Help for Regear 4.56 or 4.88?

[Swanny47]

Wondering what I should change the gears to. I believe I have stock gears front and back Dana 30 and 35 Rear. I’m running 33s and cannot pull up a hill on a highway without dropping gears.
5 Speed manual transmission.
Daily driver and I hop on the highway everyday.
Out here in Oregon so definitely some hills.
Thank you

 

[jjvw]

....
Daily driver and I hop on the highway everyday.
...

488

 

[Duck Doctor]

4.88 but you should still expect to downshift to 4th even after the regear.

 

[Wildman]

4.88 if you're staying with 33's.

 

[Oneslowtj]

488. Just regeared mine. HUGE difference

 

[jjvw]

4.88 but you should still expect to downshift to 4th even after the regear.

All correct with the understanding that he would be downshifting more often with anything less than 488.

 

[Duck Doctor]

All correct with the understanding that he would be downshifting more often with anything less than 488.

Absolutely. Didn't want the OP to think a regear was going to make downshifts unnecessary at all times when traversing hilly terrain at freeway speeds.

 

[Swanny47]

Absolutely. Didn't want the OP to think a regear was going to make downshifts unnecessary at all times when traversing hilly terrain at freeway speeds.

Of course, but every time… also barely using 5th/ overdrive only can use it going down hill…

 

[James9100]

Outta curiosity why is everyone suddenly saying 4.88 for 33s/4.0L/5spd? Previously the recommendation was always 4.56.

 

[jjvw]

Outta curiosity why is everyone suddenly saying 4.88 for 33s/4.0L/5spd? Previously the recommendation was always 4.56.

It isn't sudden. I did 488 almost ten years ago against the advice of vocal guys like Jerry who pushed for 456 without doing the math or making any comparisons to other trans and tire combinations. Back then, the smart ones who understood the details were advocating for deeper gearing .

 

[JMT]

Wondering what I should change the gears to. I believe I have stock gears front and back Dana 30 and 35 Rear. I’m running 33s and cannot pull up a hill on a highway without dropping gears.
5 Speed manual transmission.
Daily driver and I hop on the highway everyday.
Out here in Oregon so definitely some hills.
Thank you

4.88.

 

[JMT]

Outta curiosity why is everyone suddenly saying 4.88 for 33s/4.0L/5spd? Previously the recommendation was always 4.56.

Look at the AX-15 and NV3550 ratios.

AX-15

• 1st Gear: 3.83:1
• 2nd Gear: 2.33:1
• 3rd Gear: 1.44:1
• 4th Gear: 1.00:1
• 5th Gear (Overdrive): 0.79:1

NV3550

• 1st Gear: 4.01:1

• 2nd Gear: 2.32:1

• 3rd Gear: 1.40:1

• 4th Gear: 1.00:1

• 5th Gear: 0.78:1

They are nearly the same. Then ask why people kept suggesting 4.88 for the AX-15 and 4.56 for the NV3550. Then we have to have this war for 4.88 for both. It’s dumb and was always dumb from day 1.

 

[jjvw]

Look at the AX-15 and NV3550 ratios.

AX-15

• 1st Gear: 3.83:1
• 2nd Gear: 2.33:1
• 3rd Gear: 1.44:1
• 4th Gear: 1.00:1
• 5th Gear (Overdrive): 0.79:1

NV3550

• 1st Gear: 4.01:1

• 2nd Gear: 2.32:1

• 3rd Gear: 1.40:1

• 4th Gear: 1.00:1

• 5th Gear: 0.78:1

They are nearly the same. Then ask why people kept suggesting 4.88 for the AX-15 and 4.56 for the NV3550. Then we have to have this war for 4.88 for both. It’s dumb and was always dumb from day 1.

It's way dumber than that. Once upon a time, 4.88 was as deep as we could go. At the same time, 35s were the most common biggest tire being put on TJs, XJs, and YJs. That turned into 4.88 being the correct gear for 35s. 4.56 for 33s... Follow the pattern and don't think too hard about any of the nuance or any other pertinent details. That is why we still see so many under geared regears.

When 5.13 and 5.38 showed up, guys like Jerry shifted the pattern while still ignoring and dismissing many of the pertinent details, which still resulted in undergeared regears, just not as many as before.

Then add in the real problem of charts that do not include overdrive gears along with people who think OD should be ignored all together and we have the mess we still see today.

Meanwhile, in the not too distant past, Blaine and others were explaining the simple math and pointing out the wide disparity of the factory gearing from transmission to transmission. That is how I started building my long list of transmission, tire, and ratios to help push back at the decades of bad gearing recommendations by showing the variables and rpms @75mph.