Busted Front Differential

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tonycajjo

tonycajjo

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Location
CT
Hello All! This is my first post. I have a Savage KXF700, Axial .28, and a werks pipe. I noticed that under braking the truck(ATV) was a little noisy. upon further investigation i realized that it was my front diff that was making all the noise. The truck still puts power to the front but it need to be replaced, or rebuilt. I found that link from Jester that shows a diff rebuild. I may do that, i dunno what I'm gonna do. Any suggestions? just buy the parts from hpi? I know I'm gonna cry a bit first, but after that i don't know.

Any how, My buddy got one of the 1/5 Scale Buggys and he's gonna run it today and i was hoping to be doing circles around him, but my diff is NFG. I've thought about making this a 2WD for the time begin, or should i just run it (the diff) into the ground. my gearing is 18teeth on the engine and 49teeth on the spur gear. i used to have 15 and 49, but i wanted more top end, and this motor is strong enough to get it going off the line.
 
You can run it in 2wd but it gets old pretty quick. I would suggest taking apart the front end and seeing what's busted. More than likely you will have less than 20$ in parts and a couple hours of time depending on how fast you are.
 
welcome to the forum!! you have come to the right place if you have questions and we appreciate any tips or whatever you may have as well!!:cheers:
 
I agree with Blazer...tear down the front to identify the problem...it shouldn't be an expensive fix.
 
yea, when i get home from work ill take a closer look. i may just rip out whatever is broken so i can run with my buddy tonight. i was thinking of tying up the outputs, after removing the dogbones. i've never been in that area, so it may take some time pulling it all apart.

price never seems to be an issue. the car is expensive, but most stuff is inexpensive to replace. (shock parts, spur gears, clutchs.)
 
If that 1/5 scale buggy you speak of is a Baja 5B, I would reconsider the running circles around it thing. :)

*
 
Welcome to the forum Tony! :beer:

I agree with the others, check that diff out, it might be time to upgrade those diffs.

I personally would never run my truck in 2wd though...Savages are hard enough on the diffs when there are 2 of them to share the torque, let alone just one!
 
Pardon my manners Tony...Welcome aboard!!!!! :jamout:

Def don't run that truck in 2wd...you're asking for a bigger shopping list then what you are going to begin with..LOL Let your friend off with a warning that you will be back another day to run circles around him...

Good luck with the diff and let us know if you have any other questions.
 
i may still run it in two. i figure that i can upgrade both diffs at the same time. i'm a noob when it comes to 4WD. what choices do i have out there as far as diffs go so i can get some nice ones, i used to be able to go to hpi's site and pick my kfx700 and then select option parts, but this is no longer the case as the kfx has been discontinued. i'd image that when i open the front diff i notice that onle one gear is stripped and just need that one part which is probly the same as any other savage.

can i just grab on of these to swap out in the front?
http://cgi.ebay.com/NEW-HPI-SAVAGE-...ryZ44028QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

should i do the back while I'm at it. it has spider gears? dunno what that means.

whipnet, are those buggys faster than i think they are? i believe it is a baja 5B, is that the mack daddy of baja buggys or what?
 
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Same thing happened to me and I ran in 2wd for one session with no problems.
It can get expensive though-new ring and pinion, all bearings, diff gasket and o-rings, fluid and shims, maybe a new cup-it all adds up.

Welcome to the forum...

Dave
 
my diff was a little chunky but it working condition, the beveled gear had a few teeth missing. i replaced the diff anyway cause i recently upgraded the engine. i put it all back together last night, well almost all of it, i'm wait on a spur gear and debating to put in the alum clutch shoes.
 
alum clutch shoes do alot in the way of off the line kinda thing but when it comes down to it you can get away with the stock plastics so untill you truely fry the stockers as in melt them into the bell (lol friend of mine did it) they will be fine, once you melt em then go aluminum, imo
 
Dragin said:
Debating???
No debate needed. The aluminum shoes rock!! They made a HUGE difference in my truck. I can't complain about them at all.
Click to expand...

my only concern was the weight. they are 1.7g which i've read may be too light for my .28 engine.
 
I am running an OS .30 with the HPI aluminum clutch shoes with no weights in them and 1.0 springs. No problems at all.
 
nice, i'm gonna throw em in when my metal spur gear gets in. i'll have 47T metal, 52T plastic (and 49T plastic) the stock 15T and 18T bells, and i got 16T axial vented bell and a 19T vented axial bell on the way.

i imagine that with the 49T spur and 19T bell my savy is going to FLY! (after i put the wings on it) bobang
 
Since I upgraded my savage to the 4.6, I haven't been able to keep the bevel gears in one-piece. I have broken the rear gears several times and now the front. I have the maximizer lockers coming in this Friday for both the front and rear, so problem should be solved. I would rather replace dogbones then have to take the truck apart to replace bevel gears all the time.

I do have a question, though, for you guys. I have aluminum front and rear differentials and diff cups. If I ever do decide to go back to a limited slip system again (when road racing) what should I do to get more life out of these things. I have heard some about shimming the diff when putting it together, but where do the shims go? Should I also upgrade the diffs with gear oil instead of grease? Thanks guys!
 
day bay has them...theres a thread around here somewhere that shows you how to do the mod.....

ive got them in my truck, got probably 8-10 tanks on them, and they are still nice and tight.
 
The Cen diffs are very high on my wishlist. Hopefully I will be swapping very soon. My LHS tried to tell me CEN stuff was junk and couldn't understand why I wanted them?!?!?! I have heard nothing but good things about the diff mod and couldn't believe they had never heard of this mod. I hate living in the sticks sometimes.
 
my lhs didnt know about the mod either. there was a guy last time i was up there with a bag of diff parts, so i asked what what he did. he said once the first one went, he just kept blowing them up, even though they were shimmed. so i gave him the parts list, and he was gonna look into it. my lhs hadnt ever seen a hpi truck with other company parts on them, so the flm tvp's and lst shocks baffled them.
 
What ever happened to cross merchandising in retail? In the current economic state you would think they might put more effort into knowing parts that could be swapped from vehicle to vehicle to improve it. Especially popular vehicles. It's not like it is some highly guarded secret that you have to know someone who knows someone to teach you the secret hand shake and password to find out. Who really runs stock anyway?!?!?!?!
 
If anyone high jacked it's kgrames-no offense dude but you posted the same question in 3 existing threads....
I want CEN's too I just ran out of $ on my last build.
 
Thanks for the help guys. I have also heard of using silicone diff oil to help prevent the gear issue. What are you guys using?
 
Pineapple said:
If anyone high jacked it's kgrames-no offense dude but you posted the same question in 3 existing threads....
Click to expand...


Dude, read this ^, there are plenty of threads on here that can answer your questions ! :resp:
 
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