what happens if your front and rear end ratios are different? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

willett · 02-27-2009, 11:19 PM

can you do it within reason?

cdowns · 02-28-2009, 09:36 AM

with your front and rear wheels going at different speeds when you're in 4wd things wear and break quick

Longhorn321 · 02-28-2009, 02:38 PM

You might have better luck with an answer if you post your question in "Drivetrain" instead of "Electrical".

Longhorn Man · 02-28-2009, 03:25 PM

good point. I moderate both pages, and that fact slipped my mind since it first got posted.
I'll move it, but actually I'll send it to the 4X4 section.

b454rat · 02-28-2009, 06:33 PM

Most factory 4wd's have different ratios front/rear. 4.09 front, 4.10 rear. The most extreme I've seen is the early bronco's, have a set that has 3.54s up front and 3.50 for the rear. Somewhere I've read as much as 3% difference between the two....

**special-K** · 03-01-2009, 05:48 PM

The idea is keep them as close as possible,like the same.

skchevota · 03-01-2009, 10:30 PM

Bad things happen....... Ok there is always some differance, just tires being more worn on one end will change the ratio, but yes, you want to keep them as close as posible so things dont bind up. when you turn in 4x4 you will have a tire that has to slip because the front and rear are traveling around a differant size radius.If you had you ratios off it would be doing this going forward all the time, some thinng will give. If it is close and you only drive it in the mud or snow it will be fine, if you are trying to run 3.73 and 4.10 on hard dirt or road, you better call a tow truck!!!!!

skchevota · 03-01-2009, 10:50 PM

opps, posted twice...

nvrsatisfied · 03-06-2009, 02:08 PM

like what he said^ if your some really soupy stuff allowing everything to spin quite freely your good to go..as soon as it grabs you better have a friend around to tow you home.....or dog leg it with what works. get the grear ratio as close as you can.

72 CustomCamper · 03-06-2009, 03:45 PM

I think my blazer has miss matched gears. Last week we had a good snow fall. I went out using 4x. The rear felt like it wanted to over run the front, and when I hit a dry spot the front would make a popping sound. The rear has been changed to a 12 bolt, so I'm thinking I have 3:42's in front and 3:73's rear. I'm going to try to find time to pull the diff covers and make sure this weekend...

Chuck

haysonj · 03-06-2009, 08:10 PM

I actually changed my rear to a 14 bolt corp so I could get the 4.09 gear in the back to match the dana 44 in front.

02-27-2009, 11:19 PM	#1
willett Another Day, Another Dollar Join Date: Nov 2008 Location: North Vancouver, BC Posts: 1,316	what happens if your front and rear end ratios are different? can you do it within reason? __________________ -78 K20 Cheyenne 454 long box, 4" lift, 35" MT's, '84 cab, '80 box "its hip to be square"

02-28-2009, 09:36 AM	#2
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: what happens if your front and rear end ratios are different? with your front and rear wheels going at different speeds when you're in 4wd things wear and break quick __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

02-28-2009, 02:38 PM	#3
Longhorn321 Size Matters Join Date: Aug 2007 Location: Lyman, SC Posts: 9,189	Re: what happens if your front and rear end ratios are different? You might have better luck with an answer if you post your question in "Drivetrain" instead of "Electrical". __________________ "Reading the owners manual is only for quitters." Jason Harper, Bloomberg News. ...WOOOO HOOOO!!!!

02-28-2009, 03:25 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: what happens if your front and rear end ratios are different? good point. I moderate both pages, and that fact slipped my mind since it first got posted. I'll move it, but actually I'll send it to the 4X4 section.

02-28-2009, 06:33 PM	#5
b454rat Senior Member Join Date: May 2004 Location: Binghamton, NY Posts: 3,469	Re: what happens if your front and rear end ratios are different? Most factory 4wd's have different ratios front/rear. 4.09 front, 4.10 rear. The most extreme I've seen is the early bronco's, have a set that has 3.54s up front and 3.50 for the rear. Somewhere I've read as much as 3% difference between the two.... __________________ 2000 GMC CCSB 454/4L80 6” lift SAS 1999 Chevy CCSB 454/NV4500 4” SAS 1999 GMC Yukon 350/4L60 6" SAS

03-01-2009, 05:48 PM	#6
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,851	Re: what happens if your front and rear end ratios are different? The idea is keep them as close as possible,like the same. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

03-01-2009, 10:30 PM	#7
skchevota Registered User Join Date: Oct 2006 Location: Evans, Colorado Posts: 530	Re: what happens if your front and rear end ratios are different? Bad things happen....... Ok there is always some differance, just tires being more worn on one end will change the ratio, but yes, you want to keep them as close as posible so things dont bind up. when you turn in 4x4 you will have a tire that has to slip because the front and rear are traveling around a differant size radius.If you had you ratios off it would be doing this going forward all the time, some thinng will give. If it is close and you only drive it in the mud or snow it will be fine, if you are trying to run 3.73 and 4.10 on hard dirt or road, you better call a tow truck!!!!!

03-01-2009, 10:50 PM	#8
skchevota Registered User Join Date: Oct 2006 Location: Evans, Colorado Posts: 530	Re: what happens if your front and rear end ratios are different? opps, posted twice... Last edited by skchevota; 03-01-2009 at 10:52 PM. Reason: same post posted twice

03-06-2009, 02:08 PM	#9
nvrsatisfied Registered User Join Date: Oct 2007 Location: oklahoma Posts: 457	Re: what happens if your front and rear end ratios are different? like what he said^ if your some really soupy stuff allowing everything to spin quite freely your good to go..as soon as it grabs you better have a friend around to tow you home.....or dog leg it with what works. get the grear ratio as close as you can. __________________ Lug Nuts Classic Rides. (Bodywork, small fab, and Restorations) Perry, Ok. We're just two guys, trying our best. 72 cheyenne super https://67-72chevytrucks.com/vboard/...d.php?t=811512 55 chevy truck http://67-72chevytrucks.com/vboard/s...d.php?t=840174

03-06-2009, 03:45 PM	#10
72 CustomCamper huh ??? Join Date: Nov 2002 Location: Fredericksburg,Va. Posts: 3,368	Re: what happens if your front and rear end ratios are different? I think my blazer has miss matched gears. Last week we had a good snow fall. I went out using 4x. The rear felt like it wanted to over run the front, and when I hit a dry spot the front would make a popping sound. The rear has been changed to a 12 bolt, so I'm thinking I have 3:42's in front and 3:73's rear. I'm going to try to find time to pull the diff covers and make sure this weekend... Chuck __________________ 90 Blazer Silverado 350w/ 700R4 and 32" Kelly's "I am a bomb technician. If you see me running try to keep up!"

03-06-2009, 08:10 PM	#11
haysonj Registered User Join Date: Dec 2007 Location: Santa Maria, Ca. Posts: 1,423	Re: what happens if your front and rear end ratios are different? I actually changed my rear to a 14 bolt corp so I could get the 4.09 gear in the back to match the dana 44 in front. __________________ 69 Chevy 4x4 383 Power



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