Ok, I continue updating my Jeep and changing some things, this forum has helped me a lot. I don't want to go on too long with this but I need to ask since I don't have the slightest idea about transmission, axles etc... I have had a 2003 Sahara for about 3 months now and I always felt it was slow I thought it was normal until I read a little more In these forums, this jeep has 33x12 tires and a lift that according to a mechanic is 4 inches, the transmission is automatic if I'm not mistaken it is 42rle and on the rear axle it says 3.73. Does anything need to be changed in this jeep regarding the transmission or axles? I don't move on the rocks, it doesn't bother me much to go slowly, but I feel like the transmission shifts strangely, maybe it's just my paranoia and I just need to press the accelerator pedal more. please someone help me on this.
Rookie needed help
- Thread starter enmanuelrs9999
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I've never owned a 42RLE jeep, but most here will tell you that for that transmission & those tires you need 4.56 or 4.88 gears to really get the engine to spend more time in the power band. To your specific questions, you don't have a many options in the way of changing the transmission; going to a manual is your best bet but it's not the simplest task. But even then you'll still wish you were on a different gear ratio.
But "strange shifting" could be a symptom of something else as well, hard to say.
But "strange shifting" could be a symptom of something else as well, hard to say.
I understand, but would changing to 4.56 4.88 be mandatory? I mean, could I ruin something by going like that?
4.56 and 4.88 is the standard recommendation for manual transmissions and 33s. For the 42rle 5.13 would be better.
Hard ti know what is going on with your jeep but your 3.73's are definitely making that transmission work harder.
To tell what lift you have take a tape measure to the springs with the weight of the jeep on them. 16" front and 12" rear will be a 4" lift
No, re-gearing the axles is not mandatory. Nothing can be damaged Jeeping your axles the same and running 33’s with the 42rle. The Jeep will just not have much power because the shift points keep the rpm’s too low. There are a few things you can do.
1. Regear to 5.13.
2. Get the new tune by @Wranglerfix might help.
3. Flip the O/D off
4. Get a smaller tire.
Last Jeep I was a manual with 3.73 with 31" tires. It was great, highways speeds no problem and I live in a hilly area. 31's with a 4" lift is going to look silly, and I have no experience with an auto. Geared to 5.13 now with 35's and absolutely love it
Turn the OD off or get smaller tires, like @JMT said. Be happy you don't have 3.07 gearing.
A 4" lift with 31s.
A 4" lift with 31s.
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Save your penny's and do the regear
Night and day to drive especially as a DD.
I have an NV-3550 (5 Spd) with 33 x 12.5. Originally had 3.73's and acceleration was awful leaving 5th gear useless.
Went to 4.56's and gained back 5th even on long inclines. Can't say it's fast, but it's how it should be and is way more fun to drive. Could have gone 4.88's but I don't think 35's are in the plan so stuck with 4.56's. Zero complaints. Worth every penny.
Night and day to drive especially as a DD.
I have an NV-3550 (5 Spd) with 33 x 12.5. Originally had 3.73's and acceleration was awful leaving 5th gear useless.
Went to 4.56's and gained back 5th even on long inclines. Can't say it's fast, but it's how it should be and is way more fun to drive. Could have gone 4.88's but I don't think 35's are in the plan so stuck with 4.56's. Zero complaints. Worth every penny.
My neighbor ran 35s with stock gearing and that trans for many years with no damage.
Man, I would like to do it, but imagine that my closest Jeep shop came to quote me 875 for a rear seal change. This is miami fl and we are experiencing sick price gouging across the board. I would have to quote and I hope my move is not ruined if I don't do it on time. I also know that it is a big difference, I can't imagine being in a mountainous city like that.
We have the 42rle and recently went to 33's and 4.88 gears . The 4.88 gears are wonderful . 55 miles per hour is right at 2000 rpm with the overdrive on . The throttle response and transmission shifting is much better . If you don't want to spend the money for the gear swap , then I would highly recommend leaving the overdrive turned off . I ran 32's with the 3.73 gears for several years and usually kept the overdrive off .
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Don’t have your configuration but for some context back in the late 80’s used hang with a group that put anywhere from 35’s to 44’s on Toyota pick-ups. Most of us stock axles other than lift springs… meaning you can run what you got.. could it be better? Yes. Keep the auto transmission in a lower gear by manually shifting it up, turn off the overdrive. Give you time to enjoy the drive and ponder the options that your budget will support..
Thanks for sharing your experience. Speed doesn't really worry me much, I only drive about 15 miles a day with it, but it does bother me to have to change the car's transmission if it dies. I also imagine the lift kit influences my case.
Don’t have your configuration but for some context back in the late 80’s used hang with a group that put anywhere from 35’s to 44’s on Toyota pick-ups. Most of us stock axles other than lift springs… meaning you can run what you got.. could it be better? Yes. Keep the auto transmission in a lower gear by manually shifting it up, turn off the overdrive. Give you time to enjoy the drive and ponder the options that your budget will support..
It's exactly what I'll have to do for a while until my household's finances improve
If you want to protect your transmission get a temperature gauge and a sending unit installed in the pan. That will tell you your transmission temps. Then get a cooler to ensure it doesn’t get over 230F sustained.
Thanks, I will follow your advice to deactivate the overdrive too and probably prepare to regear in the future