Detroit locker with NP229

pcoplin · Post by **pcoplin** » Tue Mar 18, 2014 12:40 pm

I know of weird handling characteristics with the Selectrac NP242 case. What about auto lockers with the NP229?

I have a Detroit I can put in the front 44.

Thanks!

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Post by **Stuka** » Tue Mar 18, 2014 1:02 pm

2wd will be fine. Full time will result in horrible drive ability on the street. As in, turning will be difficult to put it mildly.

Should be fine in back though. That's really where it should go anyway.

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pcoplin · Post by **pcoplin** » Tue Mar 18, 2014 1:16 pm

I don't need 4wd on dry street and not worried about the turning. I know lockers.

On the 242 you can get some front to back ratcheting. Not sure if the 229 does thus also. .

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Post by **Stuka** » Tue Mar 18, 2014 2:30 pm

pcoplin wrote:I don't need 4wd on dry street and not worried about the turning. I know lockers.

On the 242 you can get some front to back ratcheting. Not sure if the 229 does thus also. .

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242's have an open center diff (Except for the grand cherokee version). An NP229 has a viscous coupler. If you are in 2wd mode only, its fine. If you go into full time, things will start binding up badly. Even if you are on dirt you risk damaging the VC. but offroad in low range, it will act like locking the front in any other part time 4wd. You just cannot use high range. NP242's have a 4Hi Lock, so they would be fine in that mode as well. The NP229 does not have a 4Hi Lock.

Still say it should go in back unless you already have the back locked. When climbing a hill the rear tires do the vast majority of the work, so a rear locker is far more effective there. Unless you have IFS, where you are always lifting a tire.

PS: Moving this to offroad tech.

pcoplin · Post by **pcoplin** » Tue Mar 18, 2014 4:11 pm

Good to know. I thought it may be a problem in 4 hi.

I have an LS for the rear 20. Just wanted to recycle the locker out of my TJ when I do gears.

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FSJ Guy · Post by **FSJ Guy** » Tue Mar 18, 2014 4:12 pm

Except for when turning (usually done at low speed), why would there be horrible binding and burning of the viscous coupler? It will be "stressed" when in full time 4WD and turning, with or without a rear locker.

FWIW, I ran a Detroit locker with a full time QT and it did not blow up. (I know, no viscous coupler, but it did have clutches)

Personally, I don't think it would be an issue. I'm not sure about putting in in the front, however.

pcoplin · Post by **pcoplin** » Tue Mar 18, 2014 4:12 pm

Would dual limited slips like the TruTrac work in high range?

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Jeff from Iowa · Post by **Jeff from Iowa** » Thu Mar 20, 2014 8:06 am

In front a Detroit doesn't effect your steering in the least...

The reason you cant turn is from the rear pushing the front, over powering the front tires ability to have traction to turn...unlock your rear wheel drive if you need to see for yourself.

Cecil14 · Post by **Cecil14** » Thu Mar 20, 2014 11:24 am

Jeff from Iowa wrote:In front a Detroit doesn't effect your steering in the least...

The reason you cant turn is from the rear pushing the front, over powering the front tires ability to have traction to turn...unlock your rear wheel drive if you need to see for yourself.

That will hold true as long as the Detroit stays unlocked. As soon as it thinks there's a difference in traction between the left and right wheels and locks good luck. You will NOT be able to steer, period.

aa

pcoplin · Post by **pcoplin** » Thu Mar 20, 2014 7:22 pm

Cecil14 wrote:
Jeff from Iowa wrote:In front a Detroit doesn't effect your steering in the least...

The reason you cant turn is from the rear pushing the front, over powering the front tires ability to have traction to turn...unlock your rear wheel drive if you need to see for yourself.
That will hold true as long as the Detroit stays unlocked. As soon as it thinks there's a difference in traction between the left and right wheels and locks good luck. You will NOT be able to steer, period.

aa

Uhhh...The Detroit doesn't just lock up when it wants to. Only when you are on the throttle. In 2WD it's not apparent at all. In 4WD it works just fine. And will steer just fine.

