bcane98

iTrader: (21)

So I get the truck warmed up, do some high speed passes, come to a stop to attempt a wheelie. I give the WOT shot and it just isn't taking off right... making a funny whinding (high RPM) sound... then it kicks and takes off... Hmmm... W-T-F I say.. I drive by my feet to give and initial inspection.. CB looks fine, Spur is good, no funny smells, no leaks, so I role away in a hurry (3/4 throttle)... OK, must have been a fluke... Nope! it happend quite few more time, but only when attempting to WOT take off's...

After Run Inspection: I inspected the CB and shoes, all looks fine. I have not looked into the Diff's yet. I figured if it was my rear diff, the front would pull it along and not lose much power. I have not looked into my tranny yet either... I have the spur gear spring tight, about 1/4 turn back.. I checked the grub screws on the drive train, from tranny to diff's, and they were loose...

Latest Upgrades: I just put the OFNA throttle/brake mod in... and I upgrade from the 2 clutch shoes to a 3 shoes... I will be adding a 3 speed in the near future... 3 speed is on it's way...

ntro75

have you checked to see if one of the hex'es in the back of the rims is chewit it up?maybe starting to spin in the back of the rim under heavy load?this is in a savage I presume?

bcane98

iTrader: (21)

I never thought about that, I have steel hex's... And they are fine...

The truck will not move at all when it happens... Then it kicks into gear and moves just fine...

When it does happen, I blurp the throttle, Rev Rev, lett it go to idle, then just before idle, it jerks slightly and then into gear... I think I need to remove the tranny now...

Horatio

You need to check where the centre rear dogbone (or the dogbone end of the centre rear CVD) goes into the brake hub. If you notice wear in the slot of the brake hub, the dogbone can jam or cause other problems - including grinding noises, clutch slip (damage the clutch shoes) and damage the slipper prematurely.

This jamming can put stress on other drive-train components, as well as loosen grub screws.

Might be worth checking this before opening up the 2 speed gearbox. But basically, always trust your ears - if you can hear strange noises above the noise of a Nitro engine, you can bet something aint right.

bcane98

iTrader: (21)

No funny sounds coming from the Diff's when I spin the wheels. No funny sounds from the tranny (it's out now awaiting 3 speed upgrade). No obvious wear and tear where the DB's connect...

I looked into where the Diff is and did not see anything odd? How can I check this without taking it all the way out?

Thanks for all the help so far...

bcane98

iTrader: (21)

Well I cleaned the front diff (rear diff after 3 speed upgrade) and no issues there... I looked in the gear box, looks ok. Another person stated to check the 2nd gear pin... I look in the manual and only saw one pin...

Is the 2nd gear the one with the Shift Point adjustment screw?

Oh slipper pad is crack and welded to the Spur... Looks to be worn pretty good too... but wouldn't the slipper cause it to accellerate slowly instead of pooping into gear?

Thanks for any help yall can provide...

jfc_tech

iTrader: (4)

Interesting problem...
i think it slipping...mine i screwed the spur tightly and even can double the lock nut...like what John Scultz of Rock Concepts did. After all, he won the savage slam twice in Mod. This works on high traction track...make sure u let go trottle before landing on high jump.

Horatio

This is likely to be the cause of the problem - either way, you'll need to put it right. The slipper is slipping too much (lack of drive) and friction welding to the spur (drive suddenly regained). Before long, you'll have no slipper material left at all and no drive at all. Your spur is most likely missing the 'maltese cross', or at the very least it will be partially missing or damaged. The spur may otherwise look fine, the teeth may be perfect - but it's highly likely that it's had it.

So you'll need:

new slipper pads #72131 (you get 2 in a pack), a new spur (47t,49t or 52t) and while you're at it you may as well change the spring/hex-hole washer #87042, nut Z684 (M4 Lock nut), slipper pin Z260 and the slipper plate #72130.

The slipper pads are self-adhesive and need to be alligned with the 'maltese cross' shape and adhered onto the new spur. Follow the diagram in the manual to the letter.

I've found that since I rebuilt mine, I need to tighten the spring right up tight. Before I used to back it off 1/4 of a turn, but now - even with a new sping and lock nut - I have to keep it really tight, otherwise it can (and will) slip. So take JFC's advice and tighten it up - keep things simple.

You still need to check how smooth everything rotates, including the driveshafts/UJ's etc to ensure that your damaged slipper wasn't the result of some other drive-line related issue.

Keep us posted.

bcane98

iTrader: (21)

Thanks guys... Looks like the verdict is in... Awaiting the parts now.

Just another curious questions???

I cleaned my front diff's (first timer)... I only had 5K weight OFNA diff lock fluid... I know I got this second had and did some reading, so I am ordering 50K(F) and 30K(R).

I needed to put some grease in the gear box, so I used the diff lock fluid. I then RTV'd it since they are open diff's (read on another forum). Was it ok to put the Diff lock in there?

When I get the new Diff Lock Fluid I am going to clean the diff's again and put some White Lithium in the gearbox instead if I messed it up. It can be chalked up as a learning experience and not cost me a grip of cash to repair...

mach51

iTrader: (31)

umm, do you have reverse in this truck? Ive seen LST and MGT's that sometimes wouldnt always engage completely in forward and would do what you are describing. For it to wind out and then snap into gear either should be tranny problem or clutch shoes not engaging...

bcane98

iTrader: (21)

I do have a reverse... How do I check then reverse if this is the problem?

Horatio

Regards diff fluids, it largely depends on the surface you run on and whether you race or bash. Right now I have mine setup with 10000 front, 3000 rear and I like it.

50k and 30k seems a little heavy to me, but perhaps you want to limit the diff's action? Either way, once you're happy with your diff oil weights, you'll soon appreciate that you won't want to be taking the diffs apart on a regular basis!! That's why the 4 spider diff mod was about the 1st thing I did on mine (at the time, even the SS came supplied with 2 spiders only).

Using a little diff oil to lube the crown gear and input pinion won't do any harm, but it will soon spin off and become ineffective. I used Mugen Super Grease (black grease), small amounts, for both front and rear crown gears/input pinions and also the gearbox. It sticks to the gears and stays put. When I took the 2 speed out and dropped the 3 speed in, everything was as good as when I first built the truck. Likewise, the crowngears/pinions have no sign of wear after more than 12 gallons, so I conclude that Mugen Super Grease does the job!

Join us at The Savage Thread

bcane98

iTrader: (21)

Well just tore open the rear diff and definitely some wear and tear... 3 of 4 of the small bevel gears are worn... Looks like small grooves starting in the middle of each gear... We could have a winner!!!

Always keep your diff's well oiled... I recommend you check this if you buy any RC second hand, even if the guy says he just refilled the diff's... I remember this for the next one (LMAO)...