Misc questions: what else do I 'need'? (lifts, gears, etc.)

[psrivats]

Now that I have everything immediate I wanted taken care of in my TJ Rubicon so that it's running smoothly and good for everyday use, I wanted to get some input on what other items I need do for my TJ to ensure longevity and good performance. Been reading and learning a lot about axles, axle gearing and it's effect on engine performance, different lift kits .. there is so much info on the forum and I love it.

List of things done so far:

- running all new fluids everywhere (engine oil, trans fluid, brake fluid, t-case fluid, F/R differential fluid)
- sealed beams replaced with Vision-X VX-XRD halogen headlights (may do the LED stuff if this doesn't cut the mustard in the winter/rain)
- new 265/75R16 duratacs on MOAB rims (really liking this combo)
- Iggee vinyl seat covers and bedrug front and rear (made my interior look really nice, worth every penny)
- soft top on for the summer (loving it, thanks so much to this forum)
- went back to OEM bumpers with OEM end caps replacing smittybuilt bumpers from PO

Future items already planned:

- OPDA replacement (I had my mechanic check the OEM OPDA and he said it's fine but I will get the crown replacement within the next month)
- Vanco big brake kit (hard stops with OEM brakes are a bit scary)
- a good hardtop headliner for winter (it rains a LOT here)
- a dead pedal for driving comfort

Some questions I have:

1. Prev owner had installed a 2.5" fabtech lift (this one). The jeep is at a very comfortable height with this fabtech setup and the tires I currently have. I want to stay at this overall height and no intention of moving . I see that the old man emu lift setup is highly favored here along with Rancho RS5000X shocks. Will I see a significant difference in performance with this combo compared to what I have now? In what way? This is the first vehicle I am driving with a lift so I have no previous frame of reference. FWIW, I like how my jeep feels on the road but sometimes I wish for a smoother ride. Don't mind spending the money if it'll be significant change.

2. Having a rubicon, I have 4.10 gears and my jeep has the 42RLE auto transmission. I see a lot of threads on axle regearing and lots of suggestions for folks running 33" or bigger tires. I don't think I will ever go bigger than the tires I have now, simply not needed for how and where I will be using the jeep ( I don't plan to do any heavy intentional offroading for recreation). So for my use case, is there is any need for regearing at all? One thing I have already noticed is how the overdrive works on the hilly highway roads we have here in OR and it can get annoying at times. If regearing is the fix, what ratio would I need? I know regearing is not cheap, but I will save for one if it will once again significantly change performance.

3. Transmission coolers - I saw @Chris thread on the Derale model - is this a must-have for the 42RLE? If yes, I will get this done next, price is not too terrible.

4. Are there any other must-haves that I should consider? Not creature comforts, but more towards ensuring longevity of the vehicle. I've never been a car person, but after getting this TJ I am liking it so much that I want to keep it running properly for a GOOD while.

I will add more questions to this thread as I read and learn more. Thanks in advance to your answers and thoughts.

 

[jjvw]

Regearing is primarily done to regain street and highway performance. With 33s and your transmission, 5.13 is ideal for you. It is helpful to understand that all Wranglers with the 42rle were under geared from the factory when compared to all the other transmission options.

To improve your ride comfort, look at shocks and tire pressure. I will also suggest that suspension up travel is a meaningful factor. Up travel is what allows the suspension to soak up the road before shoving the body up and of the way. A 2.5" lift is not enough to maintain the factory 4" of up travel. You need 3.5-4" of total lift to achieve this.

One important thing to add to your list is adding the correct amount of bump stop extension. The bump stops are there to keep parts from crashing into other parts. Larger tires and longer shocks require extending the bump stops. 33s by themselves need about 2.5" of extension in the front to keep them from damaging the steel fenders.

