How to understand the NP 228 combined with frewheel hubs

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dutchjeepdriver
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How to understand the NP 228 combined with frewheel hubs

Post by dutchjeepdriver »

:roll: Dear FSJ enthousiasts,

I have a 1984 Jeep GW with standard NP228 Transfercase. The vacuum system for engaging 4WD and low gear was completely junk, so I removed all vacuum stuff and bought a manual 2-stick shifter. I have changed the front axle by welding the sleeve in fixed position (4WD mode). In addition to that I have mounted locking hubs. Now my idea was to drive the GW generally in 2WD by disengaging the locking hubs, just to save fuel. But when I disengage the Locking hubs the truck drives with a lot of slippage in the driveline. I suspect the viscous coupling causes the slippage. Do I have to drive the 4WD Mode combined with locking hubs in unlock-position to drive 2WD? Anybody who can clear the mystery...Thanx, Marc, The Netherlands

will e
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Re: How to understand the NP 228 combined with frewheel hubs

Post by will e »

Hi and welcome
The 1984 would have probably had either the NP208 or the NP-229, not the np228 which was used in 1986.

How did you determine you have the 228?
81 Waggy 'WILL E' Retired
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Re: How to understand the NP 228 combined with frewheel hubs

Post by dodgerammit »

will e wrote: Sun Feb 26, 2023 1:02 pm Hi and welcome
The 1984 would have probably had either the NP208 or the NP-229, not the np228 which was used in 1986.

How did you determine you have the 228?
THIS^^^^^^^


Yeah, ummm. The 228 will not have a viscous. You should have a 229 as stated.

The absolute LAST thing you want to do is have those hubs unlocked and try to use 4x4. You'll destroy that viscous coupling in very short order. I'd highly recommend you DO NOT install lockout hubs on a FSJ with the 229 case. There's absolutely no need. Add to that, the central axle disconnect (CAD) essentially was already acting as lockouts. I recommend locking that in permanently by sliding the collar into the correct spot, then moving the fork over to the engaged position, then locking it there via the hose and clamp mod (Not welding because you may need to disassemble something in the future), and rerouting the vacuum control to operate only the case engagement.

The fuel savings idea with lockouts is a fallacy. If you want to save fuel with these, you do so via your right foot. Or swap the engine with a modern one.
84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

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Re: How to understand the NP 228 combined with frewheel hubs

Post by sierrablue »

I disagree with the statement about locking hubs. They do save a little fuel (if you don't believe me, drive it exactly the same way with the hubs locked and unlocked, and do the math on the mileage. I guarantee that it's better unlocked), but they also cut down on driveline vibrations (spinning 2 u joints vs spinning 7 u joints), and make it drive more like a normal rwd car on the street, because there's nothing linking the front wheels to each other. It's quieter and easier on your equipment. If you have them on, just leave them on, and just keep track/remember whether they're locked or not.

Also, yes I agree on the disconnect being effectively locking hubs. I totally understand why you got rid of it--those things are a royal pain.

If you're having driveline slippage like that, one of two things is probably happening. Number one, when you have the hubs locked and have it in 4wd, you don't notice the slop that the rear end has because the front hides it, but your slop is always there (either an issue inside the tcase or bad u joints, could be the rear diff/ring and pinion, too). Or two it's not truly coming out of 4wd and is trying to spin the front end, in which case you're doing what dodgeramit said burns out the viscous.

Disclaimer--I can't speak for the NP229 specifically, this is merely what I know about drivetrains and how 4wd works. Either power is still going to the front and it shouldn't be, or there is a lot of slop somewhere where there shouldn't be in the rear end. If someone swapped in a 228, same things applie, main difference is the 229 is the viscus limited slip style and the 228 is open.

By your comment about disengaging the hubs to make it 2wd, it sounds like you're leaving it in 4x4 when you do that, and the tcase would be trying to send power to the front because that's what has the least amount of traction. And that would cause weird slop and things to happen.
'71 Wagoneer (DD)
-B350 (HEI, iron 4-barrel, Edelbrock 1406), TH400, D20
-'74 D44 front (nonpower discs)
-custom headliner
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There are 2 major differences between new Wranglers and FSJs. FSJs are meant to be both utilitarian and capable, not just capable. FSJs are also rarely initially recognized as Jeeps by the average American.
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Re: How to understand the NP 228 combined with frewheel hubs

Post by Stuka »

Unlocking the hubs is about saving wear on the front end, not saving fuel. Even modern vehicles that have to meet strict fuel economy standards do not have locking hubs.

