Dear friends
How to get more speed with factory GMC CCKW split axles, transmission and transfer case?
Changing the axles gear ratio? Is there an upgraded pinion and gear supplier for the split model?
Or modifiyng the transmission components?
Suggestions are very welcome!
Thanks!
Randal
GMC CCKW MORE SPEED
Moderator: kw573
-
- G-Command Sergeant Major
- Posts: 244
- Joined: Tue May 10, 2005 8:51 am
- Location: Harney, Maryland
- Contact:
Re: GMC CCKW MORE SPEED
What speeds are you looking for? We milled out our front hubs so we're not dragging the front axle and reset the governor. We run 55 with no problem and get 10mpg
Paul Rea
MVPA #31101
1941 CCKW 352
1942 CCKW 353
1944 Ward Lafrance M1A1
1944 Brockway C666
1944 Ben Hur
1944 Willys MB
1945 CCKW Tipper
MVPA #31101
1941 CCKW 352
1942 CCKW 353
1944 Ward Lafrance M1A1
1944 Brockway C666
1944 Ben Hur
1944 Willys MB
1945 CCKW Tipper
-
- Jeep Heaven
- Posts: 49841
- Joined: Sun Mar 02, 2008 12:37 pm
- Location: Proving Ground
Re: GMC CCKW MORE SPEED
I wouldn't advise altering a CCKW into a turnpike cruiser. The truck was designed with a suspension configured for off road operation and 45 mph on hard surfaced road design from the 30's-40's.. 70 years takes a toll on these old trucks. If you want to go faster, buy a modern truck.
Split transfers will not take the pounding.
Split transfers will not take the pounding.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO
-
- G-First Lieutenant
- Posts: 615
- Joined: Fri Jan 30, 2004 9:49 am
- Location: Pembroke NH USA
- Contact:
Re: GMC CCKW MORE SPEED
Ben, I thought that the Splits would take abuse better because they have shims in the xfer whereas the banjo you just throw the parts at it?
Stephen Keith AKA Dr Deuce
www.ww2movievehicles,com
9 CCKWs 6x6
7 Chevys 4x4
www.ww2movievehicles,com
9 CCKWs 6x6
7 Chevys 4x4
- John Neuenburg
- Gee Old Hand
- Posts: 3769
- Joined: Mon Mar 24, 2003 11:18 am
- Location: U.S. Left Coast
Re: GMC CCKW MORE SPEED
Randal, do not be deterred by the "speed police" (fun police??) on the G who would have you obey the manuals, and others who will bad mouth any mods to a MV, especially the mods you can't see or hear. It's your truck and if you want to go faster just understand what your truck does and doesn't do at 50 or 60 with regards to stopping and steering.
I don't know much about jimmys but seems to me increasing the engine rpm, if it is happy, could be a good option. Decreasing driveline friction losses and fiddling with the governor makes sense. I hear there is a 302 that can drop in, and speed parts are available for those. That should get you to a higher rpm plus make more power up there so you don't slow down as much on the hills. That means higher average speed if you drive in hills.
I don't know much about jimmys but seems to me increasing the engine rpm, if it is happy, could be a good option. Decreasing driveline friction losses and fiddling with the governor makes sense. I hear there is a 302 that can drop in, and speed parts are available for those. That should get you to a higher rpm plus make more power up there so you don't slow down as much on the hills. That means higher average speed if you drive in hills.
Military Vehicle Collectors of California
MVPA 7404
1942 Ford GPW British Special Air Service Regiment Replica
1944 Willys MB
1941 Indian 640
BSA Folding Bicycles
M1942 Command Post Tent
MVPA 7404
1942 Ford GPW British Special Air Service Regiment Replica
1944 Willys MB
1941 Indian 640
BSA Folding Bicycles
M1942 Command Post Tent
-
- Jeep Heaven
- Posts: 49841
- Joined: Sun Mar 02, 2008 12:37 pm
- Location: Proving Ground
Re: GMC CCKW MORE SPEED
Split CCKW (TIMKEN) Transfers had a chronic problem of insufficient lubrication to the uppermost gears and ran super hot at increased speeds, there are bulletins in the Army Motors, etc., that warn not to use heavier lube than GO-90 as 85/140, or plain GO-140 cause more heat.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO
Who is online
Users browsing this forum: No registered users and 49 guests