How durable is the rockwell transfer case - The 1947 - Present Chevrolet & GMC Truck Message Board Network

sakohntr · 01-03-2003, 08:58 PM

I am gonna make my one ton dump truck four wheel drive and just happen to have an extra 4 spd and rockwell setup. How durable were these? I dont know if this one is gear or chain drive. Anyone broke one of these before. I have seen the chain drive 203's break. thanks for your time bruce

srhart71 · 01-03-2003, 09:19 PM

You might want to talk with PONT. I believe he blew his up not to long ago. He could probably tell you how much abuse it took.

ckhd · 01-03-2003, 09:23 PM

I'd put it up against a 205 any day. The problem is that there are almost no parts available to fix them when they break.

I like the shift pattern better too. Keeps the shifter forward and out of the way.

sakohntr · 01-03-2003, 09:42 PM

No problems with spare parts up this way. many in the junkyard......

**JIMs70GMC** · 01-04-2003, 07:21 AM

It's gear drive.

**Yukon Jack** · 01-04-2003, 09:38 AM

I'm satisfied with mine and if you've got access to parts, your good to go.

About spare parts, I'm needing the coupler that is inside the adapter that connects the SM465 to the Rockwell - a couple board members have possible leads, but I'm always asking around to see if anyone has one available - have not been able to find one locally yet.

Pont · 01-04-2003, 02:56 PM

I recently lost the Rockwell t-case in my truck but not because it's a weak transfer case. Mine has had a leaking gasket since I've owned the truck and I ran it low on gear oil. If parts were easily available in my area for these Rockwells, I would go through and rebuild mine. Compared to the NP205, I think they are at least as tough. These are not chain driven cases.

I am going with the NP205 so I won't have to deal with parts availability in the future. They quit making the Rockwell T221 in either 68 or 69 and parts are not as easy and will not become an easier to get in the future. This was the deciding factor for me to go with the 205.

If I had a good one or if mine was still good, I would not hesitate to use it. I'm a huge fan of the Rockwell for it's low rear output for the rear driveshaft. It really helps with driveshaft angle on rigs with larger suspension lifts like mine.

Hope this helps........

sakohntr · 01-04-2003, 07:19 PM

Then its offficial. I am gonna try it.

Zeke · 01-04-2003, 08:19 PM

My dad has a 69 4x4 with a rockwell transfer case. bought it new and has over 500,000 miles on it with no trouble at all. only complaint is it weighs a ton (only when he had to change clutch)

Rod · 01-05-2003, 02:04 AM

I plan on a 1 ton dually 4x4 one day too... got my 205 sitting here... sold my 4 spd 205 one a while back shouldnt have but it was from a 77. A little different but would have worked... my 205 is from an auto now,... so not sure what Im going to do... but I would like a dana 60 front... how 'bout you?

JAKES 68GMC · 05-01-2006, 04:14 PM

I've got a Rockwell underneath the bench thats just like new. All it needs is a thrust washer (some reason it only had one

), but its not for sale. Very rugged t-case IMO.

boundstaffpress · 05-01-2006, 04:47 PM

Lots of abuse on mine. No problems as of yet. 104k since 1967.

1969 GMC · 05-01-2006, 07:40 PM

I didn't like mine, and how it sorta blew up on me. I could have taken it apart and did all new seals, but it was my DD at the time. Ran low on oil and the input bearing jumped ship. Never hear of this problem with NP205's, because they are not as tall as the Rockwell. Also, I don't know how common PTO's are for these since they use the weirdo pattern.

For what its worth, you can still buy EVERY new bearing and seal for them at car parts places. Hard parts will be your problem, but you probably won't break any of them (with the exception of the drive sleeve). From when I did the swap, it looks like a SM465/NP205 sleeve could be made to work.

I think that the divorced T221 would be a good case, if you made sure it didnt leak. The married case has the weak 10 spline connection, and even then yours may or may not be worn. If its really well worn, it could be just one dumped clutch away from leaving you stranded.

my 2 cents.

JAKES 68GMC · 05-01-2006, 08:58 PM

I guess I'm dumb, because I can't understand how one of the 10-spline sleeves could strip out. Anybody want to fill me in on that info?

1969 GMC · 05-01-2006, 11:40 PM

Quote:

Originally Posted by JAKES 68GMC

I guess I'm dumb, because I can't understand how one of the 10-spline sleeves could strip out. Anybody want to fill me in on that info?

