73-87chevytrucks.com

73-87 Chevy _ GMC Trucks => 4 Wheel Drives => Topic started by: 78GMC on August 13, 2001, 09:45:00 pm

Title: gears
Post by: 78GMC on August 13, 2001, 09:45:00 pm

I'm wondering if someone knows what the gear ratio is in a 78 GMC Sierra Grande, as well as the shift pattern from top to bottom for the transfer case.  I just have a goofy picture with four wheels, no 2H/4h...nuthin.
Thanks.

Title: Re:Gears
Post by: 84Scotts on August 14, 2001, 01:52:00 am

The gear ratio of your '78 will depend on if its a 1/2, 3/4, or 1 ton. Also, what engine and transmission did the truck come with? The ratio will depend on this info, too.

The shift pattern from top to bottom for the four wheel drive should be: 2 Hi, 4 Hi, Neutral, and 4 Lo.

Go to members.aol.com/CSmith669...specs.html and it will tell you your axle ratio.

Title: gears
Post by: high rider on August 29, 2001, 09:34:00 pm

the best way to check your gear ratio is too pull the rear cover off and divide the next too the last too numbers on the ring gear.that will come out too be 308- 343-373-or 411 these are the most common gear ratios in a stock truck. your 4x4 shifter should be as follows-- starting from all the way forward with the shifter 4L-N-2H-4H  see ya, hope this helps

Title: gears
Post by: 78GMC on October 12, 2001, 07:56:00 pm

Thanks for the input and information.  

Title: full time
Post by: cooter61 on October 14, 2001, 09:26:00 am

Well that goofy shift pattern that just shows you the wheels, tells me that its a Full Time 4WD and the shift Pattern I think would be 4WHigh , 4WH Lock,  N , 4WLow Lock.
The 4WHLock and  N maybe turned around and the pattern would start at the top.

Title: Re: full time
Post by: 85 k30 502ss on December 24, 2001, 09:45:00 pm

sounds like a 203, they go from seat forward  


4hi lock, 4hi, neutral, 4low, 4low lock

Edited by: 85 k30 502ss at: 12/25/01 3:47:02 am

Title: yep thats the pattern
Post by: 1979blazer on January 06, 2002, 07:16:00 pm

yep thats it

Edited by: 1979blazer at: 4/21/04 11:42 pm

Title: Re: gears
Post by: walnut on July 31, 2002, 08:59:00 pm

i have a 78 chevy silverado and my shifter pattern is 2whi at the top then 4whi, neutral, and 4 lo