Lets fix the Savage Transmission
 

The 29T and 32T gears (HPI 86084/86098) inside the tranny tend to granade or quickly wear eachother down to nothing depending on the batch; some are brittle and most are soft.

Both the 44T (HPI 100905) and the 18/23T (HPI 102514) are hardened and don't have this issue. Obviously HPI knows how to make a decent gear, but for some reason, they refuse to fix this problem.

First Attempt: I used GPM Delrin 32T (DSAV1232T) along with the HPI 29T because I figured metal on plastic works great with the pinion/spur, so why not in the tranny. I wanted to use a hard plastic gear, but I have been unable to locate one, so I figured I give delrin a go. My truck has never run so quiet, it was GREAT until . . . after about 10 min, the weak delrin gear broke; $11 down the drain. :cry: I really think a 32T gear made out of the same plastic that the 47T spur (HPI 76937) is made out of would be the ultimate fix for this transmission. It would be plenty strong, cheap, and very quiet.

Second Attempt: Some people have had success with the HPI Lightweight Drivegears (HPI 86274/86275). I'm currently running these and my experience is they are even weaker than the stock gears and wear down even quicker because they are so thin. I've got about 15 runs on them and they are already worn down to a point.

Third Attempt: Will be to go back to the stock gears, seal up the bottom half of the tranny with silicone or liquid gasket, and throw in a little synthetic, gear, or silicone oil (just enough to get the bottom of the lower gear wet).

Any other ideas; anyone fixed this thing yet?? :neutral:

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Your third attempt idea should do the trick. The wear is caused by metal to metal contact. Oil will stop that. I have some of the stp oil additive that I have planned to run straight out of the bottle in my savage trans. Grease is just a waste of time, flings off at the rpms we turn stuff. Just wish the savvy diff cases were sealed.

Something I noticed in my Honda 1/1 when changing out the transmission fluid was a magnet at the bottom of the pan. Seems like a good idea in this application because those gears really like to eat each other up and the magnet would help prevent those shavings from getting continuously cycled through all the gears with the oil splash.

Good idea, A small high powered magnet glued into the case somewhere would be great. I have seen those magnets somewhere, I will have to look again.

15 runs is great out of any savage internal gears to me!!!

i was getting max 5-8 runs out of the light weight gears... which is the same out of the stock cast gears... so i just carried on using stock..

I like the sealed box idea, but i found the best solution which is a centre diff conversion!!! ONLY WAY TO CURE THIS WEAK TRANNY PROBLEM! get rid of it!

I have considered the center diff, but I haven't seen a straight forward way to get it done. Everyone that's done it has had to custom fab a mount. I've been holding out for some company to come out with a drop in solution for the Savage. If the tranny becomes a real pain, I will pursue the center diff for sure.

Other thing is custom length bones; sounds pricey.

it sounds pricey.. but imagine the price of a drop in centre diff conversion that will cure all the savage tranny problems? THAT WILL COST A LOT because everyone wants it...

All you need is a centre diff, diff mounts, custom alloy diff plate and maybe one custom dog bone which i paid $20 for... so its not as tough as you may think

With all the Cars and Dog bones made for them. I doubt you need any "Custom" shafts. Just takes a little time and effort to find what will work for you. I mean they make 50-145mm dogbones. Gotta be something you could use...

I agree though CD all the way. It actually makes MT handle somewhat decent... :lol:

Maybe we should get Monster Mike to make some hardened gears for the tranny that are full width instead of the narrow ones from HPI

$$$$$ :lol:

Could be worth it if the demand is high enough. There are lots of Savage owners out there...

It would be better than trying to modify everything to run a CD. Luckily I have had no problems with my HD gears so im not really worried about it.

I think all we need is a hard plastic 32T gear to run with the stock 29T and it would last for a LONG time and be cheap and easy to replace because it's the top gear. My $3.50 47T plastic spur has lasted for 6 months and is showing no signs of giving in.

Pics of my new tranny. Three magnets that I had in my parts bin. One is under the gear wedged beneath the bearing holder. Just have to wait for the top gear to come in.
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You would think that with all the Savage owners out there someone would have found the part numbers of the existing bones needed to make this happen already and it would be common knowledge. :neutral:

I'll be first in line for a relatively straight forward approach to a Savage CD.

Probably because each CD conversion seems to be different.

I guess this can be my next savvy mod after I have figured out the cen arms/hubs/cvds and the lst2 stuff...

Nothing is going to be 100% drop in, so set your punch control for 90% and run 4s lipo if you want the stock flux stuff to last...

I find the humore that after everything is said and done that a bunch of us will have more than 1k in a savage, when a 500 buck cen genesis might just be a better starting point. Stick a 1717, MMM, and 6s in that beast, basically an overbuilt savage anyways.

I will continue my savvy mods, just cause they are fun. Got the hingepin braces made, just need the trunbuckles and a suitable motor and my 15" wb savvy will be ready to roll.

Maybe... I did consider one before I got my original Savage; but parts support sucks for it, so I decided not too..

