Unlock rear diff

[ark1t3kt]

Originally Posted by RustyUs

My next option would be to possibly try some Bad Horsie Diff Locking Grease. Description says..."creating a limited-slip-like feel".

Based on the product description on their website, this product is meant to lock the diff. Probably not what you want to go with...

Originally Posted by altd896

What weight diff fluid are you guys trying to use?
Cos the 1mill weight Mugen gel I have in mine doesn't run & you don't pour it, you scoop it, use a popstick or plastic knife. By all accounts from the guys here the ½mill is still a similar sticky gel.
The guys here are using either of the above 2 gel in their Yeti, mine is in the front axle of a U4RC 2.2 trophy rig but the axle goes together exact same as Yeti rear.
Green slimed o-rings & gasket same as doing shocks.
Assembled with the just o-ring under the spider gears, drop the bottom gear in the cup, scoop gel in till its all but full, sqeeze the cross shaft & side gears in, push the other spider in & used the axle shafts to keep the gears all aligned while I screwed the ring gear down, pulled the axles out, dropped the centre in the housing & put the axles back in.
Nothing comes out while the axles are out, takes barely a minute to pull axles, drop in centre & put axles back in, you can do the centre bearing caps after the axle is in.
Been through 2 u4 race days & its still in there.

I'm trying to use something thinner, like the 20,000 that goes into the front diff. It's more watery so has more potential to leak out (in theory).

If you use something as thick and sticky as you describe, doesn't that essentially lock the diff?

[nfcrockett]

I have mine unlocked with 2.5 mil diff fluid and it's definitely not locked, still allows slip. I did add additional o-rings to the axle shafts just to hold the orange o-rings in place.

[altd896]

Neither the ½ or the 1mill fully lock the axle, they're tight make no mistake of that but they're not locked.
From what I've seen of the stock weight fluid in the front I'd just use grease instead to lubricate the gears cos it's so loose with that stock stuff it's not even worth bothering with.

[altd896]

Originally Posted by nfcrockett

I have mine unlocked with 2.5 mil diff fluid and it's definitely not locked, still allows slip. I did add additional o-rings to the axle shafts just to hold the orange o-rings in place.

Extra o-rings on the axle shaft is a good idea.


Only other option I can see to run very thin diff fluid is to drill a 2.5mm (3/32") hole in the diff centre case so you can plug it with a short M3 grub screw. Just work out which part of the diff case isn't the bit where the cross pin sits.
Should work with the plastic case but an upgrade to alloy would be better, in this case you'd be drilling right through the HR logo.
RPP hobby.com |Hot Racing CNC Aluminum Differential Case Axial
TowerHobbies.com | Hot Racing CNC Aluminum Diff Cup Exo Wraith AX10 SCX10

[BigStick]

I just assembled my new SSD Wide Centered Axle with the diff unlocked. I used water repellant bicycle grease & packed it in. O-rings on the inside only. Feels smooth. Haven't run it yet, as Im still assembling my kit & going off the map by turning it into a Trophy Truck.

[maxPOWAAA]

I just ordered a gear set, shafts, o rings and e clips. Anything else I need? I was only able to find associated 100k, is that going to be too thin?

Someone should make a diy

[altd896]

Originally Posted by maxPOWAAA

I just ordered a gear set, shafts, o rings and e clips. Anything else I need? I was only able to find associated 100k, is that going to be too thin?

Someone should make a diy

You won't need the e clips for the rear, the lock-out on the housing end retains the axle.

100K might be ok, depends on how/where your driving.

[Tommy23490]

I use 20,000 in mine.. Works fine for my application..

[maxPOWAAA]

Originally Posted by altd896

You won't need the e clips for the rear, the lock-out on the housing end retains the axle.

100K might be ok, depends on how/where your driving.

I mostly drive in tall grass, sand, gravel and cement. I do an occasional hill climb on the same terrain. I run a 3200k sct motor on 3s and beat the crap out of it

[TK-twister]

You could try drill a small hole in the Diff housing and completely assembling the axle less the diff cover. With a syringe or something fill the diff up and the screw in a set screw. Therefor everything is in place before filling and less of a chance of it leaking out.