question for the diff experts - The 1947 - Present Chevrolet & GMC Truck Message Board Network

casey · 07-27-2003, 11:59 PM

my son bought two diffs for his 77 ford 4x4, for 150.00 there 410's, heres the confusion for me the rear is 37 crown 9 pinion=4.11111111 the front is 45 crown 11 pinion=4.090909 does it matter if there not exactly the same ratio, i was going to put the rear diff together myself cause the gears come out assembled, just have to pull the axels, it looks like it a limited slip or posi, how can I tell, one more question how do you change axel and pinion seals, thanks for the help

'72 Shorty · 07-28-2003, 01:28 AM

That difference in ratios is really common, and that's why I will never run in 4wd on a hard surface. I've even run as much difference as 5.29 in one axle and 5.38 in the other. nothing to worry about.

If it's got any kind of springs or pretty much anything but 4 bevel gears and a cross shaft inside the carrier it's probably got a limited slip.

I can't remember how to change the seals on a ford rear. they aren't the simple c-clip like my chev.

Blue_71 · 07-28-2003, 01:29 AM

.02 wont affect anything, its when you get into putting like for instance 4.11 and 3,73 together

casey · 07-28-2003, 02:58 AM

have you guys ever pulled axles and just put them back in with out changing the seals

07-27-2003, 11:59 PM	#1
casey Registered User Join Date: Jan 2003 Location: Kelowna B.C. Canada Posts: 2,048	question for the diff experts my son bought two diffs for his 77 ford 4x4, for 150.00 there 410's, heres the confusion for me the rear is 37 crown 9 pinion=4.11111111 the front is 45 crown 11 pinion=4.090909 does it matter if there not exactly the same ratio, i was going to put the rear diff together myself cause the gears come out assembled, just have to pull the axels, it looks like it a limited slip or posi, how can I tell, one more question how do you change axel and pinion seals, thanks for the help

07-28-2003, 01:28 AM	#2
'72 Shorty I finally got an avatar Join Date: Jan 2003 Location: Cheney, WA Posts: 180	That difference in ratios is really common, and that's why I will never run in 4wd on a hard surface. I've even run as much difference as 5.29 in one axle and 5.38 in the other. nothing to worry about. If it's got any kind of springs or pretty much anything but 4 bevel gears and a cross shaft inside the carrier it's probably got a limited slip. I can't remember how to change the seals on a ford rear. they aren't the simple c-clip like my chev. __________________ -72 C-10 short step (straight line only) 12.922/102.28 -69 C-20 on Propane (DD) -69 C-10 -56 Mack B-753LS (tow rig) -94 Chev K2500 Short Ex-Cab -89 Isuzu Trooper...Kinda -03 Kawasaki KFX-400 -05 Suzuki DRZ-400S

07-28-2003, 02:58 AM	#4
casey Registered User Join Date: Jan 2003 Location: Kelowna B.C. Canada Posts: 2,048	have you guys ever pulled axles and just put them back in with out changing the seals



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