Engine/Transmission (1998.5 - 2002) 2002 Transfer Case Specs

[boomtown]

Ok 4WD Rammers... I'm checking in to an affordable (and reasonable I think) solution to allow us 2002 4WD guys to engage 4WLow gears on dry pavement without damaging our 4WD driveline.



In short, I'm looking at installing a disconnect device on the front drive shaft. Remco makes the device. I'm having my drive shaft modified this week. I'll post more info and pictures after I get it back on the truck.



Here's my question to the transfer case gurus: When I'm cruising down the road in 2WH, does the transfer case need to be turning to satisfy any lubrication requirements? More bluntly, does Dodge have our front drive shaft turning at all times (2WD or 4WD) for any particular (non-boneheaded) reason?



The remco device will make it possible for me to disengage the front drive shaft until I need it; almost as good as free wheeling hubs I think. I plan to leave the front drive shaft disengaged most of the time (so I can use the 4WL gears moving my trailer around) unless this will somehow damage the transfer case.



I'm looking forward to all your most excellent responses.

 

[Pit Bull]

Any 2002 that was manufactured after I think January 2002 does not have a front axle disconnect so the front differential is alway turning. Hope that helps

 

[boomtown]

Pit Bull, yes I'm aware dodge deleated the disconnect on the axle for the mid 2002 trucks; mine is one of them.



What I need to know is if I take my front drive shaft OFF the truck and go driving down the road in 2WH, will I damage my transfercase or 6-speed transmission.



Any info here would be much appreciated.

 

[boomtown]

Hey guys, I'm hoping someone out there has some info on this topic.

 

[Scrappy]

x-case

The '02 transfercase is the same as an '01. My '01 has a CAD so my driveshaft is not turning when in 2wd, so yes you can remove the front driveshaft and drive the truck without causing damage. I believe the transfercase is lubed by a pump that is connected to the rear output? (I think )

 

[Texas Diesel]

Your plan is 100% OK.



I think it is actually smart to do that, your transfer case will last longer not being turned 100% of the time. Deleting the CAD was a penny splitting move by DC. The 03's get a heavily beefed up transfer case to handle being spun 100% of the time, you late build 02 guys should be PO'd, I would (by having the 'normal' transfer case and not having the CAD to go with it) Oh well, sounds like you have a great fix coming. Would you mind posting some pics and the link to what you are installing?



And the transfercase does have the oil pump driven off the rear drive shaft so you have no lube problems.

 

[jeepit]

BOOMTOWN, I would be very interested in this. Please keep us all informed as your project proceeds.

 

[Pit Bull]

Originally posted by Tejas Deezul

Your plan is 100% OK.



I think it is actually smart to do that, your transfer case will last longer not being turned 100% of the time. Deleting the CAD was a penny splitting move by DC. The 03's get a heavily beefed up transfer case to handle being spun 100% of the time, you late build 02 guys should be PO'd, I would (by having the 'normal' transfer case and not having the CAD to go with it)

Spining some gears with no load on them should not cause any problem. Lets hear more about the 03 beefed up transfer case and why you think this is a problem in the 02's. Read one thread where the conclusion was that it was a benefit not to have the CAD??? I have no idea but would like to hear more about it.

 

[boomtown]

Thanks for the confirmation guys; this board is the best.



I hope to get my drive shaft back from the shop today or tomorrow. I should have some PICs I can upload this Friday.



In the meantime, here is the link on Remco's drive shaft disconnect product: http://www.remcotowing.com/drive.asp



For the near term, I'm just using the disconnect device and will engage it by hand (kinda like engaging manual hubs) when I want the front drive engaged. Most of the time I'll leave the device disengaged.



I don't plan on using their 'shift' mechanism; at least initially. If a shifter becomes necessary at some point, I'll try to think up a better design.

