Concentric_Killa
Well-Known Member
- Joined
- Mar 1, 2020
- Threads
- 9
- Messages
- 133
- Reaction score
- 128
- Location
- Salt Lake City
- Vehicle(s)
- 23' Rubi JT
- Build Thread
- Link
- Occupation
- Mech Engineer
- Thread starter
- #1
I have a 23' Rubicon (auto) and I just noticed this weekend that the vehicle surges while in 4lo while descending a hill in manual mode. On a flat surface or climbing, it behaves like normal (no surge).
I found a similar thread on a JL forum. The following occurs:
Put it in 4lo, 1st/ 2nd 'manual 'mode'. Descend a hill. Engine RPMs will rise and it will seem like engine braking is occuring. At some point past 2000 rpm, they will rise to 3000 (no pressing the gas) but then it will seem like engine braking or something takes over and lowers the RPM and subsequently slows the vehicle. No throttle is applied in the above situation . I didn't take a video of it, but it is quite strange. The problem is repeatable especially on long descents.
This is very annoying when trying to use the engine to slow your decent.
On all my other 4wds, you should be able to wind the crap out of any gear in 4lo without a surge.
On another note, off-road cruise control works flawlessly and behaves how it should.
On the JL forums it seems like this is how the transmission 'works'. I also don't remember experiencing this when I first got my JT back in January. Does this need a transmission flash ?
Here is JL link..
https://www.jlwranglerforums.com/forum/threads/2021-jlur-wont-coast-downhill-in-4lo.96322/
https://www.jlwranglerforums.com/forum/threads/2018-jlu-sudden-acceleration-downhill-in-4l.37338/
I found a similar thread on a JL forum. The following occurs:
Put it in 4lo, 1st/ 2nd 'manual 'mode'. Descend a hill. Engine RPMs will rise and it will seem like engine braking is occuring. At some point past 2000 rpm, they will rise to 3000 (no pressing the gas) but then it will seem like engine braking or something takes over and lowers the RPM and subsequently slows the vehicle. No throttle is applied in the above situation . I didn't take a video of it, but it is quite strange. The problem is repeatable especially on long descents.
This is very annoying when trying to use the engine to slow your decent.
On all my other 4wds, you should be able to wind the crap out of any gear in 4lo without a surge.
On another note, off-road cruise control works flawlessly and behaves how it should.
On the JL forums it seems like this is how the transmission 'works'. I also don't remember experiencing this when I first got my JT back in January. Does this need a transmission flash ?
Here is JL link..
https://www.jlwranglerforums.com/forum/threads/2021-jlur-wont-coast-downhill-in-4lo.96322/
https://www.jlwranglerforums.com/forum/threads/2018-jlu-sudden-acceleration-downhill-in-4l.37338/
Sponsored
Last edited:
