Zx5 keeps killing rear diff
 

Just popped the rear diff in my brushless zx5

Seem to be having a terrible time with it

Its got a 4600kv flux motor and runs indoor on carpet.

If i let the slipper run at a normal tension it slips constantly (tried new pads and the rest)

Now that ive ran with it pretty tight its killed 2 rear diffs.

Diff balls are now cubes and bevel gears are stripped.


Is there an uprated set up or am i going to have to buy one of those god awful durango things that the rest of my club use.

I use durango diff in the rear, and it works superb! :) There is made an thread about how to install it here on oople. It`s no big deal...

have you shimmed the diff correctly? When i ran a lazer we used to shim the diff far tighter than the manual suggested, then ran it for 5 mins to bed the gears in. We also used to run the slipper with a tiny bit of slip for the initial acceleration. Never had an issue after that.

Hi, if you do a search for posts by me with keyword diff / rebuild / setting you should find a long post covering the exact meshing process that I've always used.
The diff in my DB1 is the one out of my old ZX5 .. which became a ZX5-sp then FS then FS2 ... that car was built late 2007 / early 2008 and I've never put a crown wheel or pinion in the rear box (did kill a front one-way crown wheel after 3 years or so of use!!)

The trick is to get the mesh spot on, it will feel a little notchy with brand new gears but after 5-10mins of running it will silky smooth.

Thats me shimmed the death out of another diff

Will give it some time to bed in and hopefully itll be right this time

Managed to get a slightly notchy feel so fingers crossed!

Gave it a 5 min bed in but after 3 or 4 hard brakes outside this second hand diff is shredding as well.

Ive ordered 2 sets of bevelled gears today so fingers crossed a brand new part should sort it

Failing that durango might be the way forward.

I've stripped some on my DB1 due to improper gear mesh but once set as per manual with a small amount of grease didn't have any issue after that.

Should be either slipper too tight or too much brake but you should not have that issue at all. I wouldn't go for a Durango diff as you may have others issues using that but that's just my point.

Do you have changes diff and bevel gear when you rebuilt your gearbox?

Lots of people running those cars here without that kind of issue, some B44 or 410 owners broke that part but FS2 users hardly got to change that part.

Just read i cant get a durango diff anyway

Mine is the basic zx5 and it only fits fs.

My friends FS2 had a habbit of doing rear diff gears, turned out one of the bearings on the pinion shaft had gone and worn a grove in it allowing the pinion to move away from the crown gear under load, might be worth a look.

Pop along to NORA sometime, I've run the FS2 for a few years now and never changed the gears, just built as per manual. I can have a look at what you have and see if there is anything obvious.

Derek

If its an older car, replace the pinion shaft with a new one. The alloy shaft can ware under the bearings (it will be marked if it has) and allows too much movement and thus causing a problem.
Build as pr manual but if racing on mega high grip carpet, then take the copper shim from one side and put it on the other as to make the shimming cap 0.2 tighter (the shim is 0.1)
The other thing to look out for if its an older car is the top gerbox casing compared to the lower gearbox casing. For the small price they cost and for the peace of mind, I would replace the casings too!

Hope that has helped a little...... :)

Not sure what age the car is but i think its the rtr with brushless bits put in.

Wil have another go tonight and take photos.