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Gears not holding on steep hill

9K views 47 replies 11 participants last post by  ansisr 
#1 ·
I have a my 2014 JGC diesel Overland. For the first time since I bought it, I came across an extremely steep hill on a 4wd track. In Low Range "mud" and Offroad 2 suspension setting, I selected first gear with the paddles, to maximise engine braking - as one would in a manual transmission. Problem was, the car would suddenly upshift to second gear, and then if I let it go a bit fast, it would upshift to third. I don't know if it would have upshifted to fourth, as that would have been too fast. In fact, third was too fast.
It was not an engine revs issue, as the upshifts were occurring around 2000 rpm. It seemed to be somehow related to speed, or maybe acceleration though, as it happened as the speed built up quickly. It does not happen on the flat, and will rev to at least 4000 using the throttle.
Has anyone else experienced this, or have an explanation?
Thanks,
Russell
 
#3 ·
Yes. I started out trying to use the hill descent control, but it got too scary. The hill had large water diversion humps across it, which required a touch of throttle to get over. Touching the throttle deactivates HDC. Going down the other side of the hump, the HDC re activated again when I let off the throttle, and instantly locked up one or both rear wheels trying to control speed. Problem was it was very slippery with a sideways slope to a steep drop, and the back of the car would slide out. That's when I tried to revert to manual gears.
I have since found that there is a transmission TSB which may fix the gear holding issue, amongst other things, so I will see if I can get that applied.
Thanks,
Russell
 
#4 ·
I posted this 3 months ago, and have been hassling my dealer for a response ever since.
There is a TSB which describes the symptom fairly well, 21-012-15, but they told me that my car already has that applied. Which is strange, because I first asked for it to be applied in March after its release on February 28. Finally, I was told that this characteristic is "normal" ("they all do it"). After trying to ensure they understand I am using the paddles as in manual mode, not automatic, they say that the car will still upshift under some conditions. It's not RPM as I described above. I guess it's conceivable that load on the drivetrain can trigger an upshift.
But it is positively dangerous for the car to upshift suddenly on a steep and slippery slope, and in my opinion is totally out of character for a seriously good off-road vehicle.
Having said all that, my question is simple:
Has anyone else here experienced the same problem - car will not hold a gear selected with the paddles, in low range, down a (very) steep hill?
Thanks,
Russell
 
#6 ·
Thanks Indyof. I really do believe that is the solution - both your experience and the symptom as described in the TSB convince me of that. The mechanic has been unable to apply the update - while the info he has says it is applicable to my VIN, when he hooks it up to the computer, it just won't load. After three months of hassling, Jeep Australia techs told him that is because my car already has the update applied - which is hard to believe as my car is old (May 2013 build), the fix wasn't released until Feb 2015, and both the mechanic and I would know if it had been done. But I don't know how to prove this. In fact, the mechanic told me that he can't tell what updates have been applied by interrogating the relevant module.
So I think my best chance is to complain about the problem, and let them figure out how to fix it. However, "they all do that".
Thanks,
Russell
 
#7 ·
Has anyone else experienced this, or have an explanation?
Thanks,
Russell

Have you tried actually using Hill Descent Control and see if the behavior is reproducible ?

It might be an erroneous calibration specific to diesels, but none too different from what happens when you cruise at 35-45 mph (6th or 7th gear) and when you let go of the throttle, the car up-shifts to 8th then down-shifts entirely based on speed, and to maximize cruising distance.

The fact that you were in 4-LO should tell the transmission to avoid that behavior - but then again that is what HDC also does. But then again, one could be in 4-LO and ORA-2 and if switching between the various Selec-Terrain modes would lower the car at the worst moments. Jeep have indeed messed up some calibrations - but more than we collectively knew about.
 
#9 · (Edited)
I tried HDC, but there were large water diversion humps which required a touch of the throttle, causing the HDC to disengage, then engage violently down the almost vertical side of the hump.
Indyof, I may have asked you this before, but can you tell me the details of your car and the dealer who applied the fix?
(For some reason I assumed you're in Australia, but if not, then the dealer won't help me much! But is it a diesel?)
Thanks,
Russell
 
#11 ·
I had 21-012-15 applied a month ago during my service as I requested it saying I had two problems. 1 - ECO butin won't stay off, 2 - it wasn't downshifting correctly when cruise control was on and going down a hill, ie, it would do a piss poor job of maintaining speed, it would just keep increasing with no engine braking at all. I would go from a set 60 and keep rolling to 80, 90 etc..
I don't take our GC off road, but I know the bulletin was applied despite the fact that the wallys at Waitara don't supply me with paperwork saying it was done.

