Q- for you 4x4x nuts - The 1947 - Present Chevrolet & GMC Truck Message Board Network

DennyB · 02-01-2004, 10:55 AM

Does GM make or have they made a T-case with both FT and PT 4wd?

I know the np205 is PT and the 203 & 208 are FT.

Thanks

**kwmech** · 02-01-2004, 01:01 PM

The 208 is a part time case but usually had auto hubs in the front end. 203 is a full time case but can be converted to part time. A case that is both full and part time --- cannot think of one

nu2-72 · 02-01-2004, 01:06 PM

If you are talking up to today, I do not know how to answer that.
My new Suburban has a series of bottons on the dash for:
2wd high
4wd high
4wd low
and auto.
I can lock the transfer into full lock with either 4 lo or 4 high.
Auto gives the vehicle the ability to sense road conditions and shift in and out as needed.
Lockouts totally disengeged the front shafts independent of the T-case. Meaning if you pulled the T-case into 4Hi but forgot the lockouts, it would not work. You need both to get 4X4. Full time just required the interior shifter for in or out. Hubs were in already.
I would have to guess no until independent front ends came about.
Just my OP.

Scrub · 02-01-2004, 01:20 PM

Hmm..
I think what you are looking for is a t-case that has a "Differential" between the front and rear like the 203, but you could turn out some hubs to run smooth.

I have thought about that too. I was thinking that a stock 203 could be used with a set of hubs installed. If you wanted full time 4wd, you would lock in the hubs and run it in the normal "Unlocked" mode.
For "Froadn" you would keep the hubs in and Lock the t-case.

The abnormal operation would be to Lock the t-case and turn the hubs out. Because of the "Diff" in the t-case, if you didn't lock it in, the front axle would just spin like an open rear axle with a wheel jacked up, so you would have to lock it. The only bad part about this is the front driveline and axle would still be turning all the time, just not locked in, so gas mileage might not improve as much as it could. You would get rid of the bucking that you get on tight corners with a no-hub front axle.

203 exploded view:

http://darkwing.uoregon.edu/~jrice/N...203diagram.jpg

Anyone know why you couldn't do this? I know a 203 isn't all that strong, but I was thinking about this for a commuter rig in winter. What part of a 203 breaks?

smokekiki · 02-01-2004, 03:42 PM

I don't know how it could be full time and part time.It is or it isn't.As far as the 203 goes,it might not be quite as strong as a 205,but they don't break that easy.When the chain gets a lot of slop in it that is when most problems happen.If you are putting hubs on the front,you should also spend the $40.00 for the part time kit.It takes a few hours to put in with hand tools.The kit gives you 2wd high and low and 4wd high and low.With the hubs unlocked you need to run with the transfer in lock or it sends the power to the wheels that are slipping.All the power would go to the front axle,and with the hubs unlocked=no move.Running the transfer in lock all the time is a lot of wear and tear.

**Stocker** · 02-01-2004, 07:06 PM

Quote:

Originally posted by smokekiki
I don't know how it could be full time and part time.It is or it isn't.

I'm not so sure this is true, although it may be true as far as GM is concerned. I think Jeep has a system (Select-Trac?) which can operate as 2WD, part-time 4WD (locked in), or AWD, with center differential. At least I believe that system exists in some Jeeps.

smokekiki · 02-02-2004, 01:28 AM

I may be wrong,but I feel a full time case can't be put in 2wd.If you can put it in 2wd it is a part time system.

**JIMs70GMC** · 02-02-2004, 07:04 AM

building on Stockers reply: Two words "viscous coupling" I believe the newer jeep cherokees have this type of system with a tourqe convereter vice differential providing front / rear slip. Kinda like all wheel drive that can be locked in w/ a low range like a conventional 4wd. Well maybe they push a button to lock in true 4wd.

