Ring and Pinion Gears

[72barracuda]

Hi everyone, first I want to thank everyone for all the helpful comments over the years and the shared interest in our old Mopars. I am wanting to change out the 3.91 gears that I had installed many years ago for 3.23 which is a better match for my needs these days. I want to be sure I get the right gears for this 489 case since I am wanting to provide the parts for a local shop to do the work. Can I assume that any 3.23 gears for Chrysler 8 3/4, 489 are going to work? I see pinion spline count specified on some sets. Were pinions with different spline counts used in this housing? Looking at Yukon set on the link below. This seems a lot more cost effective than paying over $3000 for overdrive add on or $1500 for a second third member.

Chrysler 8 3/4 Tapered- Ring and Pinion

 

[Rob C]

Each case requires a gear set for that case. So, if you have 3.23 gears that are for or from a 489 case, your good to go, it doesn’t matter where it came from.

The only difference could be the spline count for the pinion. If you need a smaller count spline, 10 spline, then just make sure you have one for the pinion. They are available new. Sometimes hard to find, sometimes not.

The factory did use both spline counts in the 8-3/4. Specifically, I can’t say they did this only with……. Or only in…. Or it has to be this very particular drivetrain… etc… Just make sure that the yoke has the same spline count as the pinion and the right U joint size.

 

[Challenger RTA]

You changed out gears before? were they 3.23,where are they? I would set up a chunk for 3.23 and leave the 3.91 set up for when you feel Froggy!

 

[72barracuda]

These were changed many years ago and the old 3.23 gears were thrown out with other seemingly useless stuff that I didn't want to keep moving. Yes it would be nice to have two set ups since they are easy enough to swap and I like the acceleration that I have but there is a lot of highway driving where I live and the 3.91s are just not practical. The Gear Vendors overdrive seems perfect but I don't want to put that money in the current drivetrain right now.

 

[DaveInDenver]

Hi everyone, first I want to thank everyone for all the helpful comments over the years and the shared interest in our old Mopars. I am wanting to change out the 3.91 gears that I had installed many years ago for 3.23 which is a better match for my needs these days. I want to be sure I get the right gears for this 489 case since I am wanting to provide the parts for a local shop to do the work. Can I assume that any 3.23 gears for Chrysler 8 3/4, 489 are going to work? I see pinion spline count specified on some sets. Were pinions with different spline counts used in this housing? Looking at Yukon set on the link below. This seems a lot more cost effective than paying over $3000 for overdrive add on or $1500 for a second third member.

Chrysler 8 3/4 Tapered- Ring and Pinion

I suggest contacting either Brewer Transmissions or Passion Performance Transmissions. Both are long time MOPAR businesses. Brewer is a family ram shop with about the best prices and selection of parts. Passion is more corporate, has some customized items, but a little more pricey. I think they are your safest opportunity for quality service and support. I have used both over the years.

www.brewersperformance.com
www.passonperformance.com

 

[Dodgeboy]

Getting a second set of taller rear tires would be a option too, aslong as your current rear tires aren't very tall. I went from normal tire height with 3:23's to a 29.5" tall tire with 4:30's and my hwy rpm stayed the same, just harder to spin the tires but hey, spinnin' an't winnin'

 

[ted s]

https://www.doctordiff.com