 

[Chris]

1. Prev owner had installed a 2.5" fabtech lift (this one). The jeep is at a very comfortable height with this fabtech setup and the tires I currently have. I want to stay at this overall height and no intention of moving . I see that the old man emu lift setup is highly favored here along with Rancho RS5000X shocks. Will I see a significant difference in performance with this combo compared to what I have now? In what way? This is the first vehicle I am driving with a lift so I have no previous frame of reference. FWIW, I like how my jeep feels on the road but sometimes I wish for a smoother ride. Don't mind spending the money if it'll be significant change.

Springs aren't going to make a difference. The difference will b in the shocks, in which cace the Rancho RS5000X shocks are the best riding TJ shocks out there IMHO. I've ran Fox shocks, Bilstein 5100s, OME Nitrochargers, and not Ranchos. The Ranchos ride better than all of them. I think most would agree.

2. Having a rubicon, I have 4.10 gears and my jeep has the 42RLE auto transmission. I see a lot of threads on axle regearing and lots of suggestions for folks running 33" or bigger tires. I don't think I will ever go bigger than the tires I have now, simply not needed for how and where I will be using the jeep ( I don't plan to do any heavy intentional offroading for recreation). So for my use case, is there is any need for regearing at all? One thing I have already noticed is how the overdrive works on the hilly highway roads we have here in OR and it can get annoying at times. If regearing is the fix, what ratio would I need? I know regearing is not cheap, but I will save for one if it will once again significantly change performance.

Trust me... re-gear. Unless you drive a TJ identical to yours with 4.88 gears, you won't know what you're missing. I used to think it was hype, but when I re-geared mine (also a 42RLE with the factory 4.10 gears on 33s) to 4.88 gears, it totally woke the thing up. The hunting for overdrive won't go away entirely, but it will be much, much better. The Jeep will drive better all around, and have a much more usable power band. Don't overlook gearing. You'll be happy once you put some 4.88 gears in there (which is the ideal ratio for your transmission with 33s).

3. Transmission coolers - I saw @Chris thread on the Derale model - is this a must-have for the 42RLE? If yes, I will get this done next, price is not too terrible.

Do it! I did it on my last TJ, and I am installing one soon on my current TJ (it's sitting in my garage). They'll extend the life of your transmission, and the Derale transmission cooler is a very nice unit!

 

[psrivats]

Thanks @Chris and @jjvw.

Note that I'm running 32s (31.65 to be exact), not 33s, and I do not plan to run any bigger tires. How do I find out what's the optimum gear ratio ie 4.88 vs 5.13? I also don't want to lift any higher, this is as tall as I want it to be, in terms of road visibility and comfort. Otherwise getting in and out becomes painful. How do I find out how much bump stop extension I currently have? For this height, are Ranchos still the best shocks?

I'll get the trans cooler installed when I do the OPDA swap.

 

[jjvw]

Grimmjeeper.com is the best gear calculator because it is specific to your transmission.

32s still need a bit of bump stop. Look for the steel cup inside the coil springs. Both front and rear. Also look at the axle pad below. Is there is any kind of spacer today looks or if place, then that is the extension. Basically, the cup and pad need to make contact before other things do. Meaning over compressing the shocks, tires mashing into the fenders (ignore the flexible flares), track bar hitting the diff cover, etc.

The only real way to know what is going on if to put the Jeep on jack stands, remove the coils, jounces, disconnect the sway bar and then cycle the axle with tires on through it's entire range of movement. The first thing that hits is what the bumps need to be extended to.

Flexing with a forklift or ramp or tree stump can't do what you need to do. The idea is to recreate the dynamic loads that occur during normal everyday driving.

 

[Rob5589]

5.13 is 2650 @ 70
4.88 is 2500 @ 70
5.13 would be my choice between the two

That "lift" you showed is just a fancy spacer lift. The OME coils, BDS coils, or Pro Comp coils with some Rancho 5000X shocks would be a nice combo.