If you are driving on a normal sealed road, using cruise control set to say doing 60 or 80, and you start to go down a decent hill, does it down shit and apply engine braking to retard acceleration and bring you back to the set cruise control level? Mine now does this correctly.

If it does this, then I would say the TSB has been applied.
 
#12 ·
That is interesting. Mine has always downshifted to maintain speed - right from new. While it s possible that my early build car did not have a fault which was introduced later, my VIN still comes up as eligible for the TSB. Plus, Indyof had the same low range problem as me and the TSB fixed it.
Quite confusing actually, but your experience does add weight to JAs position.
I must go out and try it again - there's even a possibility that when the dealer thought the flash failed, it worked. This happened to me once before with Uconnect. They said they could not upgrade it because I had foreign software on my radio (Customtronix, which I had rolled back, but apparently not successfully) but in fact it had been upgraded.
Thanks,
Russell
 
#13 ·
An update: after many interactions with Jeep Australia, they insist that my car already has the tsb applied, although the mechanic and I don't believe that. In any case, the Eco light won't stay off, and that is supposed to be part of the tsb.
BUT, I have noticed another issue, which may or may not be related. In normal operation (high range on the highway), if I floor the throttle from a standing start, the car upshifts each time at 3700rpm, not the 4500 red line. So I thought I'd use the paddles in manual mode. Select "1" when stopped, and floor it. And guess what? It goes through the gears as if it was in drive (except the display shows the actual gear, not "D") up shifting at the same 3700rpm. Eco on or of, sport mode or not, in all cases, exactly the same.
Similarly, if I select say fourth, and slow to a near stop, the car downshifts to first or second, and moves off in that gear, not fourth.
Basically, I can't see what manual mode does, other than force a (very) temporary shift to a higher or lower gear.
Easy for someone else to test - please let me know if "they all do it"
Thanks,
Russell
 
#15 ·
That is probably the distinction, although I would have expectedly greater ability to control the shifts than they give me. I had a BMW years ago which had a "manual" mode, and it meant what it said - if I selected a high gear it would try to start off in that gear, and it would hold a gear to the red line. So, maybe things have just changed.
Russell
 
#16 ·
I noticed that early on. I took the GC up some tight and twisties, and then a floor it session all in paddle mode. My conclusion was that it was nigh on pointless, I could downshift slightly earlier, and that was about it.
For MY16 you will be able to permanently disable the paddles, for those that seem to knock them accidentally.
 
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#18 ·
Hello Russell
Have you found a solution to the low range issue ? .... Our 2015 does exactly the same, & I have had exactly the same response from service depts.... ie : "Your car already has the TSB update applied....... use hill descent.... blah blah blah... they all do that "
The car is simply dangerous to drive in steep country. I'm an experienced 4wder , but this transmission issue is potentially lethal ! In dry conditions, it is possible to work around it, but on our last trip on some steep, greasy clay hills I was crapping myself !!!!!! ........ in fact I've given up 4wding in this vehicle until the issue is fixed
 
#19 ·
No, it's still not solved. The tech at the dealer has now raised two requests for technical help, and each time they cut and pasted the HDC instructions for me. I have been trying to contact JRA for two months now, with no success. In my case the dealer service department agrees with me that it is a problem and HDC doesn't solve it - but they seem to have zero influence on Jeep Australia.
I'll,post any updates here. Apart from you, there was one other who had the problem, but his was fixed with the tsb. I KNOW the tsb could not have been applied, but gave up on that and focussed on the symptom - with the same non-result!
Thanks,
Russell
 
#21 ·
If you like to pm me your email@, I'll send you the email chain. The dealer has records of their interactions.
The mechanic at the dealers has reproduced the behaviour, so THEY believe me. In fact, I suspect JRA believes me, just think that HDC should overcome it, and in any case, don't know what to do.
Russell
 
#22 · (Edited)
One of us misunderstood the other. I'm on your side. I was suggesting that if there was a hill leading to the showroom that you drive the jeep through the window and say oops, then blame the ongoing problem. It would get their attention.

My bad. Thousands of comedians out of work and here I am trying to be funny. Some Union will soon be on my ass.
 
