12 bolt lockers are now available

[Ldub]

I heard that some Isuzu's came with a winter mode switch that does some crazy thing like start in 3rd gear. Actually, try icy driving with a 6" lifted YJ on 35" BFG MT's with 4.56's, Detroit locker in the rear, and Auburn LSD in the front. The only good thing there was you could glide over half the things you would normally just slide into... curbs, fire hydrants, children, your boss, etc...

LOL...sounds like a line from Johnny Dangerously.

It shoots through schools, Johnny...

[Ldub]

Got my open carrier from the man in brown today...also, from a man named Brown.(Matt)
Just sittin' on my couch, dry fitting all the new innards into it, visions of nearly vertical ascents drifting through my brain...

Dunno if I'll be able to get it done in time for Moab, but having a "sort of" pre assembled locker in your lap has a certain motivational effect...

[LittleBeast]

LDub whatever happened here?

This is the only 5.38 they have for the front now:

https://id211.chi.us.securedata.net/...roducts_id=461

So basically this "RD94 ARB Airlocker" works by using copmpressed air to lock and unlock the front end (on this particular product), so when in the "unlocked" position (in daily on road driving) how would this effect handling/drivability?

Would it be stupid to have a ARB Airlocker on the front and rear end?

[VX1032]

ARB air lockers are a lot more expensive then the aussie lockers, mainly because they allow you to choose when it is locked. They are a better locker because of it. The aussie locker is always engaged unless it senses that you need to be unlocked, like for turning. The arb you choose when it is locked and unlocked, which makes a much better solution for daily driving. Though with the cost of an ARB at $800-$900 and an aussie half that, usually that makes the choice for most people.

Also, the 5.38s are pretty low gears and would be too low for any tires we run for the street. It would take it past the stock ratio with larger tires on. You would have a lot of power, but the top end would be really limited. I think I figured with my 33" tires I would be running 3500 rpms at 60 mph, which is a far cry from my 2200 now.

[vt_maverick]

Okay, I'll be THAT guy and ask the question: What the he11 are you guys talking about?

Forgive a stupid question, just new to the offroad scene and still trying to learn all the jargon. Got a two sentence explanation for us newbs?

[LittleBeast]

I found a Tire/RPM/Ratio Chart (http://www.jeepfan.com/tech/tirerpmratio.htm) and according to the formula on that site:

60 mph + 5.38 gears + 35" tires = 3098 rpm
60 mph + 4.30 gears + 33" tires = 2627 rpm
60 mph + 4.30 gears + 29.6" tires = 2929 rpm (stock)

70 mph + 5.38 gears + 35" tires = 3615 rpm
70 mph + 4.30 gears + 33" tires = 3065 rpm
70 mph + 4.30 gears + 29.6" tires = 3417 rpm (stock)

You are right though 5.38 gears with a 33" or smaller tire would be crazy!

60 mph + 5.38 gears + 33" tires = 3286 rpm
70 mph + 5.38 gears + 33" tires = 3834 rpm

I know this is a Jeep site so for the VX this formula may be a little different, but it does not look like it mentions anything in the formula that is Jeep specific, anyone know if their formula is correct for the VX:

[(MPH x Drive Ratio)/Tire Diameter] x 336 = RPM of the VX?

Also found this one: http://www.4lo.com/calc/geartable.htm and this looks like the best one: http://www.4lo.com/calc/gearratio.htm

But it looks like we need our transmission ratio and our transfer case ratio to make the formula complete, hmm wonder what those numbers are.....

[VX1032]

Littlebeast

Our trucks came standard with 30" tires and 4.30 gears.

I would say the best thing for us would be the 4.77 gears from an 89-91 trooper with the wide tire option. I am gonna be hitting some junkyards when I get the time to look for those. That would put the 33" back to a little more then stock, which is where I want it. I would love the 5.38s for offroad, but then you can not touch the highway.

