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Wife drove in 4L for 20 Miles at 60 miles per hour.

Vinman

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What about the planetary gears? Nothing in the TC will be spinning faster than the input shaft speed.

And of course the output shaft is spinning slower than a rubicon, rubicon has 4.10 rear-end which means it needs ~20% more shaft speed to spin the wheels at the same speed as the 3.45 rigs.
Yeah, maybe youā€™re right I have my math wrong. My mistake
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Bruce Willys

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Read the rest of the thread. Itā€™s explained very well by others. They beat me to it.
Beat you to what exactly? Some guys talking about how they abused their Jeep and took it off some sweet jumps at high speed in 4L and it's not broken yet? Binding is definitely an issue on dry pavement (getting to/on the freeway), and so is overheating with high speeds. I'm not saying serious damage was done to the OP's Jeep, but driving at high speeds on pavement in 4L is definitely not recommended, c'mon now. Plenty of people on here talk about doing things that are far from recommended or cohesive to not breaking something eventually.
 

Gorilla57

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Beat you to what exactly? Some guys talking about how they abused their Jeep and took it off some sweet jumps at high speed in 4L and it's not broken yet? Binding is definitely an issue on dry pavement (getting to/on the freeway), and so is overheating with high speeds. I'm not saying serious damage was done to the OP's Jeep, but driving at high speeds on pavement in 4L is definitely not recommended, c'mon now. Plenty of people on here talk about doing things that are far from recommended or cohesive to not breaking something eventually.
Wow, you really need to read this entire thread from start to finish.

Never once did the OP state she was on the freeway, he actually said she "may have" hit 50mph, not 60.

He also said it was slippery out, so very low possibility of binding on dry pavement.

Tell me what overheated due to "high speeds" as the transfer case is an underdrive unit and nothing is spinning any faster than the output shaft of the transmission. The 4 wheel drive system is used at high speeds when in 4H, so nothing overheating there.

The OP's wife made a minor mistake that, in reality, did nothing wrong to the drivetrain on the Jeep.
 

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631_Islander

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Some of the comments in this thread about women in Jeeps are just plain ignorant. Some folks are still having a 1950s mindset. Here are some pics below to show them that we are in the 21st century in case those folks forgot that. As a father to a 3 year old girl, I can relate to the first pic for sure!

Jeep Wrangler JL Wife drove in 4L for 20 Miles at 60 miles per hour. f640d96e93cb547ab244cbcfc9d3aae2




Jeep Wrangler JL Wife drove in 4L for 20 Miles at 60 miles per hour. tumblr_p54o5clcuX1wykweko1_1280
 

OSCAR II

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I'm surprised it didn't break the front drive shaft or rip the splines out of it. Asphalt and 4wd are not a good mix and it usually doesn't take long. I've replaced a lot of driveshafts. How slippery was it?, don't know wasn't there.

Doing a little tinkering with numbers that would be like have an old time rig or car without OD with 5.75 to 1 rear gears. That's some serious gear! I don't know of any passenger vehicle coming with that much gear, heck I don't know anybody drag racing with that much gear.

Yeah the motor stretched it legs a little but how about the transmission? The output shaft had to be spinning over 7000rpm. That's more then 2x what most will ever see. For 20 minutes, I'd say that's an extended period of time. Yeah you can spin the motor up between gears but the trans internals saw speeds it will never see. That trans had to be boiling. Surprised it didn't overheat, engine hot, trans extremely hot... but it might have, didn't know she was in 4lo.

Talk about putting it to the mat. She had to be trying to put her foot through the floor, and probably saying why wont this POS go the whole time.
 

beaups

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I'm surprised it didn't break the front drive shaft or rip the splines out of it. Asphalt and 4wd are not a good mix and it usually doesn't take long. I've replaced a lot of driveshafts. How slippery was it?, don't know wasn't there.

Doing a little tinkering with numbers that would be like have an old time rig or car without OD with 5.75 to 1 rear gears. That's some serious gear! I don't know of any passenger vehicle coming with that much gear, heck I don't know anybody drag racing with that much gear.

Yeah the motor stretched it legs a little but how about the transmission? The output shaft had to be spinning over 7000rpm. That's more then 2x what most will ever see. For 20 minutes, I'd say that's an extended period of time. Yeah you can spin the motor up between gears but the trans internals saw speeds it will never see. That trans had to be boiling. Surprised it didn't overheat, engine hot, trans extremely hot... but it might have, didn't know she was in 4lo.