 

[Texas Diesel]

Originally posted by Pit Bull

Spining some gears with no load on them should not cause any problem. Lets hear more about the 03 beefed up transfer case and why you think this is a problem in the 02's. Read one thread where the conclusion was that it was a benefit not to have the CAD??? I have no idea but would like to hear more about it.

The problem is not the gears wearing but the chain drive inside the transfer case wearing and getting loose. I have seen where on Dakotas and Jeeps (no center axle disconnect [CAD] or hubs) the chain got sloppy enough to wear a hole in the side of the case (NV-231HD). A constantly spinning chain will wear faster then one sitting still. All model years since the late 80's have had hubs and then CAD. ALL years using the NV-241 or NV-241HD have had CAD, only the late build 02's have the CAD deleted. Not to mention the added wear on the front driveshaft u-joints (3 of them), pinion seal wear, and transfer case output shaft seal wear (front). Seals are realatively easy to replace but frequently the shafts wear under the seals meaning you have to replace shafts and seals. Having a CAD or hubs is sooooo much easier. The 03's have a monster transfer case and a much wider (longer lasting) chain to handle the continous duty of a full time front axle.



As far as deleting the CAD being a 'good' thing, I disagree completely. The problem with CAD is the sliding coupling or the shaft splines breaking. This occurs when the sliding coupling does not completely engage the splines. When I engage 4WD I let off the pedal, then pull the 4WD lever, then add fuel, then after a second or so I let off the pedal again. This procedure ensures the axle is not under drive torque when the vacuum motor is trying to slide the locking coupler over the splines. Try this, engage 4wd, then start making a slight turn, then push it back into 2WD, does the 4WD light go out? Answer: No. The drive line is under torque load. Engageing it is the same idea only in reverse order. The drive line (front) has to be unloaded inorder for the CAD system to lock OR unlock the front axle.



http://www.dodgeram.org/tech/specs/tranfer_case.htm



The 03's use the NV-271/273. You can see the ratings of the different cases, the 271/273 are rated much higher partly becase of a much wider drive chain which will allow full time rotation (even though it is in 2WD). The 271/273 is the strongest case mentioned on NV's site.



http://www.newventuregear.com/tcases.html

 

[Texas Diesel]

Although you didnt ask I volunteer it anyway.



The transfer case is filled with ATF at the factory. I dont like that for my truck so here is what I have used for 75k miles. Royal Purple Synchromax Synthetic lube. My transfer case used to grind when I would engage it while driving, since switching to RP Synchromax, no more grinds plus the Synchromax is synthetic. Synchromax works wonderfully in the NV-5600 too, no grinds there either. You can order it from JC Whitney.



Caveat here: warranty requires OEM specified fluids only, but then they only have to make last until the warranty expires.



Discalimer: I dont make a penny regardless of what you buy



http://www.royalpurple.com/

 

[Pit Bull]

Originally posted by Tejas Deezul

Although you didnt ask I volunteer it anyway.



The transfer case is filled with ATF at the factory. I dont like that for my truck so here is what I have used for 75k miles. Royal Purple Synchromax Synthetic lube. My transfer case used to grind when I would engage it while driving, since switching to RP Synchromax, no more grinds plus the Synchromax is synthetic. Synchromax works wonderfully in the NV-5600 too, no grinds there either. You can order it from JC Whitney.



Caveat here: warranty requires OEM specified fluids only, but then they only have to make last until the warranty expires.



Discalimer: I dont make a penny regardless of what you buy



http://www.royalpurple.com/

Thanks for the tip, but since it might blowup during the 70K mile warranty period I better stick with the OEM recommended stuff while under warranty.

 

[boomtown]

Hey guys,



I got the drive shaft back from the shop yesterday. They did do nice work on the installation of the disconnect device, however they didn't do so well in the balancing department. The drive shaft vibrated like a roto-rooter .



Anyhow, they’re fixing the problem and I'll get it back early next week.



For those interested, I'll post a new thread with some pics when I get this project finished.

 

[Texas Diesel]

That would be nice. How much $ was it?