Transfercase confussion - The 1947 - Present Chevrolet & GMC Truck Message Board Network

SanitysBane · 03-01-2010, 01:57 PM

Hey Guys,
I am new to the whole 4X4 scene and something that is totally confusing me is the terms, "part time" and "full time" 4WD. What is the difference? I thought all trucks where 2wd unless you shifted the transfercase into 4wd. Also why do some trucks have locking hubs and some do not? One final questions on my list is what is up with some transfercases having two shifters instead of just one?

Thanks and sorry for the newb questions

thirdstreettito · 03-01-2010, 02:41 PM

Full time 4WD means the truck is always in 4WD. It also means it doesnt have manual locking hubs.

Part time 4WD means it is in 2WD until you put it in 4WD. It can have either automatic hubs or manual locking hubs.

Twin-stick and triple-stick mean you can do more than 2HI(rear)-N-4LO-4HI. It means you can do 2HI(rear)-2LO(rear)-N-2HI(front)-2LO(front)-4HI-4LO.

I believe I have all that right. Please correct me if Im wrong guys.

**Stocker** · 03-03-2010, 09:27 PM

Quote:

Originally Posted by thirdstreettito

Full time 4WD means the truck is always in 4WD. It also means it doesnt have manual locking hubs.

Part time 4WD means it is in 2WD until you put it in 4WD. It can have either automatic hubs or manual locking hubs.

To further clarify (or further muddle) things....

Full-time systems have a center differential in the TC (otherwise the driveline would bind), and usually can be locked (front-to-rear) if needed. Do this only in poor traction situations where the tires can slip, or the driveline will bind.

Part-time systems lock the front & rear driveshafts together (in the TC) when 4WD is engaged -- there is no center differential.

Benelli · 03-01-2010, 09:45 PM

He's right.

Twin and triple stick often only have One shifting handle, too.

READ THE OWNERS MANUAL! It'll tell you just about everything you need to know.

onlyifihadachevy · 03-01-2010, 11:44 PM

The twin stick allows for 2hi-n-4lo-4hi. One stick controls the rear and one controls the front. SO if you weld up the front you can use front dig and make the tighter turns.

The triple stick is for a doubler only I believe. One stick controls the front case. And the other two allow for the front and rear to be chosen independently.

1969K10 · 03-03-2010, 08:54 PM

1 stick - controls 2WD & 4WD
2 stick, one controls front and 1 controls rear. allows you to engage the front axle and not the rear axle. really a serious/dedicated off-roader mod. you have the choice of hi, low and neutral.
3 sticks, i'm not certain, but i think is 1 for the 2nd X-fer case, and the other 2 acts as a 2-stick.

OrrieG · 03-03-2010, 09:08 PM

1969k10 - are you talking about 205 twin stick? I thought one controled Low-Neutral-High and the other Rear or Rear and Front together. I did not know you could lock out the rear. I twin sticked my 203 and with a part time shaft kit it operates as I described, no way to isolate the front only.

winchster · 03-03-2010, 09:24 PM

Quote:

Originally Posted by OrrieG

1969k10 - are you talking about 205 twin stick? I thought one controled Low-Neutral-High and the other Rear or Rear and Front together. I did not know you could lock out the rear. I twin sticked my 203 and with a part time shaft kit it operates as I described, no way to isolate the front only.

If you twinstick a 205 you get total control. FWD RWD 4WD in Hi and Lo

winchster · 03-03-2010, 09:28 PM

Here is an article.

Here, you can buy the twin stick kit with rails for either the 205 or 203.
http://www.offroaddesign.com/catalog...seshifters.htm

84 400 · 03-03-2010, 11:51 PM

It is not very complicated and i don't suggest getting to into it unless there is a need.

A true TWIN STICK conversion allows the driver to operate the front and rear axles interdependently. This is used if u have a locked front. Basically it works like this
R F
hi Hi
N N
low low

So the front can be in hi and the rear axle in neutral effectively giving you front wheel drive. To keep the transfer case from binding a good conversion will not allow for a mix match of ranges. In other words, you can't have the front in low and the rear in high.

