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gizard

Egress ball diff bolt PB2 made of chocolate?

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any suggestions ? I have gone through about 4 of these now Part PB2 as per the manual or 9804470 is the parts number which contains 2 and the nuts and springs. diff feels loose so I tighten it - not by much and snap! This time I have put some Tamiya anti-wear grease to see if it stiffen's it up for a bit longer.... 

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Ball diffs DO NOT STIFFEN UP into a locked diff however hard you crank it down, THAT IS NOT THEIR DESIGN!! 

If if you want a stiff diff you remove the balls and replace them with plastic pegs.

For onroad cars some ppl try other brands of diff screw eg Yokomo but it's still a 2mm tiny screw - metal either comes stiff & brittle or soft. Hence ppl change to gear diffs that they can stiffen with thick oil. 

 

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I've also snapped a bolt in TLT-1. I'll use pegs for that.  I think Tamiya's ball diff grease was developed for on-road cars, not for off-road cars.  Again, I tried Tamiya's ball diff grease on DN01 Zahhak, just because the instruction said so.  But it felt too loose.  So I took the differential out, wiped off the diff grease.  And put plumber's faucet grease instead.  It's much better.  

(below is a subjective "feel-gauge" explanation)  

With Tamiya's ball diff grease, you only get the "free-rotating-diff" feel.  Not much different from the geared differential.  You tighten the bolt to about 70%, it's engaged.  It makes little difference if you tighten it up to 90%.  It feels like either you tighten enough, or not at all.  

With plumber's faucet grease, you tighten about 60%, and it already feels like a regular geared diff.  Tighten about 70%, it feels like a sealed diff with medium thick grease in it.  Tighten about 80%, it's very stiff, like a sealed diff with heavy grease in it.  At 90%, almost locked feel.  I actually backed out from that.  You cannot lock it, though, because the balls are still rolling.  It now feels adjustable. I'm quite happy about the result.  My guess is that where I tightened to 90% before, now it's tightened to 80%.  The bolt gets less tension, and yet, the diff feels much stiffer.

I thought about using AW grease. But AW has the sticky-feel to it. I was afraid that it might just prevent the balls from rotating. So I'm curious as to your result.  

Amazon sells "Danco Waterproof Silicone Grease" for $3.50.  I'm sure silicone faucet grease can be found anywhere in the world.  I also use it to seal gearboxes for a bit of "water resistance."  Faucet grease is plastic safe.  If you want, It cleans easily too.  It's just like Tamiya's ball diff grease, just thicker. (but not as sticky as AW). 

wiuzJKE.jpg

 

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Hmm thinking more about it and doing more researching I guess ball diffs are an acquired taste for general bashing! I did have a ball diff in a TT02b for a while but ultimately it is running metal geared both front and rear with thick grease and is bomb proof (well the drive train is the lower arms etc are a different matter when I let the sons have a go!). I guess getting the avante gear diffs and putting them in the egress might be an option although can the avante geared diffs be sealed up to contain the fluid I need to look into this.

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4 minutes ago, gizard said:

I guess ball diffs are an acquired taste

One that I have definitely not acquired - I cant stand them. I either feel like im on the verge of tightening to destruction or I take the car out and it drives with a what must be a horribly loose noisy diff.

I much prefer a geared diff in front and back gearboxes.

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AVante geared diff is enclosed but no rubber seals nor gaskets; it's also a planetary diff without bevel gears. I lube them with moly grease and none escape the case so any silicone goop >10,000 should stay in too IMHO.

 

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Posted (edited)
1 hour ago, WillyChang said:

AVante geared diff is enclosed but no rubber seals nor gaskets; it's also a planetary diff without bevel gears. I lube them with moly grease and none escape the case so any silicone goop >10,000 should stay in too IMHO.

 

Hmm yes been looking are the parts - thanks

just wonder if it's viable though - the actual diff case and cover appear to be separate parts so I would need:

1. diff cases (BG1x2) 19335053

2. diff case covers (H8 & H6) 19005277

3. planetary gears (PD1x8 & PD2x4)19405431

4. diff outdrives rear (PB10 & PB11) 19804449

5. diff outdrives front. (PB8 & PB9)19804450  

6. Screws (BC4 2x6mm) x8 19608100

 

ahh at least 2. the diff case covers are included in the Egress kit - I will check when I get home that they are still there - should be.

 

Edited by gizard

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When built as directed the ball differentials are quite robust and smooth. As stated they won't feel locked. Wait for the spring to bottom out and then loosen up as directed. Mine have lasted countless track and bashing sessions with out issue .  