But really isn't modding the trucks and cars what most of us at rc-monster's forums are about? :)

yes linc... definitely have sunk in way more than $2000 into the savage! closer to $3000 i believe... but prefer the Savage to the CEN

desperate to see how those hinge pin braces turned out!

zero that is true... the support for CEN is pathetic compared... MODDING FTW

Yes it is! That is why I will continue modding my trucks!

If this STP oil trick fixes the tranny, I don't think there's much of anything else to worry about on this truck. It will be very low maintenance!

Getting a straight answer out of HPI is like pulling teeth, but I would really like to know why they left those two junk gears in there.

I think some RCM hardened Savage tranny gears would do the trick! HINT HINT HINT!

Oh yeah!

OR, instead of sealing the case and running oil inside, maybe just give the gears a nice coat of graphite.

What about some lubricant such as Gorilla Snawt that is formulated not to 'fling'?

oil works better than dry lube

grease flings, no way around that with the kind of speeds we spin stuff.

maybe some of that motorcycle chain lube, there are several different varieties of it. Some of it doesnt fling at all. I dunno.......just trying to come up with something different.

Option 3 was a success! I am very happy with this mod. Thanks for the tip linc! :yipi:

The truck has never run so quiet, which tells me there is no more gear on gear grinding inside the tranny. The truck is so silent, even at WOT, that it is hard to believe it's a FLUX.

After 6 runs, I opened up the tranny, and there are zero signs of gear wear. Only down side I can see to this mod is I will need to totally seal up the tranny to keep the lube from seeping out. Those high RPMs fling that stuff so hard that it even slides past the bearings. Pictures tell the story.
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I cleaned it up and sealed the top half to the bottom half after taking these pics. Next time I break it down, I'll look into sealing the bearings into the holders and onto the gear shafts. That should prevent the lube from sliding past the bearings, but will not hender the bearings from doing thier job.

that is awesome news... how high is the level of the oil?

I'd say there is aprox 3/8" of oil in the bottom. Just need enough to get the bottom gear teeth wet, the gear action does the rest.

What kind of oil/lube are you using?

Back in the day, Sikeston34m was using stp oil sabilizer. Thick stuff, and it really sticks to the gears. He was not having a leak issue like you are having, and all he did was use rubber sealed bearings. Pretty sure the stock bearins are rubber sealed in the flux anyways.

Glad to hear it is working well, metal gears need oil. I think using some rtv silicone would seal it all up well. I would smear some on the shafts where the bearins sit, and where the bearing contact with the case. And on the case halves too. Maybe just use some bearing grease between the top and bottom cases, so they can come apart easily.

Should make those gears last!!!

This is what i will use:

http://www.lucasoil.com/products/dis...Oil Stabilizer

Update
 

I decided to take the tranny out to clean up the sticky oil and stuck on sand and take another look at the gears inside. Since I've sealed up the case, I use the adjustment holes to check the oil and peak at the gears (hex driver makes a great dip stick). Still zero gear wear after more than a dozen runs. I'm thinking these gears are going to last for a very long time. Only thing I can see breaking them now is too much torque shearing off the teeth from locking up the tires or doing several back flips or something of that nature.

Why check the oil? Well it's gradually being forced past the bearings, so I'm just making sure there is still enough left in there to do the job. Perhaps it will get low enough that it stops leaking but still keeps the gears lubed. It's down to under 1/4" so I think it's getting close to that point. Already have a permanent fix in mind for the bearings, but I'm not ready to totally break down the case, degrease it, clean off the old RTV, etc, etc yet. :sarcastic:

Do you think white lithium grease would work as good as the STP oil treatment?

I don't think any kind of grease will stick at those RPMs, but who knows. Like someone mentioned earlier they make grease sticky enough to stick to a motorcycle chain.

I found the link to redshift's comments on the STP stuff; it's ear the bottom of the thread. Sounds like less is more. (http://www.rc-monster.com/forum/showthread.php?t=20896)

Just picked up the STP oil treatment at irving down the road lol.

Was not hard to find at all. And only four bucks!

Thanks for the info Jason

Glad I could help. Don't forget to seal the bearings to the case and to the shafts. There are also two or three holes that aren't obvious on the case that I sealed up a long time ago, before I ever thought about doing the lube thingy. Look around, you'll find them.

Final update till something breaks
 

I transferred everything over to a spare tranny case and sealed it up tight. Even though the gears have more than a couple dozen runs on them they still look brand new. :great:

Messy inside
http://i1116.photobucket.com/albums/...n/IMG_2906.jpg
After ~2 Dozen Runs
http://i1116.photobucket.com/albums/...n/IMG_2903.jpg
Cleaned them up for a closer look
http://i1116.photobucket.com/albums/...n/IMG_2908.jpg
http://i1116.photobucket.com/albums/...n/IMG_2911.jpg

they seem to be ok... But my gears always looked fine. They just broke into a million pieces when they wanted??? They never wore badly, just shattered at the most inappropriate time.

I hear ya Jahay. I think it all depends on the batch; some are hard and brittle, but most are soft and chewey. :oops: I've gone through 4 sets of the stock metal gears and 1 set of the lightweight gears. The orininal set granaded and all the others ground down to sharks teeth.