Diff gease.

[oakey4]

Hi all what's the best grease to use for a dave diff, I use the BLACK balls in case it makes any difference

Paul

[Chequered Flag Racing]

You won't go far wrong with AE diff grease that's used in 12th & WGT10 ;)

Thin smear on the diff plates, non on the balls. Works well with 12th & WGT10 so should be fine on the Mardave diff

[SlowOne]

AE grease - check. Smear it on the diff plates? Nooo.

The grease is there solely to lubricate the balls in the holes in the diff gear. Putting it on the diff plates attracts dirt and dust the very place it's not wanted. When the gear is driven it takes drive from the pinion to the spur gear. The spur gear pulls against the balls which in turn send drive to the axle via the diff plates.

When the car turns, the balls are pushed to one side of their hole or the other, but they also want to rotate as one wheel has a different speed to the other. The rubbing contact in the system is between the balls and their holes, nowhere else. The diff grease must be in the holes and on the balls for the diff to work effectively. It isn't needed on the diff plates because there is no movement between the balls and the diff plate.

You only need a smear of grease on each ball to have the desired effect, and minimise the dirt and dust that might stick to the diff. HTH :)

[LongRat]

The most important thing is that it is a silicone grease (all 'diff greases' are).
If you use an oil-based grease such as those used for ball bearing assemblies, you will get uncontrolled slip in the diff quickly leading to burn-out. This is because oil based greases get thinner under shear loads, like between the balls and rings, effectively increasing their penetration and lubricating effect. So they end up lubricating right where you don't want it - between the balls and rings.

[oakey4]

Points taken on board lads, cheers, do you use use the black plastic hub or the alley hub, I was tempted in trying the alley hub.

[SlowOne]

I've not used either yet, but I've heard people say that the plastic hub can distort when you tighten the wheel on to it. Some say the diff action is better with the alloy hub. I've ordered the plastic one and am going to experiment to see how I get on.

Anyone used both and can comment?

[LongRat]

The main problem with the plastic hub is that the bearing seat is not concentric with the outside, so it isn't balanced. I made my own alloy hub a while back (to which, incidentally the Mardave upgrade hub is essentially identical). Diff action was better and the car was smoother. Because the ring seats are dead flat, the pressure on the balls as the hub rotates is constant so the diff feels more consistent. I would like to know if the Mardave official alloy hub gives the same results but if they have machined it properly it certainly should. Also has the multiple slots so you are not limited to 6 spoke wheels.

[KJR]

I haven't used anything other than the plastic one. It's never going to be great as the diff plates don't centre on the axle never mind what the hub does. I sanded the diff plates, fitted two bellville washer, fitted the full complement of balls and my diff while not as smooth as the one in my 12th is fully functional.

I'm still fairly in the camp that Mardave or now GT12 should be as cheap as possible so I don't run any of the alloy, carbon or GRP hopups and my car goes fine.

[oakey4]

All been well I am going to order a alley hub for the diff tonight...and some grease....Paul