This is all on an NP205.

The Np203 comes from the factory being full time 4x4. This means it is always in 4x4 and does not have locking hubs but rather drive flanges.
Shift pattern
4lo loc
4lo
n
4hi (normal street driving)
4hi loc

Lock ranges are for off road or non dry pavement situations. Essentially the transfer case has in internal differential unit to reduce wear and tear. The lock position acts like a locker in an axle and sends equal power to both drive shafts. when in a non lock range power goes the way of least resistance allowing the driver to turn on dry pavement with out too much resistance.
A Np 203 can be twinsticked. However it is done to get rid of the faulty factory shifter. It is not a to allow independent axle control. In addition a partime kit can be installed which gives the driver 2wd lo and high and front freewheeling hubs. This gives the driver better fuel millage and can allow for a front locker to be installed
partime conversion
4lo
2lo
n
2hi
4hi

twinsitck but not full time
unlock lo
Lock N
---- hi

shift pattern with twin stick and parttime
2wd lo
4wd N
--- Hi

and a triple stick is used when doing an 203/205 or other types of transfer case doubler.

I have had both an np203 and np205 in my truck. The np203 was full time and i converted it to part time and before installing the 205 i twin sticked it.

I see you have an 88 K5 so none of this applies to you. What you have is called auto locking hubs. auto locking hubs automatically lock so you do not need to get out of the cab and manual lock them from free wheel to the axle. I don't know much about your year but it should have eather a np208 or an np241 transfercase.

SanitysBane · 03-04-2010, 11:01 PM

Thanks a ton guys! I think I am starting to understand this.

Right now the Blazer is all stock but I've got a built 454 (550ish hp) that is going in it and I already have the 14FF rear and am looking for a D60 front.

Which would y'all suggest running the NP205 or NP203? I've got a feeling that the stock transfer case isn't going to last long. And as a side note how hard is it to find them, or a divorced transfer case?

winchster · 03-04-2010, 11:32 PM

If you are going that far, you may as well keep the 203, find a 205 and double it.

ghettoluxury · 03-05-2010, 02:29 AM

Your sock transfer case will hold up just fine, I used to run a 208 behind a th350 and a blown 468 never had a bit of trouble with it. I am curently running a 454 with 12:1 heads and a 660/670 cam backed by th400 and a 203, the only problem I have had is breakin the rear yoke off of the transfer case twice. I solved this by ordering a larger one from advanced adapters.

84 400 · 03-05-2010, 03:03 AM

depends what you gonna use the truck for. the 208 has the lowest low range but is aluminum. The next lowest low is the np203 and the highest low range is the np305. The strongest case by far is the all gear driven np205. IF you want a crawler or trail truck I would look into a doubler. If it is for mud any would work but the 205 will be the strongest.

just my .02

These transfer cases are very plentiful. I picked up an np205 for 60 bux a few weeks back. Picked up an sm465 and a np205 with twin sticks for 250 last summer. They are all over the junk yards. The np205 is probably the most desirable and is the only one out of the three that came factory divorced i believe.

While the 208 will prob hold up I would get what u want now insteade of having to redo drive shafts later.

scooter122983 · 03-05-2010, 11:56 AM

Quote:

Originally Posted by 84 400

depends what you gonna use the truck for. the 208 has the lowest low range but is aluminum. The next lowest low is the np203 and the highest low range is the np305. The strongest case by far is the all gear driven np205. IF you want a crawler or trail truck I would look into a doubler. If it is for mud any would work but the 205 will be the strongest.

just my .02

These transfer cases are very plentiful. I picked up an np205 for 60 bux a few weeks back. Picked up an sm465 and a np205 with twin sticks for 250 last summer. They are all over the junk yards. The np205 is probably the most desirable and is the only one out of the three that came factory divorced i believe.

