Steeper descents dangerous behavior

XT Carol said:
Yes, my Rubi beats every Jeep I've ever had. The first one was a '74 CJ-5, 3-speed manual, 304 V8 AMC engine, no limited slip at all. The good thing was, as young as I was then (20's), that Jeep taught me to drive off-road. So now, in this Jeep, it's bliss.
Either the problem we are experiencing is only in a few Jeeps, or thousands of other drivers aren't really noticing as much when driving. Maybe only a very few Jeeps have the issue. And on mine, it does not set off any engine codes or CELs. If it did, I'd know and be able to read them w/the Tazer.
I eagerly await your report of descending Tazer-less!
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Removing the Tazer did not make the problem go away. I only got one down-hill run for about 15 minutes, so I may try again later to see if the transmission changes tuning over longer downhill runs. I'm comparing my 2016 Wrangler Willys to my 2020 Wrangler Rubicon. They both have the V-6 engine, so the main difference is the transmission. The 2016 acts like any other automatic transmission and gives predictable compression braking when gearing down manually. The 2020 provides the same compression braking until it throttles up. It won't go much past 3000 rpm and then it throttles back down and continues compression braking. I usually step on the brakes before the engine throttles down on it's own. I've used both Jeeps on the same steep mountain road to my cabin for several years now, so should be a good comparison.

My first Jeep was a 1949 CJ and I had learned to drive my father's 50s vintage Jeep station wagon before I was old enough to get a license. I grew up wheeling in the San Juan Mountains of Colorado. When I came back from the Navy, I was wheeling around Moab with limited slip in the back and open diff in the front before lockers became popular. I'm getting to the age where engaging the lockers or pulling out a winch line is a lot easier on my back than digging myself out with a shovel and chucking rocks under the tires. So, I greatly appreciate the Rubicon.
 
I know it's a dead horse but I still haven't seen an answer for where you all got this information that the manual tap shift would provide engine compression braking and actually hold speed.
Without that, I'm going to go out on the limb and say y'all don't understand how to drive your jeep with tap shift
 
Tree Farmer said:
Removing the Tazer did not make the problem go away. I only got one down-hill run for about 15 minutes, so I may try again later to see if the transmission changes tuning over longer downhill runs. I'm comparing my 2016 Wrangler Willys to my 2020 Wrangler Rubicon. They both have the V-6 engine, so the main difference is the transmission. The 2016 acts like any other automatic transmission and gives predictable compression braking when gearing down manually. The 2020 provides the same compression braking until it throttles up. It won't go much past 3000 rpm and then it throttles back down and continues compression braking. I usually step on the brakes before the engine throttles down on it's own. I've used both Jeeps on the same steep mountain road to my cabin for several years now, so should be a good comparison.

My first Jeep was a 1949 CJ and I had learned to drive my father's 50s vintage Jeep station wagon before I was old enough to get a license. I grew up wheeling in the San Juan Mountains of Colorado. When I came back from the Navy, I was wheeling around Moab with limited slip in the back and open diff in the front before lockers became popular. I'm getting to the age where engaging the lockers or pulling out a winch line is a lot easier on my back than digging myself out with a shovel and chucking rocks under the tires. So, I greatly appreciate th
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Thank you, Tree Farmer, I figured I'd hear back from you. I too have been driving since before I was old enough for a license. And with some similar experiences to yours it sounds like. Unfortunately where I am at the moment the forest has been hot and dry, a disappointing "monsoon" season here so far. With that happening, the Forest Service has closed off most of the "spur" roads that would be the best (steep) to test this on. I did try something yesterday, but out on pavement so I had to be careful not to do anything with other drivers around. It was kind of surprising, because I decided to leave it in Auto in the transmission, let it gradually descend, and watch at what RPM it would shift to a lower gear. That point was about 1,200. It remained at 99mpg, even as it dropped in gears. Did not try to accelerate. I'm going to experiment more, using this info, and see if on steeper descents the automatic will just upshift. I kind of fear that it will, thus no longer holding back as it needs to. I also have contacted two different manufacturers of tuning units that I learned about on another forum, asking if their product can fix this issue. I have not heard back yet. As I learn more, I will post.
Thanks again!
 
XT Carol said:
Thank you, Tree Farmer, I figured I'd hear back from you. I too have been driving since before I was old enough for a license. And with some similar experiences to yours it sounds like. Unfortunately where I am at the moment the forest has been hot and dry, a disappointing "monsoon" season here so far. With that happening, the Forest Service has closed off most of the "spur" roads that would be the best (steep) to test this on. I did try something yesterday, but out on pavement so I had to be careful not to do anything with other drivers around. It was kind of surprising, because I decided to leave it in Auto in the transmission, let it gradually descend, and watch at what RPM it would shift to a lower gear. That point was about 1,200. It remained at 99mpg, even as it dropped in gears. Did not try to accelerate. I'm going to experiment more, using this info, and see if on steeper descents the automatic will just upshift. I kind of fear that it will, thus no longer holding back as it needs to. I also have contacted two different manufacturers of tuning units that I learned about on another forum, asking if their product can fix this issue. I have not heard back yet. As I learn more, I will post.
Thanks again!
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My experience is that the JK and the JL transmissions in 4-low auto will just upshift to a higher gear on steep grades even with periodic braking. They will also down-shift when I brake enough, but 4-low auto is not useful for compression braking. In high range auto at highway speeds the JL will automatically down-shift when braking on steep grades and hold that gear for compression braking until you press on the accelerator or the engine speed is too high for that gear. It didn't take long for me to appreciate that feature of the 8 speed transmission.

I too will do more experimenting and researching. If I find something, I'll let you know. Thank you for the information and I wish you luck.
 
Tree Farmer said:
My experience is that the JK and the JL transmissions in 4-low auto will just upshift to a higher gear on steep grades even with periodic braking. They will also down-shift when I brake enough, but 4-low auto is not useful for compression braking. In high range auto at highway speeds the JL will automatically down-shift when braking on steep grades and hold that gear for compression braking until you press on the accelerator or the engine speed is too high for that gear. It didn't take long for me to appreciate that feature of the 8 speed transmission.

I too will do more experimenting and researching. If I find something, I'll let you know. Thank you for the information and I wish you luck.
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OK, I somewhat suspected that. Thank you
 
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