Flyojumper

My diff started to squeal yesterday so I thought it was time to clean it and relube it.
I took it apart, everything looked fine (no apparent gear damage or meltdown), cleaned it thoroughly and relubed it with Associated grease (http://www2.towerhobbies.com/cgi-bin...?&I=LX2882&P=7).

Today I tried out the car and at first it was silky smooth.
However after 5mn or so the diff started to squeal again...
What can I do? Maybe I didn't put enough grease? How much of that small tube are you supposed to put? (I put about 1/3 of the tube but it's a smaaall tube).
I put grease on the gears and inside the diff gear on the balls.
If I needed a whole tranny rebuild it wouldn't have been smooth during the first few minutes, no?
I tried tightening and also loosening the diff a little but the squealing stays.

Thanks for the advices.

gunnut

Is it squealing all the time as it rolls or only when partial or full power is applied?
If it's only under power then its either your diff or slipper clutch if ya got one.
if not then it's something else.

Tighten the diff quite a bit and see if that helps.

Flyojumper

I think it's squealing all the time even when I roll it manually, although in that case it's less noticeable I guess since I can't turn the wheels fast enough.
I've had my diff set pretty damn tight and it doesn't help reducing the noise. Whether it's set loose or tight I can't really tell a difference in the noise.
The slipper (I do have one) is set at a moderate level, pretty much at the same level as it's always been set since I got the car. I even put a double nut to avoid self tightening or loosening.

I made a small 20s mp3 in case someone experienced could tell from the exact noise what it could be:

[link]http://www.freewebtown.com/flyojumper/Diff.mp3[/link]

It's only 251KB.

You can tell the squealing easily at the end when I maintained a low speed.

philp37

Are you sure your diff balls and the plate that they ride on were in perfect shape. They have to be perfect. Another cause could be a bearing that is going, but that is very very rare.

Flyojumper

I know for sure that it can't be the bearings because I cleaned them and inspected them extremely thoroughly during my rebuilt and all were in tip top shape after I was done.
The diff balls and rings: they looked ok to me but I must admit I didn't spend a great deal of time examining them.
If they were anything less than perfect would they be causing that noise?
Anyone who heard my audio file and could comment on the particular rattle noise? I'm hoping someone experienced could make a good guess from the noise.

Finally, how can we explain that it ran very smoothly right after the rebuilt for about 5mn? I thought that maybe the grease got pushed back on the inside walls of the tranny after the gears spun so many times and the gears didn't have enough grease left on them to stay smooth and silent? How much exactly am I supposed to put in there? I've heard some people "filling up their tranny box", is that what's recommended?

BTW, this is an Evader Pro BX stock tranny, top shaft is steel, idler and diff gear are pastic.

CustomTamiyas4Life

My Feedback: (34)

It's defeneatly the diff. I just rebuilt my evader tranny and it squeels then is done. I then tighten it all the way down like wayyyy down and after 5min it is also slipping. I think you jus need to rebuild it agsin with more grease. I barely put any, so i bet that's my problem.

chevrolet486hp

[>:]I use lucas heavy duty oil stabilizer it bondes to the gears and never shedes to the side dif. case like grease.P.S. IT WORKS

Flyojumper

Woot, this topic has been brought back from the grave! Thanks for the suggestion, however I solved that problem a while ago already.
I'm not sure if you should use that heavy duty oild stabilizer though, I'm no expert on greasing/lubing but something that "bonds" to the gear may not be recommended in the long run since it may interfere with the mesh. Someone may be able to comment more on it.

dustbunny1309

Just curious, what was the problem? Sounded like dirt or something got into the tranny.

Flyojumper

Yep, you got it, some dust/dirt found its way back in the tranny's outdrive bearings after my relube/cleaning job. After I cleaned it again the noise disappeared but it seems like dirt has a tendancy to slip in there from time to time.
If anyone has tips to completely seal an evader tranny, please post them.

duneslider

I don't know if there is anyway to seal it completely but try using a heavier grease just in the areas where dirt could get in. The thicker grease will hang around longer and help prevent it from getting too far. If you spend a lot of time in really dusty areas then you want to clean and lube your diff more often.

I like putting in as much grease as will fit when I reassemble the diff. However, I don't think you need a lot. Just enough to coat everything.

Duneslider

Speedbasher

I've heard about putting foam in the outdrive before inserting the dogbone. This is done on the thrust bearing side to keep dirt out of there. I suppose dirt could work its way all the way into the gearbox once inside the thrust bearing assembly. Not exactly sure what else you could do.

cjg

Try putting a small, rolled up piece of soft foam rubber into the outdrive before putting the cvd/dogbone in (do both sides, dirt can work its way in past the washer on the non thrust bearing side). The foam rubber expands, seals out dust from the thrust bearing and ball diff, and doesn't interfere with the dogbone motion. I rebuilt my BX diff with carbide balls and thrust balls and doing this has helped it last two seasons.

I recommend changing the bearings and diff rings everytime you have it open. Visually inspecting those small bearings won't reveal if they are out of round or worn. Since both are cheap (especially the stock ball bearings, I admit I do reuse carbide bearings) it saves time of taking it back apart again in a few days.

Flyojumper

Thanks guys, however I already knew about that trick from the evader website (I belive it's yours cjg? it has the same pic than the one in your avatar, if that's the case grats it's a nice website where I got a bunch of info when I started with my evader).
Anyway, my problem is not about dirt/dust entering through there, the washer, thrust balls and components around are pretty clean past the initial nut, it's about it entering in the space between the outdrive and the gearbox, it's there that all my dust/dirt enters and goes straight into those giant outdrive bearings (the 12x18mm.).
The rest of the box and bearings have no problem and stay clean.
I've tried duneslider's idea of grease before butting in the bearing, but it didn't help tremendously, maybe because the grease I used wasn't especially thick.
Yesterday night I rebuild/recleaned my diff and I found a sort of ghetto solution that should work but I'm still open to ideas. I made two little cylinders (in carton) that I put around the outdrive while letting some space to spin freely without touching (cyclinders must be 8mm or so bigger in diameter than the outdrives). Then I taped the cylinders to the gearbox so there is no space open between the cylinders and the box. Hopefull this will prevent dirt from entering from the outdrive/gearbox space since now the dust would have to travel through the whole carton cylinder laterally before getting into the crack.
If anyone has some more suggestions on a more permanent fix, let me know.