While the 208 will prob hold up I would get what u want now insteade of having to redo drive shafts later.

The 205 only came divorced in a ford high boy.

ghettoluxury · 03-05-2010, 12:01 PM

Quote:

Originally Posted by scooter122983

The 205 only came divorced in a ford high boy.

They were also divorced in Dodge and International, both being passanger side drop.

SanitysBane · 03-05-2010, 12:12 PM

I may take the blazer off road but in reality its going to be my DD for when I move to Seattle so I won't have to worry about snow, ice, etc.

84 400 · 03-05-2010, 05:37 PM

If it was me then I would go with a 205 as low low is not needed. Also seems like you could get away with the 208. 203's are great in the snow but if your gonna swap in a case i would go with the 205 instead ( less weight, no chain , already partime). What size tire do you plan on running? My friend has his truck with less horse power running a 208 and 39.5 swamper boggers and it does just fine. Just an FYI swampers are junk on ice! Last trail run i did i had to be winched every place.

70 beast · 03-05-2010, 06:37 PM

Quote:

Originally Posted by 84 400

203's are great in the snow but if your gonna swap in a case i would go with the 205 instead ( less weight, no chain , already partime)

and the low range difference isn't all that great

84 400 · 03-05-2010, 09:26 PM

Quote:

Originally Posted by 70 beast

and the low range difference isn't all that great

very true. Again not a reason i would want a np203 over a 205 tho.

you should be able to fit 33x12.5 with no lift. My truck could but they will rubb on full stuff. you could even use stock springs and add a leaves or an easy rate. Since you have a blazer they tend to sag in the azz alot.

SanitysBane · 03-05-2010, 08:18 PM

Thinking about a 4inch lift with something around a 35X12 or no lift and 33X12 if they make such a creature...I tried looking around but I couldn't find anything.

Hoods69BadBowTie · 03-06-2010, 06:34 PM

Yea I vote for the 205. Some good info up there thanks everyone!

03-01-2010, 01:57 PM	#1
SanitysBane Registered User Join Date: May 2004 Location: Lubbock, Texas Posts: 2,121	Transfercase confussion Hey Guys, I am new to the whole 4X4 scene and something that is totally confusing me is the terms, "part time" and "full time" 4WD. What is the difference? I thought all trucks where 2wd unless you shifted the transfercase into 4wd. Also why do some trucks have locking hubs and some do not? One final questions on my list is what is up with some transfercases having two shifters instead of just one? Thanks and sorry for the newb questions __________________ '96 Nissan Pathfinder '02 Firebird Trans Am. '88 K5 Blazer

03-01-2010, 02:41 PM	#2
thirdstreettito Resident of Here Join Date: May 2008 Location: Wesley Chapel, FL, USA Posts: 7,716	Re: Transfercase confussion Full time 4WD means the truck is always in 4WD. It also means it doesnt have manual locking hubs. Part time 4WD means it is in 2WD until you put it in 4WD. It can have either automatic hubs or manual locking hubs. Twin-stick and triple-stick mean you can do more than 2HI(rear)-N-4LO-4HI. It means you can do 2HI(rear)-2LO(rear)-N-2HI(front)-2LO(front)-4HI-4LO. I believe I have all that right. Please correct me if Im wrong guys. __________________ ~Bradley~ 2004 Black GTO LS2/T56 too much to list Miss having a truck

03-01-2010, 09:45 PM	#4
Benelli Watchin the rust grow Join Date: Oct 2008 Location: Western Nebraska Posts: 950	Re: Transfercase confussion He's right. Twin and triple stick often only have One shifting handle, too. READ THE OWNERS MANUAL! It'll tell you just about everything you need to know. __________________ 1979 Chevy K10 (H/D Front end) - 350 w/ Holley Truck Avenger, Weinald Intake manifold, headers, bored .060 over, mild cam, Built up TH350 (TranStar Shift kit) with a part-timed NP203 t-case SOLD ($3,000) 1997 Chevy Silverado 1500 - 4.3 vortec, extended cab, 21 highway MPG, stock. "Red" SOLD ($3,000) 1987 Toyota 4wd Pick-up - work in progress, future DD SOLD ($1,850) 1998 Dodge Ram 2500 Cummins 5spd Quad cab - old 12 valve with some work done 2004 Chevy Silverado - Black, 4x4, 5.3L, stock for now Underneath that rust is a heart of gold

