When you’re passing a car that’s going 55mph, do you pass them going 58mph?
p.s. I just swapped out the manual that I’d had since 2016 last month to an auto.
Help with re-gearing
- Thread starter Bob316
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When you’re passing a car that’s going 55mph, do you pass them going 58mph?
p.s. I just swapped out the manual that I’d had since 2016 last month to an auto.
Can anybody on the forum give a single valid reason why the 5-speed is better geared at 456 than 488 with 33’s? 
Oh wait…”Jerry said…and there was this chart I read somewhere.”
Oh wait…”Jerry said…and there was this chart I read somewhere.”
When you’re passing a car that’s going 55mph, do you pass them going 58mph?
p.s. I just swapped out the manual that I’d had since 2016 last month to an auto.
You down shift to 3 rd. and pass , you don't gear your Jeep to try to pass it in overdrive.
I doubt you modified the auto NOT to downshift on the fly , however some folks don't seem to follow the concept of downshifting the manual transmission to
keep the engine in what meager amount of torque is available for our fuel injected Rambler motors.
You down shift to 3 rd. and pass , you don't gear your Jeep to try to pass it in overdrive.
I doubt you modified the auto NOT to downshift on the fly , however some folks don't seem to follow the concept of downshifting the manual transmission to
keep the engine in what meager amount of torque is available for our fuel injected Rambler motors.
After 8 years daily driving my TJ over 100k miles, I never learned how to drive a manual. It sure was a relief to finally put in an automatic last year.
OP
I haven’t started my re-gear yet so I can answer to what it cost. I was given a quote for 6000.$ to replace Dana 35 rear and Dana 30 front with Dana 44’s with my choice of 4.56 or 4.88. The second location suggests that just a gear change would be lot cheaper. To answer RHanna moving to Eastern Tennessee year round for a change of scenery and to avoid driving at highway speeds
When you gear past a certain point, 3rd in a 5 speed becomes too short to use as a passing gear because it tops out at redline at too low of a passing speed (70ish - of course depending on the ratio). At that point it is advantageous to go deeper to the point where 5th is good in many cases and 4th becomes a good passing gear to replace 3rd since it’s now too short. So that’s one reason alone to go for 4.88 over 4.56. We (or at least I) still downshift. And in doing so, I need 4th to be good since I can’t use 3rd beyond somewhat normal speeds. So it makes sense to go deeper to improve 4th.You down shift to 3 rd. and pass , you don't gear your Jeep to try to pass it in overdrive.
I doubt you modified the auto NOT to downshift on the fly , however some folks don't seem to follow the concept of downshifting the manual transmission to
keep the engine in what meager amount of torque is available for our fuel injected Rambler motors.
Can anybody on the forum give a single valid reason why the 5-speed is better geared at 456 than 488 with 33’s?
Oh wait…”Jerry said…and there was this chart I read somewhere.”
Considering the anecdotal rhetoric and invincible ignorance of those who don’t know that they don’t know it isn’t worth the effort.
You make a good point , the interesting thing is the Auto boys in 2nd are geared even lower then a AX - 15 in 3rd. At the end of the day I suppose it hinges on how you use your Jeep. At some point the LS swap might cure far more driveability ills , than the install issues it creates. You can only get so much blood out of the turnip , no matter how fast you spin it.
You make a good point , the interesting thing is the Auto boys in 2nd are geared even lower then a AX - 15 in 3rd. At the end of the day I suppose it hinges on how you use your Jeep. At some point the LS swap might cure far more driveability ills , than the install issues it creates. You can only get so much blood out of the turnip , no matter how fast you spin it.
The thing is that I don't particularly care what gear the auto downshifts into, as long as the Jeep goes. What I do know directly is that my auto is a much happier transmission with the 538s than it was with 488 on the same tires.
And thinking back to my many years with the manual, I much preferred my gearing when I didn't need to downshift as often to keep moving.
Point being that you manual guys inadvertently keep arguing for lesser drivability because you mistake your ability to shift whenever you feel like it as some fix for poor axle gearing. Then you offer up an engine swap to cover up your flawed ideology.
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There’s no reason to change axles to Dana 44’s. Dana 30/Dana 35 combo is perfectly fine for 33’s. All you need to do is regear. 4.88’s will be great. The 4.0 loves 2800-3300rpm and will do that all day and go hundreds of thousands of miles without impacting your mpg.
Based on much reading on this forum I went with 4.88 gears with my new 33's and the Jeep is really happy . I never would have went that low based on my experience with other 4x4's I've owned , but I'm sure glad I listened to the wisdom that is in this group .
I was running 35's on my one ton diesel with 3.55 gears and had plenty of pulling power with the old granny low 4speed . In my mud slinging days I even had a Chevy step side running a 4speed with 44's and 4.10 gears . I could really throw some mud with that dude . Now I prefer to trail ride in the mountains and try to stay out of the deep mud . The mountain trails require slower movement and more torque and the lower gears are much appreciated .
I was running 35's on my one ton diesel with 3.55 gears and had plenty of pulling power with the old granny low 4speed . In my mud slinging days I even had a Chevy step side running a 4speed with 44's and 4.10 gears . I could really throw some mud with that dude . Now I prefer to trail ride in the mountains and try to stay out of the deep mud . The mountain trails require slower movement and more torque and the lower gears are much appreciated .
You would have been even happier with 513 behind your 42rle. Pay more attention next time.
You would have been even happier with 513 behind your 42rle. Pay more attention next time.
I thought I was crazy going with 4.88 , but you are correct 5.13 would have been ok . But on the bright side , if I ever want to run smaller tires again it will be good to go
Nobody has brought up passing at 70 in overdrive but you. What is being explained is that gearing appropriately to make overdrive useful has no downsides in mpg or engine life and can make offroading and driving in general better
You should know better than that verbal diarrhea. It isn't transmission specific. Its a matter of not knowing what you don't know about gearing and drivability.
Engine swaps are a different topic. It isn't rocket science that different motors in a given platform need different gearing,just like different transmissions do.
The problem lies in people changing multiple variables at once and thinking its relevant to a discussion
To summarize what I’ve seen on this site, the TJ Dana 30 and TJ Dana 44 have the same exact weak points. So you might as well just build the Dana 30 with chromoly shafts. You can do a super Dana 35 in the rear and all that will be ok with 35” tires. For 6k you could regear and do selectable lockers in both axles maybe.
Living in east TN you’ll see plenty of hills and mountains. I loved living in Chattanooga and most of east TN is beautiful. There are 2 great off-road parks AOP and windrock. I think I’d go with 488 if you don’t plan on a lot of highway driving. At the end of the day it isn’t that much difference but I’d worry that you would want 35s and you’d have to regear again with 456.
J have 35” tires with the NV3550 5 speed and it doesn’t normally see highway speed but it can handle it fine.
