410 gearing to 488's

[panama rubicon]

Awesome. Can't wait to get back to Panama for the journey of jeep culture.

Thank you

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[Jteakus]

Measure from the ground to center of hub on rear tire and double it.
Sixth gear is 1.00
Lock trans in 6th gear and run 60 mph
Plug your numbers into this calculator: http://wallaceracing.com/calc-gear-tire-rpm-mph.php#google_vignette

 

[Jteakus]

That'll get you real close, at least for a guess. Jacking it up, pulling the cover and getting numbers from ring gear will speak the truth.

 

[RangerG]

Running 5:13 gears with BFG KO 2 I think I’m just over stock RPM with 33’s. Rubicon model. Gas. Like about 100 at 70

 

[Janster]

skip the 4:88 go to 5:13. That’s what I did

Don’t ya’ll have concerns about the teeth being too thin in that gear ratio?

Reason I say that… back in the day… we had a built YJ with Dana 44’s on 35’s (from a Grand Wagoneer). We put 4.56 gears to keep the ‘teeth’ stronger versus 4.88’s or higher.

But then again….. back then, 33‘s and 35’s were popular and 37’s were considered HUGE. Today? Holy crap….people be putting 40‘s on without batting an eyelash.

 

[Wheelin98TJ]

Don’t ya’ll have concerns about the teeth being too thin in that gear ratio?

Reason I say that… back in the day… we had a built YJ with Dana 44’s on 35’s (from a Grand Wagoneer). We put 4.56 gears to keep the ‘teeth’ stronger versus 4.88’s or higher.

But then again….. back then, 33‘s and 35’s were popular and 37’s were considered HUGE. Today? Holy crap….people be putting 40‘s on without batting an eyelash.

The teeth don’t get thinner or weaker as ratios change. It’s an old myth. The overall size of the pinion head is smaller which leads to the incorrect conclusion it’s weaker. It’s not. Between different ratios, the tooth counts are different so they have the appropriate tooth size and tooth surface contact areas.

 

[Stan H]

The teeth don’t get thinner or weaker as ratios change. It’s an old myth. The overall size of the pinion head is smaller which leads to the incorrect conclusion it’s weaker. It’s not. Between different ratios, the tooth counts are different so they have the appropriate tooth size and tooth surface contact areas.

I know that's what everyine says , but to tell you this I am sure I will see backlash . Let's see the data , let's see a study, let's see as many teeth stripped off a 4.10 or 4.5y pinion as a 5.13 pinion. Show that to me so I can have a different opinion.

 

[Wheelin98TJ]

I know that's what everyine says , but to tell you this I am sure I will see backlash . Let's see the data , let's see a study, let's see as many teeth stripped off a 4.10 or 4.5y pinion as a 5.13 pinion. Show that to me so I can have a different opinion.

I don't know of any data that proves this.

Best I can do is a chat I had with Dana a few months ago.

 

[OldButStillJeeping]

Sorry, but I am late to the party. The string method works well every time. I don't use a string but instead, mark the flange and diff with a Sharpy and count revolutions. The difference between 3.77 and 4.10 is very noticeable.

And I usually jack up both rear wheels and have 2 people spin the tires somewhat equally. Vehicle in neutral. It works with a spool, locker, limited slip or open diff. Doesn't require spider gears in the diff.

If you have portals it should work as well. Edit: As long as you know the portal ratio and can do a little math.

I have never pulled a diff cover to check R&P ratios. It is kinda silly. There are easy methods. I have actually done this alone: 2 small spots of spray paint on the tire tread, laying underneath I spin the tires with my feet and count revolutions looking at the driveshaft and my sharpy marks. In 4 decades of this kinda stuff I haven't been wrong... yet.

 

[AstroZombie]

get a Bluetooth obdII reader, OBDII bypass cable, download Jscan, pay teh $20 to register your VIN and check the programmed gear ratio. Have jscan is something i think everyone should have. All in probably cost
you ~$100

 

[XraytecH]

get a Bluetooth obdII reader, OBDII bypass cable, download Jscan, pay teh $20 to register your VIN and check the programmed gear ratio. Have jscan is something i think everyone should have. All in probably cost
you ~$100

100%

 

[Stan H]

get a Bluetooth obdII reader, OBDII bypass cable, download Jscan, pay teh $20 to register your VIN and check the programmed gear ratio. Have jscan is something i think everyone should have. All in probably cost
you ~$100

Which Bluetooth obdII reader and OBD bypass cable do you recommend

 

[Uparms]

I don't know of any data that proves this.

Best I can do is a chat I had with Dana a few months ago.

Not to side track but how the heck did you get them to respond. I got 4 dam messages into them this past 12 days and they can't get off their butts! WTF. @DanaAftermarket.

 

[AstroZombie]

Which Bluetooth obdII reader and OBD bypass cable do you recommend

I got these ones:
https://www.amazon.com/dp/B076XVQMVS?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1

https://www.amazon.com/dp/B08ZL4LRVK?ref=ppx_yo2ov_dt_b_fed_asin_title

 

[RangerG]

Don’t ya’ll have concerns about the teeth being too thin in that gear ratio?

Reason I say that… back in the day… we had a built YJ with Dana 44’s on 35’s (from a Grand Wagoneer). We put 4.56 gears to keep the ‘teeth’ stronger versus 4.88’s or higher.

But then again….. back then, 33‘s and 35’s were popular and 37’s were considered HUGE. Today? Holy crap….people be putting 40‘s on without batting an eyelash.

I once ask a Dana spicer representative about that. He told on the Dane 44 it doesn’t become a problem until above 6. So 513’ won’t be a problem

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