I have the same thing as #2 (intermittently occurring "clunk" when accelerating from a full stop) on my 2012 JKU. It seems to be coming from the rear underside of the vehicle . . . probably in the center but it is difficult to tell (people on sitting on either side of the vehicle in the rear report the noise appears to be coming from their side, which makes me think it is in the center)



Interested in hearing what people think about your symptoms!

 

Hello fogbutter,

Intermittent concerns can be hard to diagnose. However, if you end up going into the dealer, let me know if you need any assistance. I'd be glad to help with that process.

Jasmine
Jeep Social Care Specialist

 

#1 My wife would have her purse between the seats. Same problem of bumping into manual. I doubt this is your issue though. I'd dig into the center consul, and verify there is no switch loose, or whatever senses you putting it into manual.

#2 the clunk is your Hill Start assist releasing the brakes. It should be subtle, but I have heard it make a more noticeable clunk sound on occasion. Any other clunk would be a loose control arm.

 

#1 My wife would have her purse between the seats. Same problem of bumping into manual. I doubt this is your issue though. I'd dig into the center consul, and verify there is no switch loose, or whatever senses you putting it into manual.

Mine has accidentally shifted into "manual" mode a couple of times over the years, and it has always been due to something hitting the shift lever, like the driver, a passenger, or cargo.

 

Bryan we know you're going to get great advice but if you decide to go into the dealer, let us know. We can get your inquiry over to a Case Specialist for further handling while you're in service.

Jasmine
Jeep Social Care Specialist

 

The clunk could be a ujoint. I would crawl under and start looking for extra play or maybe a bad bushing.

Was you Jeep ever regeared?



Does your transmission only go into manual mode when stopped or when driving as well?

 

Agree on the clunk look at bushings, gears, ujoint, control arm joint. Other option: exhaust or heat shield clunking something.

It sounds like the slap shift is being engaged. Slap shift will automatically shift down at a stop or heavy acceleration. If the problem isn't physical (ie something loose/broken) maybe try disconnecting the battery for a while. I would assume the electronic nannies have their hand heavily in the slap shift. Disconnecting the battery definitely won't hurt anything either way. But electrical gremlins on the JK can behave very random.

Then ask me the sound of accidentally slap shifting while going 75 down the freeway! I had broken my ankle and was drugged out in passenger seat and accidentally hit it into lower gear. That sound awoke me even from a Percocet induced semi-coma lol!! Luckily the nannies were on the job and automatically upshifted to avoid destroying the transmission. And I went back to sleep.

@Dodge4me, automatic doesn't have hill start assist, only manual.

 

It could be a problem with the conductor plate and/or the valve body inside the transmission. There are some good YouTube videos covering this issue with the Nag1. Sometimes there are no codes with this problem, and w/o a code many techs are dead in the water.

 

@mommymallcrawler - the autos do have hill assist. At least my '14 does. You can disable it in the EVIC

 

The autos have hill descent not hill start. Hill descent will on steep grades in 4lo downhill lock to a speed determined by gear - aka 1st gear will literally lock the Jeep at 1 mph. Like a reverse cruise control. You can override with brake or gas just like cruise control.

 

I have the same clunk on my '16. I was starting to think that is the hill assist because it is only on hills when starting from a dead stop. When I have time I will check to see if it goes away when disabled.

 

I stand corrected. Autos do have hill start but it is an automatic feature, not something you engage. But you can turn it on and off. Hill DESCENT on autos needs to be engaged.

 

Bryan we know you're going to get great advice but if you decide to go into the dealer, let us know. We can get your inquiry over to a Case Specialist for further handling while you're in service. Jasmine Jeep Social Care Specialist

I have a 2022 Jeep Grand Cherokee Overland and the same thing happens to me. When I'm stopped at a light or stopped in general, from time to time, it'll shift into manual without me activating it. I'm taking my jeep to the dealer next week so they can troubleshoot. It's nice to know I'm not the only on this is happening to. Have you found the cause?

 

Hello and help, first time Jeep owner and first time in the forms.
Have 2 problems with my Jeep transmission.

2014 JK 4 door Sahara,

1)The Jeep is shifting into manual mode at random times when stopped. when I stop at a light and then go and drive away the tranny is in manual mode D1, nobody has touched the shift leaver it just goes from auto to manual for no reason, does anybody any idea what could be going on? It's been into the dealer multiple times and they say "NO CODES = NO PROBLEMS = NO FIX"
They claim the only codes stored are engine codes and no codes from the TCM or OBC are stored and if there is a problem any "faults" from the TCM and OBC automatically clear themselves when the engine is shut off.

2) Random loud "clunk" from the rear end when starting from a stop, typically (but not always) when I'm on a slight uphill and start accelerating from a stop.

Thanks,
Bryan...

I have a 2022 Jeep Grand Cherokee Overland and the same thing happens to me. When I'm stopped at a light or stopped in general, from time to time, it'll shift into manual without me activating it. I'm taking my jeep to the dealer next week so they can troubleshoot. It's nice to know I'm not the only on this is happening to. Have you found the cause?

 

The OP you quoted was talking about a 2014 Jeep Wrangler which came with the NAG1 5 speed auto trans. Your GC is a WK2 or WL and since you have an Overland it's assumed you have the Hemi 5.7 with the ZF 8 speed trans. Totally different trasmission with a totally different programming. You don't have a shifter like the NAG1 but a rotary selector more likely, and you also have paddle shifters. Lot easier to engage manual mode by mistake with those
Either that or the trans needs a software update of some sort.

 

I have a 2022 Jeep Grand Cherokee Overland and the same thing happens to me. When I'm stopped at a light or stopped in general, from time to time, it'll shift into manual without me activating it. I'm taking my jeep to the dealer next week so they can troubleshoot. It's nice to know I'm not the only on this is happening to. Have you found the cause?

Welcome to the Forum!

 

The OP you quoted was talking about a 2014 Jeep Wrangler which came with the NAG1 5 speed auto trans. Your GC is a WK2 or WL and since you have an Overland it's assumed you have the Hemi 5.7 with the ZF 8 speed trans. Totally different trasmission with a totally different programming. You don't have a shifter like the NAG1 but a rotary selector more likely, and you also have paddle shifters. Lot easier to engage manual mode by mistake with those Either that or the trans needs a software update of some sort.

Thanks. Yea, it’s definitely not the shifters. Hopefully, a software update can resolve the issue.