Should I avoid a potential TJ purchase because it has a 42RLE?

[xxthebombxx]

Well, I decided to buy the built jeep. The price, components, known history, and condition of the jeep made it a no brainer for me. If anyone is interested in a really clean, desert jeep, there is one in las vegas right now. Marketplace, 2003 wrangler tj. Pristine body condition. Red with black hard top.

Anyways, thank you for all of the information the last few days. I will post more pictures of it when its officially mine. This place is loaded with knowledge and experience. I. Looking forward to learning and owning my jeep!

 

[lBasket]

This thread got pretty exciting when you posted pictures, and with the atlas

 

[xxthebombxx]

This thread got pretty exciting when you posted pictures, and with the atlas

Thanks. I'm really looking forward to using it. Beyond my skill level right now for sure but I will learn.

 

[lBasket]

Thanks. I'm really looking forward to using it. Beyond my skill level right now for sure but I will learn.

It won't be a bad thing to be able to learn without worrying about the Jeep I bet

 

[Brianj5600]

The Atlas is possibly the prettiest Jeep jewelry available, too bad it is hidden where few will ever see it.

 

[TeeJohn]

You probably made a good choice as far as the configuration and its ready to go. I doubt you’ll feel comfortable with long highway trips with that rpm. For now I have 4:11 and 35s and I can keep up with slow freeway traffic and stay under 3000 rpm. To me the rpms just feel excessive as 3000 comes along. It’ll do it but I can’t agree with running that hard for hours. The mileage goes to heck as well. I can tow my Jeep in comfort at 70+ on a trailer behind my diesel pickup and still get better mpg on the highway part of the trip.

 

[xxthebombxx]

You probably made a good choice as far as the configuration and its ready to go. I doubt you’ll feel comfortable with long highway trips with that rpm. For now I have 4:11 and 35s and I can keep up with slow freeway traffic and stay under 3000 rpm. To me the rpms just feel excessive as 3000 comes along. It’ll do it but I can’t agree with running that hard for hours. The mileage goes to heck as well. I can tow my Jeep in comfort at 70+ on a trailer behind my diesel pickup and still get better mpg on the highway part of the trip.

Thank you for the input. I wheeled it around for a while today. Total blast. Learned how to work the atlas. Easy once you do it once or twice. Definitely fun to drive! I know I'm going to enjoy it. I need to figure out the highway situation, whether I will just drive it, even at 65mph if I have to, or tow it.

 

[davecarlson98]

My reply was partially tongue in cheek. The real issue with the 42' is not with the overdrive itself (although it is just a bit too deep), but rather that the TCU shifts into overdrive much too quickly, and winds up lugging the engine when it doesn't really need to do so.

Hi, when I read through these threads, I see alot of lugging issues in Overdrive. I know you can always turn off Overdrive, but shouldnt the transmission downshift to 3rd on its own? Why is it necessary to babysit the transmission? I am wondering if I need a modification to the PCM/TCM to get more reliable shifting....thanks in advance for any tips

 

[NashvilleTJ]

Hi, when I read through these threads, I see alot of lugging issues in Overdrive. I know you can always turn off Overdrive, but shouldnt the transmission downshift to 3rd on its own? Why is it necessary to babysit the transmission? I am wondering if I need a modification to the PCM/TCM to get more reliable shifting....thanks in advance for any tips

Unless someone has figured it out and I'm not aware, there is no way to get into the TCU to change the shift points. Many have looked for a solution, but I am not aware of one. The best solution is to gear properly for your tire size, and that makes it bearable.

 

[Jerry Bransford]

Unless someone has figured it out and I'm not aware, there is no way to get into the TCU to change the shift points. Many have looked for a solution, but I am not aware of one. The best solution is to gear properly for your tire size, and that makes it bearable.

The right axle gearing choice makes the 42RLE a good decision.

 

[davecarlson98]

Unless someone has figured it out and I'm not aware, there is no way to get into the TCU to change the shift points. Many have looked for a solution, but I am not aware of one. The best solution is to gear properly for your tire size, and that makes it bearable.

@Wranglerfix could you weigh in on this? Can modifications be made to the TCM to assure improved shifting particularly as it relates to the lugging experienced while in Overdrive? If it can be modified, is there a reason Chrysler never did it? Thanks, Dave

 

[Steel City 06]

@Wranglerfix could you weigh in on this? Can modifications be made to the TCM to assure improved shifting particularly as it relates to the lugging experienced while in Overdrive? If it can be modified, is there a reason Chrysler never did it? Thanks, Dave

It can be done with a tuner like the HPTuners model and a factory PCM. As far as I recall, the Wranglerfix PCMs are locked out of tuning.

