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-   -   2012 Manual - 3.73 vs 4.88 Video (http://www.wranglerforum.com/f274/2012-manual-3-73-vs-4-88-video-221107.html)

RRTRI 02-21-2013 01:49 PM

2012 Manual - 3.73 vs 4.88 Video
 
We picked up the wife's Jeep from the shop this morning. We had the 3.21 gearing swapped out for 4.88 this week. I don't have the chart floating around the forum in front of me but it seemed to be right in line with what we are seeing in real life.

I threw a quick video together showing the difference between the 3.73 I still have and the new 4.88's in the wife's. About 5 minutes showing the speed/rpm with the 3.73 and about 5 minutes comparing the speed/rpm with the 4.88 gearing going through all the gears. Both Jeeps are 2012 / 6 speed manuals / 35's / with bumpers and rails. The 4.88 gears are Superior brand.

Apologies in advance on the video. I did zero editing of it because I was in a hurry and need to get back to work. Hope it is helpful to anyone considering new gearing.

2012 Jeep Wrangler 3.73 vs 4.88 gearing 6sp Manual / 35's - YouTube

It has only been a few hours with the 4.88 but my initial reaction is I'm thinking 4.56 when I do mine. We take mine on any trips and it sees a lot more highway. I'm still chewing on it but that is where I'm at currently.

zx6r 02-21-2013 02:20 PM

Excellent info. Thank you very much!

foo.c 02-21-2013 02:38 PM

Confirms what I thought. Thanks.

I think 4.10 is perfect for the 6sp pentastar 35" tire combo as a daily driver. 4.56 if towing, or wanting a lower crawl ratio.

4.88 is too low. I'd have to put 37's on that rig after a week, but that's just me.

kappaknight 02-21-2013 03:00 PM

I'm now completely confused as to what I should do. Regearing is to fix the low end torque right? I currently have 4.10, and thinking about running 37's. Not sure if that effectively makes it more like 3.21's once the big boy boots go on.

jadmt 02-21-2013 03:44 PM

how about a couple roll on races from say 50mph in 5th and 6th gear etc?

WXman 02-21-2013 05:04 PM

That's what I figured. 4.88 is way too much gear for the 6-speed. 4.11 actually would be the sweet spot unless you run 37-40" tires.

RRTRI 02-21-2013 06:53 PM

I haven't been terribly bothered by the 3.73 gearing I currently have on mine when it comes to basic street driving........but it suffers big time once off the pavement and meets any kind of resistance. I had my Jeep off road about 3 times a week this past hunting season. The same trails I was driving the previous hunting season in my Toyota truck and never once put it in 4L. It of course was stock and I'm just pointing it out as an example that the trails I'm talking about aren't what you would call extreme. With the gearing and Mod weight of the Jeep (3.73) this past season I had to run a lot of those same trails in 4L as it just wouldn't go with any grace in 4H.

I'm hoping to find someone local who has 4.56 installed that will let me test drive but if I don't I'm 99% sure 4.56 is what I will end up doing. Thinking of sleeping on it a bit more until next week and then I will order them.

HydroJK 02-21-2013 07:05 PM

Thanks for taking the time to do that !!! I'll be curious of MPG changes as well...

Hydro

RRTRI 02-21-2013 07:18 PM

Quote:

Originally Posted by HydroJK
Thanks for taking the time to do that !!! I'll be curious of MPG changes as well...

Hydro

Sure thing. Will come back and update MPG once we've put some miles on it.

RUBI13 02-21-2013 07:41 PM

Nice vid.

Kappaknight, Regearing will increase the leverage the engine has for turning larger tires. Down side is you loose some MPG using larger gears/tires.

jadmt 02-21-2013 08:44 PM

You mentioned gear whine, that is one of the things I am leary of. What did the installer say?

WXman 02-21-2013 08:50 PM

After I put 4.88s in my '11 there was gear whine. It was a lot more pronounced on cold mornings.

