So i come from the JK world where we have nice engine / transmission specific gear / tire charts to use as a guide for re-gearing. I have looked around but im not seeing the same for the 4.0, does such a thing exist or do i just use the generic charts and look for what others have done?
thanks
tim
The best thing to do is tell us what engine and transmission you have, and what size tires you plan on running, and we can tell you the appropriate gearing for that set up.
You really cannot depend on the various gear charts out there because of the variables. Many of them are related to a 1:1 ratio and do not take things like overdrives into consideration or the increased rpm's needed to keep larger tires moving while staying in the power band. Many here have been regearing tj's for years and know what works for specific engine/transmission/tire size combinations.
Exactly what water dog said. Several transmissions were in use on TJ's depending on model year. Gear ratio for a tj with 42rle will be much different than a tj with AW4 or Ax15. Just give us your specs and you'll get some good info.
This gear calculator is what I use all the time. You need to know some specifics, such as transmission type, T-case, gearing, tire size. Remember that a jeep on the hwy will need higher rpm's than an econo car.
This gear calculator is a good example of what we are talking about. This particular one does not make any recommendations for what you should regear to, but simply gives you the rpm calculations. If you plug in numbers for a 5 speed and a nv231 transfer case it will give you rpm's for any gear, but it doesn't tell you that you will need more rpm's to keep those 33's turning if it's all hooked up to the 4 cylinder as opposed to the 6 cylinder. Where optimum gearing for the 6 cylinder would be 4.56, for the 4 cylinder it would be 4.88.
I agree it doesn't give recommendations, but even recommendations change with what the end user's goals are. I've just found it to be the most useful gear chart to date. For some people it can get real confusing real quick when people start tossing around tires, transmissions, gear ratios, vehicle speeds and trying to compare apples to oranges. It's good for plugging numbers in and confirming if that's what you want a combo to do.
I agree, just pointing out to the op, that all the variables need to be considered.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Ask a question
Ask a question
Jeep Wrangler Forum
9M posts
468K members
Since 2005
A forum community dedicated to Jeep Wrangler owners and enthusiasts. Come join the discussion about reviews, performance, trail riding, gear, suspension, tires, classifieds, troubleshooting, maintenance, for all JL, JT, JK, TJ, YJ, and CJ models!