 

 

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The Ball diffs are fine in use - it just when I try and adjust them I seem to over tighten and snap the screw - seems very easy to do for me. It is possible that I am actually completely compressing the spring so there is no give and then snapping the screw by turning further - perhaps if I measure accurately what thread should be visible at the top once fully tightened.

Either way I have ordered some parts to construct gear diffs for front and rear to try them out - the only thing I don't have is the 2x6mm counter sunk screws to hold them together - should be able to get some from my LHS.

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6 hours ago, gizard said:

Either way I have ordered some parts to construct gear diffs for front and rear to try them out - the only thing I don't have is the 2x6mm counter sunk screws to hold them together - should be able to get some from my LHS.

did that parts lot cost much?

Could've just made it an excuse to buy an AVante... :) 

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16 minutes ago, WillyChang said:

did that parts lot cost much?

Could've just made it an excuse to buy an AVante... :) 

£51.98 From Tony's Tamiya parts. I already have a NIB Avante for a very rainy day..... Between the two the Egress is the runner! ;) 

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Could've just 'borrowed' those diffs from the kit for a try :) 

haha yeah...5yrs have flown past since AVante & Egress got re-re'd huh. Bought the new kits but never got around to building yet; at same time did rebuild a runner of both AVante & Egress old originals and even installed SpeedPassion combos in each... don't recall taking them to the track yet. 

DSC05573-640.jpg

 

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Guys, learn from my mistake...

Even 1,000,000 CST oil will leak out of an unsealed diff and make a sticky mess of your gearbox.

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1 hour ago, Big Jon said:

Guys, learn from my mistake...

Even 1,000,000 CST oil will leak out of an unsealed diff and make a sticky mess of your gearbox.

where did it leak out from?

What if we "sealed" the edge of round lid with gasket goo or even AW grease? (Would AW get dissolved by silicone?)

 

Then again even the properly designed sealed case gear diffs made for TA05 & TA06 start weeping after a few years. They've left a puddle on the shelves :unsure:

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I am guessing it will come out where the outdrives go in. (I am talking about the geared diffs.) I presume as the silicon oil gets warmed up with use it becomes more liquid ?

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If there is a gap then it'll leak and there is always a gap. 1M cst will still leak through a hairline crack, just 1000 times slower than 1K cst, which may make the leak rate acceptable in a poorly sealed diff. Having O-rings and gaskets just reduces the leak rate substantially so thin oils can be used with an acceptable leak rate. There's no such thing as perfectly sealed, especially when outdrives have to rotate inside an o-ring, and hydraulic pressure can force the oil past a flexible seal.

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Based on the mess after a couple of runs (and a smoked Torque Tuned), I'd say that it leaked from the diff!

I really don't think that one could get an acceptable leak rate from an unsealed diff.

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Only one way to find out - hope OP reports back his results :)

Lucky the AVante gearbox is so easy to get diff in & out. 

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Parts have not arrived yet due to Bank holiday here I expect.

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1 hour ago, WillyChang said:

Only one way to find out - hope OP reports back his results :)

Lucky the AVante gearbox is so easy to get diff in & out. 

Yea after i finished my egress and went to take it for a test run and break in the ball diffs i realized i needed to tighten the rear and it was a snap to do

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2 minutes ago, Rb4276 said:

Yea after i finished my egress and went to take it for a test run and break in the ball diffs i realized i needed to tighten the rear and it was a snap to do

Pun intended?! ;) 

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2 hours ago, gizard said:

Pun intended?! ;) 

Not yet luckily, supposedly it uses the same screw as the dn01 or trf 201 so i have a few. Though when it was slipping it was making a horrible noise until tightened up. It is now butter smooth

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On 4/3/2019 at 12:49 AM, Juggular said:

Tried "3Racing Ultra High viscosity diff oil." 

It's definitely a whole lot stickier than Anti-Wear grease.  I don't think it would leak. Time will tell. 

This much made it really stiff.  Still not enough for big trucks like Juggernaut 2.  For most buggies, it will feel like honey-filled differential. (Not that you should put honey in differential. And it's not honey, don't eat it, either...)   

ckmLSDm.jpg

 

23 hours ago, Big Jon said:

Guys, learn from my mistake...

Even 1,000,000 CST oil will leak out of an unsealed diff and make a sticky mess of your gearbox.

 

I've just landed a tub of 3Racing ultra High Viscosity as per above.  You only coat the gears with it and not fill the diff case if using in an unsealed diff.  It is seriously sticky !

 

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8 hours ago, Thommo said:

I've just landed a tub of 3Racing ultra High Viscosity as per above.  You only coat the gears with it and not fill the diff case if using in an unsealed diff.  It is seriously sticky !

Ordered a tub too, want to see for myself what this miracle stuff is all about. 

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