Rear gear ratio
08-03-2008, 08:56 PM
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Car: 85 Firebird & Grand Prix GXP
Engine: LG4 305 (originally 2.8L V6)
Transmission: 700R4
Axle/Gears: 10 bolt 3:43 Open Diff.
Rear gear ratio
Anybody able to tell me what gears I have by looking at the pictures I took?
08-03-2008, 09:38 PM
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Car: 85 Firebird & Grand Prix GXP
Engine: LG4 305 (originally 2.8L V6)
Transmission: 700R4
Axle/Gears: 10 bolt 3:43 Open Diff.
Re: Rear gear ratio
I don't really know much about gears. Am I just removing that back panel? Would that leak differential fluid?
08-03-2008, 10:08 PM
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Car: 1986 corvette Z51
Engine: L98
Transmission: doug nash 4+3 speed
Axle/Gears: 3:42 posi
Re: Rear gear ratio
I just went to a local dealer ship and gave them my vin and they told me anything i wanted to know!
kevin
kevin
08-03-2008, 10:09 PM
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Car: 85 Firebird & Grand Prix GXP
Engine: LG4 305 (originally 2.8L V6)
Transmission: 700R4
Axle/Gears: 10 bolt 3:43 Open Diff.
Re: Rear gear ratio
Yeah because the car came with a V6 and was swapped out to a 305 and I wanted to know if the guy changed the gears too.
08-03-2008, 11:01 PM
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08-03-2008, 11:28 PM
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Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Re: Rear gear ratio
Looks like it has 23 year old oil in the diff. Pull the cover and change it anyway and while the cover is off, count the teeth.
08-04-2008, 06:41 AM
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Car: 85 Firebird & Grand Prix GXP
Engine: LG4 305 (originally 2.8L V6)
Transmission: 700R4
Axle/Gears: 10 bolt 3:43 Open Diff.
Re: Rear gear ratio
Alright I'll pull the cover. I just thought I heard there was something about the number of bolts on the cover that could tell what gears there are.
Seems like you guys think original gears...So that'd be 2.73 for the V6 right? Only thing I know is that I've only been able to spin one tire. Don't know if that adds anything.
Seems like you guys think original gears...So that'd be 2.73 for the V6 right? Only thing I know is that I've only been able to spin one tire. Don't know if that adds anything.
08-04-2008, 08:10 AM
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Car: 1992 Camaro RS
Engine: 305 TBI
Transmission: 700R4
Axle/Gears: 2.73
Re: Rear gear ratio
Alright I'll pull the cover. I just thought I heard there was something about the number of bolts on the cover that could tell what gears there are.
Seems like you guys think original gears...So that'd be 2.73 for the V6 right? Only thing I know is that I've only been able to spin one tire. Don't know if that adds anything.
Seems like you guys think original gears...So that'd be 2.73 for the V6 right? Only thing I know is that I've only been able to spin one tire. Don't know if that adds anything.
08-04-2008, 09:03 AM
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Car: 1990 Nissan 240SX
Engine: GMPP Gen0 350 small block
Transmission: WC T5
Axle/Gears: Nissan R200 3.133, Tomei 2-way
Re: Rear gear ratio
If you don't want to pull the cover, another way is to spin the tyres and count the driveshaft rotations.
Spin it like 5-10 times and calculate an average driveshaft rotation per tyre rotation. It's more accurate than doing it once or twice.
Spin it like 5-10 times and calculate an average driveshaft rotation per tyre rotation. It's more accurate than doing it once or twice.
08-04-2008, 10:05 AM
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Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Re: Rear gear ratio
Looking at the rear cover, the only thing that will be known is that it's a 7.5" 10 bolt but then the majority of third gens also have that.
A 1985 Pontiac F-body with a V6 only had one gear ratio option. 3.42. To know if it's a posi or not, pull the cover and look, try spinning the wheels with them off the ground to see which way they turn or look for the G80 RPO code.
A 1985 Pontiac F-body with a V6 only had one gear ratio option. 3.42. To know if it's a posi or not, pull the cover and look, try spinning the wheels with them off the ground to see which way they turn or look for the G80 RPO code.
08-05-2008, 02:21 PM
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Car: 85 Firebird & Grand Prix GXP
Engine: LG4 305 (originally 2.8L V6)
Transmission: 700R4
Axle/Gears: 10 bolt 3:43 Open Diff.
Re: Rear gear ratio
I spun the tires and counted the rotations. One tire rotation was about 2 driveshaft rotations. Odd right?
08-05-2008, 09:04 PM
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Car: 85 Firebird & Grand Prix GXP
Engine: LG4 305 (originally 2.8L V6)
Transmission: 700R4
Axle/Gears: 10 bolt 3:43 Open Diff.
Re: Rear gear ratio
Anybody know what that makes the ratio?
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