Homebrewer

My Feedback: (8)

I was bashing around on the golfcourse in my backyard. Burned 3 tanks and on the final tank I lost my rear wheel drive. I'm not missing any driveshafts or axleshafts. Is there anything common within the tranny that strips or breaks that could cause this problem? It'll be a while before I have time to tear the tranny apart and look. Hopefully, it'll be obvious. Any suggestions?

Thanks,
Drew

Savage_Dias

When I lost FWD on my Savage it was the spider gears in the front diff. Check the set screw on the center diff cup before you tear into that. Odds are it'll be gone instead of loose. It goes through the gear shaft if I remember correctly. The thread where I asked the same question is gone or my bookmark is bad but I'll pass the [link=http://savage-central.com/modules.php?name=Forums&file=viewtopic&t=2200&sid= bb58512d706ec17dac4700e040aaaa2c]4 gear mod[/link] to you.

Unstable

sit the truck up so the rear wheels are on something but the fronts are free spinning...

then turn the spur gear to spin the wheels.

now just look at the driveshafts... which are spinning, which ones arent.

if the center drive is spinning then the tranny is good...
if one or more dogbones are spinning then the diff is good..
if only one dogbone is spinning look at the hub and wheel on the side thats spinning, the wheel may be stripped out or something might be wrong with the hub.

wakbrdr

you probable sript the differetial gears, the same thing happened to my friends savage, the screws came loose and grinded down the bevel gears

Homebrewer

My Feedback: (8)

Nope, rear diffs are ok. I had a spare few minutes and looked a little closer. Looks like I'm going to have to open up the tranny and take a peak. Not sure what it could be.

Nitroaddict

this is a common problem with the savage. Most likely you stripped out and melted the rear diff gears. i encourage you to do the 4 gear mod, as it wil help alleviate this problem, and prevent it from reocurring.

liv4RC

One of the most common problems with these Savage trucks is the factory assembled differentials, main bevel gear, & pinion bevel gears. I would suspect from your descriptions, that you stripped the 13 tooth pinion gear that is encased within the differential bulkhead assembly. In addition, you probably spun the internal spider gear shaft thru the diff's plastic casing (also very common). Either way, this is a good time to fix the darn thing. There are two good threads that I have found to fix this problem. You will first need to take the whole rear-drive assembly off and open up the diff bulkheads & diffs themselves. Take the 43 tooth main bevel gear off by unscrewing the (4) M3x10 screws. Next inspect the internals of the gears and the casings. I'll bet the plastic slots that the spider gear shaft rides in are toast. In addition, by this point you would have already encountered the drive pinion gear. That is the 13 tooth bevel that drives the 43 tooth main bevel. Chances are this has broken teeth. If your pinion & main bevel gears are in good shape, thank your lucky stars that the slipper clutch worked!! If these gears are bad.... well, HPI has a long ass list of customers who have these exact parts on BACKORDER!!! AHHHHH! I have been waiting for one pinion gear for two weeks now! Anyway, this is the time to do a 4 spider gear conversion to your diffs (front & rear). You will be adding two cross shafts (4mm - either Kyosho or Ofna). In addition, I use spider gears from the Kyosho Inferno (they still ride on HPI bevel gears due to clearance issues - the Kyosho bevel gears are much taller and won't stack up correctly). Now, after installing the new spider gears & bevels into NEW diff cases, install 3000 wt silicon diff oil into the rear diff & 5000 wt into the front diff - fill both diffs up so the oil just about covers the cross-shafts. Make sure the o-rings are installed and in good shape before installing the gears & oil. Now, go down to your hardware store & get some #6-3/4" stainless steel FLATHEAD screws and re-install the 43 tooth main bevel gear. Make sure everything spins freely. Now install everything back into the bulkheads along with the pinion gear. Make sure the pinion & main bevel gears have a good layer of lithium grease or equal. That's it! Bullet proof diffs! There are many pictures available if you go on-line and type in "4-spider gear conversion for Savage". Good luck!