What is considered lugging the 4.0?
- Thread starter MrBClark
- Start date
LONGJP2
TJ Expert
ejay
TJ Addict
BAPilot2
Member
When equipped with a manual transmission lugging the engine is kind of a mute point. Lugging the engine can be easily overcome with selecting a lower shifted gear. Shift from 5th (or 6th depending upon trans type) to 4th (or 5th). That’s the beauty of a manual transmission. The ratios between the gears are much closer than with an automatic. You can run down the highway at most any RPM you want and maintain your speed. However, when it comes to mountainous terrain, or pulling a load, lower axle gear ratios are a great advantage as they increase the RPM’s throughout the shift range and into the final drive gear.
What, I can't downshift my automatic transmission like taking it out of Overdrive or from 3rd to 2nd, etc.? Huh? What have I been doing all these years then? Not to mention slightly stepping on the gas unlocks the torque converter which also raises the engine rpms.
BAPilot2
Member
Of course you can!What, I can't downshift my automatic transmission like taking it out of Overdrive or from 3rd to 2nd, etc.? Huh? What have I been doing all these years then? Not to mention slightly stepping on the gas unlocks the torque converter which also raises the engine rpms.
I guess my post was a bit too generalized.
However, the gear ratios in a manual trans are more closely spaced than in your automatic, which makes it a bit easier to run at a specific RPM and speed without the lugging.
That’s all I was getting at.
This has to be read again. So used to trying to keep it at around 2200 rpms. Albeit, all motors and drivers are different, we hope that we can keep the motor at its most efficient, particularly with a manual transmission.
DuneSeeker
New Member
Hi Flivver,
I also live in Dubai and do a lot of big dune desert driving (Liwa / Sweihan / Badayer).
I have a TJ Sport Manual Trans (6 speed) on 32" tires with stock 3.73 gears.
I end up using 4 low in the big dunes (3rd and 4th) to get the torque I need.
I have been looking into 4.56 gears so I can run more big dunes in 4 Hi and wanted to ask you how you like the 4.56 setup in the dunes with the 33s.
Low range in the sand is a very good idea, your clutch will agree. The wranglers often get into the choppy smaller dunes that require a lot more technical ability than the big dunes. The short wheel base is suitable for that. The bigger rigs avoid them like the plague. Large dune climbs take speed first, and often by the top of the dune you are running out of power and a downshift at the wrong moment can stop you dead in your tracks. That can suck in many unfavorable ways, not just loss off cool points.
I think you would find your rig much more capable in the sand with 4.56 gearing. I should have gone with 4.88's for the desert, but 4.56's were better for all around usage. The six speed and 32's would probably be better with 4.56. If your Jeep is primarily an off-road toy, go with 4.88s.
Purely for fun, every Friday a group of us get together and spend 8-10 hours wrenching. We are pretty well set up for all things TJ, but I am also working on Mercedes. It is extremely hard to find a quality, competent shop here to work on anything.
I spend a lot of time correcting what the big name 4x4 shops have F'd up. I can't think of a shop I'd trust with a regear or any but the most basic work. We do our own re-gears now. We can do it wrong much better than the guys that claim to do it right.
The job isn't hard, it just takes very careful measurement and attention to detail, and a willingness not to get frustrated when it takes you ten+ attempts to get the gears mated perfectly. BTW, it is worth considering bracing up your front axle tubes at the same time. Lots of people have bent thier front axles due to unforseen airborn antics. Welding in reinforcement can help. I suppose it all depends on how aggressive or accident prone you are.
BTW, wrenching with us is not a spectator sport. If you are not inclined to get dirty, no need to attend. Even the women who attend are twisting a wrench with gusto. It is a very social event with lots of teasing, eating, and comraderie. We all help each other and have no patience for folks not willing to help others. We vote them off the the island.
Art
801 Driver
TJ Enthusiast
My totally stock 98 TJ, 4.0 5 speed with 3.07 gears must have the "Tractor Motor" some people talk about. It is has a lot of torque at low RPM without lugging. In fact this motor seems to have a flatter power band than most of the various vehicles I have owned.
The recommended by some here of 3000 RPM engine speed running down the road would give me road speeds of 2nd gear 35mph, 3rd gear 58 mph, 4th gear 78 mph, 5th would be about 104 MPH.
I drive by feel most of the time, and I am rarely the last one up to the speed limit where ever I am driving. My Jeep spends most of its life between 1700 to 2000 RPM going down the road and is not lugging at all. My roads are relatively flat in most of this area. I find I do run in 4th if below about 55 MPH. I did need to run in 4th at 60 mph with a 28-30 mph head wind with gusts to 38-40 mph one day. That really sucked the fuel down. Ha Ha. I usually get 15-17 MPG out in my mostly rural area.
My little yellow "shift light" is behind my steering wheel but it usually goes on much earlier than I usually shift because I do not want that much of an rpm drop which would get it into the lugging feel range. I find myself shifting somewhere in the 2400-2700 RPM area when I have noticed. Just my experiences with mine.
The recommended by some here of 3000 RPM engine speed running down the road would give me road speeds of 2nd gear 35mph, 3rd gear 58 mph, 4th gear 78 mph, 5th would be about 104 MPH.
I drive by feel most of the time, and I am rarely the last one up to the speed limit where ever I am driving. My Jeep spends most of its life between 1700 to 2000 RPM going down the road and is not lugging at all. My roads are relatively flat in most of this area. I find I do run in 4th if below about 55 MPH. I did need to run in 4th at 60 mph with a 28-30 mph head wind with gusts to 38-40 mph one day. That really sucked the fuel down. Ha Ha. I usually get 15-17 MPG out in my mostly rural area.
My little yellow "shift light" is behind my steering wheel but it usually goes on much earlier than I usually shift because I do not want that much of an rpm drop which would get it into the lugging feel range. I find myself shifting somewhere in the 2400-2700 RPM area when I have noticed. Just my experiences with mine.
DuneSeeker
New Member
Thanks for this really informative reply Art ! As soon as I started reading it I knew this had to be you coz there are few people with this wealth of knowledge in our region. I have been travelling and just got to check on on this thread during my weekend.Low range in the sand is a very good idea, your clutch will agree. The wranglers often get into the choppy smaller dunes that require a lot more technical ability than the big dunes. The short wheel base is suitable for that. The bigger rigs avoid them like the plague. Large dune climbs take speed first, and often by the top of the dune you are running out of power and a downshift at the wrong moment can stop you dead in your tracks. That can suck in many unfavorable ways, not just loss off cool points.
I think you would find your rig much more capable in the sand with 4.56 gearing. I should have gone with 4.88's for the desert, but 4.56's were better for all around usage. The six speed and 32's would probably be better with 4.56. If your Jeep is primarily an off-road toy, go with 4.88s.
Purely for fun, every Friday a group of us get together and spend 8-10 hours wrenching. We are pretty well set up for all things TJ, but I am also working on Mercedes. It is extremely hard to find a quality, competent shop here to work on anything.
I spend a lot of time correcting what the big name 4x4 shops have F'd up. I can't think of a shop I'd trust with a regear or any but the most basic work. We do our own re-gears now. We can do it wrong much better than the guys that claim to do it right.
BTW, it is worth considering bracing up your front axle tubes at the same time. Lots of people have bent thier front axles due to unforseen airborn antics. Welding in reinforcement can help. I suppose it all depends on how aggressive or accident prone you are.
BTW, wrenching with us is not a spectator sport. If you are not inclined to get dirty, no need to attend. Even the women who attend are twisting a wrench with gusto. It is a very social event with lots of teasing, eating, and comraderie. We all help each other and have no patience for folks not willing to help others. We vote them off the the island.
Art
My 6 speed TJ with 32"s is primarily a desert toy and I spend a lot of time doing solo drives photographing wildlife. The 4.88 gears sound just right to be able to stay in 4 High but I will be running about 3200 RPMs on the highway at 120kmph. I am assuming this is ok for the 4.0L engine for long periods (2 hour long drives) ? Better than lugging it at least ! Would appreciate your advice on this matter.