#23 ·
Actually Govenor, I think it's my fault - I thought I was still talking to Steevo!
In any case Steevo, if you'd like the email chain, let me know.
And governor, have you heard of this problem in the States?
Thanks
Russell
 
#25 · (Edited)
EDIT: Response to It4vetter. Steve beat me to posting. I should learn to quote every post I respond to. Sorry.

Lol. Now that's funny! I've had mine about six weeks and have only been down one steep hill in four low. Everything felt weird that trip down but I have a lot to get used to. I do remember thinking the first time I heard hill descent growling like chains in a steel barrel rolling down a hill "there's no fracking way that's normal" - posts on the forum say it is. I still don't believe it lol. I can probably try to reproduce the problem in my 2011 tomorrow and report back. Some other guys and I are leasing 3700 acres of paper company land that joins my personal property. It's all hills. I'll let you know what I find. I'm kind of curious myself. It would sure be different than any other four wheel drive I've owned since '78.
 
#43 ·
I'm guessing that sound is not the hill descent but the traction control doing its thing. When a wheel looks like locking up it releases brake pressure on that wheel it short repeated bursts.
 
#27 ·
Good luck with that - please let us know if you get a response. As I offered to Steevo58, if seeing what I have written to them is helpful, pm me your email @ and I will forward the emails.
Thanks,
Russell
 
#28 ·
An update. I am currently at the dealers waiting for my JGC - spontaneously sprung a radiator leak with just 2 months of warranty to go.
Anyhow, from the technical department at JRA, in response to another tech case being opened by Shaun at the dealer:
"Shaun, as per the previous case this is normal operation for this vehicle. I have personally used hill descent on some steep hills and can confirm the same operation as the owner (if hill descent is not used the vehicle will upshift). If the hill is steep enough to cause the upshift in low range then hill descent needs to be used as this is why it was designed. There are no changes to the software coming to resolve this as the TCM is upshifting to save damage to the transmission. Please let me know if you need this case to remain open."
So, the good news is someone actually understands the problem exists, although they don't acknowledge that hill descent is not a solution on hills with large water diversion humps.
Bad news is it is a design characteristic, and not an error to be fixed.
Basically, it seems the transmission is not tough enough to work as a "proper" 4wd without being babysat by a computer.
For me, I'm probably going to give up - getting such a characteristic changed is likely beyond a consumers influence. And besides, if any other component spontaneously fails as did my radiator (a failure of the plastic), then I've decided the Jeep will go. If this had happened a week later it would have been somewhere up a 4wd drive track in western Queensland - where I'm still hoping to leave for today.
Thanks,
Russell
 
#29 ·
Hello Russell
That is a very disappointing response from FCA. Sounds like just another brush off from someone who has no understanding of, or experience in, driving a 4wd.

Do they really suggest that if we go to the Vic High country & come to those long downhills that we should drive in Hill Descent mode at a max of 8klm/hr for up to 2or 3 klm at a time ?

Our vehicle is still jumping out of gears.

Was 4wding last week with 2 x other ( very new) GC's last week & they did not jump out of gears on long downhill slopes !!!!!!!!!!!!

I am still in "discussions" with technical people at FCA, if I get a better response, I'll let you know.

Or maybe we could get a good deal on 2 x Toyotas !!!!!!
 
#31 · (Edited)
That's very interesting about the new ones. Somebody must have recognised the problem to have fixed it. Yes, please let us know how you get on.
I've been looking at Landcruiser features and pricing ! My Jeep is just about out of warranty, and after the cracked radiator, I'm a bit nervous.
Russell
 
#32 ·
I think when off-roading with a JGC or any modern SUV with 4x4 capability, it is almost a disadvantage to have traditional 4x4 experience. Shortly after I bought my MY12, I took it on a very hard track (B-class). It was sliding over rocks down a very steep hill. I had it in low range, rock mode and hill descent on. Adrenalin was rising, then I don't know what I did, I may have instinctively touched the gear stick or the brake but hill descent switched off and the car was in free fall. By some miracle I managed to control it and bring it to a stop. Since then, I put it into hill descent, touch nothing except the steering wheel and just wait till I get to the bottom. I haven't had the problem since. Likewise, going up hill, I put it low range and just chug chug slowly up the hill. I once followed a Defender with lockers and it was scrabbling and sliding while my Jeep just chugged up with hardly disturbing a pebble. For what it's worth, in my view, it's all about holding one's nerve and gently letting the car do it's thing.
 
