Gears inquiry

[Blue Streak]

5.13s have been ordered and hopefully will get installed next week. Can't wait!

 

[FlatbedHemi]

The 2020 Gas Hd”s have the 8 speed, and I don’t think it would need a re gear from all the positive posts we see. But only an owner could make that call, go drive one and see what you think.

But if he is going with 37" tires, he will still want a regear most likely. Taller tires will still reduce the overall ratio and cause the same types of issues as the 6 speed trucks.

Mathematically, I think it is close to the same, provided you get the 4.10s with the 8 speed. Thats gonna get you similar gearing through all the gears, plus having that extra cruising gear that guys like me dont have. I think IIRC, Im pretty close to the gears in the new 8 speed for gears 1-6 or maybe 1-7. Heck, the 8 spd may even have a lower 1st gear than my 66RFE with the 4.88s. I cant remember for sure, but I know it was a close comparison. That being said, it would be something I would want to drive on with the 37s first before I committed to a $3K+ swap on a brand new truck with a warranty.

 

[68PowerWagon]

Finally got my 4.56 gears installed. So far I really like them. It is not down shifting every time I hit a small grade. Not real happy that they did indeed have to change out the carrier though. Kind of weird how some are reporting with 4th gen trucks that it does have to be changed & others have not had it changed. The real test will be when I hook up to that 5th wheel. Then I will get to see how much better it pulls the big weight. Anybody want a set of 3.73's for their diesel? LOL

 

[Mountaineer83]

Awesome! Glad you like them so far. I go next week for my 4.88s and hope to be content as well. He wasnt sure about the carrier when we last spoke, but he had it all written down in the file where he quoted me. So if so it should ha e already been shown in my price. At least I hope!

Keep us updated on your thoughts as you continue driving it.

 

[68PowerWagon]

Awesome! Glad you like them so far. I go next week for my 4.88s and hope to be content as well. He wasnt sure about the carrier when we last spoke, but he had it all written down in the file where he quoted me. So if so it should ha e already been shown in my price. At least I hope!

Keep us updated on your thoughts as you continue driving it.

I will be interested in hearing if yours needed it or not. I was charged about another $500 in parts & labor!

 

[Nickx86]

I will be interested in hearing if yours needed it or not. I was charged about another $500 in parts & labor!

I was quoted about the same price from OK4wd in NJ for the carrier replacement and I wasn’t sure if that was also true

I’m curious to hear how your truck does w that big trailer of yours

 

[KarL45]

Mileage will depend on a few factors. Elevation, flat land driving, towing, and probably as much as anything, driving habits. Driving smoothly and learning how to get a quicker upshift will be a large part of it. The computer learns your style so the more efficient you drive, the better. I got about the same mileage as before (about 16 ether town or hi way) In Western Co but IMO, the overall performance (not the constant up and down shifting) made the vehicle more pleasant to drive. Towing though, while not a lot different, was slightly better but again, the difference between towing in 3rd and 4th to being able to use 5th and sometimes 6th (not in tow haul mode) Let's just say, now you have a "Truck".

 

[crazy jerry]

I will be interested in hearing if yours needed it or not. I was charged about another $500 in parts & labor!

i was looking at a site just yesterday and i swear it said these axles had no carrier break so im not sure why the carrier needed changed. what brand gears are they? maybe call the gear company and they likely could shed some light on it. the carrier change may eliminate the need for a ring gear spacer and thats why they swapped it

 

[68PowerWagon]

i was looking at a site just yesterday and i swear it said these axles had no carrier break so im not sure why the carrier needed changed. what brand gears are they? maybe call the gear company and they likely could shed some light on it. the carrier change may eliminate the need for a ring gear spacer and thats why they swapped it

I was wanting Yukon on the front & AAM in the rear cause I heard the AAM were more quiet. They talked me into Yukon front & back. Said if installed correctly that these would be just as quiet as the factory AAM's. And I have to say so far they are not noisy at all. So far I am REALLY happy with the gears. Truck can go up inclines now without shifting down. Can't wait to actually do some pulling with them.