Since buying this '12 I have noticed that it has the same gear whine on cold mornings and it's bone stock. It doesn't take much backlash adjustment to make these things start whining. I think my '12 is just a hair off from the factory but not enough to worry about.

jadmt 02-21-2013 09:00 PM

Quote:

Originally Posted by WXman (Post 3402843)
After I put 4.88s in my '11 there was gear whine. It was a lot more pronounced on cold mornings.

Since buying this '12 I have noticed that it has the same gear whine on cold mornings and it's bone stock. It doesn't take much backlash adjustment to make these things start whining. I think my '12 is just a hair off from the factory but not enough to worry about.

I am lucky because my gears are silent and that makes me hesitant to swap them out.

RRTRI 02-21-2013 09:03 PM

Quote:

Originally Posted by jadmt
You mentioned gear whine, that is one of the things I am leary of. What did the installer say?

I called the installer this afternoon but was busy when he called me back so I have not talked to him about it yet. It is just slight and I only hear it below a certain speed. I'm not overly worried about it.

Quote:

Originally Posted by WXman
After I put 4.88s in my '11 there was gear whine. It was a lot more pronounced on cold mornings.

Since buying this '12 I have noticed that it has the same gear whine on cold mornings and it's bone stock. It doesn't take much backlash adjustment to make these things start whining. I think my '12 is just a hair off from the factory but not enough to worry about.

Did it go away on the 11 after a while or once you have it you have it unless there is an adjustment?

01svtL 02-21-2013 09:20 PM

Is there a 4.30 gear for these?

jkjeeper06 02-21-2013 09:44 PM

Quote:

Originally Posted by 01svtL (Post 3403058)
Is there a 4.30 gear for these?

nope. 4.10 and then 4.56 is the next step up

zx6r 02-21-2013 09:57 PM

i still think i am going with 4.88. the local shop only deals in yukon gears and i believe they are one of if not the largest supplier on the east coast. they will install other sets of gears if i would like but discourage against it. yukon does not offer 4.56 so the next best thing is 4.88. they have a great rep in the surrounding communities so i think i am going to end up going with them and 4.88

RRTRI 02-22-2013 07:27 AM

Quote:

Originally Posted by zx6r
i still think i am going with 4.88. the local shop only deals in yukon gears and i believe they are one of if not the largest supplier on the east coast. they will install other sets of gears if i would like but discourage against it. yukon does not offer 4.56 so the next best thing is 4.88. they have a great rep in the surrounding communities so i think i am going to end up going with them and 4.88

The shop I used said they just ordered the brand that had availability at the time of ordering. It took about 3 weeks for them to show up after they ordered them.

When I was in there yesterday picking up the red one, we were talking about doing mine. They were telling me they had another customer who ordered 4.88 a few days after they ordered my wife's and were told it would be 4 weeks. I didn't ask what the brand was though.

I didn't realize the 4.56 wasn't as common as the 4.88. Or at least not available from Yukon. Makes me wonder how long it will take to get 4.56 compared to 4.88.

I'm going to call them back later this morning and will ask about the 4.56 availability.

WXman 02-22-2013 08:41 AM

Quote:

Originally Posted by jadmt (Post 3402923)
I am lucky because my gears are silent and that makes me hesitant to swap them out.

Yes...that is why I will NEVER touch the gears again. When I decided to do the 4.88s on my 2011 it turned into a NIGHTMARE. What a can of worms.. gears had to be removed/reinstalled 3 times to dial them in...then there was still gear whine on cold mornings that never went away....then the driveshafts were spinning so much faster that I got vibration above 50 MPH that I could never solve because Chrysler uses CV joints on both ends of the driveshaft so you cannot have them balanced at a driveline shop..

Just a total nightmare. I'll never have it done again. I'm going to hold onto my factory powertrain warranty as long as I can.

P.S. these were Yukon gears front/rear with new install kits.

RRTRI 02-22-2013 01:12 PM

Wanted to add another piece of info to this thread while I was thinking about it. I had used the AEV ProCal to set the new gearing but I wasn't understanding the need given that I had a manual transmission. I know on the auto trans it goes into the shift point calculation but given on a manual you pick the shift points I wanted to know why else it is a good idea.

