hey fellas i have a ? for yas! its about my 93. i have had it for over two years now and have used 4x4 high all the time in winter and its a tank there hasnt been a snow drift that i couldnt bust threw its awesome! i have never ever had a problem with it in 4x4 high! well today my dad asked me to use it to haul some wood! i said no problem. well he gets back and asks me have u ever used 4x4 LO? i said no i have never needed to. he goes on to tell me that he was in alot of mud and had a full truck of wood and put it in 4x4 LO and says the front tires r spinning but the back wheels r just draggin but in 4x4 high it works fine! he know his stuff really well been working on dodges for over 30 years and this is the first time i think hes been stumped. and now im kinda of like what the heck is going on??? so if any thoughts or info or what is tore up please give me ur opioion! thanks Andy

 

I wouldn't panic too much until you look undeneath at the shift linkage adjustment. The lever in the cab actually moves two shift rails on the transfer case underneath. Crawl underneath and look for problems like broken pivot pin or bad adjustment. Only one rail activates the light via a switch.

 

well, if your truck works in 2wd and in 4hi, the back wheels have to be getting power in 4lo. If you don't have sure grips front and/or rear, you'll only have a maximum of 2 tires spinning tho, unless traction load on a pair of tires is the same, so maybe the tires on the other side were spinning?

On a 205 is there really 2 shift rods? I'd have to go out and look, but I thought 208's and 205's only had one? I know 203's have 2, as they need to be able to go to the lo/hi side independant of coupling the t-case into loc. Part time cases don't need to be able to do that.

 

just in case someone needs this...

I don't think this 205 is for the dodge application

 

The NP205 has two shift rails, and a connector linkage that allowed Dodge to use only one shift lever for the transfer case. I always toss the link pin and install the dual levers used by GM for 20 years. Even with the rails disconnected from each other, it is not possible to have it in front wheel drive only while in low range. Your choices with the rails shifted independently are four wheel high range, two wheel high range, four wheel low range, two wheel low range, and neutral.

It is also much tougher and far more reliable than any other production transfer case ever installed by the mainstream automotive manufacturers.

A 4X4 is generally built with a very slightly numerically lower (higher gear) ratio on the front axle. This keeps the front end from binding and plowing into a ditch when being overrun by the rear axle during four wheel drive useage. Every one I own will slip the front tires in muck or snow before they slip the rear tires. Normally, it is not something you would ever notice. However, if you get the front wheels spinning with chains you will feel the truck snaking around a bit as the rear axle tries to keep up. The problem gets exacerbated by the front wheel with the least traction dramatically increasing its spin rate by the differential feed to the tire with the least traction causing the rotating speed to be significantly faster on that side.

 

It is possible for the NP205 to get in a 2 LO / front drive only situation. I had it happen to me once before. I am not sure if it was caused by a worn/sloppy transfer case, or just happening to get the shifter/gears in the "right spot" (wrong spot?).

There is no adjustment on the shift linkage in the NP205, you may be thinking of the NP203?

205's do have two shift rails.

I would just try it again, and make sure to push the shifter all the way forward while feathering the throttle a little to help it slide in.

 

[quote author=RCW link=board=9;threadid=23369;start=0#msg219823 date=1070845683]
A 4X4 is generally built with a very slightly numerically lower (higher gear) ratio on the front axle. This keeps the front end from binding and plowing into a ditch when being overrun by the rear axle during four wheel drive useage. Every one I own will slip the front tires in muck or snow before they slip the rear tires. Normally, it is not something you would ever notice. However, if you get the front wheels spinning with chains you will feel the truck snaking around a bit as the rear axle tries to keep up. The problem gets exacerbated by the front wheel with the least traction dramatically increasing its spin rate by the differential feed to the tire with the least traction causing the rotating speed to be significantly faster on that side.
[/quote]

Huh? ???

 

i have had this happen to me 2 times in the last 7 years. first time was pulling a 555 back hoe with a dead engine. dry ground, low range would only spin one front wheel, rears did nothing. put it in high range and drove off. been in the repair bus. 40 years. have a lot of friends in repair business they all say it cant happen?

 

one could have something wrong with their t-case, but I don't see how the 'loc' portion can be good in hi but not in lo. The tcase will be shifted into the same position along the 'loc' lever for either 4lo or 4hi
If your linkage was bent or out of adjustment of course it'd be possible to not fully get into the loc postion in 4lo, but that most certainly would not shift power to the front wheels only. Use that diagram up there and explain to us how that could happen? ???

