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rc18t diff issues
Posted: Wed Nov 07, 2012 11:48 am
by jimbo74
any love for the rc18t here?
i did a search and didn't find much
i am having an issue with my diffs that i cant find an answer to....
i run mip superdiffs front and rear
anyway, the rear diff loosens itself up, completely, after about a minute of running..... how can i fix that?
Re: rc18t diff issues
Posted: Wed Nov 07, 2012 12:10 pm
by jwscab
not too many post on the '18' chassis, but I'm sure the diff is similar to any other ball diff.
it's possible that you have the diff installed so the adjustment screw is on the wrong side, and in running in the forward direction, has a tendency to loosen over time. I 'know' that it's not really supposed to matter, but I have seen it happen.
your adjustment screw needs either more threadlock, or to be 'locked' however the manufacturer recommends, ie, maybe you need a new bolt with fresh loctite, or a set screw lock of some sort?
Re: rc18t diff issues
Posted: Wed Nov 07, 2012 12:48 pm
by jimbo74
it has a nylon locknut
there really is no way to reverse it
the whole setup is pretty new, less than 3 packs total on it
i do have some blue threadlocker, also superglue and accelerator if need be

Re: rc18t diff issues
Posted: Wed Nov 07, 2012 12:57 pm
by jwscab
I'd give either the blue thread lock or the super glue a try. just a smidge, for sure.
Re: rc18t diff issues
Posted: Wed Nov 07, 2012 1:56 pm
by jimbo74
before i do things to it, i want to find out what is going on.... i shouldn't need to superglue it or even add blue threadlocker
Re: rc18t diff issues
Posted: Wed Nov 07, 2012 2:35 pm
by jwscab
are those all the parts in that picture? there should be a thrust washer/balls too.
Re: rc18t diff issues
Posted: Wed Nov 07, 2012 3:01 pm
by jimbo74
i have these in there as well

Re: rc18t diff issues
Posted: Thu Nov 08, 2012 1:49 pm
by jimbo74
anyone have any more ideas?
Re: rc18t diff issues
Posted: Thu Nov 08, 2012 5:28 pm
by BigPun76
About the only other thing I could think of is if the spring for the diff is new, you're supposed to compress it a few times with a pair of pliers or whatever to get the spring steel to "set"; springs will sag after "working" if they are new so this is to get it closer to normal length/height than if it wasn't compressed to begin with.
That's all I can think of... if this makes any sense to you!
Allen
Re: rc18t diff issues
Posted: Thu Nov 08, 2012 8:52 pm
by jimbo74
hopefully it is fixed... i tore it down and rebuilt it.... one of the little washers was broken.... also, i applied blue loctite to the screw, and i superglued the big D washers to the outdrives (have seen this recomended before) after it was all tightened down, i unscrewed it 1/8th turn.... and from the outside of the outdrive i applied a small dab of superglue to the very tip of the exposed thread.... this should end my problem
Re: rc18t diff issues
Posted: Thu Nov 08, 2012 9:21 pm
by camlchris
jimbo74 wrote:hopefully it is fixed... i tore it down and rebuilt it.... one of the little washers was broken.... also, i applied blue loctite to the screw, and i superglued the big D washers to the outdrives (have seen this recomended before) after it was all tightened down, i unscrewed it 1/8th turn.... and from the outside of the outdrive i applied a small dab of superglue to the very tip of the exposed thread.... this should end my problem
What material is the outdrive made of ? Aluminum or Composite Plastics ( like the stock rc18T) ?
Re: rc18t diff issues
Posted: Thu Nov 08, 2012 9:31 pm
by jimbo74
it is hard metal, not sure what metal it is, but it is the mip superdiff
http://miponline.com/store/mip1444.html
Re: rc18t diff issues
Posted: Thu Nov 08, 2012 9:33 pm
by jimbo74
just looking at it, i think i might have built the diff wrong... well.... i think i put the locknut, on the insdie of the collar..... it should be on the outside according to the pics... maybe this was my issue?
Re: rc18t diff issues
Posted: Thu Nov 08, 2012 9:58 pm
by camlchris
jimbo74 wrote:just looking at it, i think i might have built the diff wrong... well.... i think i put the locknut, on the insdie of the collar..... it should be on the outside according to the pics... maybe this was my issue?
You can try a self-lock nut & a longer screw. This may fix the loose problem.
I have experienced with a diff which has Aluminum outdrive, and its design is more or less like the MIP. Eventually , I switch back to AE stock diff , not only because the loose problem, but also the Alu. outdrive will be eaten up by the dog-bone drive pins easily.
Re: rc18t diff issues
Posted: Thu Nov 08, 2012 10:13 pm
by jimbo74
i was wrong, the mip site makes it look like the nut goes on the outside, but the directions say the opposite...
i built it right, now, there just isnt a drop of superglue on it.... maybe i will add one again... later though, i did put new threadlocker on it, so we will see tomorrow night if that worked or not
the mip is definitely not aluminum, it is a hard metal, not soft....