Chevy diff. ratios - Pirate4x4.Com : 4x4 and Off-Road Forum

OverThrottle · 06-13-2003, 07:23 PM

One of my friends has a mid 70's blazer and he was telling me that while replacing the tie rods, he discovered that the front differential had a different gear ratio then the rear. I had never heard of this and wanted to see if that was possible. It seems to me that unless the tires are of different size, (which they are'nt) or the transfer case compensated for this, the while thing would bind up whenever you put it into 4WD.

Anybody ever heard of a setup like this?

Toploader · 06-13-2003, 08:00 PM

Someone before him must have swapped gears, I dont think there was a factory set-up like that.

OverThrottle · 06-13-2003, 08:03 PM

Hmm... If that is the case, would it even be drivable in 4WD? I am not sure what transfercase he has (I thin it may be a NP208 but am unsure) and if it happened to have a internal diff. in the transfer case (like the NP203) would that allow it dirve normally?

SCOTTS_4X · 06-13-2003, 08:18 PM

how far off was it? was it like 4.09's and 4.10's or 4.11's? because the early dana 44's used a 4.09 ratio with the 4.10 rear gear. if it was any further off than that is was someone that wither installed one set of gears and not the other, or swapped an axle with a miss-matched ratio.

-Scott

Oatmeal · 06-13-2003, 08:39 PM

It's because the front axle is made by Dana/Spicer and the rear is a corporate 12 bolt, so if the rear is, say, a 4.10 the closest ratio Dana used was a 4.09. It's normal. Heck, Ford used a 4.11/4.09 combo. So, I wouldn't be too concerned unless we're talking about a major difference in ratios

06-13-2003, 07:23 PM	#1 (permalink)
OverThrottle Registered User Join Date: May 2003 Member # 19500 Location: Ohio Posts: 407	Chevy diff. ratios One of my friends has a mid 70's blazer and he was telling me that while replacing the tie rods, he discovered that the front differential had a different gear ratio then the rear. I had never heard of this and wanted to see if that was possible. It seems to me that unless the tires are of different size, (which they are'nt) or the transfer case compensated for this, the while thing would bind up whenever you put it into 4WD. Anybody ever heard of a setup like this?

06-13-2003, 08:00 PM	#2 (permalink)
Toploader Registered User Join Date: Jan 2003 Member # 16737 Location: Chillin with Clayton Bigsby Posts: 2,206	Someone before him must have swapped gears, I dont think there was a factory set-up like that. __________________ 72 Rockwelled yeah whatever... All my shits heavy.

06-13-2003, 08:18 PM	#4 (permalink)
SCOTTS_4X Registered User Join Date: Jul 2002 Member # 12780 Location: Paso Robles, ca Posts: 1,772	how far off was it? was it like 4.09's and 4.10's or 4.11's? because the early dana 44's used a 4.09 ratio with the 4.10 rear gear. if it was any further off than that is was someone that wither installed one set of gears and not the other, or swapped an axle with a miss-matched ratio. -Scott __________________ "A fear of weapons is a sign of retarded sexual and emotional maturity." -Sigmund Frued

06-13-2003, 08:39 PM	#5 (permalink)
Oatmeal Registered User Join Date: Oct 2002 Member # 14600 Location: Covina,Ca. Posts: 1,010	It's because the front axle is made by Dana/Spicer and the rear is a corporate 12 bolt, so if the rear is, say, a 4.10 the closest ratio Dana used was a 4.09. It's normal. Heck, Ford used a 4.11/4.09 combo. So, I wouldn't be too concerned unless we're talking about a major difference in ratios Last edited by Oatmeal; 06-13-2003 at 08:43 PM.

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06-13-2003, 08:03 PM	#3 (permalink)
OverThrottle Registered User Join Date: May 2003 Member # 19500 Location: Ohio Posts: 407	Hmm... If that is the case, would it even be drivable in 4WD? I am not sure what transfercase he has (I thin it may be a NP208 but am unsure) and if it happened to have a internal diff. in the transfer case (like the NP203) would that allow it dirve normally?