 

let us add a little more mystery to my problem. i unlocked the hubs on one of the tests. with hubs unlocked the rear wheels pulled like they are supposed to. on that day i was not doing 12 oz. curls. have a witness to all of this. i say it cant happen but it did.

 

FWIW, when it happened to me, I was hauling a heaping load of sand, and went to leave after loading. I put it into 4 lo, and the front wheels dug into the sand and sunk. I then made sure the shifter was all the way forward, and then the rear wheels hooked up and off I went. So, with the loose sand, it was easy to verify that it truly was only the front wheels pulling. It's just one of those things that aren't supposed to happen, but do.

 

Thanks to westcoaster for posting the parts diagram for the 205 (I think it's for a Ford style driver's side drop case -- the guts are the same tho'). The rear output shaft and clutch gears are to the top of the picture, and the front is to the bottom. Interchangeable parts on the front output and rear output shafts are labeled with the same number which makes it a little confusing BUT:

When in 2HI power is transferred through the input shaft to the rear output shaft via clutch gear 2196-rear.

In 4HI power is transferred through the input shaft to the rear output shaft via clutch gear 2196-rear AND power is transferred through the input shaft, counter shaft, gear 2238, and clutch gear 2196-front to the front output shaft.

In 4LO power is transferred from the input shaft to the countershaft to the rear output shaft via gears 2232 and 2185-rear and clutch gear 2196-rear (now engaging gear 2185-rear instead of the dogs on the input shaft). The front output shaft is driven by clutch gear 2196-front which is engaging 2185-front, that is driven from the countershaft gear 2232.

Effectively, the front and rear shafts are two separate "transmissions" that share a single countershaft. Thus it is possible, if the lock-out pins (2221) between the shift rails (2217 & 2218) & shift linkage don't work exactly correctly to shift the front into either HI or LO while the rear is still in neutral. It is also what makes it possible to convert to a twin stick shift set-up that allows you to use 2LO.

The way the lock-out pins are set up, you have to shift the front shaft into LO before the rear shaft will go into LO (and the switch for the light is driven off of the front shift rail so it comes on before 4LO is fully engaged -- in my truck the light actually goes out again when you are all the way in 4LO).

I hope this was helpful on how the transfer case works.

As for the front/rear axle ratio: Many older 4x4's used to use front axle ratio's that were higher than the rear -- say a 4:10 in front and a 4:11 in the rear, or even more of a difference. When you turn, the front wheels have to travel farther than the rear wheels, and the sharper the turn, the more this is true. The difference in ratios was to make up for this without using a center differential, however, when you are going straight, it is better to have the same ratio, and most vehicles now seem to have materially the same ratios front and rear.


Alec

 

so you're saying the rear shaft is basically hung up still from the transision from neutral? It would seem as though some interference (and noise indicating it) should be experienced from these guys then, unless they both (3, 4, however many of ya) have managed to all shift into some kind of sweet spot where the rear shaft is neither hitting neutral or low (assuming if Neutral on the shifter works for them that the rear shaft shouldn't still be solidily in N)? I would venture at that point that they should have trouble getting into 4hi then, as full travel may well be a problem in the opposite direction? I would expect some of these fwd only lo range trucks would be rwd only in 4hi.

most of the 203 trucks I've had were 4.09 up front and 4.10 out back. I believe my 78 was 3.53/3.54
Never had a part time truck with different ratios.

 

??? ???

When the rear shaft is in neutral, it is in neutral, and can spin or not spin freely -- just like the front shaft when in 2HI. I don't get what you mean. The problem is that if you don't push the lever far enough, it is possible to engage the front output shaft in LO while the rear shaft is still in neutral because they use two separate shift rails, one for the front, and one for the rear. If you take the inter-lock pin out, it is possible to shift the front into LO and the rear into HI at the same time, and vice versa. If you modify the interlock detents that the pin rides in, you can run front wheel drive HI and LO, rear wheel drive HI and LO, and 4x4 HI and LO . . .

It isn't like the 203; it is very similar to the Dana 20.

 

where I was going with that statement was this- if the linkage and such is in good enough shape to get it into neutral and 4hi, it seems funny that this problem happens. Unless the interlocks and/or rails tend to get slop only in one direction.

Basically I'd expect the t-case to be generally hard to get it in the mode you want all of the time, rather than just this special case, unless the linkage is really touchy and the last little bit of travel going forward has such a ratio that it does quite a bit of work inside the case