Other than clearance... what is the advantage of the high 9 over a 60 (if any)? They are the same price on Currie's website.
And what is the difference in clearance?
And what is the difference in clearance?
The gear deflection on the hi9 is basically 0 when ran in front , and on a low9 when ran in rear, making the R&P stronger than a 60I think you would see jeeps that get jumped running 9s more often because an aftermarket 9 can be trussed differently than a 60. I believe the Currie 9s are lighter than the Currie 60s.
The other thing that I have read is that the ring and gear contact pattern may be better on a 9 than a 60, but I don't know this for sure.
Couldn't you just use this housing (Currie F9 housing) with a 9" 3rd member?The currie high nine 3rd member uses ford 8.8 gear. And does not have the front pinion support bearing of a normal 9 inch. Check true high 9 it cost alittle more the the currie set up but you actualy get an 9 inch ring gear.
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Currie F9 housings and all fabricated 9" housings (Spidertrax, Diamond, Ruff Stuff, Tubeworks, Dirt Tech, etc) share the same stud pattern and can bolt up to any standard 9" third members like a Strange or a Yukon.Couldn't you just use this housing (Currie F9 housing) with a 9" 3rd member?
Ok, thats what I thought. So its just Curries 3rd member that should be avoided as it uses the 8.8RG? I'm running a Currie RJ60 in the rear. Im thinking I'm going to go with an F9 in the front. I realize the gear ratios will be off slightly, but I don't think it will be a problem and I talked to a tech at Currie and he agreed that it shouldn't be an issue.Currie F9 housings and all fabricated 9" housings (Spidertrax, Diamond, Ruff Stuff, Tubeworks, Dirt Tech, etc) share the same stud pattern and can bolt up to any standard 9" third members like a Strange or a Yukon.
Yeah thats the way I understood it to be on the ratios too. As long as you're in the next closest number up or down you should be ok. And seeing as I'm probably never going to be in 4wd on pavement anyways (unless I go up to the mountains and have trouble in snow) It really shouldn't be an issue (Ill also have manual hubs when I do the front axle).Currie's HIGH PINION third member is the only one that uses the 8.8. They contract with Strange Engineering (I think) to produce a low pinion case that accepts the across the board standard 9" gears. Ford occasionally dropped a tooth out of their ring gear to create better engagement, that's why they have those funky ratios like 4.86, 5.14, and 5.43s. I can't remember the margin percentage but I think numerically it is +/- 0.04 on the ratio. So if you keep 4.88 like your sig says, you should be fine with anything from 4.84 to 4.92....but I'm no expert, so make sure you double check that one with a non-web wheeler like me lol.
I talked to an old ARB tech and he has had a lot of luck extending the life of the RD99 by running bigger gauge airline and a higher PSI than ARB directions recommend. Somewhere in the 150PSI range depending on your setup. He told me a lot of failures he saw were from crimped air lines, which doesn't let the collar engage fully or lets it slip out and then they slip and grind each other to holy hell.
And then there's a few ways to beef it up mechanically. Spidertrax and Beyond Insanity make upgraded 4340 Chromoly engagement collars. These are the same shape as the stock ARB collar, just made of 4340. Here's the Beyond Insanity one installed...
They're both around 200 bucks + install price (unless you do it yourself). Not too bad.
Then there's the Ashcroft upgrade. Ashcroft Transmissions is UK company and they have put together a pretty savage upgrade. They rework the end cap, piston, locking ring, and change out the return springs.
End cap and piston:
Locking ring in end cap:
Compare that to the standard style locking collar from above and you can see they did some serious reworking. But it costs a minimum of 500 dollars and involves shipping a 40lb ARB to the UK. Are we really that hardcore? This seems like overkill to me and is best left for racers. The effort, downtime, and shipping hassles really seem to outweigh the benefits for a weekend wheeler. And to be honest I am not sure how proven it is. It didn't get much attention on pirate, but even the best stuff from the UK doesn't make waves here so who knows. Next time I talk to the guy I'm buying my 9" from I will see what his opinion of this one is and will post it here if any one is curious.
It would be nice if ARB would fix this, they have acknowledged there is a weakness, but last I heard they have no plans to alter the locker. They don't feel it would be cost effective. I read that it shares some features with a D44 RD109, making it easy to produce. Changing it to use a bunch of unique parts would cause a price bump I guess. But I'm not too clear on the details there. All I know is that we shouldn't expect any changes to come from ARB. The design flaw isn't so much a flaw as it is a limitation. The 9" diff is only so big, they couldn't squeeze any more engagement out of the case.
I thought the same thing you did but a lot of guys have been upping their pressure without blowing seals. I imagine if you push it up to the 200 range you could get in hot water but there's been a lot of success with this method. I think the idea is to keep as much pressure on the collar to keep it locked and prevent it from walking back under load and becoming partially disengaged.Yeah thats the way I understood it to be on the ratios too. As long as you're in the next closest number up or down you should be ok. And seeing as I'm probably never going to be in 4wd on pavement anyways (unless I go up to the mountains and have trouble in snow) It really shouldn't be an issue (Ill also have manual hubs when I do the front axle).
Thanks for all the info. So its better to run ARB's at a higher PSI? i thought that would blow out seals? And larger line to the locker is against what ARB recommends because they say it takes up way more air (which makes sense) and there may not be enough air to keep pressure with a larger line, especially if you need lock the locker several times in a short period. I don't think I'd have a problem with that as I have a Kilby OBA with a 2.5gal tank but it still seems inefficient to run larger line. I don't see the benefit there.
I like the looks of those upgrade kits. I'll have to see what my options are when I'm ready to do this mod. And I wouldn't put it past Currie to do an upgrade. They already upgraded their D60 lockers in the last year or so. So it is possible. (I talked to an ARB rep on that...came up in convo when discussing an issue I was having).