No oil in factory diffs...BEWARE !!!

[militarymaxx]

During my dismanteling of my stock chassis (see thread about weekend damage), I figured I would go over everything thoroughly before I put it all back on. When it came to cleaning up and inspecting my diffs I opened them up and noticed that they weren't full of diff oil like I thought. Instead the spider gears were coated (lightly) with some general purpose grease. My Storm came with a setup sheet with a factory racing setup and it gave diff oil weight recommendations. I just assumed that it came with some kind of diff oil. Maybe not the weight the racers used, but some none the less. So here I am talking smack at the track about, "Yeah, I use 5000, 1000, 3000 in my buggy, what you got?" So, I will get to use my newly purchased bottles of oil and try and save face.

 

[DarthRacer]

I just picked up my Storm today and the first thing I did is start ripping the diffs out to fill them with silicone fluid. I assumed that there would be none and was correct. There is only a light grease inside as you stated. (BTW, did you have any damaged diff shims? Be very careful to have the proper amount of shims on the ring gear side to make sure there is no side to side play in the diff. It is easy to bend the shims when putting the diff cover on.)
I'm going to try 5/5/1 and see how it goes.

 

[militarymaxx]

Yes, I did notice two very thin shims on the gear side. Nothing on the other side. They both looked good. I only had time last night to fill one diff (the rear) and I have it sitting on my bench to see what kind of seal I have around the bearings. This morning it was still dry on the outside, so the seal is good and that's with 1000 weight oil (the thinnest I am using) and it didn't leak out at all. I'm going with the following: (front 5000, center 7000, rear 1000).
I will say that the tolerances between the gears was tight, no slop at all, no play. I was thinking about going with the better diffs but man, those babies are expensive. But after looking at the stock diffs, I'm good with these for a while.

 

[RobH]

Funny you guys should bring this up. I have to replace all the stock diff gears in my lightning pro and I'm going to tune them with silicone oil while I'm at it.

When I took my diff case apart, I saw some greasey junk on the diff canister and all over the inside of the case. After I change my gears, fill and reassemble my diffs, do I need to grease where the drive shaft gear the meets the gear on the outside of the diff canister? I assume so, but what do I use? general purpose automotive grease?

-Rob

 

[militarymaxx]

Yeah, I had a light coat of what appeared to be what we in the Navy call "peanut butter grease", or general purpose grease on the outer ring gear. I am going to recoat mine with a light coat of
molybedium (sp?). Not sure what yours is, but on the Storm the bottom of the diff case is open and no gasket between it and the chassis. I guess the factory thought it unecessary and that the seal would be ok. As long as the two surfaces are mated smooth, things should be ok.

 

[DarthRacer]

Originally posted by RobH
Funny you guys should bring this up. I have to replace all the stock diff gears in my lightning pro and I'm going to tune them with silicone oil while I'm at it.

When I took my diff case apart, I saw some greasey junk on the diff canister and all over the inside of the case. After I change my gears, fill and reassemble my diffs, do I need to grease where the drive shaft gear the meets the gear on the outside of the diff canister? I assume so, but what do I use? general purpose automotive grease?

-Rob

I have high-temp automotive grease I've used in my T-Maxx and it works OK. Just don't overgrease it.

 

[militarymaxx]

Just finished re-building all three diffs. The front and rear had been properly greased but the center one, man......had hardly any lube at all on it. No damage done, good thing. From what I've seen and read, the center diff usually has the higher weight oil in it and in the condition it was in with little to no lube, it couldn't have been hooking up at all. I would spin the drive cups and it was basically free spinning with no resistance. Now with 7000 weight in it, I have plenty of grab. Can't wait to get back on the track and see how well it hooks up at all four corners. Met a guy at work who runs the CNC machine. Deals were made, promises were promised and hopefully I will have a 4 mm aluminum chassis free of charge tomorrow. Well almost free. Had to trade some Maxx parts for it.

 

[HumboldtBlazer]

you will notice a world of DIFFerence now that you all rebuilt and filled with oil those diffs. Now go drive it!