A fix for the RD99 ?

[jpcrawleram]

this is what it should look like:

[Tech Tim]

Wow Andrew, that is pretty intense.

How do the ring gear bolt holes look?

[jpcrawleram]

Ring gear bolts were all fine... In the past I have had bolts come loose (not back out but hand tight) in this carrier so that could have fatigued it for sure.

I will mic the holes tomorrow to see if they were wolloed out at all.

Last time I had this 3rd out was this summer for annual maintance.

[Gravy]

wow~

[Agrover]

Originally Posted by jpcrawleram

a year and a half since I put in / tested Beyond Insanitys ARB ring
I guess I found a new weak link


Ring is good as new!!! The rest of the small case half looked fine as well.

Im running this Locker in the front end of my YJ buggy
4.0 aw4 atlas 5.0 5.38's 39 reds full of water and lots of AZ wheeling.

I was concerned about the same thing happening when I originally installed my McNamara Toyota Hilux lockers and used a liberal amount of Loctite Super Bearing retaining compound on the ring gear spigot diameter after reading that Renault do this without bolts to retain the ring gears on one of their puss box models.
Agrover.

[Acerni Offroad]

After many collars break, now I try to run the Aschcroft prototype on my 9" ARB. Today I've disassemble the differential and I found the classic breakage of the collar's tooth.




Below, the difference between the stock RD99 and the new version with modified collar.



I run on my Jeep the HI9 3rd member with thrust block then the locker case need to be machined the OD loosing the self center of the two side of the case. For this reason, before machine the case, I've drilled 4 holes 10mm diameter and I've insert 4 steel pins that keep the two sides centered.



The new RD99 come with a mask for drill 4 new holes in the old case for the 4 main spring that push the engage collar back when the locker is switched off.





The side gear need to be machined and to fit in the new case..

[Acerni Offroad]

The new locker have two inlet line for the air, this will make the engagement collar lift constant, a problem that we have in the old RD99 version with only one air way.



Here the new case with engagement collar, side gear and steel pins ready to be fitted with the other side of the case.




Tomorrow I will install the locker in the case and check the gear setup...

[whypave]

Since your old side gear was damaged did you buy a new one from ARB or does it come with Ashcrofts kit?

[Indy Will]

Gonna be putting in an ARB in my Hi9 in a couple weeks...got me thinking again...

Why are we still turning down the ARB housings and not modifying the load bolt instead?

My Hi9 is in a housing right now and has a spool anyway...but... my low pinion with an ARB has a good 3/8" of ring gear exposed on the outside of the ARB ring?

Seems like a notched out load bolt would still get the job done and we wouldn't have to modify a problematic locker any more than we need...?

Or is the ring gear surface that much smaller than a standard 9"?


Or have I not been inside my Hi9 recent enough to remember how it works?...

[ashtrans]

Hi Pier,

good to see you are getting it fitted at last,

you may find you will have to grind a little from the inside of the diff housing as the side flange we supply is 3mm wider,

post up some more once it's in stalled,

we have now fitted about 10 sets in the UK and they are all working very well,

Dave

[Acerni Offroad]

Originally Posted by whypave

Since your old side gear was damaged did you buy a new one from ARB or does it come with Ashcrofts kit?

The Ashcroft kit come without the side gear. I think you can change the left and the right side gear, probably it are the same...

[Acerni Offroad]

Originally Posted by Indy Will

Gonna be putting in an ARB in my Hi9 in a couple weeks...got me thinking again...

Why are we still turning down the ARB housings and not modifying the load bolt instead?

My Hi9 is in a housing right now and has a spool anyway...but... my low pinion with an ARB has a good 3/8" of ring gear exposed on the outside of the ARB ring?

Seems like a notched out load bolt would still get the job done and we wouldn't have to modify a problematic locker any more than we need...?

Or is the ring gear surface that much smaller than a standard 9"?


Or have I not been inside my Hi9 recent enough to remember how it works?...

