Locker questions ?????

[jeepcoma]

Amatuer opinion ahead, to not be taken as fact. Semi-educated guesses below:

 

My only thought is that the caution is really intended for vehicles that do not have selectable 4wd and are permanently in their 4x4 mode. In general, those types of 4x4 systems are not quite "heavy duty" and are lighter weight, smaller, and not intended for "serious" off-road use. Those that are operated by a viscous coupling (or clutches or whatever) to differentiate power front and rear will send some power to slipping wheels, but not all of it, so by locking the front you'd be putting a lot more stress on the tcase differentiation (since it can no longer choose to distribute power between FR and FL but instead is forced to split it 50/50) which could lead to a lot of heat buildup and premature failure. Additionaly, and I think more importantly, even with regular driving where 4x4 is not needed, the front will not differentiate when turning (if power is applied), which forces the tcase's viscous coupling to act as the differential, something it's not designed to do.

[JACKED88]

OK, so I'd be better off with a 231 t/c intended for offroad use only. That suits me just fine since I'll likely never need 4x4 on tha streets. The only time I might need 4x4 on pavement would be to pull my boat up a boat ramp.

 

I'm thinkin Aussie in tha front and a Trutrac in tha rear would be tha best setup for my application. While in 2x4 I'll maintain near stock driveabilty on tha street but have tha advantage of a locked front for offroad 4x4 use.

[Blue XJ]

For the cross pin issue....

 

Even with 4.56 gears you have to grind down a couple teeth on the ring gear to get the cross pin installed. The gear set is rather thick and it blocks access to the hole in the carrier. I have a set of previously installed 4.56 gears sitting on my work bench, I'll grab a pic of the ground gears for you tomorrow.

[JACKED88]

For the cross pin issue....

 

Even with 4.56 gears you have to grind down a couple teeth on the ring gear to get the cross pin installed. The gear set is rather thick and it blocks access to the hole in the carrier. I have a set of previously installed 4.56 gears sitting on my work bench, I'll grab a pic of the ground gears for you tomorrow.

Thanks!!! I appreciate all the info and tips I an git. That'll come in very helpful prior to my distroying a perfectly good set of gears. :wall:

Naaa, I'm actually pretty good with a wrench and having been a machinest for about 15 years I'm pretty sure I can grind down a few teeth for clearances.

As for seting up tha ring and pinion, I'm pretty sure I can do it. (along with a little help from something we as men would NEVER git caught looking at much less reading. I think their called INSTRUCTIONS. :???: :rotf:

[mvusse]

I don't see the problem. Why clearance teeth on the ring gear to allow the cross shaft to fit by. Install the cross shaft, THEN bolt the ring gear on. No grinding necessary.

 

What am I missing?

[JACKED88]

I don't see the problem. Why clearance teeth on the ring gear to allow the cross shaft to fit by. Install the cross shaft, THEN bolt the ring gear on. No grinding necessary.

 

What am I missing?

I don't git it either but we're obviously missing something. I've read it has to be done on several diff builds and on least two gear manufactorers web sites.

All I can figure is it has to do with properly setting up tha ring and pinion gears. I think they have to be set up before you can install tha spider gears or a locker.

[Eagle]

However, if I wanted to go with an Aussie in tha front and a LSD in tha rear, who's LSD works/is tha best?

From what I read, Auburn, Eaton and Detriot appear to be tha top three. Oddly enough, each of those are designed differently. Auburn/cone driven, Eaton/clutch driven and Detroit/gear driven. Which is better, cone, gear, or clutch?

I kinda like tha Auburn but I'm not so sure about their steel or steel cone design. Same for tha gear driven Detroit. Two steel surfaces sliding/slipping against each other sounds like they'd be prone to getting hot and galding. (regaurdless of lube) Clutches on the other hand were designed to slide/slip against each other. Maybe with all tha new technology those steel on steel units are OK but we all know that clutches have been well proven to work and last for years.

Clutch types, whether it's the Auburn cone-shaped clutch or the Trac-Lok flat type clutch, wear out. If used for serious wheeling, "lasting for years" might be two years. Trac-Locs (Dana-Spicer) can be rebuilt. There is no rebuild for the Auburn, except to ship it back to the factory and pay them to refurbish it. I don't know anything about the Eaton.

 

The Detroit True Trac never wears out. It doesn't require any friction modifiers to the gear lube. I don't understand your concern about steel sliding against steel -- what do you think the ring gear and pinion gear are doing? I have Trac-Lok in all my XJs and a True Trac in the '88 MJ. The True Trac is smooth on pavement, but much more positive in engagement when needed. You're not supposed to use it with anything larger than 32" tires, but 33s might be okay. Larger tires are also very tough on clutch-type LSDs.

[Eagle]

Here's something I read about lockers and have a question about .......

"Automatic lockers cannot be used in front axles of constant 4Wheel Drive vehicles. Some vehicle manufacturers offer a part-time 4WD option and automatic lockers can be installed."

OK ..... so does that mean while offroad you can't run in full-time 4WD inwhich allows tha front and rear axles to turn at different speeds? If so, tha full-time 4x4 capability of a 242 t/c is then rendered unuseable and or worthless.