03-01-2010, 11:44 PM	#5
onlyifihadachevy Registered User Join Date: Mar 2009 Location: seaside,ca Posts: 778	Re: Transfercase confussion The twin stick allows for 2hi-n-4lo-4hi. One stick controls the rear and one controls the front. SO if you weld up the front you can use front dig and make the tighter turns. The triple stick is for a doubler only I believe. One stick controls the front case. And the other two allow for the front and rear to be chosen independently. __________________ 72 gmc 2500 2wd drive convert My 72 thread http://67-72chevytrucks.com/vboard/s...d.php?t=346712 THe other truck, wheeler 69 1/2 4x4, yellow and rusty. http://67-72chevytrucks.com/vboard/s...d.php?t=350300

03-03-2010, 08:54 PM	#6
1969K10 Senior Member Join Date: Jul 2004 Location: Clarks Hill, Indiana Posts: 733	Re: Transfercase confussion 1 stick - controls 2WD & 4WD 2 stick, one controls front and 1 controls rear. allows you to engage the front axle and not the rear axle. really a serious/dedicated off-roader mod. you have the choice of hi, low and neutral. 3 sticks, i'm not certain, but i think is 1 for the 2nd X-fer case, and the other 2 acts as a 2-stick. __________________ 1969 K10 - V8, 465, 205, 12 bolt, D44 2002-current 1969 K20 - V8, 465, 221, Eaton, D44 2012-current Nothin' but drums on all 4 corners! past horses in the stable 72 C10-short step (97-02), 68 C10-long fleet (06-12)

03-03-2010, 09:08 PM	#7
OrrieG Registered User Join Date: Jun 2006 Location: Idaho Posts: 8,800	Re: Transfercase confussion 1969k10 - are you talking about 205 twin stick? I thought one controled Low-Neutral-High and the other Rear or Rear and Front together. I did not know you could lock out the rear. I twin sticked my 203 and with a part time shaft kit it operates as I described, no way to isolate the front only. __________________ 1959 Chevy Short Fleetside w/ 74 4WD drive train (current project) OrrieG Build Thread 1964 Chevelle Malibu w/ 355-350TH (daily driver) Helpful AD and TF Manual Site Old Car Manual Project

03-03-2010, 09:28 PM	#9
winchster Registered User Join Date: Jul 2006 Location: Fort Worth, TX Posts: 220	Re: Transfercase confussion Here is an article. Here, you can buy the twin stick kit with rails for either the 205 or 203. http://www.offroaddesign.com/catalog...seshifters.htm Attached Images __________________ '49 AD 5 window deluxe cab sitting on a '78 K5 chassis Support our troops, stand behind 'em or get in front of 'em. What country can preserve its liberties if its rulers are not warned from time to time that their people preserve the spirit of resistance? Last edited by winchster; 03-03-2010 at 09:35 PM. Reason: added link