#33 ·
I do understand that Bob, and I'm more than happy in almost all situations to let HDC do its thing. The problem I have is that on very steep fire trails, they build very steep mounds/berms or whatever, across the track to divert water to the sides. The approach side of these berms is distinctly "uphill", even though the track itself is steep downhill. With HDC on, the car stops when it starts to climb the berm. This means that you need to touch the throttle. When you touch the throttle, the HDC disengages, which is fine, except when you release the throttle as you cross the top of the mound, the HDC *suddenly* reactivates. It decides you are now going too fast down the almost vertical downside of the berm, and applies the brakes. When it did this to me the first time, it was on a track which sloped to the side - towards a ravine. Locking the back wheels caused the rear of the car to slide towards the ravine - very scary.
The only way down was to turn the HDC off, select low first with the paddles, use the brakes, and keep reselecting first as it shifted up.
If HDC worked to also apply throttle to maintain its selected speed, maybe it would be OK, but it doesn't.
 
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#34 · (Edited)
Ah, I see. Yes that would be tricky. I tried to replicate it locally but was unable to do so. I have the 5-speeder with the transfer box. I might be different with the 8-speeder. In auto mode, low range and HDC on, it went down hill smoothly and even allowed me accelerate a bit. At the bottom of the hill, it stopped. I applied some acceleration and off it went up hill as well but the HDC stayed on. OK, this is no way near as extreme as your situation. Next time I'm off-road I'll try it again.
 
#41 ·
Just came across this discussion in regard to your WK2 not holding gears in Low Range and actually changing into 2nd or 3rd which scares the crap out of you as you take off at great speed when you actually want to crawl.
I have a diesel 2015 WK2 Laredo with the Trail Rated Pack. I do a lot of 4WD in steep country. My Jeep has had this problem from the start and after many complaints to my dealer, and actually having their software specialist come with me so I could show him the problem, the end result has been that there is nothing that could be done to make the gear box hold 1st gear in low range. It changes up to 2nd and 3rd every time when going down very steep tracks. The trigger seems to be when load comes off the gear box as I go over a 'whoop de do' (i.e. a graded ridge to reduce washouts). It changes up with a mind of it's own every time I go over the ridge of dirt.
Trying to keep the speed down and keeping it smooth has been a juggling exercise of prudent use of the Hill Descent Control with feathering of the throttle so that it doesn't apply the brakes viciously when you back off. It's a bitch but there does not seem to be a fix from FC. Their engineers and software guys do not obviously drive their product over terrain which we in Australia consider to be everyday 'normal'.
In regard to Transfer Case issues mine broke whilst under warranty and to FC's credit they looked after me and replaced the transfer case without a single question regarding where and how I was driving. Their Customer Care in this regard was fantastic!
 
#42 ·
I had a similar scary experience with MY12. We were on a steep track with hill descent on going over a boulder being guided down from below by experienced people. I don't know if I touched the brake or the accelerator or just did nothing but suddenly it jumped out of gear and we took off. People scattered is all directions. I brought it to a halt. Both side-steps popped off (since been replaced by rock rails) and I later discovered one of the steering knuckles had bent. I have never been able to replicate it, don't really want to actually.
 
#44 ·
This may or may not help....
But automatic transmissions have had safety features from even the early years of purely hydraulic controls, they wouldn't allow you to downshift to low for the speed you were driving, I've tried it in older cars I've had, manual moved the lever at a speed to high for 1st gear and the trans simply did not shift until I slowed to a certain speed....

In electronic trans, they do the same and even include upshifts..... ....I've read posts about the steering wheel paddle switches, with people saying they allow you to manually shift the trans to a "Point".... ....when you get to situations where its just stupid to hold a particular gear, like you might do damage, it will upshift, you try to downshift at a speed that might do damage, it will refuse to downshift until you slow down....

I'm not saying your complaint isn't 100% valid, I'm saying part of what could be wrong is the trans is acting like it should "normally" and that is probably the function of the "Hill Descent" button, it should signal the trans not to act normally, you will hold this gear, despite all your programming saying to upshift........
 
#46 ·
The upchanges are not related to engine revs. It simply upchanges when there is less resistance on the gearbox ie when going over a dirt bump/mound.
Every owner of other brands of automtic 4WD's that I have spoken to, say their vehicles hold whatever gear you select. Our problem with the Jeeps seems to be unique and they ignore what we, the users and drivers, are telling them is wrong with their gearbox programming.
 
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