I cut my finger on one of the edges. Scary huh?

Americanrider · 05-02-2006, 10:07 AM

Quote:

Originally Posted by JAKES 68GMC

I guess I'm dumb, because I can't understand how one of the 10-spline sleeves could strip out. Anybody want to fill me in on that info?

Simple, the more splines you have the more surface area you have to "carry" the torque load. 10 coarse splines does not have as much surface area as a 27 or 32 fine spline coupler. Just in the same way you can put more torque on a fine thread bolt than a corse thread because it has more surface area to distribute the load evenly.

http://www.offroaddesign.com/NP205tech.htm

01-03-2003, 08:58 PM	#1
sakohntr Registered User Join Date: Mar 2002 Location: Floodwood Minnesota Posts: 1,057	How durable is the rockwell transfer case I am gonna make my one ton dump truck four wheel drive and just happen to have an extra 4 spd and rockwell setup. How durable were these? I dont know if this one is gear or chain drive. Anyone broke one of these before. I have seen the chain drive 203's break. thanks for your time bruce __________________ 1967 K30 Napco 292/SM420 original paint 30k miles 1968 K60 Napco 396/5spd. dbl frame 52" michelins 1969 K10 SWB GMC 454/4spd 6" 35's posi,hooks 1972 C30 longhorn,BB/AT,A/C,Tilt,Toolbox,lokr 1987 K20 Chevrolet Suburban. 6" lift. 5.7L/TH400 1979 K60 GMC Coleman 4x4, 427/Allison.

01-03-2003, 09:23 PM	#3
ckhd Registered User Join Date: Oct 2000 Location: St. Johns, Arizona Posts: 2,660	I'd put it up against a 205 any day. The problem is that there are almost no parts available to fix them when they break. I like the shift pattern better too. Keeps the shifter forward and out of the way. __________________ my 2¢ - t.i.o.l.i. Bowen 1968 K20 fleet 1969 K10 swb fleet 1972 K10 Suburban 1972 C10 lwb step 1992 K1500 'burb 1995 K2500 'burb 1997 C1500 'burb 1999 K1500 2000 K1500 'burb Why do I own so many Suburbans?

01-03-2003, 09:42 PM	#4
sakohntr Registered User Join Date: Mar 2002 Location: Floodwood Minnesota Posts: 1,057	parts available No problems with spare parts up this way. many in the junkyard...... __________________ 1967 K30 Napco 292/SM420 original paint 30k miles 1968 K60 Napco 396/5spd. dbl frame 52" michelins 1969 K10 SWB GMC 454/4spd 6" 35's posi,hooks 1972 C30 longhorn,BB/AT,A/C,Tilt,Toolbox,lokr 1987 K20 Chevrolet Suburban. 6" lift. 5.7L/TH400 1979 K60 GMC Coleman 4x4, 427/Allison.

01-04-2003, 07:21 AM	#5
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	It's gear drive. __________________ 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

01-04-2003, 09:38 AM	#6
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,684	I'm satisfied with mine and if you've got access to parts, your good to go. About spare parts, I'm needing the coupler that is inside the adapter that connects the SM465 to the Rockwell - a couple board members have possible leads, but I'm always asking around to see if anyone has one available - have not been able to find one locally yet. __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14

01-03-2003, 09:19 PM	#2
srhart71 Registered User Join Date: Jul 2002 Location: China Grove, NC Posts: 147	You might want to talk with PONT. I believe he blew his up not to long ago. He could probably tell you how much abuse it took.

01-04-2003, 02:56 PM	#7
Pont I need another Barley Pop Join Date: Feb 2001 Location: Grants Pass, OR Posts: 1,629	I recently lost the Rockwell t-case in my truck but not because it's a weak transfer case. Mine has had a leaking gasket since I've owned the truck and I ran it low on gear oil. If parts were easily available in my area for these Rockwells, I would go through and rebuild mine. Compared to the NP205, I think they are at least as tough. These are not chain driven cases. I am going with the NP205 so I won't have to deal with parts availability in the future. They quit making the Rockwell T221 in either 68 or 69 and parts are not as easy and will not become an easier to get in the future. This was the deciding factor for me to go with the 205. If I had a good one or if mine was still good, I would not hesitate to use it. I'm a huge fan of the Rockwell for it's low rear output for the rear driveshaft. It really helps with driveshaft angle on rigs with larger suspension lifts like mine. Hope this helps........ __________________ 67 Short Fleet 4x4 04 Honda CRF450R 89 Toyota 4-Runner 34 Ford 2 door sedan - Long term project ---------------------------------------------- There is a very fine line between "hobby" and "mental illness"