03-03-2010, 11:51 PM	#10
84 400 Sb 400 club Join Date: Nov 2005 Location: NH / MA Posts: 2,746	Re: Transfercase confussion It is not very complicated and i don't suggest getting to into it unless there is a need. A true TWIN STICK conversion allows the driver to operate the front and rear axles interdependently. This is used if u have a locked front. Basically it works like this R F hi Hi N N low low So the front can be in hi and the rear axle in neutral effectively giving you front wheel drive. To keep the transfer case from binding a good conversion will not allow for a mix match of ranges. In other words, you can't have the front in low and the rear in high. This is all on an NP205. The Np203 comes from the factory being full time 4x4. This means it is always in 4x4 and does not have locking hubs but rather drive flanges. Shift pattern 4lo loc 4lo n 4hi (normal street driving) 4hi loc Lock ranges are for off road or non dry pavement situations. Essentially the transfer case has in internal differential unit to reduce wear and tear. The lock position acts like a locker in an axle and sends equal power to both drive shafts. when in a non lock range power goes the way of least resistance allowing the driver to turn on dry pavement with out too much resistance. A Np 203 can be twinsticked. However it is done to get rid of the faulty factory shifter. It is not a to allow independent axle control. In addition a partime kit can be installed which gives the driver 2wd lo and high and front freewheeling hubs. This gives the driver better fuel millage and can allow for a front locker to be installed partime conversion 4lo 2lo n 2hi 4hi twinsitck but not full time unlock lo Lock N ---- hi shift pattern with twin stick and parttime 2wd lo 4wd N --- Hi and a triple stick is used when doing an 203/205 or other types of transfer case doubler. I have had both an np203 and np205 in my truck. The np203 was full time and i converted it to part time and before installing the 205 i twin sticked it. I see you have an 88 K5 so none of this applies to you. What you have is called auto locking hubs. auto locking hubs automatically lock so you do not need to get out of the cab and manual lock them from free wheel to the axle. I don't know much about your year but it should have eather a np208 or an np241 transfercase. __________________ 1984 chevy c10, built 400sb,.(SOLD) 77 K10 Project / daily driver "The Grinch" http://67-72chevytrucks.com/vboard/s...d.php?t=318363 1956 Willys Wagon (327 chevy) Project (Now Buick 225) 1980 Corvette L-48 4 speed 1992 Mustang GT built 5.0 5 speed 1985 C10 LWB Sold 1982 K10 SWB plow truck Parted out 1986 D30 M1028 fire brush truck Parted out Last edited by 84 400; 03-03-2010 at 11:52 PM.

03-04-2010, 11:01 PM	#11
SanitysBane Registered User Join Date: May 2004 Location: Lubbock, Texas Posts: 2,121	Re: Transfercase confussion Thanks a ton guys! I think I am starting to understand this. Right now the Blazer is all stock but I've got a built 454 (550ish hp) that is going in it and I already have the 14FF rear and am looking for a D60 front. Which would y'all suggest running the NP205 or NP203? I've got a feeling that the stock transfer case isn't going to last long. And as a side note how hard is it to find them, or a divorced transfer case? __________________ '96 Nissan Pathfinder '02 Firebird Trans Am. '88 K5 Blazer

03-04-2010, 11:32 PM	#12
winchster Registered User Join Date: Jul 2006 Location: Fort Worth, TX Posts: 220	Re: Transfercase confussion If you are going that far, you may as well keep the 203, find a 205 and double it. __________________ '49 AD 5 window deluxe cab sitting on a '78 K5 chassis Support our troops, stand behind 'em or get in front of 'em. What country can preserve its liberties if its rulers are not warned from time to time that their people preserve the spirit of resistance?

03-05-2010, 02:29 AM	#13
ghettoluxury Registered User Join Date: Apr 2009 Location: Waynesfield Ohio Posts: 1,991	Re: Transfercase confussion Your sock transfer case will hold up just fine, I used to run a 208 behind a th350 and a blown 468 never had a bit of trouble with it. I am curently running a 454 with 12:1 heads and a 660/670 cam backed by th400 and a 203, the only problem I have had is breakin the rear yoke off of the transfer case twice. I solved this by ordering a larger one from advanced adapters. __________________ 1949 Five Window, 1973 Step Side, 2000 Z71 Last edited by ghettoluxury; 03-05-2010 at 02:30 AM.

