rear end questions? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Brently · 04-19-2004, 08:28 AM

i have checked the rear end by pulling the cover off and trying to count the gears to find out what gear ratio it is - i know it is a posi and i believe it to be a 3.42 is this possible? also it seems to have stopped the popping in the rear end with slow turns by changing the fluid and adding additive - still pops ever so often - my other question is how much fluid do i put in it? fill plug is low in differential - do i just fill it up until it comes out of the fill hole? help - thanks, Brent

**smitty62** · 04-19-2004, 09:03 AM

How are you going to fill it above the fill hole?

JimKshortstep4x4 · 04-19-2004, 09:49 AM

When empty it will take about 3 1/2 pints. You can fill it until it comes out or until you can touch the fluid.

The ring gear should be stamped with the teeth count/ratio.

Jim

Brently · 04-19-2004, 02:16 PM

does the gear ratio of 3.42 sound like it is correct? for a posi? again i am ignorant on this subject? thanks, Brent

JimKshortstep4x4 · 04-19-2004, 02:48 PM

It is possible to have a 3:42 posi as they are available aftermarket.

Jim

**smitty62** · 04-19-2004, 03:59 PM

Also available from late 70's on--until they went to 10 bolt.

flip66 · 04-19-2004, 05:29 PM

I have a 69 with 3:42 posi show on the factory build sheet.

lukecp · 04-19-2004, 06:31 PM

Quote:

Originally posted by flip66
I have a 69 with 3:42 posi show on the factory build sheet.

It says 3.42 posi on the build sheet? I'd like to see a pic of that.....everything i have came across has said that the only 1/2 ton 12-bolt ratios were 3.07, 3.73, and 4.11.

1969 GMC · 04-19-2004, 06:39 PM

i'd like to see that too...the only 3.42's i've seen were in C/20 BB trucks w/ Dana 60 rear.

flip66 · 04-19-2004, 09:29 PM

you got me I got home and looked at the build sheet and it shows positrack but I dont see where it says 3.42. I thought I saw it on there. I have had it apart and it dose have 3.42. I was told they did come with 3.42. This truck was a special orderd and built 08/18/69 so I figer its possiable. If I can get a good copy of this sheet can I post and some help me figure out waht this stuff means.

Vince M · 04-19-2004, 10:24 PM

Can you post some details of your truck. You didn't really say it was a 1/2 ton or 3/4 ton and whether it is a Chevy or GMC. All of this might help.

Mike C · 04-19-2004, 10:29 PM

The Dana 60 trucks had 3.54. There is a 3.3 ratio 60 gearset that was available in the 80's, but not 67-72.

so cal tz · 04-21-2004, 04:39 PM

I have question? I have newer style rear end, say a mid to late 80's 12bolt 5 lug rear end. Will the gear's ( 3rd member ) fit or interchange white a 69 chev 1/2 ton 12bolt 6 lug rear end. Before I start tearing things apart. PLEASE HELP My only means of transportation right now.

04-19-2004, 08:28 AM	#1
Brently Registered User Join Date: Feb 2002 Location: Chattanooga Posts: 151	rear end questions? i have checked the rear end by pulling the cover off and trying to count the gears to find out what gear ratio it is - i know it is a posi and i believe it to be a 3.42 is this possible? also it seems to have stopped the popping in the rear end with slow turns by changing the fluid and adding additive - still pops ever so often - my other question is how much fluid do i put in it? fill plug is low in differential - do i just fill it up until it comes out of the fill hole? help - thanks, Brent

04-19-2004, 09:03 AM	#2
smitty62 Registered User Join Date: May 2002 Location: North Carolina Posts: 1,234	How are you going to fill it above the fill hole? __________________ Stepsides look like real trucks! Smitty

04-19-2004, 02:16 PM	#4
Brently Registered User Join Date: Feb 2002 Location: Chattanooga Posts: 151	rear end gear does the gear ratio of 3.42 sound like it is correct? for a posi? again i am ignorant on this subject? thanks, Brent

04-19-2004, 03:59 PM	#6
smitty62 Registered User Join Date: May 2002 Location: North Carolina Posts: 1,234	Also available from late 70's on--until they went to 10 bolt. __________________ Stepsides look like real trucks! Smitty

04-19-2004, 06:39 PM	#9
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	i'd like to see that too...the only 3.42's i've seen were in C/20 BB trucks w/ Dana 60 rear. __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

04-19-2004, 09:49 AM	#3
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	When empty it will take about 3 1/2 pints. You can fill it until it comes out or until you can touch the fluid. The ring gear should be stamped with the teeth count/ratio. Jim

04-19-2004, 02:48 PM	#5
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	It is possible to have a 3:42 posi as they are available aftermarket. Jim

04-19-2004, 05:29 PM	#7
flip66 Registered User Join Date: Jan 2004 Location: Garland TX Dallas area Posts: 658	I have a 69 with 3:42 posi show on the factory build sheet.

04-19-2004, 09:29 PM	#10
flip66 Registered User Join Date: Jan 2004 Location: Garland TX Dallas area Posts: 658	you got me I got home and looked at the build sheet and it shows positrack but I dont see where it says 3.42. I thought I saw it on there. I have had it apart and it dose have 3.42. I was told they did come with 3.42. This truck was a special orderd and built 08/18/69 so I figer its possiable. If I can get a good copy of this sheet can I post and some help me figure out waht this stuff means.

04-19-2004, 10:24 PM	#11
Vince M Senior Member Join Date: Apr 2000 Location: Orlando, FL Posts: 1,076	Can you post some details of your truck. You didn't really say it was a 1/2 ton or 3/4 ton and whether it is a Chevy or GMC. All of this might help. __________________ ............................................................ 68 Chevy CST SWB w/LS1, carb & 700r4. Golden Anniversary clone with a few improvements.

04-19-2004, 10:29 PM	#12
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,723	The Dana 60 trucks had 3.54. There is a 3.3 ratio 60 gearset that was available in the 80's, but not 67-72. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

04-21-2004, 04:39 PM	#13
so cal tz Registered User Join Date: Apr 2004 Location: san diego ca Posts: 32	I have question? I have newer style rear end, say a mid to late 80's 12bolt 5 lug rear end. Will the gear's ( 3rd member ) fit or interchange white a 69 chev 1/2 ton 12bolt 6 lug rear end. Before I start tearing things apart. PLEASE HELP My only means of transportation right now. __________________ 67heaven327



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