Engine braking in an automatic???? - Page 2 - JeepForum.com
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post #16 of 25 Old 05-12-2013, 11:21 AM
COLOUXJ
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2010 JK Wrangler 
 
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Quote:
Originally Posted by Ironhead View Post
my question is why? is it really that out of control during descents?
I always use engine braking when driving here in CO. Both on the trail as well as mountain passes. Its not for having "more control" its to save the brakes from overheating.

I find I have more slowing power when using the transmission to control my speed more so than using the brakes.

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post #17 of 25 Old 05-12-2013, 01:20 PM
jay-h
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Quote:
Originally Posted by LimeLJ View Post
No.



On the topic: Engine braking with an automatic transmission is fine. Note that engine braking with the 42RLE automatic with heavy loads puts the transmission fluid way into over heating. A transmission cooler is required in those cases.

...
I think I would qualify that. I run a temp gage on a TF999 and have never had the transmission fluid get overly hot during engine braking off road, but you are correct it does increase the heat load.

The only time I've encountered heating was long (as in several miles) steep upgrades at road speeds, judicious use of 2nd gear brought the temperature back down (going down hill you want the opposite, keep it in high gear)

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post #18 of 25 Old 05-13-2013, 05:11 AM
vadslram
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As all have said engine braking with an auto is fine and actually happens in normal operation. JUST BEWARE mid range rpms in third gear equal rod tossing spins in first. Our heaps are light enough that 2nd gear and light braking will keep them in control.
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post #19 of 25 Old 05-13-2013, 09:02 AM
JIMBOX
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My engine /auto braking has increased dramatically since I've regeared and really helps when I'm towing my off-road trailer-

Makes long hills on the hiwy much easier on the brakes and off road phenomal !

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post #20 of 25 Old 05-19-2013, 05:32 AM
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This makes good sense. Subscribing to this thread.
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post #21 of 25 Old 05-19-2013, 08:17 AM
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I engine brake all the time, especially on the bike. I do it regardless of whether or not the vehicle is automatic or manual- hybrid or CVT equipped vehicles are bit more unique..

All about that unibody life.
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post #22 of 25 Old 05-19-2013, 08:34 AM
LaddieHanus
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I drive this on a regular basis



The other way to work is longer but only a 10% grade in spots.

First gear is required and you can tell at the bottom who hasn't downshifted by the brake smell. Even so I replace brake pads about twice as often in the TJ with the auto vs. the YJ that has a 5 speed. I did have to rebuild the trans in the TJ at 120k miles but that was for other reasons.

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post #23 of 25 Old 05-19-2013, 09:38 AM
jay-h
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Quote:
Originally Posted by Xpress View Post
I engine brake all the time, especially on the bike. I do it regardless of whether or not the vehicle is automatic or manual- hybrid or CVT equipped vehicles are bit more unique..
There is no traditional 'engine braking' on a hybrid, but there is dynamic braking. Theoretically, using the 'brakes' to retard on a long grade will actually not use the brakes much at all but will use the electric motor to partially recharge the batteries.

That's one of the weird things about hybrids, you don't really control the brakes. Instead, depending on your foot pressure and speed, the system decides whether to use brakes, dynamic braking or a mixture.

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post #24 of 25 Old 05-19-2013, 09:50 AM
DeafJeep
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This was in the 1940's. I am sure with the advances made in the Jeep since then has broken the charts but this should give you a good idea of what the Jeep of the 1940's could handle on a steep grade.

http://www.42fordgpw.com/grade.html
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post #25 of 25 Old 05-19-2013, 09:54 AM
DeafJeep
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This is for today's Jeeps from the official Jeep website.

http://www.jeep.com/en/4x4/off_road_guide/
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