03-05-2010, 03:03 AM	#14
84 400 Sb 400 club Join Date: Nov 2005 Location: NH / MA Posts: 2,746	Re: Transfercase confussion depends what you gonna use the truck for. the 208 has the lowest low range but is aluminum. The next lowest low is the np203 and the highest low range is the np305. The strongest case by far is the all gear driven np205. IF you want a crawler or trail truck I would look into a doubler. If it is for mud any would work but the 205 will be the strongest. just my .02 These transfer cases are very plentiful. I picked up an np205 for 60 bux a few weeks back. Picked up an sm465 and a np205 with twin sticks for 250 last summer. They are all over the junk yards. The np205 is probably the most desirable and is the only one out of the three that came factory divorced i believe. While the 208 will prob hold up I would get what u want now insteade of having to redo drive shafts later. __________________ 1984 chevy c10, built 400sb,.(SOLD) 77 K10 Project / daily driver "The Grinch" http://67-72chevytrucks.com/vboard/s...d.php?t=318363 1956 Willys Wagon (327 chevy) Project (Now Buick 225) 1980 Corvette L-48 4 speed 1992 Mustang GT built 5.0 5 speed 1985 C10 LWB Sold 1982 K10 SWB plow truck Parted out 1986 D30 M1028 fire brush truck Parted out

03-05-2010, 12:12 PM	#17
SanitysBane Registered User Join Date: May 2004 Location: Lubbock, Texas Posts: 2,121	Re: Transfercase confussion I may take the blazer off road but in reality its going to be my DD for when I move to Seattle so I won't have to worry about snow, ice, etc. __________________ '96 Nissan Pathfinder '02 Firebird Trans Am. '88 K5 Blazer

03-05-2010, 05:37 PM	#18
84 400 Sb 400 club Join Date: Nov 2005 Location: NH / MA Posts: 2,746	Re: Transfercase confussion If it was me then I would go with a 205 as low low is not needed. Also seems like you could get away with the 208. 203's are great in the snow but if your gonna swap in a case i would go with the 205 instead ( less weight, no chain , already partime). What size tire do you plan on running? My friend has his truck with less horse power running a 208 and 39.5 swamper boggers and it does just fine. Just an FYI swampers are junk on ice! Last trail run i did i had to be winched every place. __________________ 1984 chevy c10, built 400sb,.(SOLD) 77 K10 Project / daily driver "The Grinch" http://67-72chevytrucks.com/vboard/s...d.php?t=318363 1956 Willys Wagon (327 chevy) Project (Now Buick 225) 1980 Corvette L-48 4 speed 1992 Mustang GT built 5.0 5 speed 1985 C10 LWB Sold 1982 K10 SWB plow truck Parted out 1986 D30 M1028 fire brush truck Parted out

03-05-2010, 08:18 PM	#21
SanitysBane Registered User Join Date: May 2004 Location: Lubbock, Texas Posts: 2,121	Re: Transfercase confussion Thinking about a 4inch lift with something around a 35X12 or no lift and 33X12 if they make such a creature...I tried looking around but I couldn't find anything. __________________ '96 Nissan Pathfinder '02 Firebird Trans Am. '88 K5 Blazer



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03-06-2010, 06:34 PM	#22
Hoods69BadBowTie Chevys Kick A$$ Join Date: Jan 2005 Location: Zootown, MT Posts: 12,699	Re: Transfercase confussion Yea I vote for the 205. Some good info up there thanks everyone! __________________ HOODS is what I answer too -'79, '77, '88 Pickup Sold, '85 Camaro, '83 T/A, '81,'83,'90 K5 Blazer All Sold -'79 3/4 ton "Big Yellow Bananna" Lifted 4spd. 39.5 TSL Swampers, The money Pit -'86 K5 Blazer Silverado 6.2 4" lift 35"s -'95 Ext. Cab Shorty 4" Tuff Country rolling 35" M/T's -'83 Monte Carlo T-Tops. 126,500 Original Miles -LATER I would rather push a Chevy then drive a ford!!

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