NP203, NP205, NP208 Differentiating Power to front and rear axles.

[HotRodPC]

Might be the only way you get anything out of the Th350/NP203. I'm still on the fence, but I'm thinking I might want to run a NP203 on the other 4x4 truck I have. I like the idea of HI-LOK and Low LOK. If understand right, NP205 and NP208 don't have that feature where they send equal power to the front and rear differentials.

 

[bucket]

If understand right, NP205 and NP208 don't have that feature where they send equal power to the front and rear differentials.

How can they not? They don't have a differential in them.

 

[davbell22602]

Cool info

 

[HotRodPC]

So you're saying NP203 has a differential in it, but the NP205 and NP208 do not? So then the NP205 and NP208 DOES send equal power to both front and rear axles even in standard 4 HI and 4 LO ? I'd have thought so, but been told, NO they don't. That only a percentage of power gets to the front axles where most of the poower is to the rear axles.

 

[89Suburban]

So you're saying NP203 has a differential in it, but the NP205 and NP208 do not? So then the NP205 and NP208 DOES send equal power to both front and rear axles even in standard 4 HI and 4 LO ? I'd have thought so, but been told, NO they don't. That only a percentage of power gets to the front axles where most of the poower is to the rear axles.

The 203 has the open diff in it for regular all time 4WD on the 70's Chevys and Dodges.

So it supplies power to all wheels, but will differentiate for turning. So if you get stuck, it is possible for just one wheel to spin. Then you put it in lock, and it locks the diff in the t case and puts equal power to front and rear shafts, forcing both axles to have drive, equally.

All other cases I assumed were for 2WD only output unless you locked it and it would drive front an rear equally.

You are losing me saying that a rear axle get's more power than the front in any of those situations. Teach me, I am listening.

 

[HotRodPC]

The 203 has the diff in it for regular all time 4WD on the 70's Chevys and Dodges.
So it supplies power to all wheels, but will differentiate for turning. So if you get stuck, it is possible for just one wheel to spin. Then you put it in lock, and it locks the diff in the t case and puts equal power to front and rear shafts, forcing both axles to have drive.

All other cases I assumed were for 2WD only output unless you locked it and it would drive front an rear equally.

You are losing me saying that a rear axle get's more power than the front in any of those situations. Teach me, I am listening.

I'm not 100% positive myself John. I was hoping this thread might generate some answers for me too. I thought NP205 and NP205 when in 4HI/LO worked like NP203 did in LOK position, but I was reading somewhere, this is not true. I do not recall where I seen the info, but it said something like rear wheels get 70% of the power and front wheels get 30% of the power? WTF kinda **** is that? I want it to be, if I had locker diffs, then I have a true 4x4 and equal power to all wheels.

 

[89Suburban]

I'm not 100% positive myself John. I was hoping this thread might generate some answers for me too. I thought NP205 and NP205 when in 4HI/LO worked like NP203 did in LOK position, but I was reading somewhere, this is not true. I do not recall where I seen the info, but it said something like rear wheels get 70% of the power and front wheels get 30% of the power? WTF kinda **** is that? I want it to be, if I had locker diffs, then I have a true 4x4 and equal power to all wheels.

Yeah, that don't sound right to me, I'd like to see that source of info for myself.

 

[bucket]

I'm not 100% positive myself John. I was hoping this thread might generate some answers for me too. I thought NP205 and NP205 when in 4HI/LO worked like NP203 did in LOK position, but I was reading somewhere, this is not true. I do not recall where I seen the info, but it said something like rear wheels get 70% of the power and front wheels get 30% of the power? WTF kinda **** is that? I want it to be, if I had locker diffs, then I have a true 4x4 and equal power to all wheels.

I have never heard of any 70/30 split mentioned before. I do know that even when out of the truck, if a 205 or 208 are shifted into 4lo/hi and you turn the input by hand, both outputs turn the same amount. I have also seen all the guts of a 205, there's no diff that I'm aware of.

The only good use of a 203 (IMHO) is for the use of a doubler setup. They are big, heavy, and the shifter sucks big time.

 

[HotRodPC]

I have never heard of any 70/30 split mentioned before. I do know that even when out of the truck, if a 205 or 208 are shifted into 4lo/hi and you turn the input by hand, both outputs turn the same amount. I have also seen all the guts of a 205, there's no diff that I'm aware of.

The only good use of a 203 (IMHO) is for the use of a doubler setup. They are big, heavy, and the shifter sucks big time.

I hope that's actually how they do work Andy. So you're saying a NP205 and NP208 while in 4Hi or 4Lo are equal to NP203 in 4LOC position???

 

[bucket]

I hope that's actually how they do work Andy. So you're saying a NP205 and NP208 while in 4Hi or 4Lo are equal to NP203 in 4LOC position???

Exactly.

 

[HotRodPC]

I hope so. As a matter of fact, it was a Newbie on here that was looking for a Jeep Tcase for his Square I do beleive. He was the one saying, NP205 and 8 do not send equal power to the axles, so he wanted to find this Jeep Tcase. That's what I understood anyway. I'll see if I can find the thread.

 

[HotRodPC]

http://www.gmsquarebody.com/forum/showthread.php?p=74853&posted=1#post74853

There is the link now. I think I get it now. He's wanting to option for both differential full time 4wd like an AWD system, and the locked diff in the Tcase for true 4wd but still have the 2wd option.

 

[78shortandwide]

I would think that the 205 split the power equally. You can put a twin stik in a 205 and send all the power to either the front or the back...
http://ivanribic.clubfte.com/page2.html
same as an atlas transfercase.

 

[HotRodPC]

I would think that the 205 split the power equally. You can put a twin stik in a 205 and send all the power to either the front or the back...
http://ivanribic.clubfte.com/page2.html
same as an atlas transfercase.

With that, it does make sense that an NP205 in 4Hi and 4Lo would be equal to a NP203 in 4H LOC and 4L LOC. What I want, is when I'm in 4HI, with locker axles that have the same gear ratios, that all 4 wheels will turn equally. Not the rear wheels turning faster than the front wheels or vice versa.

 

[sean1960]

The 205 is all gears. you get the same power front and rear when in 4wd. The 203 is the one that is split 30 front 70 rear when not in 4 hi loc or 4 low loc. I have heard this for years and I think its true. My last truck had a 203 in it and when I took it to a friends shop we put it on the rollers used for inspections and it would not pull itself off the rollers unless we gave it a lot of gas. It was full time 4wd and we did not have it in 4hi loc or low loc just normal 4 hi.