Cecil14 · Post by **Cecil14** » Thu Mar 20, 2014 7:46 pm

In fulltime 4wd there will be power to the front diff. Drive at your own risk. You may never have a problem, you may always have problems. In a completely part time setup, of course, no issues. I certainly wouldn't risk causing an accident in a fulltime setup, though. Turning requires the wheels to spin at different speeds; exactly what a locker is designed to prevent (while locked).

edit: I'm not trying to argue with you here, simply giving possible problems. Should it ever lock up while you're driving? Obviously not. Will it? Only time can tell there. However, if lockers performed perfectly all the time no one would have bothered engineering a selectable locker. Just food for thought.

Personally I would never compromise safety for a little more traction, but that's very much my own personal opinion.

aa

Post by **Stuka** » Thu Mar 20, 2014 9:07 pm

Every vehicle I have driven with a detroit up front has had steering issues when in 4wd. As you turn, and the front and rear axles bind up (normal operation), the detroit essentially has force being applied to the pinion, this is what causes it to lock. No power, then it it acts like a normal diff.

But I personally would never put an automatic locker into a vehicle with full time 4wd. Or, if I ever had to drive in snow (Which I do). A front locker makes driving in snow a nightmare. The vehicle will not steer where you want it to.

pcoplin · Post by **pcoplin** » Thu Mar 20, 2014 10:52 pm

I have a Detroit in the front of my other Jeep. Every year in snows, and I go snow wheeling. I guess watch out, my Jeep is unsafe.

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will e · Post by **will e** » Thu Mar 20, 2014 10:59 pm

We don't have a popcorn smilely?

jaber · Post by **jaber** » Fri Mar 21, 2014 5:44 am

Post by **Stuka** » Fri Mar 21, 2014 7:25 am

pcoplin wrote:I have a Detroit in the front of my other Jeep. Every year in snows, and I go snow wheeling. I guess watch out, my Jeep is unsafe.

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Wheeling is in no way the same as driving on hard pack on the streets. In deep snow, it is not an issue at all. But on hard pack there is little to no lateral traction. Because traction is low, the detroit does not have enough resistance to unlock. With it staying locked, your vehicle is not going to go where you want it. Even a tight limited slip can cause this when in a front axle.

Heck the detroit in the rear axle of my J10 (and my Cherokee before it) acts goofy on hard pack snow. Its very mild on pavement, but on ice and snow, it bangs and jerks and is actually a bit annoying. Both Jeeps did it, one had a D44, other is an M20.

pcoplin · Post by **pcoplin** » Fri Mar 21, 2014 8:18 am

It also snows on the roads here. It's always been fine for me I guess I have a larger tolerance for an off road rig..

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Post by **Stuka** » Fri Mar 21, 2014 10:30 am

pcoplin wrote:It also snows on the roads here. It's always been fine for me I guess I have a larger tolerance for an off road rig..

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Obviously everybody has their own opinion on what is safe, what is, whats acceptable, what isnt.

For instance I am ok with the quirks my truck has in the snow. But I would NEVER let my Wife drive it in the snow. She would pile it up on the first corner she hit when the back end swings out because of the locker.

When giving advice on these forums, I give advice without knowing that person, what their driving abilities are, and so forth. I also take into account that people may read this post 5 years from now. I do not want some average joe to think throwing a locker in the front axle will have no adverse driving effects, because thats not the case. You and me may be fine with these quirks. But somebody else may be very surprised by them, and it could even result in an accident.

So i stand by my opinion that front lockers can greatly alter the way a vehicle drives when in 4wd mode, and because of this, could result in unexpected handling, especially on low traction surfaces such as hard pack snow and ice.

will e · Post by **will e** » Fri Mar 21, 2014 1:45 pm

Stuka wrote: So i stand by my opinion that front lockers WILL greatly alter the way a vehicle drives when in 4wd mode, and because of this, WILL result in unexpected handling, especially on low traction surfaces such as hard pack snow and ice.

Fixed it for ya. It's just a fact, it will drive different. I have an aussie up front in mine, I have not driven it in the snow but even in the dirt there is a difference. (When I am in 4wd with the front hubs locked). If I am in 2 wheel rear drive it acts the same regardless if the hubs are locked or not.

haminawag · Post by **haminawag** » Wed May 07, 2014 4:54 pm

More, more. I'm learning stuff here, keep it coming please.

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