Some differential help please

[Drewster126]

Hey guys so I got a problem. I was leaking diff fluid about a month into owning this car so I called Traxxas and they were cool nuff to send out 2 rebuild kits since both from and rear were leaking. It was my first time taking these things apart but they are fairly straight forward (or so I thought). After taking everything apart and even using a new housing (cause I also stripped the last ones for the screws on the bottom to screw into) I put it back together and noticed a grinding/gritty noise. There is a lot of resistance almost like the gear is rubbing against plastic/metal and I cant find any signs of ware after reving the engine a little bit to try and find out maybe if it was rubbing somewhere. I been at this for 4 hours now trying to figure it out and took it all apart 4 times and then played with it and it really only goes together one way. So I am very confused if anyone has any ideas what to look for or maybe there is a common mistake it would be very helpful, Thank you very much.

[pedecrawler]

What did you fill the diffs up with?

[bigdummy]

saw this on here.think this may be the problem. http://monster.traxxas.com/showthread.php?t=513438

[Drewster126]

I am putting 20,000 wt in the diff. I looked at that post and I am already doing that cause the rebuild kit they sent me was for a revo. But that sounds exactly like my problem that he described its crazy.

[Drewster126]

Man this freaking sucks lol... I even took out the washer trying that and its binding up. Its completely clean in there and everything is in the correct place/order. I dont know what to do anymore I guess I its just time to wait for some help.

[rustler09]

could it be that a washer was put back wrong, there for setting the diff closer to the diff case and causeing the grinding noise. just a thought.

[Drewster126]

Well there is only 1 washer in there and I made sure it was in the right spot. The slash exploded view is wrong and the revo view is correct. I did it both ways though and even took the washer out and tried it and its still doing it. Im about to take this thing and throw it away its ****ing me off so much. Stupid traxxas is closed today too why why why!

[rustler09]

can you see on the inside of the diff case where it is hitting it?

[Drewster126]

Nope, no plastic rubbing off or little particles flying around at all. *Hulk*

[rustler09]

when you had/have the diff out in your hands chould you feel/hear the noise or binding in the diff? if so then i would try and reassemble it again or if you have a lhs near you take it to them, if not then your problem is else where.

[Drewster126]

No I dont hear it at all. I even put the housing together without screws and place it on the chassis. I mount it with the single mid bottom screw to hold it down. I turn it and dont hear anything. I then start putting the top screws on and then I start to hear it when they are tight holding the case together. But there is no marks on the inside of the housing at all! I dont get this ARGHHHHHHHHHHH

[rustler09]

hmmm, i can see where this would be a big pain in the rear. so there is no marks on the houseing, what about on the diff gear itself, anything there? is it possible you might be over tightening the houseing on the top screws?

[Drewster126]

I really dont see any marks on the diff either, or any of the gear at that...

[SirSlash4x4]

I'm getting really worried. Now it seems as if everyone's having problems with the diffs

[keithy4129]

make sure you didnt tighten the screws too much that hold the ring gear on, those screws being a little to tight cause the gears to bind

[rustler09]

i have heard of a lot of people haven to shim the diffs to get rid of some noise, but this is weird that you can here the noise but there isnt andy kind of marks anywhere!!!!

might it be the internals of the diff gear? such as parts #6882.

[yeti as3]

Revo/slash diff uses the same stuff. O-ring goes in the cup 1st and then the washer (just in case). What I like to do...support the cup in a socket or something,install o-ring and washer on side gear and slip it in, fill 1/2 with fluid,drop the spider gears in, fill to top (or close). Now... set the rubber gasket in, eyeball the center and set the other side gear in it. Carefully sset the steel gear over the side gear, align the pins and insert screws. The assy is very sensitive to screw pressure. You may not think it isn't tight enough, but its not going anywhere. It will feel tight by hand but with wheels on it will feel better (leverage)

[DrFizz2k1]

saw this on here.think this may be the problem. http://monster.traxxas.com/showthread.php?t=513438

This is your issue.. read it again.... you are still probably too tight on the 4 screws holding the ring gear on the diff housing... start loosening them one eighth of a turn each and try it again.. do this untill you either lose the binding or the screws come out in which case, it wasnt this that was causing the problem.. but I believe it is...

[Drewster126]

Ok guys thanks for tips im heading to work right now and will try it tomorrow or tonight and let you guys know what happens.

[kaafsa]

There are 2 ring gears for the 4x4! Front AND Rear!

One with a darker metal color and one with a lighter metal color. I don't remember which one must go front or rear, but there is a difference between them also the order numbers are different.

I wil make a photo and tell ya which one must go front and rear tomorrow

[Drewster126]

There are 2 ring gears for the 4x4! Front AND Rear!

