Just Went to 33s / Do I Go to 4.30 or 4.56 ?

[Jakef7]

100%

I've got slightly wider A/T on mine with 3.73 and just don't think it's worth any gear changes. Even towing it's ok.
I can see changing if I ever went to 33s but then a 33 like Jeep uses is 32.7 while the stock 32s are 32.2 so we're talking only a whopping 1/2" total height difference.


That's a sticky question - it's done in classic cars a lot, but not with high mileage gears, and it's not something that I feel easy about. Unless it's low miles set and you match the pattern perfect, there's risk...... can't see it being really worth it since a big chunk of the cost is the labor of doing it correctly.
I can't imagine a GOOD shop taking on a used gear swap - they just can't guarantee things.

See Case in point, you fall into the group that is perfectly happy with the 3.73 set up and I think that’s great. However, if you could magically flip a switch and have a 4.56 gear, I don’t think you would ever switch back to 3.73.

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[ShadowsPapa]

See Case in point, you fall into the group that is perfectly happy with the 3.73 set up and I think that’s great. However, if you could magically flip a switch and have a 4.56 gear, I don’t think you would ever switch back to 3.73.

No way I'd ever go that deep. Why would I? Mine is fine.
The most I'd do is 4.10s but then that's not worth the effort or cost. Why would I want my engine RPM to be higher, dump my mpg?
Mine works quite well as it is.
I've towed and backed up pretty decent loads up steep inclines and driveways. I can't see a need and I have another car to drive if I want to hear an engine screaming going down the highway.
I can squeal tires as it is, and when towing, take off easily with over 5,200 pounds behind me.

 

[Rocksalt]

mine is fine on 3.73 gears and 33" tires... I simply used Jscan to calibrate the diiff from oem tires

 

[Jakef7]

No way I'd ever go that deep. Why would I? Mine is fine.
The most I'd do is 4.10s but then that's not worth the effort or cost. Why would I want my engine RPM to be higher, dump my mpg?
Mine works quite well as it is.
I've towed and backed up pretty decent loads up steep inclines and driveways. I can't see a need and I have another car to drive if I want to hear an engine screaming going down the highway.
I can squeal tires as it is, and when towing, take off easily with over 5,200 pounds behind me.
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I am glad you feel that yours is fine and it works well for you. That’s really all that matters.

Do you ever use 8th gear when towing that much on the highway?

 

[ShadowsPapa]

mine is fine on 3.73 gears and 33" tires... I simply used Jscan to calibrate the diiff from oem tires

I had so-called "33's" on my 2020 for a while - JSCAN as well.
Because there's really only about 1/2" total difference in height, it's hardly a big deal. Looking up the difference in the number of revolutions per mile - minimal.

As far as 8th gear when towing - people forget, 8th is there for when you are not towing, running where you can drop the RPM down and don't care and get great mpg.
Even my Chevy and Ford - guess what they did in tow mode? Locked out the OD gears! LOL - so, the Jeep is doing exactly like Chevy and Ford!
Tow mode in those totally changed shift patterns and basically got rid of OD.
So if you don't see 8th in a Jeep while towing - why does that even come up as a question?
The top gears are OD.

 

[Vtur]

I appreciate the input. However, I just bought this truck and I do not plan on getting rid of it anytime soon. I thought about the diesel but I make very short trips to and from work and around town and that can be bad on a diesel motor. I would’ve really enjoyed that low end grunt though. However, I think doing a set of gears with this NA 3.6 will make the difference I’m looking for.

I recommend go 4.56 just incase you want to go to 35s in future. Trust me, your 33s might looks a touch too small later on if you keeps on visiting this forum ?.

I was in the same boat as you as i do lots of short trips dropping and picking up my son from school. I chose the diesel because life is too short that i'd rather deals with something that may or may happen than having to deals with issues right out of the gate.

