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View Full Version : 229 no LS/locker


Blackjack
02-11-2003, 09:32 AM
OK here's a question, NO I didn't do an exhaustive search, actually I'm also padding my post count.........but I digress:

I read somewhere that running a locker or any sort of LS on a NP 229 is not a good idea. If this is true I'd assume it's cause of the viscous coupler. Question is WHY :confused:
Get technical I can handle it, I'm trying to learn as much about this TC as I can.

TIA ;)

Marc

porchpiggy
02-11-2003, 10:49 AM
I don't see any reason not to run a locker or LS on the back of a 229 equipped truck, I think where all the mis information is coming from is that a locker on the front of ANY full time 4wd rig ( or for that matter, any with a constantly turning front axel) will result in very poor road manners, and the lack of turning ability.

Mud Thrasher
02-11-2003, 12:42 PM
Correct me if I'm wrong but doesn't all Fsj come with LS front and rear?

Blackjack
02-12-2003, 06:40 AM
porchpiggy, thanks for your reply!
Mudthrasher, that's not the case.

Anyone else got any info on this?

Thanks

FrankenJeep
02-12-2003, 06:49 AM
A problem with an 83 NP229 and a locker is the vacuum disconnect. The Dana 44 vacuum operated front uses the principle of an open differential to disconnect from the transfer case. It disengages on axle shaft from one side (the driver's side IIRC) and the other stops spinning also. If you install a Lim-Slip or Locker, there will always be "power" supplied to the other half shaft and it will always spin the front drive shaft.

Come to think about it, this is essentially what the 85/UP Dana 44's do anyway without the vacuum disconnect. If a LS will fit inside the vacuum pumpkin, then the fork that disengages the half-shaft will eliminate the mechanical connection between the front wheels.

The only down side that I can think of is the front drive shaft will always turn, but this is how the late model GW's work from the factory. I don't think there will be any undue wear since once side will be mechanically disconnected and therefore shouldn't be causing undue loading on the LS clutches.

Hmmm ... you've given me something to think about.

You could also look into an ARB or Eaton unit. Though they may not fit inside a Vacuum Disconnect axle.

Hope this helps ...

[ February 12, 2003, 01:56 PM: Message edited by: FrankenJeep ]

Iron Horse
02-12-2003, 07:04 AM
My 87 has an NP229 and a L/S rear....from the factory. Part of the optional "tow package".

rustywag
02-12-2003, 08:49 AM
I'm thinking GFD was referring to a LSD for the rear. I have similar concerns given that I have an 87 G-wag with the same x-fer case. My thought is that if the LSD (viscous coupling) in the X-fer case is torque biased then the addition of additional rear torque throught the input/effect of two tires with an LSD versus one without a LSD in the rear may upset the torque biasing operations of the T/C VC. I have never heard/seen a discussion of this potential I just kinda dreamed it up on my own. I suppose input from others who have added LSD's to the rears of these T/C equipped FSJ's would prove most beneficial. Especially if they had coupling failures after installation of LSD's. Additionally, if we were to learn that the viscous coupler was different for vehilces with/without factory limited slips it would tell us something.

Mud Thrasher
02-12-2003, 12:56 PM
My 88 wag came with the tow package I think. So are you saying that if I have the tow package that it would have the LSD in it?

Blackjack
02-13-2003, 12:52 AM
Originally posted by rustywag:
I'm thinking GFD was referring to a LSD for the rear... My thought is that if the LSD (viscous coupling) in the X-fer case is torque biased then the addition of additional rear torque throught the input/effect of two tires with an LSD versus one without a LSD in the rear may upset the torque biasing operations of the T/C VC......Rustywag has hit the nail on the head, this is exactly what I was reffering to but didn't state so well in my original post.
I know that this was discussed previously but a while ago.
Someone must know the answer....-joe or BobBarry you out there?????????

Thanks guys

Iron Horse
02-13-2003, 01:37 AM
Originally posted by Mud Thrasher:
My 88 wag came with the tow package I think. So are you saying that if I have the tow package that it would have the LSD in it?Not all factory tow package GW's had the LSD in the rear....it was an option.

scotty
02-13-2003, 02:28 AM
Originally posted by GFD:
</font><blockquote>quote:</font><hr />Originally posted by rustywag:
I'm thinking GFD was referring to a LSD for the rear... My thought is that if the LSD (viscous coupling) in the X-fer case is torque biased then the addition of additional rear torque throught the input/effect of two tires with an LSD versus one without a LSD in the rear may upset the torque biasing operations of the T/C VC......Rustywag has hit the nail on the head, this is exactly what I was reffering to but didn't state so well in my original post.
I know that this was discussed previously but a while ago.
Someone must know the answer....-joe or BobBarry you out there?????????