01-04-2003, 07:19 PM	#8
sakohntr Registered User Join Date: Mar 2002 Location: Floodwood Minnesota Posts: 1,057	case's Then its offficial. I am gonna try it. __________________ 1967 K30 Napco 292/SM420 original paint 30k miles 1968 K60 Napco 396/5spd. dbl frame 52" michelins 1969 K10 SWB GMC 454/4spd 6" 35's posi,hooks 1972 C30 longhorn,BB/AT,A/C,Tilt,Toolbox,lokr 1987 K20 Chevrolet Suburban. 6" lift. 5.7L/TH400 1979 K60 GMC Coleman 4x4, 427/Allison.

01-04-2003, 08:19 PM	#9
Zeke Active Member Join Date: Jun 2002 Location: L.A. Lower Alabama Posts: 453	My dad has a 69 4x4 with a rockwell transfer case. bought it new and has over 500,000 miles on it with no trouble at all. only complaint is it weighs a ton (only when he had to change clutch) __________________ 1969 C10 350 3spd 1995 GMC 3500 XC 350 dually When Thomas Edison worked late into the night on the electric light, he had to do it by gas lamp or candle. I'm sure it made the work seem that much more urgent. George Carlin

01-05-2003, 02:04 AM	#10
Rod Join Date: Dec 1999 Location: Eastern - Manitoba Canada, Winnipeg Posts: 4,369	I plan on a 1 ton dually 4x4 one day too... got my 205 sitting here... sold my 4 spd 205 one a while back shouldnt have but it was from a 77. A little different but would have worked... my 205 is from an auto now,... so not sure what Im going to do... but I would like a dana 60 front... how 'bout you? __________________ Senior active founding member. 70 3/4 ton GMC Suburban 4x4 250/4 spd. 71 1/2 ton Suburban Chevy 4x4, 350/350 72 Chev 1 ton tow truck 402BB w/Holmes 440 wrecker on propane 2005 FLSTSCI Harley Springer 85 FXSB Harley Lowrider 72 Triumph 650 Bonneville 5spd "Poor people don't have hobbies" Quote from wife.

05-01-2006, 04:14 PM	#11
JAKES 68GMC Aluminum slot wheels rule... Join Date: Jan 2006 Location: Maine Posts: 6,212	Re: How durable is the rockwell transfer case I've got a Rockwell underneath the bench thats just like new. All it needs is a thrust washer (some reason it only had one ), but its not for sale. Very rugged t-case IMO.

05-01-2006, 04:47 PM	#12
boundstaffpress Jamie Hyneman is my twin Join Date: Nov 2005 Location: La Junta, Colorado Posts: 705	Re: How durable is the rockwell transfer case Lots of abuse on mine. No problems as of yet. 104k since 1967. __________________ Justin SOLD 1967 K10 Fleetside, 283, Front and Rear Posi SOLD Color Wiring Diagrams Now in High Resolution V8 and Cab and Cab and Chassis

05-01-2006, 07:40 PM	#13
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	Re: How durable is the rockwell transfer case I didn't like mine, and how it sorta blew up on me. I could have taken it apart and did all new seals, but it was my DD at the time. Ran low on oil and the input bearing jumped ship. Never hear of this problem with NP205's, because they are not as tall as the Rockwell. Also, I don't know how common PTO's are for these since they use the weirdo pattern. For what its worth, you can still buy EVERY new bearing and seal for them at car parts places. Hard parts will be your problem, but you probably won't break any of them (with the exception of the drive sleeve). From when I did the swap, it looks like a SM465/NP205 sleeve could be made to work. I think that the divorced T221 would be a good case, if you made sure it didnt leak. The married case has the weak 10 spline connection, and even then yours may or may not be worn. If its really well worn, it could be just one dumped clutch away from leaving you stranded. my 2 cents. __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

05-01-2006, 08:58 PM	#14
JAKES 68GMC Aluminum slot wheels rule... Join Date: Jan 2006 Location: Maine Posts: 6,212	Re: How durable is the rockwell transfer case I guess I'm dumb, because I can't understand how one of the 10-spline sleeves could strip out. Anybody want to fill me in on that info?



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