 

[Heavy D]

No way I'd ever go that deep. Why would I? Mine is fine.
The most I'd do is 4.10s but then that's not worth the effort or cost. Why would I want my engine RPM to be higher, dump my mpg?
Mine works quite well as it is.
I've towed and backed up pretty decent loads up steep inclines and driveways. I can't see a need and I have another car to drive if I want to hear an engine screaming going down the highway.
I can squeal tires as it is, and when towing, take off easily with over 5,200 pounds behind me.

My mpg fell off significantly when I went to the 33s with the stock gears... I wasn't using 7th or 8th gear.
Again I haven't put enough miles on my new set-up (4.56) to give an accurate review but in the 300 miles I've put on em so far my mpg is steadily improving.... and I'm once again using all 8 gears.

 

[Jakef7]

I had so-called "33's" on my 2020 for a while - JSCAN as well.
Because there's really only about 1/2" total difference in height, it's hardly a big deal. Looking up the difference in the number of revolutions per mile - minimal.

As far as 8th gear when towing - people forget, 8th is there for when you are not towing, running where you can drop the RPM down and don't care and get great mpg.
Even my Chevy and Ford - guess what they did in tow mode? Locked out the OD gears! LOL - so, the Jeep is doing exactly like Chevy and Ford!
Tow mode in those totally changed shift patterns and basically got rid of OD.
So if you don't see 8th in a Jeep while towing - why does that even come up as a question?
The top gears are OD.

I was just curious if it ever shifted into 8th while towing. I do understand your point though.

 

[Jakef7]

My mpg fell off significantly when I went to the 33s with the stock gears... I wasn't using 7th or 8th gear.
Again I haven't put enough miles on my new set-up (4.56) to give an accurate review but in the 300 miles I've put on em so far my mpg is steadily improving.... and I'm once again using all 8 gears.

I can definitely see why the MPG‘s are improving now because your motor is no longer having to lug. That’s great!

 

[Heavy D]

I would really like to get some feedback from you regarding the 4.56 gear swap. I have 3.73’s in mine and I’m having the same issues you were. I’d really like to re-gear so I can have some better power down low. This is my daily and I plan on staying with a 32” tire but will probably jump from a 255 to a 285 down the road just for a wider stance. I was thinking about 4.88’s but I think that will be too steep with 32’s. What RPM are you running at 70mph with the new 4.56’s?

Just for you brother. This was today... I'm gonna call it 2,150 rpms

 

[ShadowsPapa]

I was just curious if it ever shifted into 8th while towing. I do understand your point though.

Down hill or on a totally flat spot (rare, here) with no wind. Generally, no.

 

[Jakef7]

Just for you brother. This was today... I'm gonna call it 2,150 rpms

Now that’s what I’m talking about! Big thanks!!! Of course I’m running the slightly shorter tire, so I’ll be running a little bit higher, but that’s not bad at all.

 

[Heavy D]

Now that’s what I’m talking about! Big thanks!!! Of course I’m running the slightly shorter tire, so I’ll be running a little bit higher, but that’s not bad at all.

I measured my BFG's at just under 32.5
Am satisfied so far with the set-up but am most likely gonna go to 35s soon.

 

[WILDHOBO]

I get your point. I can honestly say that I will not be doing any rock crawling. I do mostly in town driving with some occasional highway when I go see my folks that live about 40 minutes away.

This topic does seem to be very subjective. There are many out there that are perfectly happy with running the 3.73 or 4.10 even with larger tires than OEM. However, I fall into the other group that is always trying to make it better or wanting more performance. This is actually my first Jeep. I come from of a hot rod/sports car background and I know gear swaps can make a huge improvement with acceleration and that’s what I’m looking for. Of course there are limitations and I don’t want to be running 3000 RPM at 70 miles an hour. However, with 4.56’s I think I will be in a good spot. The 4.88 would probably be too steep with a 32” inch tire for my needs. If I was planning on doing a 35” plus tire I think the 4.88 would be the route to take but I never see that in my future.

From that perspective, have fun. I’m running 5.13’s with 37’s and see 8th gear all day. And I run around 2200 at 70mph.

 

[Camaroboi13]

If you’re running 33s only I would swap the 3.73s for some 3.45s. You know, personal preference and all.

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