However, if it feels like it is slipping, it means it is not in 2wd. It means it is in 4wd High. And the slippage feeling means you have a 229 (which is correct for that year). A 228 would feel like you were in neutral.

As you replaced the vacuum with a mechanical shifter, it sounds like the cable adjustment may be off. The shifter may indicate you should be in 2wd, but its likely in 4wd while in that position. 4wd REQUIRES the front hubs to be locked.
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Re: How to understand the NP 228 combined with frewheel hubs

Post by dodgerammit »

sierrablue wrote: Sun Feb 26, 2023 2:51 pm I disagree with the statement about locking hubs. They do save a little fuel (if you don't believe me, drive it exactly the same way with the hubs locked and unlocked, and do the math on the mileage. I guarantee that it's better unlocked), but they also cut down on driveline vibrations (spinning 2 u joints vs spinning 7 u joints), and make it drive more like a normal rwd car on the street, because there's nothing linking the front wheels to each other. It's quieter and easier on your equipment. If you have them on, just leave them on, and just keep track/remember whether they're locked or not.
Disagree all you want.

I did the math. On these rigs, the difference is nil. My front CAD is locked in now and I get no difference in economy. This was with the AMC motor. Same before and after. Again, if you're concerned with economy, a: you're driving the wrong vehicle, and b: train your right foot to be gentle with the throttle application. That made all the difference in mine.

Also, these rigs ride very smooth and have no vibrations due to case design (full time with differential).

As long as you're in 2wd at the case, they drive exactly like a normal 2wd car on the street regardless. They are unlinked with an open diff in both the axle and the case.

As Stuka mentioned. If it actually made a difference on economy, every new 4wd vehicle would have lockout hubs.
84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

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Re: How to understand the NP 228 combined with frewheel hubs

Post by sierrablue »

The hubs are irrelevant to the question, which is a problem with the tcase.
'71 Wagoneer (DD)
-B350 (HEI, iron 4-barrel, Edelbrock 1406), TH400, D20
-'74 D44 front (nonpower discs)
-custom headliner
-Front shoulder belts (rears eventually)

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There are 2 major differences between new Wranglers and FSJs. FSJs are meant to be both utilitarian and capable, not just capable. FSJs are also rarely initially recognized as Jeeps by the average American.
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Re: How to understand the NP 228 combined with frewheel hubs

Post by dodgerammit »

sierrablue wrote: Sun Feb 26, 2023 4:50 pm The hubs are irrelevant to the question, which is a problem with the tcase.
Seriously?

Literally in the post title itself.

It is very relevant since, if the case is engaged and the hubs are unlocked irreversible damage will happen to the silicone fluid filled coupler. That coupler is unavailable. Once it's done, the main feature of the 229 is done.
84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

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Re: How to understand the NP 228 combined with frewheel hubs

Post by sierrablue »

Yes, the question was if those were the problem, and what the problem was. If the stock vacuum disconnect were still there the EXACT same problems would come up. The hubs aren't the problem, they just show the symptoms.
'71 Wagoneer (DD)
-B350 (HEI, iron 4-barrel, Edelbrock 1406), TH400, D20
-'74 D44 front (nonpower discs)
-custom headliner
-Front shoulder belts (rears eventually)

viewtopic.php?t=23070

There are 2 major differences between new Wranglers and FSJs. FSJs are meant to be both utilitarian and capable, not just capable. FSJs are also rarely initially recognized as Jeeps by the average American.
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Re: How to understand the NP 228 combined with frewheel hubs

Post by tgreese »

Guys, our Dutch friend has not been back since he first posted. When he returns (ca 6 hours ahead of us), I hope he can extract a direct answer from your replies.

If you want to debate the merits of locking hubs, you could start another thread.

My understanding -

1) a NP228 uses an open differential and does not include a viscous coupler.
2) an '84 would have a NP229, which does use a viscous coupler.
3) adding locking hubs (free-wheeling hubs) to a NP229 equipped Jeep will ruin the transfer case.