Is that discussing a locking differential in the front, or automatic locking HUBS on the front axle?

 

My only thought is that the caution is really intended for vehicles that do not have selectable 4wd and are permanently in their 4x4 mode. In general, those types of 4x4 systems are not quite "heavy duty" and are lighter weight, smaller, and not intended for "serious" off-road use. Those that are operated by a viscous coupling (or clutches or whatever) to differentiate power front and rear will send some power to slipping wheels, but not all of it, so by locking the front you'd be putting a lot more stress on the tcase differentiation (since it can no longer choose to distribute power between FR and FL but instead is forced to split it 50/50) which could lead to a lot of heat buildup and premature failure. Additionaly, and I think more importantly, even with regular driving where 4x4 is not needed, the front will not differentiate when turning (if power is applied), which forces the tcase's viscous coupling to act as the differential, something it's not designed to do.

The Jeep 242 transfer case uses a mechanical differential for the full-time mode, not a viscous coupling. And it certainly is designed to act as a differential. On pavement, whether the front axle is locked or not, around corners the front wheels swing a wider radius and travel farther than the rear wheels. They put the differential in the transfer case specifically to allow for that. Viscous couplings, for those cases that use them, are for the same purpose. Locking the front axle does not "force" the transfer case to split 50/50 if it has a differential or a viscous coupling.

[jeepcoma]

The Jeep 242 transfer case uses a mechanical differential for the full-time mode, not a viscous coupling. And it certainly is designed to act as a differential. On pavement, whether the front axle is locked or not, around corners the front wheels swing a wider radius and travel farther than the rear wheels. They put the differential in the transfer case specifically to allow for that. Viscous couplings, for those cases that use them, are for the same purpose. Locking the front axle does not "force" the transfer case to split 50/50 if it has a differential or a viscous coupling.

 

Right, but the 242 is not a permanent "full time" 4x4 system like I was referring to, it's selectable. I was thinking more along the lines of "all wheel drive" systems like the Subaru that are designed for road use more than off-road. I'm not all that knowledable about Subarus but I think the older models were primarily FWD, with torque going to the rear wheels in low traction situations.

 

I would not hesitate using a 242 with a locked front and rear (in fact I'm hoping to swap one in this summer).

[Blue XJ]

I don't see the problem. Why clearance teeth on the ring gear to allow the cross shaft to fit by. Install the cross shaft, THEN bolt the ring gear on. No grinding necessary.

 

What am I missing?

I don't git it either but we're obviously missing something. I've read it has to be done on several diff builds and on least two gear manufactorers web sites.

All I can figure is it has to do with properly setting up tha ring and pinion gears. I think they have to be set up before you can install tha spider gears or a locker.

 

 

Its a c-clip axle. You have to put the shafts in to get the c clips in, which means the carrier needs to be installed in the axle at that time, so the gear has to go on it first.

 

I forgot to take a picture today, :doh: I'll snap one tomorrow for you. :thumbsup:

[JACKED88]

 

My concern about metal on metal was for the exact reasons you pointed out. It wears out.

I git your point about tha r&p gears basicly doing tha same thing but somehow I see tha frictional forces applied to tha clutches and or cones somewhat differently. Hence tha reason they wear out faster than a set of r&p gears.

Since that post I've learned a little more about tha True Trac and understand a little better how its design and tha way it operates would prevent it from wearing out like either of the other two LSD's mentioned.

As for flat clutches, I would have thought they'd last longer than a couple of years. Paticularly in my case since I don't do hard core offroading. Wasnt it a flat clutch design we ran in all of our 70's muscle cars and trucks that practicly lasted for tha life of tha vehicle? :hmm:

 

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"Is that discussing a locking differential in the front, or automatic locking HUBS on the front axle?"

 

:dunno: I don't remember. I think it was saying you couldnt run auto lockers in tha front axle of constant 4Wheel Drive vehicles unless you had manual hubs. ?????

I looked but couldnt find where I read about it. I'll look more later and update if I find it.

 

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Let me be sure I've got this streight .......... You CAN run a 242 t/c in Full-Time 4 wheel drive with a locker in tha front axle. Right???

Are there any exceptions or precautions that should be taken when doing so?

[mvusse]

I don't see the problem. Why clearance teeth on the ring gear to allow the cross shaft to fit by. Install the cross shaft, THEN bolt the ring gear on. No grinding necessary.

 

What am I missing?

I don't git it either but we're obviously missing something. I've read it has to be done on several diff builds and on least two gear manufactorers web sites.

All I can figure is it has to do with properly setting up tha ring and pinion gears. I think they have to be set up before you can install tha spider gears or a locker.

 

 

Its a c-clip axle. You have to put the shafts in to get the c clips in, which means the carrier needs to be installed in the axle at that time, so the gear has to go on it first.

 

I forgot to take a picture today, :doh: I'll snap one tomorrow for you. :thumbsup:

 

Doh!

 

I did know that. For some reason I was thinking D30 front axle, which does have a C clip on the disco side, but that clip is optional.