One with a darker metal color and one with a lighter metal color. I don't remember which one must go front or rear, but there is a difference between them also the order numbers are different.

I wil make a photo and tell ya which one must go front and rear tomorrow

Just got home from work and will try this tomar night after work also. Thanks for the tips guys and if you could please do that Kaafsa that would be great will take any tips

[kaafsa]

Front Dark metal color
Rear Light metal color

Always rebuild the diffs one at the time or when you rebuild all of them at the same time like me. The best thing you can do keep the parts from the front and rear diff separate from each other and mark it with a piece of paper 'F' and 'R'.

[Drewster126]

Okay so I tried loosening the screws and it seemed to start working little by little as i made them looser and looser the problem started to go away little by little. Now I am at the point where there is not a seal on the diff and it starts to slowly leak but the noise is 90% gone. What now? Im so confused and pist off right now

[Drewster126]

Anyone else got any ideas? Im lost and traxxas is closed still today

[rustler09]

did you check to see if the front parts are in the front and the rear parts are in the rear? as shown above.

[Drewster126]

Well I actually have not taken out my rear diff yet so its only my front diff that I have even taken apart

[rustler09]

so you havent taken the rear apart yet at all?? not evan to fix the leak you mentioned.

[Drewster126]

Not yet... My front and rear are leaking and I started with my front and rebuilt it then ran into this problem... Why take apart the rear and mess it up if I cant figure out the front yet

[rustler09]

hmmm i take it you have looked at your exploded views and everything looks to be in the right spot!! i would set in the corner for a few days and try it again. i haven't a clue.

[Drewster126]

Yeah I have looked at the exploded view and everything is perfect

[bigdummy]

maybe you should CAREFULLY and very SLOWLY take the rear apart and keep seperated from the front and make sure you are putting the front diff together right i think that maybe you will find the cause.hope you get this worked out.

[Drewster126]

I have taken it apart about 15 different times and its all exactly how its supposed to be.... It turns fine before I screw it down onto the bulk head or whatever its called..

[Green Machine!]

This is my experience. I did the same thing trying differant fluids and I figured out what I was doing wrong with trial and error. "spins fine until you tighten the four screws, then it seems to grind and bind", correct? 1) the fluid needs to be below the rubber gasket line on the casing. I was over filling it at first. 2) only snug the screws down by feel. Too tight will tweak the gasket and leak, and smash the gears together. That fixed it. Guarenteed. Don't be scared that the diff will leak. Just don't over tighten. After your firtst run, inspect it and wipe the excess oil that seeped out through the screw holes. Then it shouldn't leak anymore.

[DrFizz2k1]

The exploded views for the Slash 4x4 are WRONG. You need to be looking at the Revo exploded views... The ones that come with the rebuild kits.... If you read my whole thread about this.. I had the same issues.. took me days to get it working properly... and in truth, it's smooth now, but doesnt feel like it did new... the front diff action is perfect, no binding at all.. with the washer in place properly... but the binding in the ring and pinion was my big issue... making sure its tightened EVENLY is the most important thing.. you want it to just barely seal on the rubber gasket, and be EVENLY tight on all 4 screws...

[Mozez]

Hi all, I seem to have the same problem.
Look at this:
http://www.youtube.com/watch?v=dk3S5YwaHNs

As soon as I tilt it backwards, the little pinion "falls" back towards the ring gear and creates the noice.

Is it really the same problem as you DrFizz2k1? How can a washer inside the diff have any effect on the ring gear and pinion outside the diff?

[rex cars]

i had a similar problem reassembling my front diff. the rear went fine, but try as i might, the front would feel 'lumpy' or too tight. backed off the screws till it was smooth and ran it like that. leaked like a sieve. when i was reassembling it after another rebuild, i noticed that the rubber seals were oozing out of their pockets before i could put it back together. i took it all apart, re installed the o rings and output gears (washer in the proper place) then put the output yoke on to hold the output gear and seal in place. this took care of the problem for me. regular refill and reassembly after that.

[RonJ]

Hey guys, I was experiencing the same issue. It ended up not being the diff, but it ended up being that I was tightening the Diff plate (I think that's what its called) too tight onto the Diff housing. Once I loosened that up to the point where it wasn't up against the housing, it fixed all issues. When it's tightened down too much the ring gear and pinion bind, but when it's loosedned (or eliminated completely) it works fine.

Try that out, and let me know if it works. The Diff plate is the little blue plate that you tighten to the outside of the housing.

[Mozez]

Tore down my rear diff yesterday, and I think I found the issue. The blue rubber sealing on the ring gear end was shattered. That allowed that axel to slightly shift in and allow the ring gear to get too close to the pinion.

Ordered a new set of rubber sealing, hopefully that will take care of the problem!