racefans26

Alright, almost everytime out i keep busting diffs or the bevel gear, this one lasted 2 tanks??? i have 3 speed, 15 tooth bell, 47 spur, 40 series crimefighters. I have checked the slipper a thousand times!!!! Any ideas??

SportsFans

Are the bearing seated properly in the bulk head? Also are you letting off the gas when landing after a jump? Everything shimmed up properly in the diff? Finally any damage to the pinion gear (look close). Oiled or greased up good in the diff? Just a few thoughts.

madmax22

did you shim the diffs?

racefans26

yeah seated right, i dont even have to be jumping, this time today i was runnung on flat ground, in short fresh cut grass and busted the rear. I have ran with little grease, alot of grease, even no grease with the same result. i looked at the pinion and ring gear It is the pinion (bevelgear), that i break the most. Bevel gear stock part # 86031

racefans26

no shims. they seem to ride on eachother great. not to tight not to loose, just like new..

SportsFans

Ok that gear, that's the one I refered to as the pinion gear. Now I had one of those go also, because the diff was running out of alignment due to one bearing on the diff wasn't seated in the bulk head properly causing that bearing to fail. After the bearing failed it was quick work before the pinion or bevel gear was toast. Make sure the bearings are in good shape and no exessive play when the bulk head is all buttoned up. Oh all the gears in the diff and on the diff have the word "bevel" in their name.

Revomad1

With a 3 speed and lightweight tires like the crimefighters, you should be able to run a 16 or 17 tooth clutch bell. The 15 tooth clutch bell will be giving you insane low end torque, which will put a lot of stress on your drive train. A larger clutch bell will smooth out the power delivery and prevent your engine from getting into it's peak power zone too early.

SportsFans

The diffs should've come with shims in them stock. There should not be any play on the inside of the diffs. With no shims you run the risk of breaking internal bevel gears on the inside of the diffs. Is this happening in the front and rear diffs?

racefans26

Yes front and rear... I have bought all new everytime. even just bought the whole diff assembly and with the same result. And Revo I just put that bell on today, that is the only one my LHS had in stock.. and the rest of the broken parts were with the stock bell and spur...

SAVAGEJIM

Since you did shims & all that, the other thing you can do to prevent stripping teeth on your diff outer bevels and piinions is to make sure that when you land, you have your finger off the trigger when you land. Make sure that trigger is in neutral position when the Savage hits the ground. If you a gassing it or are on the brakes, you WILL strip teeth.

ThunderbirdJunkie

My Feedback: (3)

I think you pulled the crush sleeve too far in

racefans26

i think i dont know lol that is like set # 4 lol

HPI_Savage_RC

http://rcbasher.com/savcendiffs.html

SAVAGEJIM

Wow, you are well on your way to filling up a bucket or junked parts. You might be able to take them to the recycler and sell them the metal

SAVAGEJIM

Oh yeah! I love the Cenchain (CEN) GST/Genesis/Nemesis diffs! They are thicker teeth and definitely tougher, but I have never taken the risk of trying to find out if the teeth wil strip when landing while gassing or braking. Too bad that all the Ebay chop shops charge an arm and leg for them; then never even offer a buy-out option so you have to bid-fight for them

racefans26

well thanks guys...Got a whole new savy on the way tomorrow so we will see what happens!!!!!!!!!!

kevinmansouri

you might want to check your diff cases. if you have a striped screw it could be flexing under load and allowing the gears to slip. just a thought

02R6420

You bought a whole new savage because of a diff problem? I'll take the old one off your hands. lol

SAVAGEBANE

I have never had any diff problems, and I dont want them of course. what I do want to know is what causes them to strip? from what I gather, if you land a jump with the throttle or brakes engaged.... then stuff is definitely going to break because of stress. Is there anything else from normal running and bashing that will strip diffs?
should i have diff grease/fluid in there?

racefans26

I didnt buy it cause my diffs, It was such a deal i couldnt pass it up...

bionictony

looks like you need #86922 HPI Machined Heavy Duty Bevel Gear

http://www3.towerhobbies.com/cgi-bin...?&I=LXTSY7&P=7

rclugnut10

My Feedback: (1)

i've never had any trouble with my diffs and i've landed many a time on power one one wheel then bounced around, going on and off power, and no failure here, maybe your carrier bearings are seiezed that happened to me once, but thats really odd

the lug

HPI_Savage_RC

An auction with a buy it now option will occasionally surface. I won a GST7.7 diff for $16, then found a buy it now auction for another offered by the same seller for $29. I've seen them go for cheaper, but $45 for 2 is pretty good, and I would have ended up paying an extra shipping cost if I waited around for another extremely good deal, which would offset any savings. There are 3 buy it now auctions on eBay right now. 2 of them are $55 each (Ouch), and another is $30.

I don't think the CEN ring and pinion teeth would fail in the case of a WOT landing. You would most likely break less durable drivetrain parts, such as the screw pins that attach the transmission output cups to the final drive gear shaft, or dogbones if you are running the stock pieces.

cheiro

Have you tried to shim the bearings on the diff so that the crown gear is forced against the bevel gear.

osuwins

what savy and motor are you busting diffs in, lets see a pic. of your setup, 40 series tires and rims are big and heavy your drivetrain may not be able to handle a dead stop to a wot