 

[crazy jerry]

yukon seem to be very good from everything ive read. i wouldnt hesitate to use them

 

[Mountaineer83]

I drop mine off tomorrow evening so they can start Wednesday hopefully. If not he said thursday. Mine will be Yukon I assume in 4.88s.

 

[Bldrinker]

I drop mine off tomorrow evening so they can start Wednesday hopefully. If not he said thursday. Mine will be Yukon I assume in 4.88s.

I can’t wait to hear how you like it

 

[FlatbedHemi]

I was wanting Yukon on the front & AAM in the rear cause I heard the AAM were more quiet. They talked me into Yukon front & back. Said if installed correctly that these would be just as quiet as the factory AAM's.

Thats because they are cut exactly the same as the AAM. From what I understand, they're practically interchangable, and Yukon markets these sets as "AAM Cut".

 

[68PowerWagon]

i was looking at a site just yesterday and i swear it said these axles had no carrier break so im not sure why the carrier needed changed. what brand gears are they? maybe call the gear company and they likely could shed some light on it. the carrier change may eliminate the need for a ring gear spacer and thats why they swapped it

I was wanting Yukon on the front & AAM in the rear cause I heard the AAM were more quiet. They talked me into Yukon front & back. Said if installed correctly that these would be just as quiet as the factory AAM's. And I have to say so far they are not noisy at all. So far I am REALLY happy with the gears. Truck can go up inclines now without shifting down. Can't wait to actually do some pulling with them.

Thats because they are cut exactly the same as the AAM. From what I understand, they're practically interchangable, and Yukon markets these sets as "AAM Cut".

Yeah I noticed that while shopping for gears, I would see both names in the description of the gears. Thanks for that info.

 

[CheechDogg.0n37s]

Well I know that this is the Power Wagon forum and I have a 1500 with 37s and 4.88s that just got re geared a month ago and SOB am I loving it, holds 8th on the highway all the time and even up hills without down shifting, so you guys should definitely be happy with 4.88s for your Power Wagons.

I went with Revolution Gears and SOB they are quiet, they really did a great job ...

 

[Ratket]

Well I know that this is the Power Wagon forum and I have a 1500 with 37s and 4.88s that just got re geared a month ago and SOB am I loving it, holds 8th on the highway all the time and even up hills without down shifting, so you guys should definitely be happy with 4.88s for your Power Wagons.

I went with Revolution Gears and SOB they are quiet, they really did a great job ...

of you don’t mind what shop and where did you have them done?

 

[Mountaineer83]

I can’t wait to hear how you like it

So far I love it. I haven't towed anything really of weight, but man the everyday driving is awesome now. As everyone has said, just so much smoother and effortless driving over stock. The 4.88 is not even close to overkill. They feel almost perfect to me.

 

[Bldrinker]

So far I love it. I haven't towed anything really of weight, but man the everyday driving is awesome now. As everyone has said, just so much smoother and effortless driving over stock. The 4.88 is not even close to overkill. They feel almost perfect to me.

what size tire?

 

[Bldrinker]

Getting ready to start shopping for places to do my gears.

trying to decide what ratio I want.
Biggest tire I will go with is a 295/70/18

This first chart is 4:10 with 275/70/18

vs

4:88 295/70/18

looks like I would loose rpm.

compare this to the second chart.

 

[Bldrinker]

Use a calculator, no guessing required.

Select the 68 RFE in the drop-down menu for your transmission. It’s the same exact gear ratios as our 66 RFE

Then all you have to do is put in your desired gear ratio and tire size and then you can mess with the calculations at the bottom and see your exact speed and rpm.
Add about 50-75 rpm for wind resistance

http://www.grimmjeeper.com/gears.html

I have 4.88’s and I’m running 35s. I kinda wish I went to 5.13’s.

IMO

33”tires need 4.56
34”tires need 4.88
35” or large need 5.13

Again... JMO


My next set of tires I’m going to go a tiny bit shorter but a little wider. I’d like to get a tad more RPM.

Sent while firmly grasping my redline lubed RAM [emoji231]

what are your rpms at with 35’s and 4:88? 55 65 & 70mph

I’m trying to decide on 4:88 or 5:13 with 295/70/18