VT Maverick

The numbers are differential axle ratios. Our truck has a 4.30 in the differentials. As you get larger tires on the vehicle the truck has to do less revolutions per mile and ultimately you run less RPM on the engine. If you get a numberically higher gear in the differential, the driveshaft has to turn more times to get the wheel to do a revolution. Therefore your rpms go up. Typically, when you start putting larger tires on your truck you can eventually regear it so it drives like it did when it was stock. However, you can go beyond it and have a lot more low end power, but have no top end due to the RPMs it will run. That is the situation with 5.38 in our trucks. You can get a tire to match up to stock (36" I believe) but that is hard to fit in our wheel wells.

***edit: I know what I am talking about here, but did you get it?***

lockers are in the differential and lock each of the axle shafts together. This always provides an even 50/50 torque split on the axle. Normally axles need to move independently of each other to allow cornoring. With a locker, cornoring has a lot of stress on the axle. When they move independently the power goes to the wheel with the least resistence, so if your one wheel is in the air it will get 100% power. Not ideal for offroad driving. Our trucks all have a LSD (limited Slip Differential) which moves some power to the other wheel, but still not ideal. Locker is best.

[vt_maverick]

***edit: I know what I am talking about here, but did you get it?***

Thanks for taking the time to write the detailed explanation! I think I get most of it, but are you saying with the lockers you're literally "locking" it into 4WD ALL the time? And regardless, why are 12 bolts better than 10?

Sorry everyone, not trying to hijack the thread, just learning! -Thx

[LittleBeast]

Alright found some info on our 4L30E transmission:

"Used 1990-up.
There are MANY versions and are used in the Cadillac Catera as well many Foreign vehicles and Postal trucks.
This is a computer controlled overdrive transmission.
Rear cooler line is the cooler return line.
Band adjustments:
Intermediate = not used
Reverse = 5 turns

Optional Gear Ratios:
2.86:1 1st gear
1.62:1 2nd gear
1.00:1 3rd gear
0.723:1 4th gear
2.00:1 reverse"

We have the Borg Warner 4422 transfer case:
http://cobratransmission.blogspot.co...-isuzu-wg.html

[etlsport]

from the VX Knowledge Base link on the side bar of this site

Transmission gear ratios - (:1)
1st: 2.86
2nd: 1.62
3rd: 1.00
4th: 0.72
Rev.: 2.00

Transfer case ratios - (:1)
High: 1.00
Low: 2.48

Axle gear ratios - (:1)
Front: 4.30
Rear: 4.30

[Ldub]

LDub whatever happened here?

This is the only 5.38 they have for the front now:

https://id211.chi.us.securedata.net/...roducts_id=461

So basically this "RD94 ARB Airlocker" works by using copmpressed air to lock and unlock the front end (on this particular product), so when in the "unlocked" position (in daily on road driving) how would this effect handling/drivability?

Would it be stupid to have a ARB Airlocker on the front and rear end?

Unfortunately, I haven't installed mine yet. Summer sort of slipped away...

I'd check with Matt(Indy 4 X) via phone call before getting a setup third with 5:38's...Unless he's been able to get some 5:38's made for the rear 12, you'll have a hard time (if at all) finding matching ratio rear gearing.

IIRC, the only Isuzus that could use 5:38's, were the ones that came with Dana 44's...check it out, I hope I'm wrong.

[VX1032]

Matt is advertising matching 5.38 locked third members with an ARB in the front and an Aussie in the rear. I think they are 1000 and 1700 each.

5.38s were made for the 12 bolt. They were originally from the icelandic troopers, and then he got them made somewhere.

[Ldub]

Matt is advertising matching 5.38 locked third members with an ARB in the front and an Aussie in the rear. I think they are 1000 and 1700 each.

5.38s were made for the 12 bolt. They were originally from the icelandic troopers, and then he got them made somewhere.

Thanks for bringing me up to speed on that, just got back from a look at Indy4X's website...WOW, what a change since the last time I looked!

I just gotta get out more...

[LittleBeast]

I reworked the numbers for our 4th gear (over drive) and got this:
Stock Tire/Stock Diff = 60mph @ 2117rpm and 70mph @ 2470rpm
33" Tire/Stock Diff = 60mph @ 1899rpm and 70mph @ 2216rpm
35" Tire/5.38 Diff = 60mph @ 2241 and 70mph @ 2614rpm

That doesn't sound right but according to the formulas and numbers it should be, oh well, I think the 5.38s with 35"s would work.