Blazer1970 · 02-02-2004, 10:35 AM

Your question isn't real clear, but the NP203 is a full time case (all wheel drive in the normal HI an LO positions), and it acts exactly like a part time case in 4 wheel drive mode when in the high lock and low lock positions (center diff locked).

bills · 02-02-2004, 10:44 PM

looking for info about 55 2nd series on a mid 70s 2wd 1/2 ton frame hay dennyb did to remove your truck from frame yet if so is the 2wd frame for sale i live in nj and would like buy it if its forsale thanks bills

Devil'S Ride · 02-03-2004, 02:47 AM

just my .02$ I got the 203 with a PT kit, it is fairly handy, but I have worn it out or something, as it doesnt always shift into gear, leaving me stranded, having to crawl underneath and shift it from there,
but the 2wd low has been really helpful a few times....

DennyB · 02-04-2004, 10:04 AM

Thanks for the input guys.
I know of a 80s blazer that has the NP208 and the front axel was swapped for an earlier one where you can turn the knob on the front hubs to lock.
Any one know what the advantage to this is?

bills, You have email

smokekiki · 02-04-2004, 12:43 PM

Devils Ride,Check to make sure your shifter linkage is adjusted right.If you can shift it from underneath,I would think the internals are ok. 1-place shift lever in neutral.2-unhook the adjustable rod ends from the transfer case levers.3-insert a 11/64th drill bit through thealignment holes in the shifterlevers[these are the levers attatched to the shifter,not the ones attatched to the transfer case]4-place the range shift lever in neutral,this is the outer lever.5-place the lockout shift lever in the unlocked position,this is the inner lever.Both levers should be vertical.6-adjust the shifter linkage to fit.7-remove drill bit.Hope this helps your shifting.

72SWB4X4 · 02-10-2004, 09:36 PM

how can you tell the 205 and 203 apart???

the 208 with added hubs works SO NICE as you do not have to backup 50 ft to unlock the front hubs BUT you will have to get out and physically lock in the hubs before you can 4by

**JIMs70GMC** · 02-10-2004, 10:11 PM

The shift patterns is one way, but the easiest would be on the back of the 205 in the center of the case is a cover about 2.5" round with three bolts.

72SWB4X4 · 02-10-2004, 10:21 PM

well i guess i have a 205 and i think that is good??

**JIMs70GMC** · 02-10-2004, 10:24 PM

Yep! The only other thing it could be if it were stock would be a dana 20 and they only came in K5s with an inline 6, or something weird like that.
The NP205 is regarded as one of the best.

72SWB4X4 · 02-10-2004, 11:55 PM

well i guess it is all good BB to 350 turbo to 205 to 12 bolt posi

smokekiki · 02-11-2004, 01:46 AM

Might want to be a little easy on the right foot.A big block can get to be a little to much torque for a 350 trans.

**JIMs70GMC** · 02-11-2004, 06:49 AM

...and the 12 bolt! LOL!

02-01-2004, 10:55 AM	#1
DennyB Led Sled! Discs R 4 ME! Join Date: Jan 2001 Location: Toms River, NJ, USA (Transplanted Hoosier) Posts: 7,327	Q- for you 4x4x nuts Does GM make or have they made a T-case with both FT and PT 4wd? I know the np205 is PT and the 203 & 208 are FT. Thanks __________________ "Never ride faster than your Angel can fly" I.M.O.M,W,J&C Patriot Guard Rider

02-01-2004, 01:06 PM	#3
nu2-72 Senior Member Join Date: Apr 2001 Location: Amazonia, Mo. USA Posts: 2,821	If you are talking up to today, I do not know how to answer that. My new Suburban has a series of bottons on the dash for: 2wd high 4wd high 4wd low and auto. I can lock the transfer into full lock with either 4 lo or 4 high. Auto gives the vehicle the ability to sense road conditions and shift in and out as needed. Lockouts totally disengeged the front shafts independent of the T-case. Meaning if you pulled the T-case into 4Hi but forgot the lockouts, it would not work. You need both to get 4X4. Full time just required the interior shifter for in or out. Hubs were in already. I would have to guess no until independent front ends came about. Just my OP. __________________ 72 3/4 4x4 350 4spd 72 3/4 4x4 350 auto 2004 Duramax Silverado 4x4 2006 Duramax Crew cab 4x4 2010 Harley Ultra Limited 2011 Harley Street Glide

