Nitro gears: 4.88 or 5.29? (2 Viewers)

[Squeegee]

Just get 5.29s. Please

 

[eurorom]

I did the Transfer case regear to bring back to stock with 35" tires.

I do not recommend, my cruise control on baby hills downshifts.

Now I am thinking 34.2" tires all around!

Let's put miles on my YOKOHAMA MT Extreme tires first...lol

 

[bwakeling]

has anyone tried running 4.88 gears with 40s on a 80s series?

5.29's and a turbo is good with 40's otherwise going to be slow.

 

[AcroSteve]

What's the overdrive gear ratio on the 80?

 

[JoeCova]

What's the overdrive gear ratio on the 80?

Gear ratios, A redux

salvaged and re presented for your reading enjoyment, or whatever. FJ80 A440F 1-90 to 7-92 1st 2.950:1 2nd 1.530:1 3dr 1.000:1 OD .717:1 R 2.678:1 fluid cap 16.4 US qts FZJ80 A442f 8-92 to 12-94 1st 2.950:1 2nd 1.530:1 3rd 1.000:1 OD .765:1 R 2.678:1 fluid cap 16.4 US qts...

forum.ih8mud.com

 

[Marco Lau]

has anyone tried running 4.88 gears with 40s on a 80s series?

If your running 40s, you will need 529 or crawler gear. Assuming you are running 40s for rocks and not for pavement...lol

 

[JoeCova]

If your running 40s, you will need 529 or crawler gear. Assuming you are running 40s for rocks and not for pavement...lol

tbh it's kind of moot. It's a 7% difference. Crawl ratio with a 3.1 trans and 4.88s is 89 with 5.29 it's 96. The difference between 89 and 96 is not even perceived especially with Autos.

 

[Marco Lau]

tbh it's kind of moot. It's a 7% difference. Crawl ratio with a 3.1 trans and 4.88s is 89 with 5.29 it's 96. The difference between 89 and 96 is not even perceived especially with Autos.

I dunno, i was running 488 on 37s and now added crawler gear in my TC and it was night and day when i was in 4Lo.

 

[AgentOrange]

tbh it's kind of moot. It's a 7% difference. Crawl ratio with a 3.1 trans and 4.88s is 89 with 5.29 it's 96. The difference between 89 and 96 is not even perceived especially with Autos.

Maybe I'm just lost, because I am a lot, but crawl ratio on my Cruiser with 3.1 transfer case gears and 4.88 is 44.77. If I went to 5.29, it becomes 48.53. It's still only a 9 percent change, but it's enough to notice and be worth looking into when you're going to tear open the diffs regardless.

 

[JoeCova]

I dunno, i was running 488 on 37s and now added crawler gear in my TC and it was night and day when i was in 4Lo.

If you are referring to the 3.11 low range there is a about a 20% difference which is much more significant of a change moving from 2.49 to 3.11.

Maybe I'm just lost, because I am a lot, but crawl ratio on my Cruiser with 3.1 transfer case gears and 4.88 is 44.77. If I went to 5.29, it becomes 48.53. It's still only a 9 percent change, but it's enough to notice and be worth looking into when you're going to tear open the diffs regardless.

Crawl Ratio is Trans Gear (1st) * TC Gear * Diff gear * Stall Torque (if auto) = crawl ratio

2.95*3.11*4.88*2= 89.54
2.95*3.11*5.29*2=97.06

You are correct that its 9% but it's really hard to perceive this crawling with such low ratios. Most of this is noticed in a manual because the lack of TC, auto not as much.

My Tacoma had a 99 ratio and my cruiser currently has 75 and even then its extremely situation to see the difference

Is 5.29 mathematically better, probably but not worth someone beating themselves up over.


I run 40s on my Jeep and have 5.38s but I went with 538s not because of 40s but because with a manual trans I needed to get as close to 100:1 as possible for comfortable offroading due to clutch management

 

[AgentOrange]

If you are referring to the 3.11 low range there is a about a 20% difference which is much more significant of a change moving from 2.49 to 3.11.



Crawl Ratio is Trans Gear (1st) * TC Gear * Diff gear * Stall Torque (if auto) = crawl ratio

2.95*3.11*4.88*2= 89.54
2.95*3.11*5.29*2=97.06

You are correct that its 9% but it's really hard to perceive this crawling with such low ratios. Most of this is noticed in a manual because the lack of TC, auto not as much.

My Tacoma had a 99 ratio and my cruiser currently has 75 and even then its extremely situation to see the difference

Is 5.29 mathematically better, probably but not worth someone beating themselves up over.


I run 40s on my Jeep and have 5.38s but I went with 538s not because of 40s but because with a manual trans I needed to get as close to 100:1 as possible for comfortable offroading due to clutch management

Ok, you're assigning a 2X multiplier for the torque converter blanketly across the gear. That's what I was lost on. I understand it's not going to lock up in 1st gear ever, but it's not typically static as RPMs rise, so I was just looking at the gears themselves. Thank you! I'm not so lost anymore lol

 

[JoeCova]

Ok, you're assigning a 2X multiplier for the torque converter blanketly across the gear. That's what I was lost on. I understand it's not going to lock up in 1st gear ever, but it's not typically static as RPMs rise, so I was just looking at the gears themselves. Thank you! I'm not so lost anymore lol

Ya the stall torque from the TC for the 80 series is 2:1