stupid question ??? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jcueckert13 · 09-02-2003, 05:44 PM

i am looking at getting a new trans in my gmc. currently i have a four speed with an underdrive(sm465?) and i like having the underdrive but i also want a 5th gear. i am wondering if there are any trans that fit this idea or if it is just not possible. btw it is a 69 gmc lwb 4x4

Longhorn Man · 09-02-2003, 10:55 PM

Well, all trannys have the aformentioned under drive. Every gear except the final drive on an old tranny is underdrive. The final gear is one to one...direct drive, and then the newer overdrives that'll spin the drivce shaft faster than engine speed.
I'll asume you actually mean a granny gear, or a gear that is worthless in all real aplications in day to day life.
I am unaware of any overdrive trannys with a granny gear in them at all.
If your truck is a 3/4 ton or a one ton, your granny gear may actually be the low gear in the rear axle, and a 'normal' first gear.

1969 GMC · 09-03-2003, 12:03 AM

i think the NV4500 may have a granny gear, but maybe its not as low as the SM465's (i.e. you can actually use it when driving).
i know that the clark 5 speed, and 5 speed OD manual trannies have a pretty low first gear, like 6.5 to 1.

jcueckert13 · 09-03-2003, 06:01 PM

thanks for the info i did mean granny gear and ill look in to the clark five speed

jcueckert13 · 09-03-2003, 06:20 PM

hey 1969 gmc the nv4500 has a 6.3 to 1 granny gear and the sm465 has 6.5 to 1. i think i made my decision and will go with the nv4500. thanks again

09-02-2003, 05:44 PM	#1
jcueckert13 Registered User Join Date: Apr 2003 Location: Edgewood New Mexico Posts: 2,088	stupid question ??? i am looking at getting a new trans in my gmc. currently i have a four speed with an underdrive(sm465?) and i like having the underdrive but i also want a 5th gear. i am wondering if there are any trans that fit this idea or if it is just not possible. btw it is a 69 gmc lwb 4x4

09-03-2003, 12:03 AM	#3
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	i think the NV4500 may have a granny gear, but maybe its not as low as the SM465's (i.e. you can actually use it when driving). i know that the clark 5 speed, and 5 speed OD manual trannies have a pretty low first gear, like 6.5 to 1. __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

09-03-2003, 06:01 PM	#4
jcueckert13 Registered User Join Date: Apr 2003 Location: Edgewood New Mexico Posts: 2,088	thanks for the info i did mean granny gear and ill look in to the clark five speed __________________ 1990 subaru legcy (daily driver) 1987 Toyota 4runner (weekend toy) 1968 C30 flatbed dually 1970 C10 longbed stepside (in pieces) 1976 Dodge Dart 1963 Dodge Dart

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

09-02-2003, 10:55 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Well, all trannys have the aformentioned under drive. Every gear except the final drive on an old tranny is underdrive. The final gear is one to one...direct drive, and then the newer overdrives that'll spin the drivce shaft faster than engine speed. I'll asume you actually mean a granny gear, or a gear that is worthless in all real aplications in day to day life. I am unaware of any overdrive trannys with a granny gear in them at all. If your truck is a 3/4 ton or a one ton, your granny gear may actually be the low gear in the rear axle, and a 'normal' first gear.

09-03-2003, 06:20 PM	#5
jcueckert13 Registered User Join Date: Apr 2003 Location: Edgewood New Mexico Posts: 2,088	hey 1969 gmc the nv4500 has a 6.3 to 1 granny gear and the sm465 has 6.5 to 1. i think i made my decision and will go with the nv4500. thanks again



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.