02-01-2004, 01:20 PM	#4
Scrub Collector of rusty Items Join Date: Dec 2001 Location: Sisters,Oregon USA Posts: 731	Hmm.. I think what you are looking for is a t-case that has a "Differential" between the front and rear like the 203, but you could turn out some hubs to run smooth. I have thought about that too. I was thinking that a stock 203 could be used with a set of hubs installed. If you wanted full time 4wd, you would lock in the hubs and run it in the normal "Unlocked" mode. For "Froadn" you would keep the hubs in and Lock the t-case. The abnormal operation would be to Lock the t-case and turn the hubs out. Because of the "Diff" in the t-case, if you didn't lock it in, the front axle would just spin like an open rear axle with a wheel jacked up, so you would have to lock it. The only bad part about this is the front driveline and axle would still be turning all the time, just not locked in, so gas mileage might not improve as much as it could. You would get rid of the bucking that you get on tight corners with a no-hub front axle. 203 exploded view: http://darkwing.uoregon.edu/~jrice/N...203diagram.jpg Anyone know why you couldn't do this? I know a 203 isn't all that strong, but I was thinking about this for a commuter rig in winter. What part of a 203 breaks? __________________ Scrub Sisters, Oregon - Home of the Sisters Rodeo. 70 GMC 1,000,000 + miles 72 K-20 project, 456 Dana60 front, Corp14 rear w/locker, 265R19.5 tires 20-ply. Warn 12k winches both ends, Cross-over steering with raised tie-rod, Powerbox steering, 4500 watt 120-AC power, Air, Hydraulic aux power, 4 inch lift, 5000 lb air-bags both ends.

02-01-2004, 03:42 PM	#5
smokekiki Mike Join Date: Jan 2003 Location: west chester pa Posts: 2,474	I don't know how it could be full time and part time.It is or it isn't.As far as the 203 goes,it might not be quite as strong as a 205,but they don't break that easy.When the chain gets a lot of slop in it that is when most problems happen.If you are putting hubs on the front,you should also spend the $40.00 for the part time kit.It takes a few hours to put in with hand tools.The kit gives you 2wd high and low and 4wd high and low.With the hubs unlocked you need to run with the transfer in lock or it sends the power to the wheels that are slipping.All the power would go to the front axle,and with the hubs unlocked=no move.Running the transfer in lock all the time is a lot of wear and tear. __________________ 70'c/10, 71 suburban4x4 402bb, 72suburban 4/6 drop, 72k/5 4x4 blazer 4" lift 35 tires

02-02-2004, 01:28 AM	#7
smokekiki Mike Join Date: Jan 2003 Location: west chester pa Posts: 2,474	I may be wrong,but I feel a full time case can't be put in 2wd.If you can put it in 2wd it is a part time system. __________________ 70'c/10, 71 suburban4x4 402bb, 72suburban 4/6 drop, 72k/5 4x4 blazer 4" lift 35 tires

02-01-2004, 01:01 PM	#2
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,572	The 208 is a part time case but usually had auto hubs in the front end. 203 is a full time case but can be converted to part time. A case that is both full and part time --- cannot think of one

02-02-2004, 07:04 AM	#8
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	building on Stockers reply: Two words "viscous coupling" I believe the newer jeep cherokees have this type of system with a tourqe convereter vice differential providing front / rear slip. Kinda like all wheel drive that can be locked in w/ a low range like a conventional 4wd. Well maybe they push a button to lock in true 4wd. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

02-02-2004, 10:35 AM	#9
Blazer1970 Registered User Join Date: Dec 1999 Location: Old Mission, MI, USA Posts: 2,510	Your question isn't real clear, but the NP203 is a full time case (all wheel drive in the normal HI an LO positions), and it acts exactly like a part time case in 4 wheel drive mode when in the high lock and low lock positions (center diff locked). __________________ Tim

02-02-2004, 10:44 PM	#10
bills Registered User Join Date: Feb 2004 Location: jn Posts: 3	mid 70s frame under 55 2nd series 1/2 ton looking for info about 55 2nd series on a mid 70s 2wd 1/2 ton frame hay dennyb did to remove your truck from frame yet if so is the 2wd frame for sale i live in nj and would like buy it if its forsale thanks bills