Called AEV and spoke with Jordan a bit ago. If I understood him correctly the different systems (RPM, wheel speed, etc) report in every every 10 milliseconds. ESP takes all of those reports coupled with gear ratio to determine how/if it should respond. So not setting the gear ratio correctly (even in a manual) could cause the ESP to take a different action than it was designed to because it has false data as part of the calculation it makes. By setting the correct gear ratio you ensure ESP has all of the correct data it needs to perform its function.

The other impact is some kind of wide open throttle response. It apparently also requires knowing the final drive size to do its calculation.

Mopar2Ya 02-22-2013 01:40 PM

What's the opinion of an auto w/35"(loaded) & 4.88's?

zx6r 02-22-2013 04:37 PM

Quote:

Originally Posted by WXman (Post 3404553)
Yes...that is why I will NEVER touch the gears again. When I decided to do the 4.88s on my 2011 it turned into a NIGHTMARE. What a can of worms.. gears had to be removed/reinstalled 3 times to dial them in...then there was still gear whine on cold mornings that never went away....then the driveshafts were spinning so much faster that I got vibration above 50 MPH that I could never solve because Chrysler uses CV joints on both ends of the driveshaft so you cannot have them balanced at a driveline shop..

Just a total nightmare. I'll never have it done again. I'm going to hold onto my factory powertrain warranty as long as I can.

P.S. these were Yukon gears front/rear with new install kits.

These and other reasons are why i keep dragging my feet on the regear. I am sure i will still go through with it but i would be so bummed if any problems would arise. Not to mention how bummed i would be if i was so unhappy i couldn't stand to drive my jeep anymore.

RRTRI 02-25-2013 08:39 AM

After sleeping on this over the weekend, driving the wife's every time I had an excuse, reading and rereading everything I could find on gearing and talking to a friend who is very knowledgeable in this area....I'm thinking I will shy away from 4.56 go ahead and do the 4.88's on mine after all.

Here is my logic/reasoning:

I called the shop that did the install on the wife's and talked to them. We went through the math together and came up with 4.6 as the ratio that would take it back to stock with 35's. I then went through the math with my friend and he came up with the same 4.6 number. I don't recall what the math was but I'm sure someone up here will know what it is.

4.6 is obviously higher than 4.56 meaning 4.56 wouldn't completely bring it back to "stock". The other considerations are that my tires are 35's (315) but when I measured them to set the speedo with the ProCal they measure 33 3/4ish. If I decide to go to a different tire in the future that actually measures 35 that will help bring the rpm's down just a bit. I don't have any plans or see myself going larger than 35's but if I find an excuse down the road and I went 4.56 I'm under powered again. 4.88 would leave me some room for growth.

The last consideration is the math says 4.6 to get back to stock but I'm not running stock weight. The bumpers, winch, rails and so on have added several hundred pounds over stock weight. The extra bit of power around town is nice even if it means sacrificing a couple hundred rpm's at highway speeds.

One note about the whine I mentioned. In driving it around the last couple of days I've not heard it. Like I said before it was very slight anyway. I don't know if it was just breaking in or if the temps being a bit warmer the last few days have made a difference and it will come and go with the temps?

We just filled the wife's up on Saturday so once she runs through that tank I will have some gas mileage numbers to report. She doesn't drive much (only 7k in the last 12 months) so I don't know how long it will take. Although she is headed out to the country today to help a friend with a project on their hunting land. I believe the friend was going to drive but I will see if I can get my wife to drive to burn through some of her gas at highway speeds.

foo.c 02-25-2013 10:07 AM

Quote:

Originally Posted by RRTRI (Post 3417142)
4.6 is obviously higher than 4.56 meaning 4.56 wouldn't completely bring it back to "stock".

The difference is less than 1%, I doubt you would ever notice the difference between 4.56 and 4.6. It would be about 20 rpm less at highway speed.

Not trying to change your mind, but they are practically the same.

RRTRI 02-25-2013 10:40 AM

Quote:

Originally Posted by foo.c (Post 3417514)
The difference is less than 1%, I doubt you would ever notice the difference between 4.56 and 4.6. It would be about 20 rpm less at highway speed.