[JACKED88]

I don't see the problem. Why clearance teeth on the ring gear to allow the cross shaft to fit by. Install the cross shaft, THEN bolt the ring gear on. No grinding necessary.

 

What am I missing?

I don't git it either but we're obviously missing something. I've read it has to be done on several diff builds and on least two gear manufactorers web sites.

All I can figure is it has to do with properly setting up tha ring and pinion gears. I think they have to be set up before you can install tha spider gears or a locker.

 

 

Its a c-clip axle. You have to put the shafts in to get the c clips in, which means the carrier needs to be installed in the axle at that time, so the gear has to go on it first.

 

I forgot to take a picture today, :doh: I'll snap one tomorrow for you. :thumbsup:

CRA-P!!! I was wrong again? :wall: That makes twice ............. this year. :rotf:

 

 

 

How tha hell do yall put multiple quotes in one reply??? :dunno:

[Eagle]

As for flat clutches, I would have thought they'd last longer than a couple of years. Paticularly in my case since I don't do hard core offroading. Wasnt it a flat clutch design we ran in all of our 70's muscle cars and trucks that practicly lasted for tha life of tha vehicle?

I have no idea what you ran on your muscle car, but if it was a clutch-type LSD I'll guarantee you it didn't last the life of the car ... unless the life of the car was less than two years.

 

The original Trac-Lok on my '88 Cherokee (which I bought new) lasted a bit over 100,000 miles. The thing is, you can't tell it's worn out. There are no grinding noises or anything. It just stops being a LSD and operates like a normal, open differential. I knew mine was bad when I couldn't get up a snowy hill in 4WD. My friend the former AMC service manager added some shims to it, and that got me another 25,000 miles or so. But by then I was active in NAXJA and doing more wheeling. I finally replaced it at somewhere around 175,000 miles. Since Paragon closed and Connecticut is cracking down on wheeling in the state forests, I'm not getting off-road much so the new one is still holding up ... but it's probably not as aggressive as it was when it was first installed.

 

Back when I was racing Javelins and AMXs, the stock LSD couldn't stand up to wide tires and big V8s. Everyone who was at all serious about performance took it out and installed a Detroit Locker.

 

By contrast, the True Trac in the '88 Comanche is still just as positive as it was the day it was installed. And I've probably wheeled that harder than I ever wheeled the XJ.

 

Let me be sure I've got this streight .......... You CAN run a 242 t/c in Full-Time 4 wheel drive with a locker in tha front axle. Right???

Are there any exceptions or precautions that should be taken when doing so?

Yes, you can. But you have to be aware that, just like a front wheel drive car, if you run with a locker in 4WD the front is going to tend to "push" in a straight line rather than turn corners in slippery conditions. If you normally drive "aggressively" ... don't do it. If you're willing to slow down and pay attention to the road and your vehicle in "iffy" conditions, running a front locker with full-time 4WD should be no big deal.

[JACKED88]

Yes, you can. running a front locker with full-time 4WD should be no big deal.

 

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Thanks. Thats what I though. Based on that article I read, I just wanted to be sure instead of finding out tha hard way.

[Blue XJ]

Here are the pics of the tooth that needs to be ground down to fit the cross pin into the carrier. These are Yukon 4.56 gears on a stock carrier.

 

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My last set of 4.56's needed to have a little more material ground off to get the pin past, they were also Yukons.

[JACKED88]

Thank you. Great pix. I would have scared to death removing that much material off one of those teeth had I not seen it for myself.

 

Couldnt you do tha same thing by remove half as much material off of the front of one tooth and tha back of another? In doing so make use of the space in between tha teeth for additional clearance.

[Blue XJ]

I guess you could, but it depends on how the ring gear bolts on. This one required that tooth to be removed, since it lined up directly with the cross pin.

 

I am pretty sure they sell notched cross pins as well, but I don't think they are as strong.

 

edit: here's the pin

 

http://www.summitracing.com/parts/RMG-80-0278-1/

[JACKED88]

I guess you could, but it depends on how the ring gear bolts on. This one required that tooth to be removed, since it lined up directly with the cross pin.

 

I am pretty sure they sell notched cross pins as well, but I don't think they are as strong.

 

edit: here's the pin

 

http://www.summitracing.com/parts/RMG-80-0278-1/

:doh: I forgot to take into consideration the alignment of tha teeth to tha hole not really being optional once its bolted on. Maybe before tha gear is bolted on you could rotate it around on its bolt circle and check for tha best alignment of teeth to be ground.

I agree on that notched pin not looking as strong. On tha flip side I can't say I care much for having to grind a quarter or more of one of my gears/teeth off either.

[Blue XJ]

I think its better to remove the top portion like in the pictures than part of the front and rear faces. If you remove part of the face, when the gear comes around and tries to make contact with the pinion there wouldn't be material there for it to contact. The ring gear might 'slip' a little until it makes contact, then when the next tooth comes around it might not mesh properly.

 

If that makes sense.

[Pete M]

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regardless of how scary it may look, the above procedure has a great track record. :thumbsup:

[JACKED88]

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regardless of how scary it may look, the above procedure has a great track record. :thumbsup:

If thats been proven to be tha best way then thats tha way I'll do it. :thumbsup: