Regearing the 6 Speed NSG370

[JMT]

So, I've been through this before, I just want some help making a final decision on parts. I currently have the 6-speed with 33's and 3.73 gears. My calculations for 33's give me 4.34, so I'd up the regear to 4.56. For 35's my calculations give me something like 4.71, so I could up the re-gear to 4.88. In my thinking, 4.56 may be a good choice for either, so if I decide to stay at 33's I'm good, and not bad at all for 35's if I ever decided to go that far (but I'm not planning that anytime soon as its my DD. I'd have to dedicate it to off-road use to go that far). However, I could also go 4.88 for either 33's or 35's. That would be some deep gearing for 33's. It's a DD and weekend warrior (rock crawling mainly). So my question is this, on 33's with 4.88's, are my gears going to be so short I get tired of shifting all the time? I know its a personal preference, but I don't want to be wearing myself out shifting. And that would be an effect of opting for 4.88 over 4.56, right? Also, is my top speed with 4.88's going to be less? Not that I'm trying to run the Indianapolis 500, just wondering. Especially @Rob5589, @Jerry Bransford and other gearheads.

FYI: revolution gears, revolution super 35, E-locker all running $1542. Install shop I'm talking to won't warranty any breakage whether they sell you the parts or not. They sell Yukon and G2, but there is no break on prices if you buy those parts from them. From all the numbers he gave me, they don't make money on selling parts, just on labor. I found this different and interesting. The guy said, get what parts you want and bring them in, we've been doing this for 29 years and abuse is what breaks them, so $1150 for total install of all parts, no warranty. The shop was recommended to me by a friend and owner of an OHV park. They do all the Jeeps of Austin's premier Jeep club and have been for years. Any thoughts?

 

[ATTolan]

Your talking axle gearing not the physical transmission.

4.88s is what I’ll be running with 35s for my DD rubicon with the nsg370 6 speed. I would agree they might be a little much for 33s. 4.56 would be ideal for 33s as I have the metric equivalent of them with 4.11s and it’s a pooch to say the least. If your going to stay at that tire size 4.56 all day, but we always want to upgrade right? I’d say go 4.88 and 35s you’ll be more than happy on and off road.

 

[JMT]

Your talking axle gearing not the physical transmission.

Yes, just wanted everyone to know what transmission I had....My thread title is misleading! LOL. Thanks for the feedback. As you might see, my dilemma is whether I ever will go up to 35's, as I only want to do this once! So, still curious if anyone running 33's with 4.88 gears, or if the numbers indicate I'll just be revving high rpms all the time and changing gears every other second. Last time this came up several said 4.88's would be really awesome, but this is a DD and I don't want to be miserable in that department. Thanks.

 

[ATTolan]

I’m not sure what it is with the 6 speed but i know with the 5 speed at 60 or 70 mph there’s like 200-300 rpm difference maybe less with a 6 speed and the extra gear? I’m also newer to the whole 6 speed trans.

 

[JMT]

I’m not sure what it is with the 6 speed but i know with the 5 speed at 60 or 70 mph there’s like 200-300 rpm difference maybe less with a 6 speed and the extra gear? I’m also newer to the whole 6 speed trans.

I think that's why I was wondering if I could get away with 4.56 for either 33's or 35's. My wife can barely get in the Jeep with 33's, so 35's is another inch, and her step is moving up with rock sliders sometime soon. We're both vertically challenged. She's almost taller than me. But I like taller women, and if I can pull that off, well, so be it! In any case, 4.56 is still an option for me. It's very close to 4.71 and I could always run a metric equivalent in the 34 range.

 

[ATTolan]

My wife is also vertically challenged (5’2”) I got a good deal on 37s bought them then told her I got them. So that’s not happening any more 35s it is! she can hardly get in with the 32s I normally run. I’m sure if you do some more research you might find your answer or something “good enough?”

 

[derekmac]

My 6spd Rubi with the factory 4.10's and my 33's is IMHO a great combo. I can still start out in 2nd easily, and hold hills without losing speed in 6th.

 

[ac_]

So, I've been through this before, I just want some help making a final decision on parts. I currently have the 6-speed with 33's and 3.73 gears. My calculations for 33's give me 4.34, so I'd up the regear to 4.56. For 35's my calculations give me something like 4.71, so I could up the re-gear to 4.88. In my thinking, 4.56 may be a good choice for either, so if I decide to stay at 33's I'm good, and not bad at all for 35's if I ever decided to go that far (but I'm not planning that anytime soon as its my DD. I'd have to dedicate it to off-road use to go that far). However, I could also go 4.88 for either 33's or 35's. That would be some deep gearing for 33's. It's a DD and weekend warrior (rock crawling mainly). So my question is this, on 33's with 4.88's, are my gears going to be so short I get tired of shifting all the time? I know its a personal preference, but I don't want to be wearing myself out shifting. And that would be an effect of opting for 4.88 over 4.56, right? Also, is my top speed with 4.88's going to be less? Not that I'm trying to run the Indianapolis 500, just wondering. Especially @Rob5589, @Jerry Bransford and other gearheads.

FYI: revolution gears, revolution super 35, E-locker all running $1542. Install shop I'm talking to won't warranty any breakage whether they sell you the parts or not. They sell Yukon and G2, but there is no break on prices if you buy those parts from them. From all the numbers he gave me, they don't make money on selling parts, just on labor. I found this different and interesting. The guy said, get what parts you want and bring them in, we've been doing this for 29 years and abuse is what breaks them, so $1150 for total install of all parts, no warranty. The shop was recommended to me by a friend and owner of an OHV park. They do all the Jeeps of Austin's premier Jeep club and have been for years. Any thoughts?

Back in the days when I was wheeling a lot more hard core I built my YJ with AX15 with 33's and 4:56 front rear ARB's The combo was good all around. I wish I had a little more overdrive on the freeway and I wish I was slightly lower off road. It was pretty decent for all around use though. I would say take some time and really try and decide if you are or might go to 35's I think you will be disappointed with the 4:56 and the 35's. I think you will be happy with the 4:56 and 33's, but all in all I don't think you will be that disappointed with 4:88. Although I don't know what the 6th gear feels like. It may make the 4:88's nice on the freeway. Really if your actual numbers are 3:71 That is really in between either way.

Knowing how you like to modify and how much you like to go to the beach and wheel, I don't think you will be disappointed with the 4:88's, and you can scale with it, but it may feel like the brakes are on when you coast on the freeway. I am not sure with the 6th gear as I have never had one.

I know that is clear as mud. but I think you will be happy either way. It is going to really be the degree of happiness that will change.

 

[bobthetj03]

Factor in needing better brakes if you go 35's, and losing some uptravel if you keep the stock fenders. 4.88's, 33's, and my 5 speed would be too much gear for my DD duties, IMO. Your 6 speed might be ok. I would think that 4.56's on 35's would put you at a similar performance level that you have now with your 33's/3.73's. If you can live with how it's performing now, then maybe 4.56's?

 

[JMT]

Factor in needing better brakes if you go 35's, and losing some uptravel if you keep the stock fenders. 4.88's, 33's, and my 5 speed would be too much gear for my DD duties, IMO. Your 6 speed might be ok. I would think that 4.56's on 35's would put you at a similar performance level that you have now with your 33's/3.73's. If you can live with how it's performing now, then maybe 4.56's?

I won’t go to 35’s unless it’s no longer my DD. That’s highly unlikely for a number of years.

3.73’s are bearable, but not at all desirable for performance or gas mileage. But 4.56 vs 4.88 is much closer than 3.73 vs 4.56, unless I’m not understanding gear ratios. Thus, the reason I thought eventually I could run 35’s on. 4.56 would be substantially better than 33’s at 3.73

 

[ac_]

I won’t go to 35’s unless it’s no longer my DD. That’s highly unlikely for a number of years.

3.73’s are bearable, but not at all desirable for performance or gas mileage. But 4.56 vs 4.88 is much closer than 3.73 vs 4.56, unless I’m not understanding gear ratios. Thus, the reason I thought eventually I could run 35’s on. 4.56 would be substantially better than 33’s at 3.73

I think that's fair.

 

[Rob5589]

Personally, I would go 4.88. @70 with a 32.5" tire you would be right at 3k rpm. We all know the 4.0 is fine running there but we also know some freak the hell out. The benefits are a super low crawl ratio in 1st/4lo which is great for those nasty descents you seem to enjoy and plenty of gear in the hills. And if 35's are possible, 4.88 is a no branier. Now, if you wanna run 75+ down the hwy (not sure what the limits are in TX) then 4.56 is probably your better choice. Still good off road but more leeway when running down the highway.

 

[JMT]

Personally, I would go 4.88. @70 with a 32.5" tire you would be right at 3k rpm. We all know the 4.0 is fine running there but we also know some freak the hell out. The benefits are a super low crawl ratio in 1st/4lo which is great for those nasty descents you seem to enjoy and plenty of gear in the hills. And if 35's are possible, 4.88 is a no branier. Now, if you wanna run 75+ down the hwy (not sure what the limits are in TX) then 4.56 is probably your better choice. Still good off road but more leeway when running down the highway.

Very helpful. Thanks Rob!

 

[jjvw]

For comparison, my 75mph is at 3k rpm with 33s, 4.88, 5 speed. I like that setup. Low gears make everything better.

2003 Rubicon

 

[jeep_boss]

I'm not sure why 35's are such a turn off for DD's, I drive all day long on 35's - as long as you get good AT's you're good ;-)

 

[glwood]

I'm not sure why 35's are such a turn off for DD's, I drive all day long on 35's - as long as you get good AT's you're good ;-)

Most likely it's not driving on them that's the turn off, just getting into a Jeep with 35s that's the issue...:sisi3:

 

[jjvw]

Most likely it's not driving on them that's the turn off, just getting into a Jeep with 35s that's the issue...:sisi3:

Right. What kind of dummy spends all that time and money modding their daily driver to be a well performing rock crawler!

 

[Neal]

Now, if you wanna run 75+ down the hwy (not sure what the limits are in TX) then 4.56 is probably your better choice. Still good off road but more leeway when running down the highway.

I'm running 35's with 4.56 gearing on my 6-speed LJ. At 75 MPH I'm seeing 2900 RPM in 6th gear, although I rarely bother to go that fast. Most of my highway driving (which I try to keep to a minimum, I've been driving Jeeps too long to get a kick out of driving fast) is at 65 or so, which comes out to right at 2500 RPM. Very comfortable.

 

[Mike Jolley]

I'm running 35's with 4.56 gearing on my 6-speed LJ. At 75 MPH I'm seeing 2900 RPM in 6th gear, although I rarely bother to go that fast. Most of my highway driving (which I try to keep to a minimum, I've been driving Jeeps too long to get a kick out of driving fast) is at 65 or so, which comes out to right at 2500 RPM. Very comfortable.

Me too, same gears trans and rear end. I also have a set of 33s, they run fine too.