I did my own re-gear: the saga continues

[AndyG]

Here I sit in Gatlinburg , Tennessee, about 275 miles from home in Huntsville, here to celebrate my 25th anniversary.

Jeep was great for the ride. Averaged 18 mpg. Ran 65-70 most tof the time . Jeep is lifted 4" , has 33's with beadlocks .

No leaks , the differentials are not hot , and it's quiet enough to live with .

I'm glad it's ok , and the regear change was just fantastic...fuel economy and performance wise . Big tires kill a 4.0.

At the same time , I know I outsmarted myself trying to do it , and would probably have a smoother machine had it been done right to begin with by a real pro. I'll run it a while , drive some similar rigs , and see how it goes .

It seems , and I may be wrong , that folks hesitate the most on getting a regear , but jump fast on every mod they can afford .

In my book , the regear is simply an essential adjustment you need the second you put on oversized tires, it's not a " hey check this out " upgrade. It's more like buying bigger pants if you gain weight...a practical idea.

Please don't let my posts discourage anyone , at the same time , realize it's a specialists' job at heart .

 

[Rob5589]

It seems , and I may be wrong , that folks hesitate the most on getting a regear , but jump fast on every mod they can afford

I say this all the time; people can see big tires, big bumpers, lifts etc, but cannot see gears. Many people have a hard times spending significant money that will have no "visual" return. Maybe I need to come up with some clear acrylic covers

 

[tomtaylz]

It seems , and I may be wrong , that folks hesitate the most on getting a regear , but jump fast on every mod they can afford

I say this all the time; people can see big tires, big bumpers, lifts etc, but cannot see gears. Many people have a hard times spending significant money that will have no "visual" return. Maybe I need to come up with some clear acrylic covers

Agree 100%. I’ve been doing a lot of non sexy mods in mine, switching out a cheap 4” lift with a good 4” lift and sometimes I need to remind myself how much I have done.

 

[AndyG]

I think most of the time , folks buy a Jeep with oversize tires that hasn't been regeared ...so they don't comprehend how off the gearing is.

 

[Markymech]

This is a great thread to read! I literally grew up with tools in my hands and typically do all my own mechanical work (and construction work, electrical work, plumbing work...) and I've helped with diff set-up in my old man's pulling tractor...but that was 30 years ago. So yeah, with a re-gear coming up I've started thinking "maybe it's time to set my considerable ego aside and pay an actual expert to do this..."
Decision now made. Thanks!

 

[twp1963]

The whole spreader thing scared me away. I have done Chevy 12 bolts before but I was in a hurry and wanted to be sure the gears were setup right and have a guarantee. The guy that did it had done work for me before so I trusted him. He fixed some other small issues as well as the gear change. He couldn’t get in the shin kit he needed cause everyone was out. After a month I got my tj back. Ran great with the new 4.56 gears. Felt like it had a v8 in it with 31’s compared to factory gears. Then a month later I was in a drive through and started to pull out and it sounded like someone hit my diff with a sledgehammer. I took it across the street to a shop to minimize doing anymore damage. Getting my gears setup cost $1200. When the new garage opened the diff there were NO carrier spacers. It cost me another $1000 just to get the rear redone. When I went to the old shop the guarantee was only good for 30 days. So if you can -do them. If not get them done but make SURE you get someone reputable and a good warranty in hand to back up their work.

 

[mrblaine]

It seems , and I may be wrong , that folks hesitate the most on getting a regear , but jump fast on every mod they can afford

I say this all the time; people can see big tires, big bumpers, lifts etc, but cannot see gears. Many people have a hard times spending significant money that will have no "visual" return. Maybe I need to come up with some clear acrylic covers

I know this is a few months old but it popped up on the suggestions. The mods you need but can't see are the bane of my existence at times.

The rest is I am fairly talented mechanically and I grasp mechanical concepts with a quickness that most don't have. I envy three groups of folks in the mechanical world. Good Tig welders which I will never be, good automotive electrical troubleshooters and schematic decipherers, and gear setters. I know what I am not good at and I won't do gears or even try to learn. I've seen what it takes and pulled lots of diffs apart to fix various things so my hat is off to every good gear setter out there and I can't thank ya'll enough for doing something that makes our rigs work so much better.

 

[Cudabnu]

I know this is a few months old but it popped up on the suggestions. The mods you need but can't see are the bane of my existence at times.

The rest is I am fairly talented mechanically and I grasp mechanical concepts with a quickness that most don't have. I envy three groups of folks in the mechanical world. Good Tig welders which I will never be, good automotive electrical troubleshooters and schematic decipherers, and gear setters. I know what I am not good at and I won't do gears or even try to learn. I've seen what it takes and pulled lots of diffs apart to fix various things so my hat is off to every good gear setter out there and I can't thank ya'll enough for doing something that makes our rigs work so much better.