 

[bobthetj03]

What shocks are on your rig now? Tera's?
Bumpstop extensions are usually added to the lower spring pad in the front, and the jounce bumper cup in the rear. With that lift and those tires, you should have at least a minimum of 1"-1.5" of added bumpstop to keep the tires out of your inner fender wells.
Here is an example of 2" of added bumpstop to the front coil spring lower pad. Yes you'll need to pull the springs, drill/tap threads in the lower pad to add more bumpstop.

Example of 1" added bumpstop in the rear.

 

[psrivats]

What shocks are on your rig now? Tera's?
Bumpstop extensions are usually added to the lower spring pad in the front, and the jounce bumper cup in the rear. With that lift and those tires, you should have at least a minimum of 1"-1.5" of added bumpstop to keep the tires out of your inner fender wells.
Here is an example of 2" of added bumpstop to the front coil spring lower pad. Yes you'll need to pull the springs, drill/tap threads in the lower pad to add more bumpstop.
View attachment 45853
Example of 1" added bumpstop in the rear.
View attachment 45854

@bobthetj03 I have Fabtech suspensions. The jeeo had 17" rims and 33.5" mud tires when I bought it and I hated both the looks and the ride. However, my mechanic said there is no rubbing even on that set up. I'm now running smaller wheels and tires. Let me check what's under there when I get home from work. Thanks a ton for your photos.

@Rob5589 Thanks.

@jjvw I will check and post here as to what I have. I do have bumpstops but not sure how much. I don't think anything is hitting anything or rubbing, but I have to check with my mechanic if he's done the detailed check you are talking about when the Jeep was in the shop. I'll talk to him later today.

 

[bobthetj03]

Also, let us know what tire pressures you are running.

 

[Chris]

Thanks @Chris and @jjvw.

Note that I'm running 32s (31.65 to be exact), not 33s, and I do not plan to run any bigger tires. How do I find out what's the optimum gear ratio ie 4.88 vs 5.13? I also don't want to lift any higher, this is as tall as I want it to be, in terms of road visibility and comfort. Otherwise getting in and out becomes painful. How do I find out how much bump stop extension I currently have? For this height, are Ranchos still the best shocks?

I'll get the trans cooler installed when I do the OPDA swap.

For 32s I would still go with 4.88. You could go with 4.56, but in all honesty, going from 4.10 factory gears to 4.56 wouldn't make that much of a difference. Go with 4.88s, trust me.

As for bump stop, you can check out this thread for how to measure that:
How to set your bump stop on a Jeep Wrangler TJ

 

[jjvw]

... However, my mechanic said there is no rubbing even on that set up. I'm now running smaller wheels and tires. ...


... I do have bumpstops but not sure how much. I don't think anything is hitting anything or rubbing, but I have to check with my mechanic if he's done the detailed check you are talking about when the Jeep was in the shop. I'll talk to him later today.

I would be surprised if your mechanic fully cycled the suspension. Is he a Jeep guy? Even that guarantees nothing. Many rely on some kind of flex test, if anything. Others will just assume that the kit will cover everything. You may potentially not have any rubbing. But if the shocks are acting as your bump stops, then it is only a matter of time before something breaks.

 

[TJ2]

psrivats, if only you have access to a fork lift to lift one tire at a time.

 

[jjvw]

psrivats, if only you have access to a fork lift to lift one tire at a time.

That won't tell you if the track bar is hitting the diff cover. And again, the fork lift won't replicate dynamic loads on the suspension. The only thing that does is removing the coils and cycling the axle with a floor jack.

 

[TJ2]

WOW.
I swear you know a lot about suspension.

 

[Equilibrium31]

Noob question, but can you seriously use hockey pucks as bump stocks?

 

[jjvw]

WOW.
I swear you know a lot about suspension.

A medium amount.

 

[TJ2]

A medium amount.

Always good to have experienced guys in this forum.

 

[Rob5589]

Noob question, but can you seriously use hockey pucks as bump stocks?

Sure, have seen several folks use them. Plus, if a random hockey game breaks out, you're set

 

[bobthetj03]

They've worked well for me. Have 2 on the front lower pads.