@Flyin' Ryan Performance offers canned tunes for factory PCMs, and if I recall correctly there is shift point modification for the autos. I would go check my FRP tune to verify but I have a six-speed.

 

[Jerry Bransford]

If it's geared wrong for larger tire sizes and lugging it'll still be geared wrong and lugging after reprogramming the shift points.

 

[NashvilleTJ]

It can be done with a tuner like the HPTuners model and a factory PCM. As far as I recall, the Wranglerfix PCMs are locked out of tuning.

@Flyin' Ryan Performance offers canned tunes for factory PCMs, and if I recall correctly there is shift point modification for the autos. I would go check my FRP tune to verify but I have a six-speed.

That’s pretty cool. Do you know of anyone on the forum who has done it?

That would correct the biggest issue with the 42’ in my opinion. A lot of folks complain about the .69 overdrive - but to me it’s a good thing as it allows you to run 5.13’s or 5.38’s with 33“ or 35“ rubber. As I noted the issue is that in the stock config it just shifts into OD way to early.

 

[Jerry Bransford]

No matter when it shifts into Overdrive it will still have the same .69 OD ratio.

 

[Steel City 06]

That’s pretty cool. Do you know of anyone on the forum who has done it?

That would correct the biggest issue with the 42’ in my opinion. A lot of folks complain about the .69 overdrive - but to me it’s a good thing as it allows you to run 5.13’s or 5.38’s with 33“ or 35“ rubber. As I noted the issue is that in the stock config it just shifts into OD way to early.

There are a couple of old threads on it:

https://wranglertjforum.com/threads...possible-to-program-42rle-shift-points.42931/
https://wranglertjforum.com/threads...access-for-2005-2006-jeep-wrangler-tjs.16403/

 

[Irun]

If it's geared wrong for larger tire sizes and lugging it'll still be geared wrong and lugging after reprogramming the shift points.

Couldn't agree more! I really don't understand the hate for the 42RLE. I've owned several TJ/LJ Jeeps, and a JK, with the 42RLE and it has always been highly reliable. Sure, it's not the best transmission in the world, and the .69 overdrive can be annoying, but it's also not the worst. There are two universal truths with the 42RLE, i.e. you must:

- re-gear to the absolute max gearing possible for the tire size
- install the best quality transmission cooler possible, coupled with a transmission temperature gauge

You can also install the TransGo shift kit, as you have done, but this honestly doesn't make a huge difference. I guess the bad rap really stems from the '05 - '06 computer issues. Thankfully, @Wranglerfix came to the rescue, when Chrysler basically abandoned us. For me, I have zero issues purchasing any Jeep with a 42RLE. Okay, I'm done!

 

[Juggernaut]

That’s pretty cool. Do you know of anyone on the forum who has done it?

That would correct the biggest issue with the 42’ in my opinion. A lot of folks complain about the .69 overdrive - but to me it’s a good thing as it allows you to run 5.13’s or 5.38’s with 33“ or 35“ rubber. As I noted the issue is that in the stock config it just shifts into OD way to early.

I have changed the shift points with HPT and I’m extremely happy with the results. It no longer feels like your skip shifting as you can delay the upshift to 4th until the engine has the rpm/torque to pull the gear. I believe I described the workings of the shift schedule in more detail in a previous thread. Between the added power and adjusted shift points, the 42rle works very well.

 

[NashvilleTJ]

I have changed the shift points with HPT and I’m extremely happy with the results. It no longer feels like your skip shifting as you can delay the upshift to 4th until the engine has the rpm/torque to pull the gear. I believe I described the workings of the shift schedule in more detail in a previous thread. Between the added power and adjusted shift points, the 42rle works very well.

Wow - I think I may have to switch back to the ole’ 42’!

 

[Brianj5600]

I have changed the shift points with HPT and I’m extremely happy with the results. It no longer feels like your skip shifting as you can delay the upshift to 4th until the engine has the rpm/torque to pull the gear. I believe I described the workings of the shift schedule in more detail in a previous thread. Between the added power and adjusted shift points, the 42rle works very well.

Once I got my ignition timing and power enrichment delay tidied up I no longer felt the need mess with shift points.

Wow - I think I may have to switch back to the ole’ 42’!

LOL