In the pictures below you can see the load bolts and the surface were it works. I think is not possible modify the bolts insted of the locker case...

[Acerni Offroad]

Like Dave wrote, the new case is 3mm wider than a stock ARB then the new locker hurt the bearing support. A grind is needed





And now ready to be tested....

[whypave]

There is a hardened cap pressed onto the core of the threaded load bolt. I'm sure Chris and Mike wouldn't recommend it but you could turn down the load bolt to remove that pressed on piece and then thread the remainder of the load bolt (which would be shorter) in farther. But the hardened cap is rockwelled to the same hardness of the ring gear and the core may not be. I don't think that would gain you back the entire stock OD of the ARB but it would make it stronger potentially by splitting the difference. add a 1/4" to the OD of the ARB by reducing the load bolt by 1/8th.

I don't think there is room to change the radius the load bolts are spaced at and the cases come machined along that radius.

But those load bolts do seem to be a larger diameter than required to control deflection given most other axles we run don't have any and the true hi 9 has two.

[ashtrans]

Hi Pier,

have you tried it ?

what do you think ?

Dave

[Agrover]

I would assume everyone modifying their 3rds with load bolts are using Nodular Iron housings or similar? otherwise you'd be wasting your time and will end up with your pinion hanging down on the floor still attached to the driveshaft.
AG.

[Acerni Offroad]

Bad news Dave...

[Agrover]

Originally Posted by Acerni Offroad

Bad news Dave...

Not sure how relevant it is to this issue but I've seen a similar problem with LandRover range change selector collars over the years.They shorten every second female tooth instead of every 4th one ,to make range changing on the fly easier. Problem is that you have a 50% chance of engaging and driving on the smaller surface area of the short tooth and a taper wears quite quickly, it jumps off the short tooth with enough force and momentum that it will jump a couple of long ones too. Even when a long tooth engages it will drive the short one when in reverse gear.
AG.
Edit after thinking about it for a while the above doesn't seem relevant.I'm guessing low air pressure.
PS. What's with what appears to be weld splatter n the locking ring?

[ZukIzzy]

Better parts don't fix a bad design, It is just a flaw in the timed locker mechanism. Props for the attempt though.

[ashtrans]

Nooooooooooooooooooooo!

just dug this thread up and found this, we have done about 20 of these now with no problems for people that were regularly having problems with the stock and Spidertrax ones.

looks to me like it was only getting partial engagement, maybe the lock ring was jamming.

Pier, if you want to send me the complete airlocker I will sort it out for you, new lock ring etc and check it's working OK with full engagement

let me know,

Dave

[Acerni Offroad]

Dave

I'll ship out my complete locker soon. Now I'm running a Detroit for fix the problems but next month I will go in Andorra for the Xtrem Challenge and I'd like to run the ARB for that race..

Pier

[ashtrans]

Hi Pier,

I think I see the problem,

in the fitting notes you have to machine the gear which I see you have done but also machine the main body,



when you fit our kit you have to machine the diameter marked red down to the same height as the face marked green, if you don't then the lockring will not get the full engagement, this is your photo from post 231, the red looks higher to me, pls confirm,

[Indy Will]

Originally Posted by ashtrans

... we have done about 20 of these now with no problems for people that were regularly having problems with the stock and Spidertrax ones.

Which competitors do you have testing these? Sounds promising. I'd like some pricing information.

[ashtrans]

Hi,

sorry I don't know in the US, 'Tech Tim' fitted 1 or 2 but I am not sure in who's car, most have been in the UK and europe,

I will check I have some kits in the next couple of days and work out a price,

Dave

[ashtrans]

Hi Indy Will,

I have checked stock today and we only have 2 kits left which I need for a customer,

the kit consists of :

lock ring
end flange
piston + O rings
side gear washer
4 return springs
template for machining work,

if I make 20 more kits they will come out at £ 275 ea, approx £ 415 + carriage,

is it worth me making them ? what interest is out there ?

Dave