To dutchjeepdriver, welcome from Boston MA USA. First post!
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Re: How to understand the NP 228 combined with frewheel hubs

Post by sierrablue »

tgreese wrote: Mon Feb 27, 2023 9:28 am Guys, our Dutch friend has not been back since he first posted. When he returns (ca 6 hours ahead of us), I hope he can extract a direct answer from your replies.

If you want to debate the merits of locking hubs, you could start another thread.

My understanding -

1) a NP228 uses an open differential and does not include a viscous coupler.
2) an '84 would have a NP229, which does use a viscous coupler.
3) adding locking hubs (free-wheeling hubs) to a NP229 equipped Jeep will ruin the transfer case.

To dutchjeepdriver, welcome from Boston MA USA. First post!
You said what I was trying to say in my last post, only better.

Also, the locking hubs will only hurt anything if you try to run it in 4x4 w/o unlocking the hubs. It sounds like the 228/229 they have isn't going into 2wd since the mechanical shifter was installed. Thus it's the tcase that is the problem, and the hubs are irrelevant. If the vacuum disconnect were still functional, they'd be fighting the EXACT same issue.

As tgreese said, welcome! Sorry for my part into turning this into a mess to understand.
'71 Wagoneer (DD)
-B350 (HEI, iron 4-barrel, Edelbrock 1406), TH400, D20
-'74 D44 front (nonpower discs)
-custom headliner
-Front shoulder belts (rears eventually)

viewtopic.php?t=23070

There are 2 major differences between new Wranglers and FSJs. FSJs are meant to be both utilitarian and capable, not just capable. FSJs are also rarely initially recognized as Jeeps by the average American.

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Re: How to understand the NP 228 combined with frewheel hubs

Post by will e »

sierrablue wrote: Mon Feb 27, 2023 10:47 am

Also, the locking hubs will only hurt anything if you try to run it in 4x4 w/o unlocking the hubs.
Did you mean 'w/o LOCKING the hubs'?


My thoughts. We probably need to give our Dutch friend a chance to answer a few of the questions before giving definitive advice. We really are not certain which transfer case he has. My 82 came with a NP-219. I swapped in a NP208. Didn't even bother to change the flag shifter. I can imagine what might happen to one in Europe where spare parts are even harder to find.
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

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Re: How to understand the NP 228 combined with frewheel hubs

Post by sierrablue »

No, I mean WITH locking hubs, if you run it in 2wd, it shouldn't be a problem. If there's no power going through the front driveline, there's no reason you need to have the wheels connected to the axle shafts. Now, if it's not going into 2wd when they want it to, then you have problems.
'71 Wagoneer (DD)
-B350 (HEI, iron 4-barrel, Edelbrock 1406), TH400, D20
-'74 D44 front (nonpower discs)
-custom headliner
-Front shoulder belts (rears eventually)

viewtopic.php?t=23070

There are 2 major differences between new Wranglers and FSJs. FSJs are meant to be both utilitarian and capable, not just capable. FSJs are also rarely initially recognized as Jeeps by the average American.
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Re: How to understand the NP 228 combined with frewheel hubs

Post by dutchjeepdriver »

Dear All,

thanks so much for all valuable information. It might be it is a NP 229, I will double check!

best regards, Marc (www.insane-cardoctor.com (in Dutch language only for this moment)
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Re: How to understand the NP 228 combined with frewheel hubs

Post by dutchjeepdriver »

In addition to the "thanks", I only drove a short distance with the hubs in unlock position and normal 2WD (What is 2WD? In fact it is all-time 4WD with an unlocked third diff, which I assume it is the viscous coupling). So hopefully my viscous coupling is not burned. I am not going to change anything anymore on the front axle, just keeping the Freewheelhubs in "locked". I was considering to change the NP229 for the NP208. Before this great truck I had a 1984 Ramcharger with a NP 208 TC. With the Ram you could run just 2WD with unlocked hubs, and less noise and unnecessary rotating parts.

Again, thanx to all!!

