i Found one hidden in a box at my LHS! It may be the last one in existence. I now don’t want to drive the flux, Incase something else breaks. (Which I’m really good at doing) it may be time to shelf this monster.
 

olds97_lss

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According to rc4me.us, they will get more in no later than Sept 24th. I sent them an inquiry to find out. They responded 30 minutes later.
 

olds97_lss

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I thought about trying CEN genesis/reeper diffs... not sure if they fit or not though, but they run big teeth like the BP diffs. Guessing they are probably at the very least a different tooth count, so you would have to do both the front and rear at the same time, an $80 experiment.
 

X

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Savage 6768

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Just putting it out there but can the diffs from a 1/8 buggy/ truggy platform be used as replacements ? I would hate :argh: to see the savage be a distant memory as it is such a seriously cool MT
 

olds97_lss

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Just putting it out there but can the diffs from a 1/8 buggy/ truggy platform be used as replacements ? I would hate :argh: to see the savage be a distant memory as it is such a seriously cool MT
They might, I never tried. But there are very few that have the big teeth like the BP ring/pinion. The big CEN trucks are the only ones I've seen with massive ring/pinion teeth. The smaller teeth just don't hold up as well, even if they are machined vs sintered.
 

twhit17

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I have a vorza buggy. I will give it a try. I did order the hot racing ring and pinion as I couldnt find any bullet proof diffs anywhere. Are the Hot Racing gears as strong as the bullet proofs ?
 

twhit17

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https://www.ebay.com/itm/382559408464
 

olds97_lss

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I never tried them. They could be harder on the bearings. From what I've read, helical cut gears are harder on bearings because they try forcing the pinion into the it's bearing. They are also more sensitive to proper meshing, so make sure you dry fit them and get the shims in so the mesh is nice and smooth before you fill the diff with oil and finish installing it.

I'm guessing you will need to do both the front and rear diffs at the same time, since they differ in tooth count from the BP's, which also differ in ratio to the standard gears.
 

twhit17

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Would a diff gear ratio of 4.3 be a huge difference from the stock 3.22?
 

olds97_lss

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Would a diff gear ratio of 4.3 be a huge difference from the stock 3.22?
Different enough to have to do both the front and rear, yes. I think it increases top speed, so you may have to gear it down a tooth on the bell/pinion if your running the 43/13 ring/pinion now. I think that was the original tooth count... can't recall.
 

Northernnightmare

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Messages
166
Not sure how this question comes up so often, but its been answer a few times buy me and a few others in the past

You can run almost any true 1/8 diff so long as you use the savage outputs.

The good. other diffs are usually cheaper, easy to find, and most have the bigger 8mm bearings

Negatives not all them have the same gear ratio so you need both F/R, and you need to look over the shim stacks

Installing the outputs is been easy on the units i try'd but I'm sure not all are so easy

The Hot-Racing heli cut r/p is very strong also, and is a direct replacement
 

olds97_lss

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Not sure how this question comes up so often, but its been answer a few times buy me and a few others in the past
You can run almost any true 1/8 diff so long as you use the savage outputs.
The good. other diffs are usually cheaper, easy to find, and most have the bigger 8mm bearings
Negatives not all them have the same gear ratio so you need both F/R, and you need to look over the shim stacks
Installing the outputs is been easy on the units i try'd but I'm sure not all are so easy
The Hot-Racing heli cut r/p is very strong also, and is a direct replacement

There aren't many that are as tough as the BP gears. Without buying a bunch of cups, I'm not sure what cups fit the BP gears or if the output shafts are the same diameter. I wouldn't mind replacing my cups with something like the LST2+ had with the steel inserts, steel output collar so I could use 2 8x16 bearings. I'm just not sure if they fit the ring gear, or if the output hole is the same ID or what internal gears can be used.
 

orzowei69

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Messages
94
Location
Spain
Hi guys,
I got fed up of replacing bullet proof pinions. The last three I had to change had the same problem: One broken tooth.
The teeth in these pinions are too much thinned at their base (anyone can explain the reason for this?) and thats the weak point were they are cracking.
I am changing all future broken pinions to helical pinions which have the same relation of teeth and do not have this problem.
I have been using them for some time without any issues in one of my savages with 6S.
I share some pics so that you can see the thinned teeth base and the comparison with the helical type.
 

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olds97_lss

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Hi guys,
I got fed up of replacing bullet proof pinions. The last three I had to change had the same problem: One broken tooth.
The teeth in these pinions are too much thinned at their base (anyone can explain the reason for this?) and thats the weak point were they are cracking.
I am changing all future broken pinions to helical pinions which have the same relation of teeth and do not have this problem.
I have been using them for some time without any issues in one of my savages with 6S.
I share some pics so that you can see the thinned pinion base and the comparison with the helical type.
Got a link or brand and part number for the helical ring/pinions you go with instead?

Are they the hot racing ones?
https://hot-racing.com/?partnumber=HSF299X;c=462
 

orzowei69

Active Member
Messages
94
Location
Spain
Got a link or brand and part number for the helical ring/pinions you go with instead?

Are they the hot racing ones?
https://hot-racing.com/?partnumber=HSF299X;c=462
Hi. They have the HR logo although they are not publicited as Hot racing or any other trade mark.
I got it from a Chinese web and they sell them as:
"#105551 #102692 Hard Steel 8T-26T Differential Ring Pinion Gear Set For RC Car Racing HPI 1/8 Savage Flux HP XL 5SC 5.9 3.5 SS"
They match with the picture on the link that you sent.
There is a slight difference with the first helical types that I tried a couple of years ago. In these ones the grooves on the ring are deeper, allowing for bigger sized pinion teeth. They are so deep that the outer edge of the grooves are not backed with metal. This can be noticed well when you look at the back of the ring. This also matches with the description of the revised version of HR helical pinions that is mentioned on the link.
 

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Goose1072

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75
Location
NYC
I have these helical sets and have not been able to fit them in the diff case, they seem to rub no matter what I do to them.
 

SavageXL85

Active Member
Messages
109
Weird how some people say these gears are great then you get people who can’t even get them to fit in ?
 

Jabbo

Active Member
Messages
104
I believe they just need fine shimming. If their little off, they wont "fit, work".
I will give them a try if the new forged ones wont last.
 

orzowei69

Active Member
Messages
94
Location
Spain
The first ones I tried about two years ago were not HR make and they did rub inside the old style diff case. I had to dremmel about 1mm off the top of one of the internal bumps (see picture).
 

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