Do you still use 4 low in the desert on your rig with 4.56? Or would you advise limiting its use to only when it is necessary? I have been debating between regearing or just sticking with 4LO in the desert. As you know - going up big dunes in 4LO, I am not staying below the recommended 10mph for the TC and we are often pushing 50kmph in 4th / 5th gear (4 low). I was concerned that this is where I am putting excess strain on my drive train - but when I regear - it seems like I am still going to putting down a lot more torque and so there is going to be similar strain on the drive train. So final question remains whether to re-gear or just drive in 4LO?
I would love to wrench with you guys when Im back in Dubai.
If I do regear would you be willing to quote me for this?
Thank you once again !
I have the 3 speed auto, 3.07's, and 35's and "here" I rarely lug my engine. I'm around 1700 rpm's to run 65 mph. I can accelerate plenty fast to keep up with traffic and once up to speed it doesn't take much to maintain it (little to no lugging). There are lot's of gearing horror stories on this forum and I can't speak for the manual boys but my auto seems to handle the tall gearing just fine. When I approach a hill I just bump the throttle a bit and the rpm's increase by a few hundred, and it will hold it's own. I have never been able to tell if it's down shifting or just dropping out of overdrive? Mostly flat here in Indiana though. I've done very little driving out West but I do know that my gearing would be miserable for how hard the mountains and wind speeds can be there. I'm no expert on the 4.0 engine but typically inline 6 cylinder engines are built for torque and to handle lugging. I would think a little bit of lugging would not hurt the engine. Driving hours into a headwind may be bad.
kenosha whiz six
TJ Enthusiast
Yea I like what you said about finding the sweet spot for economy.if your on level ground and the vehicle is maintaining speed without having to feel as tho you need to push the pedal more to maintain,you’re set.I have the six spd and never get in sixth till I’m rollin at hiway speed.when I went to 33s I regeared up from the 3.73s to 4.11s And 70mph in sixth I’m still only turning 26ish rpms.also I was curious bout someone’s comment bout having3.07s?that’s awfully hiway-geared for a jeep
(I sold my TJ) I used both high and low range in the desert, depending on which dunes I was in. For the long hill climbs I got up speed in high range and did my best to maintain momentum. I rarely got above second gear high range.
My engine and drive train were in very good condition so I had no problem pushing it to 4-5K rpms. A good cooling system and stellar maintenance, I had no issues.
You really need to factor what is the primary purpose of the rig. If it is predominantly a daily driver, 4.56's are more than enough for your rig. If it is mainly for desert fun, you could consider the 4.88s or perhaps a serious weight reduction. Removing the rear seat, hardtop and full doors makes a huge difference in how it behaves in the deep sand.
The guy who bought my Jeep started stripping everything heavy off of it (even the spare tire and winch). He will use it primarily in the sand.
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I still wrench on lots of Jeeps every Friday, but right now I am also wrenching on and driving a couple of old Mercedes. They are a lot of fun and surprisingly well laid out for a mechanic to work on. My next one will likely be a S600 with the V12.
Lugging is also a Class C Forum offense, punishable by having your information sold to the same companies we sold Zorba’s too.
Trust me, you don’t want that to happen. When your wife thinks you got her something romantic then it fits you, it causes a lot of strain on a marriage.
We might bump it down to a Class D if you have an NV 3550 and can’t afford a regear, but don’t assume anything until we update the Forum Handbook. It’s just on the table right now.
Nothing wrong with 3.07,s its a myth created by those who need to see a rev counter hit the red on a slow moving brick! Manual is more fun changing up and down to rev match road speed on hills and inclines.
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Or, if 3.07's are good then 4.10's and 35's would be awesome. I got to drive one we did a few things to and it had 35's. If that gear ratio was the only option, no one, not even the most forgiving with very low standards would drive that piece of shit for long. They would put it back to stock. Easily one of the more disappointing vehicles I've had the displeasure of driving around.Nothing wrong with 3.07,s its a myth created by those who need to see a rev counter hit the red on a slow moving brick! Manual is more fun changing up and down to rev match road speed on hills and inclines.
I struggle to understand how the engine is lugging if it is able to maintain it's speed without having to feel like you need to give it more throttle to do so. Not trying to be a smart ass but my Jeep simply isn't the dog that everyone claims it should be.That IS lugging the engine.