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Re: How to understand the NP 228 combined with frewheel hubs

Post by will e »

Let us know what you find! It can't hurt to run with the hubs locked.
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

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Re: How to understand the NP 228 combined with frewheel hubs

Post by will e »

sierrablue wrote: Mon Feb 27, 2023 11:25 pm No, I mean WITH locking hubs, if you run it in 2wd, it shouldn't be a problem. If there's no power going through the front driveline, there's no reason you need to have the wheels connected to the axle shafts. Now, if it's not going into 2wd when they want it to, then you have problems.
Okay, maybe I misunderstand, or perhaps you are not being clear. You wrote:
sierrablue wrote: Mon Feb 27, 2023 10:47 am
You said what I was trying to say in my last post, only better.

Also, the locking hubs will only hurt anything if you try to run it in 4x4 w/o unlocking the hubs. It sounds like the 228/229 they have isn't going into 2wd since the mechanical shifter was installed. Thus it's the tcase that is the problem, and the hubs are irrelevant. If the vacuum disconnect were still functional, they'd be fighting the EXACT same issue.

As tgreese said, welcome! Sorry for my part into turning this into a mess to understand.
I read this as 'The locking hubs will only hurt anything if you try to run it in 4x4 (four wheel drive) w/o (with out) unlocking the hubs'.

'Without unlocking the hubs' means the hubs are not locked.

This is opposite of my understanding of how the hubs should be set (locked or unlocked) when in 4x4 (four wheel drive). By 'unlocking the hubs' the tire and wheel are not connected to the shaft. They spin independently. If they are selectable hubs don't you want them locked when you are in 4x4 (four wheel drive)?
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

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Re: How to understand the NP 228 combined with frewheel hubs

Post by sierrablue »

You're right I worded that wrong. The hubs should be locked in 4x4 and can be unlocked in 2. Sorry for the confusion.
'71 Wagoneer (DD)
-B350 (HEI, iron 4-barrel, Edelbrock 1406), TH400, D20
-'74 D44 front (nonpower discs)
-custom headliner
-Front shoulder belts (rears eventually)

viewtopic.php?t=23070

There are 2 major differences between new Wranglers and FSJs. FSJs are meant to be both utilitarian and capable, not just capable. FSJs are also rarely initially recognized as Jeeps by the average American.

will e
Posts: 5096
Joined: Sat Aug 18, 2012 8:21 am

Re: How to understand the NP 228 combined with frewheel hubs

Post by will e »

sierrablue wrote: Tue Feb 28, 2023 2:46 pm You're right I worded that wrong. The hubs should be locked in 4x4 and can be unlocked in 2. Sorry for the confusion.
No worries, I sometimes typo stuff too. My fingers get ahead of my brain. ;)

The important thing is that it's clarified for folks who have a bit less experience. Take care!
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

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Re: How to understand the NP 228 combined with frewheel hubs

Post by sierrablue »

dutchjeepdriver wrote: Tue Feb 28, 2023 10:56 am In addition to the "thanks", I only drove a short distance with the hubs in unlock position and normal 2WD (What is 2WD? In fact it is all-time 4WD with an unlocked third diff, which I assume it is the viscous coupling). So hopefully my viscous coupling is not burned. I am not going to change anything anymore on the front axle, just keeping the Freewheelhubs in "locked". I was considering to change the NP229 for the NP208. Before this great truck I had a 1984 Ramcharger with a NP 208 TC. With the Ram you could run just 2WD with unlocked hubs, and less noise and unnecessary rotating parts.

Again, thanx to all!!
This is just my understanding of the 229--I could be totally wrong. What you described should be the 4wd high setting, but it should have 2wd (i.e. power going exclusively to the rear wheels) available too, and it sounds like you're not getting that. As Stuka said previously this seems like the new shifters are out of alignment. Are you sure you're getting all of your options? You should have 2 hi (rear wheels only), 4 hi (in your case, full time with a viscous limited slip between the front and rear wheels), N (no power anywhere), and 4 lo (front and rear locked together, and an underdrive so the wheels go less distance for every rev of the engine). Does all this sound right?
'71 Wagoneer (DD)
-B350 (HEI, iron 4-barrel, Edelbrock 1406), TH400, D20
-'74 D44 front (nonpower discs)
-custom headliner
-Front shoulder belts (rears eventually)

viewtopic.php?t=23070

There are 2 major differences between new Wranglers and FSJs. FSJs are meant to be both utilitarian and capable, not just capable. FSJs are also rarely initially recognized as Jeeps by the average American.
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