02-03-2004, 02:47 AM	#11
Devil'S Ride Registered User Join Date: Nov 2003 Location: Grants PassOregon Posts: 335	just my .02$ I got the 203 with a PT kit, it is fairly handy, but I have worn it out or something, as it doesnt always shift into gear, leaving me stranded, having to crawl underneath and shift it from there, but the 2wd low has been really helpful a few times.... __________________ The Devil 1983 ONE TON 454/400/208 11" of lift on 44's

02-04-2004, 10:04 AM	#12
DennyB Led Sled! Discs R 4 ME! Join Date: Jan 2001 Location: Toms River, NJ, USA (Transplanted Hoosier) Posts: 7,327	Thanks for the input guys. I know of a 80s blazer that has the NP208 and the front axel was swapped for an earlier one where you can turn the knob on the front hubs to lock. Any one know what the advantage to this is? bills, You have email __________________ "Never ride faster than your Angel can fly" I.M.O.M,W,J&C Patriot Guard Rider

02-04-2004, 12:43 PM	#13
smokekiki Mike Join Date: Jan 2003 Location: west chester pa Posts: 2,474	Devils Ride,Check to make sure your shifter linkage is adjusted right.If you can shift it from underneath,I would think the internals are ok. 1-place shift lever in neutral.2-unhook the adjustable rod ends from the transfer case levers.3-insert a 11/64th drill bit through thealignment holes in the shifterlevers[these are the levers attatched to the shifter,not the ones attatched to the transfer case]4-place the range shift lever in neutral,this is the outer lever.5-place the lockout shift lever in the unlocked position,this is the inner lever.Both levers should be vertical.6-adjust the shifter linkage to fit.7-remove drill bit.Hope this helps your shifting. __________________ 70'c/10, 71 suburban4x4 402bb, 72suburban 4/6 drop, 72k/5 4x4 blazer 4" lift 35 tires

02-10-2004, 09:36 PM	#14
72SWB4X4 Florida Key's Member Join Date: May 2003 Location: Key West Florida Posts: 143	interuption how can you tell the 205 and 203 apart??? the 208 with added hubs works SO NICE as you do not have to backup 50 ft to unlock the front hubs BUT you will have to get out and physically lock in the hubs before you can 4by __________________ Craig Wood 1972 SWB Chevy Cheyenne 4X4 Restored stock except 454 (481 cu. in. now) most options Available pictures of my truck http://myoldtruck.com/gallery/browse...500&userid=528 Come to florida and visit www.Paradisewatersports.com

02-10-2004, 10:11 PM	#15
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	The shift patterns is one way, but the easiest would be on the back of the 205 in the center of the case is a cover about 2.5" round with three bolts. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

02-10-2004, 10:21 PM	#16
72SWB4X4 Florida Key's Member Join Date: May 2003 Location: Key West Florida Posts: 143	ok then well i guess i have a 205 and i think that is good?? __________________ Craig Wood 1972 SWB Chevy Cheyenne 4X4 Restored stock except 454 (481 cu. in. now) most options Available pictures of my truck http://myoldtruck.com/gallery/browse...500&userid=528 Come to florida and visit www.Paradisewatersports.com



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02-10-2004, 10:24 PM	#17
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	Yep! The only other thing it could be if it were stock would be a dana 20 and they only came in K5s with an inline 6, or something weird like that. The NP205 is regarded as one of the best. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

02-10-2004, 11:55 PM	#18
72SWB4X4 Florida Key's Member Join Date: May 2003 Location: Key West Florida Posts: 143	drivetrain well i guess it is all good BB to 350 turbo to 205 to 12 bolt posi __________________ Craig Wood 1972 SWB Chevy Cheyenne 4X4 Restored stock except 454 (481 cu. in. now) most options Available pictures of my truck http://myoldtruck.com/gallery/browse...500&userid=528 Come to florida and visit www.Paradisewatersports.com

02-11-2004, 01:46 AM	#19
smokekiki Mike Join Date: Jan 2003 Location: west chester pa Posts: 2,474	Might want to be a little easy on the right foot.A big block can get to be a little to much torque for a 350 trans. __________________ 70'c/10, 71 suburban4x4 402bb, 72suburban 4/6 drop, 72k/5 4x4 blazer 4" lift 35 tires

02-11-2004, 06:49 AM	#20
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	...and the 12 bolt! LOL! __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

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