I'm in the same boat, I can fix pretty much anything mechanical, My brother is a electrical wiz and builds high end home audio for a living, so between us most things on all my cars get done by ourselves. I tried to re-gear my 70 cuda once many years ago and realized at that time it was something that was worth it to pay an expert to do.

 

[AndyG]

I know it comes across wrong here on the forum , because everyone wants to defend their ego , but people need to let a pro set the gears when possible . It is an intense Job .

I am dropping mine off Sunday night after church at the shop I use for new gears front and back - I put on a hardtop and I can't take the jet like noise anymore .

 

[mgroeger]

Whew... man that sucks and makes me glad I made the right decision with mine. Had leaking front axle seal and said, hmmm... nah I'm taking it in. For $525 (including tax) I got...

All work done by East Coast Gears in Durham NC
New inner seals on front axle
After market greasable outer dust seals
Front backlash was .032 from PO now it's correct at .008
Rear diff checked and found to be good at .009
Fluids changed in both axles with Lucas Oil (they swear by the stuff)

I thought that was a darn good price for peace of mind that true professionals did the work and warranty the front seals for 2 years.

Plus I got to check out their 2018 JL with a Dana60 on the front and Dana80 on the rear. NICE!!!

 

[AndyG]

I absolutely love what proper gearing does... There are so many Jeeps running around with big tires and the wrong gearing.

In my mind it is not a modification but a necessary adjustment due to the change in final drive ratio.

 

[mgroeger]

I'm running 4.88 gears and 33" tires. Would I be able to run 35" tires with these gears?

 

[Alex01]

I'm running 4.88 gears and 33" tires. Would I be able to run 35" tires with these gears?

What transmission? I have the 5 speed and 4.88 / 35s is perfect.

 

[mgroeger]

It's a 2004 LJ with an automatic tranny so I believe that is the 4 speed auto.

 

[Chris]

I'm running 4.88 gears and 33" tires. Would I be able to run 35" tires with these gears?

If your 2004 is an automatic, 4.88 gears and 35s will suck.

Ideally you'll want 5.38 with an automatic 42RLE, but if you don't have Rubicon axles, that's not possible, so 5.13 will be your only option. It won't be perfect, but it will be better than 4.88.

 

[mgroeger]

I do have Rubi axles in it. I find that when going up hills the engine bogs down because that tranny does not like coming out of OD so I simply hit the OD switch to knock it out of OD. It's a pain but it is what it is. My understanding is that's the way that tranny works... it loves OD.
So if I understand you correctly I will only make this scenerio worse by increasing tire size.

 

[Mr. Bills]

. . . So if I understand you correctly I will only make this scenerio worse by increasing tire size [to 35" with 4.88 gears and my 42RLE transmission].

Yes, you are correct. 5.38:1 is the optimum gear ratio for a TJ with 4.0 engine, 42RLE transmission, Dana 44 axles and 35" tires. Your 42RLE overdrive will be next to useless with 4.88 gears and 35" tires. BTDT.

 

[Chris]

I do have Rubi axles in it. I find that when going up hills the engine bogs down because that tranny does not like coming out of OD so I simply hit the OD switch to knock it out of OD. It's a pain but it is what it is. My understanding is that's the way that tranny works... it loves OD.
So if I understand you correctly I will only make this scenerio worse by increasing tire size.

Yes, it will only make that worse by adding 35s. Going to 5.38 gears will help, but I have a 42RLE with 35s and 5.38 gears in mine, and it still "hunts for overdrive" as we call it.

It's a lot better than it was on 4.10s, but just know that there's no way that will ever go away completely, it's just the nature of the poorly designed .69 OD gear.

 

[mgroeger]

Yes, it will only make that worse by adding 35s. Going to 5.38 gears will help, but I have a 42RLE with 35s and 5.38 gears in mine, and it still "hunts for overdrive" as we call it.

It's a lot better than it was on 4.10s, but just know that there's no way that will ever go away completely, it's just the nature of the poorly designed .69 OD gear.

"Hunts for overdrive"?!?!?!?! Trust me it FINDS OD and does NOT like to come out of it unless you mash the pedal or force it out with the switch... lol
We should call it "Loves to stay in OD", unless of course I'm not understanding how the OD function works on these trannies.

 

[mgroeger]

BTW... this sucks. I know I said I'm happy with 33's and you guys said "Oh just wait, you'll want to go bigger" and here I am. I can't justify ti now because of the cost of the re-gear and 33's with 90% tread life left.