[Chief]

Does anyone else run their car with the diff all the way tight? I do and im wondering why they dont make a one piece diff and outdrive, so it will stay locked up and not have to have the ball bearings and slipper assembly. MY question is, the diff bearings have stripped the 'bearing seats' from being locked up and still trying to slip a little. The diff teeth are all fine. Can i just screw it tight and not worry about it???tranny is still smooth running that way. Does anyone have any info on this?

[Spinner2]

screw the MF as tight as you can with your hands, and that should be just tight enough... dont over-do it though. loose is bad and will eventually melt out the diff gear

[StevePond]

Why is the MF necessary? Is it too hard to just say "screw it in as tight as possible?"

To answer your question, it sounds like the diff was too loose at some point and you've melted the diff gear slightly. IF that's the case, then you hould invest in some new parts. Your truck won't drive too well with the diff locked, but if you're not racing, I suppose there's no harm in locking it up, but I wouldn't do it.

[Spinner2]

Oh, i just threw that in therebecause I didnt screw it in tight enough the first *NINE* times I did it... finally got it right on the tenth try... MANY diff gears later... I sorta have a grudge against it

[Chief]

Thanks guys.

[Chief]

ok just one more question about this. If everyone else tightens it up all the way, then why is the slipper even there? Why isnt the diff gear and the outdrives one piece and locked up? Posi-traction

[Railman]

Chief, Diffs are for turning. If the wheels are locked, the inside wheel will fight the outside wheel. They need to turn at different
speeds because they each have different turning radius. Locked diffs are only good for going in a straight line. However on RC cars, if the diff isn't free, they will drive like your on ice, even on straights, if the track is at all loose. I believe this is due to the large amount of rear toe in. Keep your diff in good working order (smooth with no slip) for an easy to drive car.

BTW, even positraction has diff action. They use slipping clutch packs to limit the free action of the diff, so as to give a partial lock of the axles, but will still allow the inner & outer wheels to rotate at different speeds when turning. Posi diffs used to be common on full size station wagons & passenger vans. There are also full lock diffs that can be locked by driver command. The one I've always heard of was the "Detroit Locker". They are common on big trucks that frequent off road work, where there's a good chance of getting stuck in mud.
Joe

[Chief]

i understand how the turning works with the inside wheel turning less the the outside wheell in a turn. What i dont understand is how does it work if everyone has the diff as tight as it will go. If everyone says no slip is best how will it slip in the turn?

[Railman]

Chief, I don't have an xxxnt, but from what I've heard they can be a bit of trick to get the diff just right. An awfull lot of guys run an Assoc. diff spring instead of the cone washers, even a lot of factory drivers. It makes it a lot easier to get & maintain the proper tension. You might want to ask Aron Waldron (losifreak2004) in the xxxnt thread, in the vehicle forum. He's very knowledegable & helpfull. Again the diff should not slip, but then again, it should also be free. That's a major factor to not pushing in turns.
Joe

[dirtdevil]

I've "done it all" as far as diffs go. Even tried the associated diff spring. My advice after all this is to build your diff per instructions (yes, use the washers!!). After your tranny is back in your truck, run a couple of laps and bring it in. tighten the slipper down all the way and then tighten the diff as tight as you can get it by hand (i put a allen wrench up throught the bottom ot the truck through the outdrive and lodge it in the slot of the diff screw. Hold the right rear tire and spur gear still with your right hand and then tighten your diff by turning your left tire clockwise as tight as you can get it and then try to tighten it once more to be sure!!) Take out the allen wrench. Now back off on your slipper adjusting nut 3-5 turns to the point that it just starts to slip (see your instructions or check out the losi web site. ) You should be set!!

[purplerides]

Chief - when we are talking about the diff. slipping were not talking about the diff action from left to right that should be smooth , when the diff slips the outdrives left and right turn at a slower speed then the diff gear (not good) , the slipper should slip before the diff slips .

[diesel757]

Originally posted by dirtdevil
My advice after all this is to build your diff per instructions. After your tranny is back in your truck, run a couple of laps and bring it in. tighten the slipper down all the way and then tighten the diff as tight as you can get it by hand (i put a allen wrench up throught the bottom ot the truck through the outdrive and lodge it in the slot of the diff screw. Hold the right rear tire and spur gear still with your right hand and then tighten your diff by turning your left tire clockwise as tight as you can get it and then try to tighten it once more to be sure!!) Take out the allen wrench. Now back off on your slipper adjusting nut 3-5 turns to the point that it just starts to slip (see your instructions or check out the losi web site. ) You should be set!!

this is from the xxx-nt forum, but xxx-s adjustment the same minus the slipper part. It is a must to check and retighten your diffs very often when the're fairly new. This should all be in you manual.

[diesel757]

sorry, trying to put this thread into the xxx-s forum
please disregard

there's nothing to see hear