Rear End Numbers and Ratio - The 1947 - Present Chevrolet & GMC Truck Message Board Network

StuckinAz · 02-27-2010, 04:32 PM

I am in the middle of servicing the rear diff. on my 64 1/2 ton GMC. It has a tag on it that say "46-13" on the top and "3.54". Now i'm thinking 3.54 gears....What is this thing and whats it doing under my truck?

It has patent #'s on it twice and the only other # was C90294 at the top right rear and 44-1 at the right bottom rear. Its a 3 rib on the driver side and 1 rib on the passeger side of the carrier. Any idea what I'm looking at without seeing a pic?

rwgregory · 02-27-2010, 11:04 PM

Sounds to me like you are looking at a Dana 44 rear axle with a 46 tooth ring gear and a 13 tooth pinion that would calc. out to a 3:54 rear end ratio. What it is doing under your truck is probably pushing it down the road with power from the engine and trans.
All kidding aside, GMC's came stock from the factory with Dana rear axles. 1/2 tons had Dana 44's and 3/4's came with Dana 60's.

*LILRED66* · 02-27-2010, 11:06 PM

Nicely put...

StuckinAz · 02-27-2010, 11:09 PM

That explains it. I couldnt find anything that would help on the GMC. Everything point to 3.55. Thanks for your help!

02-27-2010, 04:32 PM	#1
StuckinAz GM ONLY Join Date: Feb 2010 Location: Goodyear, Arizona Posts: 73	Rear End Numbers and Ratio I am in the middle of servicing the rear diff. on my 64 1/2 ton GMC. It has a tag on it that say "46-13" on the top and "3.54". Now i'm thinking 3.54 gears....What is this thing and whats it doing under my truck? It has patent #'s on it twice and the only other # was C90294 at the top right rear and 44-1 at the right bottom rear. Its a 3 rib on the driver side and 1 rib on the passeger side of the carrier. Any idea what I'm looking at without seeing a pic? __________________ "59 Apache Short Step "64 GMC Short Wide "07 Crewcab "08 Tricked Tahoe Last edited by StuckinAz; 02-27-2010 at 04:50 PM.

02-27-2010, 11:04 PM	#2
rwgregory Registered User Join Date: Apr 2005 Location: Chula Vista, California Posts: 495	Re: Rear End Numbers and Ratio Sounds to me like you are looking at a Dana 44 rear axle with a 46 tooth ring gear and a 13 tooth pinion that would calc. out to a 3:54 rear end ratio. What it is doing under your truck is probably pushing it down the road with power from the engine and trans. All kidding aside, GMC's came stock from the factory with Dana rear axles. 1/2 tons had Dana 44's and 3/4's came with Dana 60's. __________________ rwgregory 67 GMC 2500 ,2w/d wide box 305 V-6, 4-speed

02-27-2010, 11:06 PM	#3
LILRED66 Account Suspended Join Date: May 2005 Location: Kansas City, KS Posts: 3,906	Re: Rear End Numbers and Ratio Nicely put...

02-27-2010, 11:09 PM	#4
StuckinAz GM ONLY Join Date: Feb 2010 Location: Goodyear, Arizona Posts: 73	Re: Rear End Numbers and Ratio That explains it. I couldnt find anything that would help on the GMC. Everything point to 3.55. Thanks for your help! __________________ "59 Apache Short Step "64 GMC Short Wide "07 Crewcab "08 Tricked Tahoe Last edited by StuckinAz; 02-27-2010 at 11:14 PM.



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