10 Bolt Inners 12 Bolt Differential??
#1
10 Bolt Inners 12 Bolt Differential??
Help?!
The late Octania's wife has an issue. I am trying to keep up with Octania's (aka Chris Witt) 68 442 W30 Convertible. Type O
Years ago, he changed the mild 3:08 into a 4:11 that gives me a headache. I want to go more than a 1/4 mile at a time. Problem? No idea what happened to the old 3:08 ring and pinion. No longer available. I really want my driver back to original. Any suggestions? Am I making sense?
The late Octania's wife has an issue. I am trying to keep up with Octania's (aka Chris Witt) 68 442 W30 Convertible. Type O
Years ago, he changed the mild 3:08 into a 4:11 that gives me a headache. I want to go more than a 1/4 mile at a time. Problem? No idea what happened to the old 3:08 ring and pinion. No longer available. I really want my driver back to original. Any suggestions? Am I making sense?
Last edited by rocketette; May 13th, 2019 at 01:24 PM. Reason: More information
#2
Yes, perfect sense. It's good to hear from you, and also to know that you are still enjoying the '68.
I would be surprised if the W-30 originally had a 3.08 rear gears, so that may have been a donor from another vehicle. Anyway, that doesn't matter at this point.
You need to verify which carrier is in there so that you can ensure you get the right gears for it as there are three different series carriers for different gear ratios. If it is the same rearend and carrier that had the 3.08 gears, then the current 4.10 gear set may be the Richmond Gear aftermarket gears that are made to fit the 3.08-3.23 carrier (#671 posi). That would make finding replacement gears a bit easier as it would give an additional option of the aftermarket 3.42 gears in addition to the factory 3.08 and 3.23 gears..
Here's some info that Brian Trick posted a long time ago that explains the different carrier / gears:
O-Type 12 Bolt
Here is a list of the posi units & what gears they will fit:
#673 = 2.56 & 2.78 ratios, 28 spline
#671 = 3.08 & 3.23 ratios, 28 spline
#588 = 3.42 & anything numerically higher, 28 spline
#672 = 3.42 & anything numerically higher, 31 spline
***The 31 spline axles were offered in late 67-68 OAI cars only.
Once you know what you have, post in the parts Wanted section for the ring and pinion gears.
I would be surprised if the W-30 originally had a 3.08 rear gears, so that may have been a donor from another vehicle. Anyway, that doesn't matter at this point.
You need to verify which carrier is in there so that you can ensure you get the right gears for it as there are three different series carriers for different gear ratios. If it is the same rearend and carrier that had the 3.08 gears, then the current 4.10 gear set may be the Richmond Gear aftermarket gears that are made to fit the 3.08-3.23 carrier (#671 posi). That would make finding replacement gears a bit easier as it would give an additional option of the aftermarket 3.42 gears in addition to the factory 3.08 and 3.23 gears..
Here's some info that Brian Trick posted a long time ago that explains the different carrier / gears:
O-Type 12 Bolt
Here is a list of the posi units & what gears they will fit:
#673 = 2.56 & 2.78 ratios, 28 spline
#671 = 3.08 & 3.23 ratios, 28 spline
#588 = 3.42 & anything numerically higher, 28 spline
#672 = 3.42 & anything numerically higher, 31 spline
***The 31 spline axles were offered in late 67-68 OAI cars only.
Once you know what you have, post in the parts Wanted section for the ring and pinion gears.
Last edited by Fun71; May 13th, 2019 at 05:24 PM.
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