[The Sub Vet]

The wife pulled up to a stop light and had the snow option on while driving. When she got entirely stopped the transmission started making loud clunking noises unless
it was in neutral. The engine runs fine, but the minute it is put into Drive, Reverse, or any gear it starts clunky like something is spinning.

Is this a drive shaft issue? I would think if it were a transmission or transfer case issue it would not move at all after a mechanical or software failure.

It's pretty dang cold right now in Colorado, so I have not had a chance to get under it and take a look.

Thanks,

The Sub Vet
TheSubVet.com
Submarine Media and Podcasting

 

[Gary Kline]

1. Do you have any way to plug into the OBD connector and see if there are any codes?

2. With the SelectTerrain knob in "AUTO" do you still get the sound? (from a flat stop this usually leaves the card in FWD mode).

3. There's a fuse in the engine compartment fuse block you can pull to disable the 4WD mechanism. (I think it's "F10" but there's a diagram on the underside of the fusebox lid) Pull the fuse. if the issue continues to happen, it's not with the axle-back to the rear of the car (meaning the issue is probably with the transaxle (front) or the Power Transfer Unit (PTU). Note when you pull the fuse the car will report "SVC 4WD" this is normal (since the fuse has been pulled).

 

[The Sub Vet]

Thanks, Gary. I will pull codes tomorrow and try the fuse pull as well and report back... Thanks for the intel and a great starting point for troubleshooting.😊

 

[Flybynightcru]

The wife pulled up to a stop light and had the snow option on while driving. When she got entirely stopped the transmission started making loud clunking noises unless
it was in neutral. The engine runs fine, but the minute it is put into Drive, Reverse, or any gear it starts clunky like something is spinning.

Is this a drive shaft issue? I would think if it were a transmission or transfer case issue it would not move at all after a mechanical or software failure.

It's pretty dang cold right now in Colorado, so I have not had a chance to get under it and take a look.

Thanks,

The Sub Vet
TheSubVet.com
Submarine Media and Podcasting

Try pulling the F10 fuse, which disables the PTU, rendering FWD only. If the car drives, and doesn't make noise this will definitely narrow it down, but sounds like the PTU (transfer case) or the RDM (rear differential)...😎

 

[Gary Kline]

BTW, which model do you have (TH, Latitude, Sport, Limited etc.). If possible, look underneath at the transmission (drivers side front) and power transfer unit [if possible], (middle area of engine bay toward the rear). Anything like oil on the casings or other obvious physical damage/issues. We'll hear back from you tomorrow!

 

[Gary Kline]

Try pulling the F10 fuse, which disables the PTU, rendering FWD only. If the car drives, and doesn't make noise this will definitely narrow it down, but sounds like the PTU (transfer case) or the RDM (rear differential)...😎

@The Sub Vet , probably the fuse number @Flybynightcru mentioned (F20) is the correct one. Disregard the number I noted (F10). Either way, there's a diagram on the underside of the lid.

 

[Flybynightcru]

@The Sub Vet , probably the fuse number @Flybynightcru mentioned (F20) is the correct one. Disregard the number I noted (F10). Either way, there's a diagram on the underside of the lid.

It's the F10. I edited my original post.

 

[The Sub Vet]

Trailhawk Sport Utility. Super Clean. No leaks anywhere when I changed the oil last and crawled around under it. Wife's car and she takes good care of it. Garage parked.
88k miles.

 

[The Sub Vet]

She did tell me it was getting a slight bump when accelerating from a stop. I drove it for a short drive to the store the other day and noticed it too, and just thought it was the clunky 9-speed. We have a Chrysler Pacifica with a 9-speed trans and same engine but a 2017.

 

[The Sub Vet]

It's the F10. I edited my original post.

Thanks, Brother.! Im about ready to go out in the ice storm and check it out! Not!! lol. I hope I can get into the garage tomorrow so I can work on it with some heat. I have not had to really work on this Jeep that much other than oil changes and tune up's and such. Just did the front-end suspension, shock towers, and lower control arms on my 2008 Dodge Caliber RT and Im pretty sore from it. Still turning a wrench even after knee replacements and old age. I hate Mopar stuff, don't know why I own 3 of them. I have a hooptie 2001 honda accord as my daily with 200k plus and still running strong.

 

[benjeepers]

Check out the middle-front area underneath the Jeep. That's about where the PTU lives and the bolts CAN/DO back out completely or shear off which leaves your PTU flapping in the wind and will make lots of noise and clunks.

Mine was making ungodly noises and flopping into the body under torque. Good luck

 

[The Sub Vet]

Check out the middle-front area underneath the Jeep. That's about where the PTU lives and the bolts CAN/DO back out completely or shear off which leaves your PTU flapping in the wind and will make lots of noise and clunks. Mine was making ungodly noises and flopping into the body under torque. Good luck

Thanks Brother. First goal is to get if off the ice in front of the house so I can look at it. Would like to get into the garage, but I'm on a incline. This makes the most sense based on the symptom at hand. We are looking at it today as its warming up to 45 degrees. Cant wait to see what this hot mess looks like.

 

[The Sub Vet]

No codes are present. trying f10 just to see if it will go in fwd....... F10 didn't work. Sounds like the world is coming apart down there. Svc 4wd on dash though.

 

[yodog]

If you took f10 out and still hear the noise then it’s from your front transmission / axle / differential areas. Maybe something got lodged and stuck inside somewhere it isn’t supposed to be?

 

[The Sub Vet]

Hope its something like that! Have a service park brake symbol now. Waiting on a tow truck to help get it in my garage. Hope I can talk him into it.

 

[The Sub Vet]

Found negative battery terminal heavily corroded. Cleaned it up and it reset all the dash alarms, but there is something mechanical going on. sounds like splines slipping in a socket to me. But were?
I can t rip into this thing until the tow truck gets here to hopefully put it in my garage for me. Its up in the front center like you said.

 

[The Sub Vet]

I'm having it towed to the dreaded jeep dealer where it was bought in 2014. Looks like to much for me to do with parts issue and disassembling the transaxles and exhaust to get to the PTU, and then find out its the transmission possibly??!!. It was under warranty until May of 2020. Damn the bad luck. Talk to a mechanic I trust for regulars repairs when I don't have time on my other vehicles, and he said a lot of times its cheaper for the dealer to do these jeeps because they get better deals on parts and sometimes warranty swaps on specific issues depending on what part failed inside a PTU for example. And then there is software updates with the expensive scanners I don't have. Sucks!!!! At least its paid for, now I wonder if I should sell it once it is fixed?

 

[Flybynightcru]

At least its paid for, now I wonder if I should sell it once it is fixed?

It's still going to always be cheaper to fix your old, and paid for vehicle, than buying a new one...😉😎

 

[The Sub Vet]

Is there a active recall on the PTU's??, because that's the issue. Its at the jeep dealer and they are playing dumb and said it wil be 4500 big ones if and when they can get one in to do the job.

 

[benjeepers]

There is on select KL's...You may have received a letter about it that extends the warranty on the PTU only. I forget the specifics.

FYI...my PTU bolts came out and all I had to do was install new bolts. It was 100% fine after that. Did it in the garage myself. Exhaust was easy to remove, bolts were a pain to install. Took it to a shop to have the bolts torqued.

EDIT; oop here we go

PTU Warranty

Just got a letter today saying my 2017 TH PTU warranty has been extended to 8 years/150,000 miles from FCA. Covers 2014-2017. That’s nice to know. Also covers previous repaired PTU prior to this.

www.jeepcherokeeclub.com