only126db

I bought this Savage Used, looked like it was in great condition, barely any scrapes on it at all.

I bought a Dynamite 053 pipe, put 50 weight shock oil in and everything else is stock.

I have run less than 2 quarts through it since I got it and always on icy roads or through snow, thats all there is here right now.

Yesterday I ran it up and down the road a couple times, I heard a noise then shortly after that it ended up getting stuck on the side of road in what I thought must have been soft snow, but it wasnt, I had lost my RWD! It sort of catches but then doesnt, you can hear it grind inside.

I just ordered new front and rear 'Bulletproof' diff's which were pulled from an XL, I read they fit and have stronger gears, I hope it is true, anybody know for sure? (I know I probably should have asked before spending the money)

Any knowledge of what else I will need to make them work with my Savage x 4.1, I saw where they bolted right up but that was just one person I saw who said that.

I was kind of in a hurry since it was an auction ending quickly and I got them for a pretty decent price.

-SomeGuy-

I dont know the newer trucks enough to help with compatibility but I can say that until you get it sorted out, put the front diff in the rear and have RWD only rather than FWD only. Just be careful because braking will be greatly reduced.

only126db

Well the new diff's should be here either today or tomorrow, once I take it apart, if I need other parts it will just stay apart till the other needed parts get here.

only126db

I didnt really think of all thats going to be involved when switching diff's and cases (no choice though). They came in today, both fully assembled brand new diff's (housings everything) pulled from an XL for $61 shipped (2 days to my door). Pretty good score if I do say so. I just looked at the truck, I think I am going to pretty much tear the entire truck apart for this retro fit. Does anyone know of a video showing removal of the entire diff housings and not just the guts??

-SomeGuy-

I remember my first teardown, looked scarier than it really was. You can get the manual on HPI's site. Its easy enough to follow so you shouldn't have any problems.

About those diffs, I remember something about them only working with the bigger dogbones. Check the cup size compared to what you have now, if its bigger then you need quite a few more parts to complete this upgrade.

only126db

Wife is gonna kill me!!! Found out I need the Heavy Duty Drive Kit to make this mod work. It will be the beefiest drive line I can do besides doing alum housings and steering knuckles. Damn HD Drive kit is around $80, seems a pretty steep price for what it is....

-SomeGuy-

You're only running a .25 engine. Not like you have to much power on tap so the HD kit is not really needed at this point. IMO get a new regular diff and keep the HD ones for when you get a new engine. Look up diff shimming to remove any slack, that will help with keeping them in one piece. You might have to adjust the way you drive as well. I used to go through diffs like crazy at first until I started paying attention to what I was doing wrong. Like most I was either braking or throttling while landing a jump and that will destroy a diff in no time, even an HD one. Does your truck have alloy diff cups? That will help allot with keeping those gears tightly meshed. The plastic ones tend to warp at higher speeds and leads to breakage.

Look at it this way, most of the problems you're having are caused by user error so its not just the truck that needs upgrades. What you're experiencing is the exact same we all went through at first. I strongly recommend you do a complete teardown of the truck, not just to repair it but to get to know it inside out. If you don't already have one, one of those 3.6v screwdrivers is a must for repairs and you will need some loctite for those metal on metal screws. Avoid stainless steel screws at all costs! Black oxide are the best.

This is what my truck looks like after I gathered enough knowledge to get what I considered to be the best upgrades needed to make it last and what a solid truck it turned out to be. Mind you this was a few years ago and having kids has put my RC days on hold, things have changed a bit in the world of savages since then.



I drove the crap out of this truck and it just kept on going and going. The right upgrades in the right places is all it takes, no need for plenty of alloy everywhere. This truck started as a savage 4.6 SS I got on ebay barely used but badly upgraded. Got it for a song since the previous owner was in over his head and had no idea how to make it better. He basically thought bigger was better and when I drove it it was an overweight turd with lots of potential. He had put some money in the electronics and they went well with what I added.

only126db

I have not jumped this truck, when it happened I was driving straight down the road. As for shimming the diff's the ones I bought are the complete gear boxes, I wont be buying another set, I will just get the parts to do the HD dogs and axles and be done with it. I can get the parts separately for 1/2 the price as the kit.

SyCo_VeNoM

should still shim the diffs

Anyways as for why you blew the diff if the diff had no traction then hit solid ground causing it to catch it wouldn't be much different then landing while your finger is on the throttle. Basically it would trash the diff.

And yea to change both diffs you pretty much need to take the whole truck apart except for the tranny.

Other note they should bolt right up, and you should be able to use your old hardware. Hell I slapped hooked flux diffs on a .21's tranny on after market plates before only real difference in savages was the .21/.25 to X as the diff holders were different.

only126db

Just looked at the gear boxes, they may need shimming. Do you know of a good tutorial?

ryans hpi

i personally have never shimmed my gen1 savage ss 4.6, but i have to on my revo through the spider cup. sort like some people like to run oil in sealed diffs, but i just run a thick moly grease in spiders, and a good mid thick on my ring and pinion. still together after 4 years of racing and running with a O.S. Max 30 ported and worked