If possible looking for Speedo/Tachometer pics of JTDiesel auto w/ 37's and 4.56 gears @ 55,65 mph

[Jefe1018]

The picture thing… that makes little sense to me… they also don’t get to tell you they won’t do 4.10’s, you are the dog and they are the tail. They could not recommend it, but does your dollar not spend or do they just have too much?

Anyways, now that 4.30’s are no longer going to be made by Nitro… 4.56 is the next greatest thing.

Here’s a thread that might help you OP, it’s been going for a while now:

https://www.jeepgladiatorforum.com/forum/threads/gearing-for-gladiator-ecodiesel.67159/page-6

Try PMing some folks in there with 4.56’s, I bet a few reply with the pics you want.

I sit at 75mph at like 1,600 RPMs and it’s the greatest thing ever with stock gears and 37’s.. for whatever that may be worth to you’d here’s a pic.

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[Vtur]

I appreciate it but really want to see the 4.56 numbers. so AEV is running 4.56 on the JT370. My gear shop is highly suggesting 4.56 for the diesel with 37's, said they wouldn't do a 4.10 for me because it isn't enough difference from the 3.73 to spend the money on.

Here is the problem, after going through the JL forum and this one, reading everything I can find, there is no consensus on RPM, MPG or anything really, everything is subjective, 2 comments in a row will yield totally different opinions on 4.56 w 37's, some love 4.10 some don't. I really just want to see RPM's at 55 or 65, I guess 75 and 85 might be a bit much but the idea is how fast is that diesel spinning at highway speeds with 4.56 gears. MPG not the primary thing here. Wear on the engine and turbo, transmission matter. If its a couple hundred rpm different from stock its not a big deal but some posters are talking about 400-500 rpm difference which matters.

The idea for this post comes from seeing a few of those pics of gauges while driving, they are helpful.

I don't think photos of the analog gauges is helpful when we are talking couple hundreds rpm. Sounds like that shop hasn't done many diesels or else they would have those numbers. Only thing i can help you with is you posting your current 3.73 mph+rpm at those speeds via digital numbers like a Scangauge set to monitor rpm and set your mid display to read mph. I can post my 4.10, then you can do the math to come up with 4.56 numbers.

 

[Jteakus]

4.10's for 37's, 4.56 for 39's

Tire Size Change Gear Ratio Calculator | Interco Tire

#math

 

[Gvsukids]

there is no consensus on RPM, MPG or anything really, everything is subjective,

Well sure. Weight and aerodynamics and terrain are a factor in gearing.

 

[Volt0]

Need pics. Gear shop asking for mine apart from their calculators, so want to see what others are getting

Dear OP, I’m trying to be direct here, it’s fairly clear that someone is telling a yarn. Gear shops don’t need analog photos ( that’s laughable at best ).

is it possible, that they simply responded with that statement after being pressed for some tidbit of info that can easily be found online? If so, they were metaphorically telling you to go pound sand, so that they could move onto the next customer. If not, maybe it’s in your best interest to reach out to another gear shop ( with better customer service ), and solicit their feedback about what you’re trying to accomplish. Photos of analog gauges will do little to nothing in assisting you with your endeavors.

peace out, and good luck.

 

[Gvsukids]

Dear OP, I’m trying to be direct here, it’s fairly clear that someone is telling a yarn. Gear shops don’t need analog photos ( that’s laughable at best ).

is it possible, that they simply responded with that statement after being pressed for some tidbit of info that can easily be found online? If so, they were metaphorically telling you to go pound sand, so that they could move onto the next customer. If not, maybe it’s in your best interest to reach out to another gear shop ( with better customer service ), and solicit their feedback about what you’re trying to accomplish. Photos of analog gauges will do little to nothing in assisting you with your endeavors.

peace out, and good luck.

Sure makes a great thread though.

 

[sharpsicle]

The most respected and oldest gear shop in town. They have all the charts and programs but wanted to get a snapshot of my gauges at freeway speed. I guess they are thorough.

