1968 Rockwell Transfer Case....is this rare? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

eastcoastcivil · 07-13-2009, 08:47 AM

I have a 68 GMC 4x4 with a 250 inline 6, 4 speed Muncie tranny, Rockwell transfer case and 12 bolt rear. I was just wondering about the transfer case...its a T221 and I was wondering how rare these are now? I beleive these are the same transfer cases the rock crawler fellas look for.

martindc1 · 07-13-2009, 10:03 AM

The Rockwell is par for the course on the 67 and 68s. They are strong and if you make sure they have fluid you will be good. If they get low on fluid they have issues with some of the bearings. I don't think you can get many new parts for them now other than seals. Yours probably leaks some, I know mine does. I am not sure about the rock crawler guys, but I would think they would look for the NP205 over the Rockwell T221, which is the T221's successor. Not that the T221 isn't a good case, its just there are more parts out there for the NP205 and more transmission options. The NP205 was made from 69 through around 92 or so and was used on both automatic and manual transmissions, is found in both passenger and drivers drop configurations, both divorced and married configuration and was used in Fords and Dodges in addition to the GM trucks.

My 67 K20 is essentially the same setup as yours with a 250, sm420 transmission, and Rockwell T221 transfer case. Tough mine is a 3/4 ton and therefore has the ho52 rear axle with 4.57 gears. Interestingly it had a factory option of a PTO shaft coming out of the transfer case, though most of those parts have been lost somewhere along the way. With the PTO it has a factory tach and a hand throttle.

Oh and as far as finding these cases, they are around. They were also used on the 60-66 trucks independent of the transmission.

1969 GMC · 07-13-2009, 05:58 PM

no, they are not rare, and no, the rock crawler fellas do not look for them.

1969K10 · 07-13-2009, 09:34 PM

As much as I liked my Rockwell, once you have to do more than replace seals, they really aren't worth more than boat anchors. I would rather have my old Rockwell instead of this NP205, but I needed parts. The few parts I could find for it, you'd of thought were made of gold. It'd be awesome to find one close that had good parts that I needed.

And as stated, the wheeler's use the 205 due to part availability.

duallyjams · 07-15-2009, 07:32 AM

I have a couple of those boat anchors laying around.

**gmc 2500 4x4** · 03-29-2012, 05:25 AM

Quote:

Originally Posted by duallyjams

I have a couple of those boat anchors laying around.

jim do ya have the shifter bracket and linkage off one ? thanx, paul

martindc1 · 07-16-2009, 01:48 PM

Wonder how much gear whine these are supposed to have? I believe they have straight cut gears.

**Yukon Jack** · 07-16-2009, 04:36 PM

They are definitely louder than the NP205.

Redcap · 03-29-2012, 10:21 AM

Like the others have said, the T221 is a decent transfer case...but not as good or tough as the NP205. And they aren't rare at all.

67gmcstepside · 03-29-2012, 11:16 AM

Matter of fact I am junking 2 this weekend for scrape.

Redcap · 03-29-2012, 01:37 PM

Quote:

Originally Posted by 67gmcstepside

Matter of fact I am junking 2 this weekend for scrape.

I've scrapped more than a couple as well...always save the NP205s though!

andrewmp6 · 04-13-2012, 02:02 AM

Yeah a full size truck a np205 is the best oem t case made.On a jeep a dana 300 is the one they all love.

Dillon Rock · 06-21-2014, 11:53 PM

Anyone know the serial number rap sheets for the T221's off hand and what the 60-66 k series ran? Lookin to do an era correct 4x4 install and kinda need info before I go and do something bad.

**'68OrangeSunshine** · 06-22-2014, 06:12 PM

'68 was the only production year for the SM465/T221 transfercase. [GMC and Canadian plants - maybe into 1969]. After that they went to the SM465/NP205 and before that it was the SM420/T221. So it's kinda rare.

Dillon Rock · 06-22-2014, 07:53 PM

Ok well I found an add for a couple T221's on my local craigslist and two were divorced style and the third on was set up for a married application. All for an SM420 is what they were pulled off of. What would I have to do for frame member wise to cross from a c20 to a k20? Also front and rear suspension as well. I know leafs but how to go about modding it.

63chevyll · 06-24-2016, 02:31 AM

Wow. The stuff i find google searching stuff. Always brings me bak to here

07-13-2009, 08:47 AM	#1
eastcoastcivil Registered User Join Date: Apr 2007 Location: New Brunswick, Canada Posts: 201	1968 Rockwell Transfer Case....is this rare? I have a 68 GMC 4x4 with a 250 inline 6, 4 speed Muncie tranny, Rockwell transfer case and 12 bolt rear. I was just wondering about the transfer case...its a T221 and I was wondering how rare these are now? I beleive these are the same transfer cases the rock crawler fellas look for. __________________ If your not living for something, your dieing for nothing...