Talk about putting it to the mat. She had to be trying to put her foot through the floor, and probably saying why wont this POS go the whole time.
I guess I did the math wrong earlier. At 4K engine rpm in 8th gear the trans output shaft would be spinning at 5970 RPM (itā€™s 4000 / .67 not 4000 * .67). The Driveshafts would then be spinning at 2194 RPM. Neither of those speeds are anything crazy, especially considering how people around here love their 5.13 gears.
 

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_olllllllo_

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Just a thought:

Who here thinks the HUSBAND actually did this, and is too embarrassed to admit it?...

As one poster said, "we have all done stupid things at one time or another"...

Just sayin...

All in good fun!
Maybe he was asking "for a friend" ;)
 

OSCAR II

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I guess I did the math wrong earlier. At 4K engine rpm in 8th gear the trans output shaft would be spinning at 5970 RPM (itā€™s 4000 / .67 not 4000 * .67). The Driveshafts would then be spinning at 2194 RPM. Neither of those speeds are anything crazy, especially considering how people around here love their 5.13 gears.
Driveshaft speed is nothing, its the same as if it was in 2 hi. 60 is 60, driveshaft speed is the same. 5790, just think if it wasn't an OD the engine would be spinning at that speed. Normal highway driving the output shaft of the trans is about 2200 rpm. You don't think that's excessive? 5.13 gears, stock tires, daily driver? Engine rebuild shops must be making a bundle!
 

Bruce Willys

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Wow, you really need to read this entire thread from start to finish.

Never once did the OP state she was on the freeway, he actually said she "may have" hit 50mph, not 60.

He also said it was slippery out, so very low possibility of binding on dry pavement.

Tell me what overheated due to "high speeds" as the transfer case is an underdrive unit and nothing is spinning any faster than the output shaft of the transmission. The 4 wheel drive system is used at high speeds when in 4H, so nothing overheating there.

The OP's wife made a minor mistake that, in reality, did nothing wrong to the drivetrain on the Jeep.
Oh really? They originally claimed 60 mph for a solid 20 miles, then later said it ā€˜may haveā€™ been closer to 50 mph but they donā€™t know. Iā€™d be most worried about all the stress that binding causes driving on the street going around turns, driving around a clover leaf to get on/off the freeway, and tight turns at lights at speed. How slick are we talking here? A little water on the pavement is not enough slippage (seriously, on public roads? We talking dirt roads, or pavement? Iā€™m assuming pavement considering the claimed speeds and it couldnā€™t be that slick out considering the speed claimed) and the stress that causes to components in the transfer case is significant. Itā€™s not recommended, itā€™s silly that anyone would claim itā€™s just fine to do so and that zero wear will/can occur.

Overheating sounds like less of a concern in this situation, but Iā€™d be interested in checking out the fluid to see its condition if this were my Jeep. Saying that nothing was done wrong is false, mistakes were made by driving on pavement in 4L when the conditions allow for highway speeds.

And again, just because people go full Lite Brite on their Jeeps does not make it ok to do. Iā€™ve known a lot of people that wheel like that over the years, and they do break stuff regularly. I applaud the people that go hard, but hopefully people new to wheeling donā€™t read some of this stuff and think the Jeep can take it in stock form without likely taking some damage. Nobody should be driving on the pavement in 4L unless the pavement is covered significantly by something else.
 

beaups

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Driveshaft speed is nothing, its the same as if it was in 2 hi. 60 is 60, driveshaft speed is the same. 5790, just think if it wasn't an OD the engine would be spinning at that speed. Normal highway driving the output shaft of the trans is about 2200 rpm. You don't think that's excessive? 5.13 gears, stock tires, daily driver? Engine rebuild shops must be making a bundle!
Correct on the driveshaft speed, strictly vehicle speed + rear end gearing affected. 5790 on the input side is high, but it isn't crazy. Owners running high speed on 5.13 gears are approaching 5k output shaft speed. The ZF8 runs much higher output speeds on other applications, so I doubt doing it for a few minutes on the JL isn't too much to worry about.
 

word302

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Driveshaft speed is nothing, its the same as if it was in 2 hi. 60 is 60, driveshaft speed is the same. 5790, just think if it wasn't an OD the engine would be spinning at that speed. Normal highway driving the output shaft of the trans is about 2200 rpm. You don't think that's excessive? 5.13 gears, stock tires, daily driver? Engine rebuild shops must be making a bundle!
Whoā€™s running 5.13 gears with stock tires?
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