All due respect, but they're messing with you then. This isn't like MPG where there are more factors than you can account for in determining the number. Gear ratios are gear ratios. Based on what you have installed, one engine rotation will equal x driveshaft rotations, and x wheel rotations, which translates to x speed.

The math isn't subjective. What is subjective is someone saying whether or not it "makes enough of a difference".

Plus, if "[they] wanted to get a snapshot of [your] gauges at freeway speed" why would you be asking for others? If they want to use it to verify your install, you need to get your gauges. Not someone else's.

Something doesn't add up here (unlike gear calculators, which do the math for you).

 

[Vtur]

All due respect, but they're messing with you then. This isn't like MPG where there are more factors than you can account for in determining the number. Gear ratios are gear ratios. Based on what you have installed, one engine rotation will equal x driveshaft rotations, and x wheel rotations, which translates to x speed.

The math isn't subjective. What is subjective is someone saying whether or not it "makes enough of a difference".

Plus, if "[they] wanted to get a snapshot of [your] gauges at freeway speed" why would you be asking for others? If they want to use it to verify your install, you need to get your gauges. Not someone else's.

Something doesn't add up here (unlike gear calculators, which do the math for you).

The OP got 4.56 and were planning on installing them but are having a second thought due to some members are saying that it's too low for 37s. I'm just trying to helps him out knowing that shop didn't requested photos.

 

[Steven_B]

Posting these so they help others when searching the forum.

4.10's, 37" Nitto Recons.

 

[Rusty PW]

Something else to think about. Not all 37's are the same height. Have 37" KO's that measures way short vs a Super Swamper at 37. You're talking close to 1.5" difference in height.

 

[RoamingGladiator]

37s on a 21 JTRD with 3.73s, I noticed zero difference and I continue to get insane fuel economy on the highway.

I agree with a lot of the folks that 3.73 vs 4.10 really isn't that big of a difference, and you'll find plenty of people on this forum that say after they went to 4.10s they noticed very little to no improvement to the point that regearing to 4.10 was a waste of money.

The general consensus is unless you haul a ton of weight, don't bother regearing with 37s on the 3.73 ratio. There's a ton of threads on here that discuss gearing on the EcoDiesel.

 

[Wheelin98TJ]

Someone post a pic of a speedo showing 55 MPH/1,600 RPM and 65 MPH/1,900 RPM so we can make OP happy.

It doesn't have to be a diesel since they have the same trans ratios as a gas model. OP won't know if its a diesel or not and it doesn't matter.

 

[Vtur]

Here's the rpm at 80 mph on 37s with 4.10.

 

[PaulW]

OP
What ever your concerns are about choosing a gear are misguided.
The correct gear has a number value that matches the factory overall design as close as possible. The result will be optimized wear, long life, trans shifting, and MPG. And that is the best that is possible. Oddball gear choices are not wise.
If you do the math you will find 4.88 will be close for 99% of all 37s.
If your gear shop cannot deal with the correct gear choice for factory equivalent then find a different gear shop and one with a tuner to get final adjustments.
The tire diameter to use will be the tire manufacturers "rev/mile" for the specific tire you have.
Not exact but as close as possible.

 

[MaxStrategery]

All due respect, but they're messing with you then. This isn't like MPG where there are more factors than you can account for in determining the number. Gear ratios are gear ratios. Based on what you have installed, one engine rotation will equal x driveshaft rotations, and x wheel rotations, which translates to x speed.

The math isn't subjective. What is subjective is someone saying whether or not it "makes enough of a difference".

Plus, if "[they] wanted to get a snapshot of [your] gauges at freeway speed" why would you be asking for others? If they want to use it to verify your install, you need to get your gauges. Not someone else's.

Something doesn't add up here (unlike gear calculators, which do the math for you).

Here's the rpm at 80 mph on 37s with 4.10.

Thank you and this why I was asking for a picture of real world. According to the Grimm jeeper calculator it should be at 1996 rpm which isn't much difference but still isn't as accurate as real world. 4.56's it is.

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