07-13-2009, 10:03 AM	#2
martindc1 Registered User Join Date: Jul 2009 Location: La Crosse, WI Posts: 218	Re: 1968 Rockwell Transfer Case....is this rare? The Rockwell is par for the course on the 67 and 68s. They are strong and if you make sure they have fluid you will be good. If they get low on fluid they have issues with some of the bearings. I don't think you can get many new parts for them now other than seals. Yours probably leaks some, I know mine does. I am not sure about the rock crawler guys, but I would think they would look for the NP205 over the Rockwell T221, which is the T221's successor. Not that the T221 isn't a good case, its just there are more parts out there for the NP205 and more transmission options. The NP205 was made from 69 through around 92 or so and was used on both automatic and manual transmissions, is found in both passenger and drivers drop configurations, both divorced and married configuration and was used in Fords and Dodges in addition to the GM trucks. My 67 K20 is essentially the same setup as yours with a 250, sm420 transmission, and Rockwell T221 transfer case. Tough mine is a 3/4 ton and therefore has the ho52 rear axle with 4.57 gears. Interestingly it had a factory option of a PTO shaft coming out of the transfer case, though most of those parts have been lost somewhere along the way. With the PTO it has a factory tach and a hand throttle. Oh and as far as finding these cases, they are around. They were also used on the 60-66 trucks independent of the transmission. __________________ Currently truckless, previous trucks: 67 K20, 87 K10 aka V10 & 72 C10 Last edited by martindc1; 07-13-2009 at 10:04 AM.

07-13-2009, 05:58 PM	#3
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	Re: 1968 Rockwell Transfer Case....is this rare? no, they are not rare, and no, the rock crawler fellas do not look for them. __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

07-13-2009, 09:34 PM	#4
1969K10 Senior Member Join Date: Jul 2004 Location: Clarks Hill, Indiana Posts: 733	Re: 1968 Rockwell Transfer Case....is this rare? As much as I liked my Rockwell, once you have to do more than replace seals, they really aren't worth more than boat anchors. I would rather have my old Rockwell instead of this NP205, but I needed parts. The few parts I could find for it, you'd of thought were made of gold. It'd be awesome to find one close that had good parts that I needed. And as stated, the wheeler's use the 205 due to part availability. __________________ 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)

07-15-2009, 07:32 AM	#5
duallyjams Registered User Join Date: May 2007 Location: Deale Md Posts: 4,663	Re: 1968 Rockwell Transfer Case....is this rare? I have a couple of those boat anchors laying around. __________________ James 63 GMC V6 4speed carryall 65 chevy swb bbw V8 auto 68 K20 327/4 speed, buddy buckets 2002 GMC CC Dually Duramax 64 GMC lwb 3/4 V6 4speed SOLD 66 GMC swb bbw buddy buckets SOLD IG duallyjams The only thing that stays the same is constant change!

07-16-2009, 01:48 PM	#7
martindc1 Registered User Join Date: Jul 2009 Location: La Crosse, WI Posts: 218	Re: 1968 Rockwell Transfer Case....is this rare? Wonder how much gear whine these are supposed to have? I believe they have straight cut gears. __________________ Currently truckless, previous trucks: 67 K20, 87 K10 aka V10 & 72 C10

07-16-2009, 04:36 PM	#8
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,686	Re: 1968 Rockwell Transfer Case....is this rare? They are definitely louder than the NP205. __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14

03-29-2012, 10:21 AM	#9
Redcap Registered User Join Date: May 2010 Location: Lewis County, WA Posts: 1,523	Re: 1968 Rockwell Transfer Case....is this rare? Like the others have said, the T221 is a decent transfer case...but not as good or tough as the NP205. And they aren't rare at all.

03-29-2012, 11:16 AM	#10
67gmcstepside Registered User Join Date: Jan 2010 Location: jackson Posts: 676	Re: 1968 Rockwell Transfer Case....is this rare? Matter of fact I am junking 2 this weekend for scrape.

04-13-2012, 02:02 AM	#12
andrewmp6 Registered User Join Date: Jan 2009 Location: Louisville,Ky Posts: 5,811	Re: 1968 Rockwell Transfer Case....is this rare? Yeah a full size truck a np205 is the best oem t case made.On a jeep a dana 300 is the one they all love.

06-21-2014, 11:53 PM	#13
Dillon Rock Registered User Join Date: Dec 2012 Location: Bangor, Michigan Posts: 375	Re: 1968 Rockwell Transfer Case....is this rare? Anyone know the serial number rap sheets for the T221's off hand and what the 60-66 k series ran? Lookin to do an era correct 4x4 install and kinda need info before I go and do something bad. __________________ That's the thing about a Chevrolet, no matter how they look, whether it be a trailer queen or a good ol' used farm truck, no other truck on the road will always look that damn good wearing a Bowtie.

06-22-2014, 06:12 PM	#14
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,504	Re: 1968 Rockwell Transfer Case....is this rare? '68 was the only production year for the SM465/T221 transfercase. [GMC and Canadian plants - maybe into 1969]. After that they went to the SM465/NP205 and before that it was the SM420/T221. So it's kinda rare. __________________ Every 25 years I like to rebuild that 292, whether it needs it or not.

06-22-2014, 07:53 PM	#15
Dillon Rock Registered User Join Date: Dec 2012 Location: Bangor, Michigan Posts: 375	Re: 1968 Rockwell Transfer Case....is this rare? Ok well I found an add for a couple T221's on my local craigslist and two were divorced style and the third on was set up for a married application. All for an SM420 is what they were pulled off of. What would I have to do for frame member wise to cross from a c20 to a k20? Also front and rear suspension as well. I know leafs but how to go about modding it. __________________ That's the thing about a Chevrolet, no matter how they look, whether it be a trailer queen or a good ol' used farm truck, no other truck on the road will always look that damn good wearing a Bowtie.

06-24-2016, 02:31 AM	#16
63chevyll gets board easy....... Join Date: Mar 2009 Location: Colorado Springs Posts: 717	Re: 1968 Rockwell Transfer Case....is this rare? Wow. The stuff i find google searching stuff. Always brings me bak to here



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