Thanks guys</font>[/QUOTE]it will be just fine. the torque biasing qualities of the 229s viscuous coupling cneter diff will not be affected by the addition of a welded,locked,or limited slipped rear diff. or a front diff,for that matter if you want to add lockouts and forget about ever using full time 4x on pavement again.

think of it like an axle diff. each drivesahft is like the axlesahft that goes to a wheel. when slippage at either side occurs,plates have to shear thru the silicone filled coupling,thus limiting the slip from one shaft to the other.

granted,it is slightly different since there is a diff at the end of each "axlesahft",but that doesnt really matter, as far as the transfer case is concerned. when the one drivesahft starts pinnning faster than the other,the viscuous cupling does not know or care if both wheels at the end of that shaft are spinning,or jsut one. its job is to try and keep the driveshaft speeds front/rear the same.

further,while locked in low range,the 229 is like any other part time case,so a traction device at either or both axles wont be any different.

in 2wd,you will have to have lockouts to retian turnability on the street,but other than that, you can run a full time rig off road with a locker in both axles.again,the xfer case keeps the drivesahft speeds the same,and it does not care that both wheels are spinning on both axles.

ok,now for the downside: if you add lockouts to a 229 equipped rig,you gotta be very careful not to engage 4hi with the hubs unlocked,as the front drivesahft will spin out alot of the power-just as the limited slip in a rear axle would do if you lifted a tire off the ground. a v/c in good shape will actually move the rig with hubs unlocked. however,it will only do so for a short period of time before expensive damage has been done.

the 229 is a good case for street driving,and if you want to add a lsd to the rear,fear not it will not hurt anything.

for a hardcore trail rig,however,while it is possible to run front/rear lockers i wouldnt advise it,as the case is not kown for its ability to withstand lots of abuse,and you cannot limp home onthe front drivesahft in the event of rear breakage,unless youre close enuff to drive there in 4lo :eek:

my $.02 anyway smile.gif

other than that,why do you have to "pad your post count"? we are not pirate 4x4-over here we do not care if you have 10 posts or 10,000.

id reccomend doing a search,as you will prolly come up with other good info that want mentioned here smile.gif since some of us here have answered these questions many times,we prolly do not answer them as thoruoughly as we did the first time.

[ February 13, 2003, 09:31 AM: Message edited by: scotty ]

Blackjack
02-13-2003, 02:46 AM
Scotty,
Thanks alot for that reply, that was the kind of info I was looking for and could'nt come up with in a search.

Originally posted by scotty:
other than that,why do you have to "pad your post count"? we are not pirate 4x4-over here we do not care if you have 10 posts or 10,000.
[/QB]Scotty,
I was replying tongue in cheek to this post (http://www.ifsja.org/ubb/ultimatebb.php?ubb=get_topic;f=3;t=010071) . You probably haven't read the whole thing, but it's a pretty long thread about padding post counts and the like.
Don't get me wrong...I in no way am interested in padding my post count. As you can see I've been a member for almost two years and haven't even hit 1000 yet ;)

scotty
02-13-2003, 02:56 AM
ahhh,i gotcha smile.gif indeed,i hadnt read that post.

at any rate,glad the info was useful. i ran a welded rear end with my np219(also a viscuous couling center diff) and a good friend used to run a welded rear in the rear of his xj with a 229. never any prollems with either,let me know if ya have further ques smile.gif

rustywag
02-13-2003, 03:14 AM
I, too am thankful for the info. I had suspected that the V/C was torque sensing, it would seem I was mistaken. Always glad to replace suspicion with fact.

Thanks,

scotty
02-13-2003, 04:10 AM
ya,the viscuous coupling is not the most complex piece of automotive equipment ever created ;)

it is simply filled with a funky,liquidy silicone fluid that special plates have to force their way thru in order for one side to spin faster. the faster one side tries t spin,the harder it becomes to shear thru the silicone. not overly complex,but quite clever,IMO and they work very well when theyre in good shape. smile.gif

the 219 and 242 also use it,as well as the single speed 119 and 129 used in the amc eagles smile.gif

Rockwagon
02-13-2003, 08:34 AM
I am welded front and rear turning 42"s with a 229. I have broke 2 in 4 years but niether were fault of the VC. One was the chain and the other was the case it self. I acutuly took pieces from both to build the one that I have now. It is not the stongest but it can do the job.

Blackjack
02-13-2003, 10:02 AM
Good to know Rockwagon...thanks
;)