need help with rearend posi or not? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

baggedondubs67 · 04-26-2003, 09:36 PM

I need help in finding out if my dads rearend for his 49 chevy is posi or not and if U can tell what it came off of. The number on the rearend is 5PMC337 thanks.

72 CustomCamper · 04-27-2003, 01:51 AM

The easiest way to tell is jack it up and spin a tire, if they turn in the same direction it has a posi, if they turn in opposite directions it has an open diff...

Chuck

baggedondubs67 · 04-27-2003, 01:33 PM

it is a posi but I want to know the gear ratio if someone could tell me please. thanks

beau396 · 04-27-2003, 01:48 PM

Without dropping the dif cover, or 3rd member if it is that type, and physically counting the pinion and ring gear teeth you only have two choices. You can chalk or make a mark on the drive line, and one on the wheels. spin the wheel one revolution and count the number of times that the drive shaft spins, for example if the driveline spins 4 times and a little past your reference mark you can guess that it has 4:10's or 4:11's. This will give you an approximate value for your gear ratio and get you in the ball park. The other meathod is to look for either a stamped metal tag with manufactures part numbers, sometimes attatched to the dif cover, or sometimes there will be numbers stamped on to one of the axle tubes. You maybe able to get a parts house, that sells Dana corp parts, to look in one of there catalogs and decipher the numbers for you. Try Six States or a ring and pinion shop.

04-26-2003, 09:36 PM	#1
baggedondubs67 Registered User Join Date: Jan 2003 Location: Avenal, Ca. Posts: 22	need help with rearend posi or not? I need help in finding out if my dads rearend for his 49 chevy is posi or not and if U can tell what it came off of. The number on the rearend is 5PMC337 thanks.

04-27-2003, 01:51 AM	#2
72 CustomCamper huh ??? Join Date: Nov 2002 Location: Fredericksburg,Va. Posts: 3,369	The easiest way to tell is jack it up and spin a tire, if they turn in the same direction it has a posi, if they turn in opposite directions it has an open diff... Chuck __________________ 90 Blazer Silverado 350w/ 700R4 and 32" Kelly's "I am a bomb technician. If you see me running try to keep up!"

04-27-2003, 01:33 PM	#3
baggedondubs67 Registered User Join Date: Jan 2003 Location: Avenal, Ca. Posts: 22	it is it is a posi but I want to know the gear ratio if someone could tell me please. thanks

04-27-2003, 01:48 PM	#4
beau396 Registered User Join Date: Nov 2002 Location: oak harbor wa Posts: 61	Without dropping the dif cover, or 3rd member if it is that type, and physically counting the pinion and ring gear teeth you only have two choices. You can chalk or make a mark on the drive line, and one on the wheels. spin the wheel one revolution and count the number of times that the drive shaft spins, for example if the driveline spins 4 times and a little past your reference mark you can guess that it has 4:10's or 4:11's. This will give you an approximate value for your gear ratio and get you in the ball park. The other meathod is to look for either a stamped metal tag with manufactures part numbers, sometimes attatched to the dif cover, or sometimes there will be numbers stamped on to one of the axle tubes. You maybe able to get a parts house, that sells Dana corp parts, to look in one of there catalogs and decipher the numbers for you. Try Six States or a ring and pinion shop. __________________ '67 C10 short box fleet side wood bed small rear window frame off restoration. 396BB,Th400, ps, pwr disc 5 lug, posi 3.07, 2000 Suburban 60/40 pwr seats, 2.5" front drop 4" rear, powder coated running gear.



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