Not trying to change your mind, but they are practically the same.

Thanks for the input and agree. The anxiety I'm having over it is at 4.56 I'm still technically not back at stock ratios (per the math). Far better than the 3.73 I have now but if I'm going to spend the money I don't want to regret it.

I know I won't regret the 4.88's around town or wheeling. I'm unsure if I will regret it taking longer trips.

I swear I didn't put half as much thought into getting married, having kids, or buying a house. :)

foo.c 02-25-2013 11:21 AM

Have you taken a look at the gear chart?

4.56 + 35" tires is pretty close to 4.10 + 32" tires (stock Rubicon ratio).

Personally, I didn't care for the stock Rubi setup. The gears are too close together and too short. I used to shift into 5th driving on residential roads. I did like the crawl ratio though, but I rarely took advantage of it. Also it towed my pop up like it wasn't even there, and I only had to downshift for steep hills.

4.88's + 37's is slightly lower than that. I couldn't take it on 35's. JMO.

But, everyone is different. You might not find objectionable, or even like it.

RRTRI 02-25-2013 09:05 PM

Quote:

Originally Posted by foo.c (Post 3417810)
Have you taken a look at the gear chart?

4.56 + 35" tires is pretty close to 4.10 + 32" tires (stock Rubicon ratio).

Personally, I didn't care for the stock Rubi setup. The gears are too close together and too short. I used to shift into 5th driving on residential roads. I did like the crawl ratio though, but I rarely took advantage of it. Also it towed my pop up like it wasn't even there, and I only had to downshift for steep hills.

4.88's + 37's is slightly lower than that. I couldn't take it on 35's. JMO.

But, everyone is different. You might not find objectionable, or even like it.

Thanks. Yeah I've looked at that chart more than I care to admit and it was considered when we selected 4.88 on the red one. Late this afternoon I went ahead and ordered the 4.88's for mine so I can stop thinking about it. Hopefully they will be installed by mid March.

You are right about the short shifting. This weekend while driving the red one around I was noting the same thing about being in 5th on roads I wouldn't dream of in mine. Everything is at least one gear higher. Normally I'm going to 2nd when making a right hand 90 degree turn....in the red 4.88 I'm going to 3rd and quickly to 4th.

zx6r 02-25-2013 10:18 PM

Well i bit the bullet and ordered 4.88's today. Its not my highway/daily driver and anyways I think.i am gonna really dig all that . The shop is backed up for two months so the install is a little ways off yet but i will post my thoughts when it is done.

JeepHerz 02-25-2013 10:33 PM

So I am an auto and installing 4.56s ourselves as mentioned. What a nightmare.
Just a couple of thoughts: newly installed gears shouldn't make noise. At least according to the dealer. I am obsessing over gear patterns and parts- he said if it doesn't make noise and the diff fluid is clear- I am good. A slight whine could be backlash and that's easy to look at- as someone mentioned. It might be worth asking about OP.
Also, I can't remember who is doing them- but 4.33s are on the way. With 34s I expect 4.56s will be too much, but since 4.10s are stock I didn't want to go there either. If I had patience, which I don't, I'd wait for 4.33s.

Blkfenderslookbetter 02-26-2013 11:49 AM

Quote:

Originally Posted by RRTRI (Post 3402290)
Sure thing. Will come back and update MPG once we've put some miles on it.

:popcorn:

I know you said it may be a while before you can report back on MPG. But I'm real curious about this. I have the same setup as your Gecko (6sp., 3.73, & 35's)

I was more than a little disappointed in my drop in MPG's after installing the 35's, but that being said, I'm not unhappy at all with the power I have in the other gears. And if I raised (or lowered) my ratios to 4.56 or 4.88 I'd be shifting a whole lot more, especially in town. The only time I really feel underpowered is rolling on the throttle in 6th gear. I downshift to 5th and I'm good to go. So it begs the question, what would I gain to do this? If it's for better off roading, fine. I don't do a great deal of off road, and certainly nothing too extreme. If it nets me better fuel mileage, then I might be interested, then again... I'll just stay in 5th. Mission accomplished.


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