WK Grand Cherokee Diesel

[ericjon262]

Get a gauge on the AC low and high sides. What you're describing sounds like a classic low refrigerant condition. I bet adding a little bit will stop tripping the low side switch.

Temperature throughout the day could also cause a low refrigerant condition to appear worse or magically fixed too.

[The Dark Side of Will]

Get a gauge on the AC low and high sides. What you're describing sounds like a classic low refrigerant condition. I bet adding a little bit will stop tripping the low side switch.

Temperature throughout the day could also cause a low refrigerant condition to appear worse or magically fixed too.

It's not pressure... the HVAC panel/controller just doesn't turn on.
I've had the pressures checked; the A/C cools when the panel turns on; a low pressure safe state would cause the A/C to blow ambient temp. That's not what happens... The HVAC just does not turn on: no blower.

It's more that something is always broken on them.

Curious if you've circled back to this post and realized he was right?

The alternator wasn't awful, but being the latest in a long line of very needy needs has driven home that the vehicle was not what I was thinking it was when I bought it.

The fact that it was neglected for at least 150,000 of the 212,000 miles does NOT help. There's nothing more expensive than a cheap Mercedes.

[Emc209i]

Is it a situation where the panel knows it can't command cold air and doesn't want to shower you with warm ambient air in the summer? Our Lexus monitors engine and ambient temp and won't turn on the blower until the coolant reaches a specific heat in the cold so that it isn't blowing cold air on the passengers. Until it reaches its threshold, it appears not to be on.

[The Dark Side of Will]

Is it a situation where the panel knows it can't command cold air and doesn't want to shower you with warm ambient air in the summer? Our Lexus monitors engine and ambient temp and won't turn on the blower until the coolant reaches a specific heat in the cold so that it isn't blowing cold air on the passengers. Until it reaches its threshold, it appears not to be on.

I don't have that level of insight into what the panel is "thinking"... although I do need to download JSCAN and see what it has to say.
The only visual indicator I have the light in the A/C button. The A/C button latches, so mechanically the A/C stays on. The blower and A/C light come on at the same time.

If the vehicle is running with the HVAC blowing (blowing cold since the A/C is on) and I shut the engine off, remove the key and leave the vehicle for a couple of minutes, the HVAC might or might not turn back on when I restart the engine. IOW, no operating conditions have changed, but the HVAC performance is unpredictable. That's what makes me think it's a weird power supply problem with the HVAC control panel. Add in that the instrument panel continually gives false indications of low system voltage, and it sounds like there's an electrical distribution problem. The false indication of low voltage and the HVAC coming on do not seem to correlate.

[The Dark Side of Will]

The diff bushings are trashed. I have a new set. One of two bolts at each front lower control arm rear pivot is broken... I need to snag new bolts for both front LCA pivots, then get the old ones out, breaking them if necessary. At that time I can also replace the lower ball joints. Control arm work and diff bushings should be most of the work the front suspension needs.

I found another local dealership that wanted half of what the closest dealership wanted for the front suspension bolts, so I bought everything there. The lower control arm rear pivots have the bushings in "pillow block" style fixtures that are held by 4x M12x65ish bolts with captive washers and pilot tips. They work with nuts that have captive cages built in to keep them aligned with the bushing carrier. The LCA forward pivots are conventional, with M16x135 or so bolts and more nuts with captive cages. With those in hand, there's no worry about the possibility of breaking the current ones doing an alignment. There a bolt on each side where the strut gizmo meets the control arm... I guess I need to look into getting that bolt/nut combo as well.

Between the two pivots and the shock/strut attachment, there are three bushings per control arm plugs the lower ball joint. I'll probably snag all of those from RockAuto pretty soon, then have the local shop do all of this work. After all, replacing ball joints is straight up mechanic's work.

[The Dark Side of Will]

I ordered suspension parts, as noted above.
The most efficiently packed shipment I have EVER received from RockAuto:



Still need 1 more of the M16 cage nuts for the control arm pivot bolts and the nut/bolt combo for the shock to control arm attachment. There's no reason that combo should be weird... I just didn't take the time to investigate it this weekend. Oh well... add it to the list for the three day weekend coming up.

[The Dark Side of Will]

Checked out the shock to control arm bolts. There's an anti-rotation tang staked to the bolt head, but the nut appears to be a normal deformed thread steel lock nut. I sprayed everything down with penetrating oil in prep for having this suspension work done.





Except the sway bar end link bolts... I didn't get them done. D-oh.

Also looked at how to get the head unit trim off:
Just grab the top behind the head unit and pull



The side clips popped right out for me



The bottom clip was slightly bent and got caught. I had to be fairly careful to get it out without bending it wide open.



As a result I squeezed down all the metal clips to reduce the likelihood of having that problem again. This also reduces their holding force, but that's not a big deal for me.

There are a few plastic clips along the top edge as well, but I think they're just for alignment.

[The Dark Side of Will]

WK2 Grand Cherokees had a 17x8 wheels as the very base base... I'm thinking I'll snag one of those and start developing a fitment from it... Once I get The Mule running.

[The Dark Side of Will]

Ran into some more info on the Quadra-Drive II system:

https://www.jeepcommander.com/threads/h ... deo.14195/

https://www.youtube.com/watch?v=FpiFq63N0Ac

It's not super easy to see from the video, but there is a clutch pack between one axle and the carrier, and a gerotor pump across the same axle and the carrier. When the axle turns relative to the carrier, the gerotor pump pulls oil from the bottom of the diff housing and pushes it into the piston that squeezes the clutch pack. The volume feeding the piston is ALSO connected to a solenoid dump valve controlled by a computer. The computer sees wheel spin and energizes the normally open valve, closing it and allowing the gerotor pump to build up pressure on the clutch pack.

The WK has these devices front and rear, as well as inside the NV245 T-case. I haven't tried mine in the snow yet, but I've heard they're basically unstoppable in the snow.

[ericjon262]

that's an interesting setup, any idea on clutch life?

[The Dark Side of Will]

The WK has these devices front and rear, as well as inside the NV245 T-case. I haven't tried mine in the snow yet, but I've heard they're basically unstoppable in the snow.

Actually, I had a brain fart on that one. The clutch pack in the T-Case is squeezed by the T-Case shift motor, similar to a bunch of other T-Case mechanisms. However, the NV 245 is full time geared AWD and only uses the clutch pack to control slip.

that's an interesting setup, any idea on clutch life?

Long enough that they do wear out but it's not usually a big deal?

Edit: Understanding more about how Quadra-Drive II works also removes any concerns I might have had for wiring up "cheat switches" to lock the diffs from the dash... Since the diffs have solenoids rather than motors, I should just be able to wire up override switches on the dash to keep them constantly energized--or even de-energized, although externally de-energizing them may cause the system to set codes, since it will try to control wheel spin and see wheel spin remain uncontrolled.

[The Dark Side of Will]

I haven't tried mine in the snow yet, but I've heard they're basically unstoppable in the snow.

Well now I've tried it in the snow and it's as unstoppable as I've heard. It just did not care. It's pretty much a fully locked 4wd on the snow. It gives zero fucks at all and just goes. It's possible to get it stuck, of course, but I'd really have to try. It definitely eliminates the possibility of doing everything right and still getting stuck like I did with the Benz in the season's first snowfall.

[The Dark Side of Will]

Did a little research and found on page 7096 of the 7199 page service manual, there's a diagram of the blend door actuator AND mode door actuator. They're both on the driver's side of the HVAC unit. The mode door actuator is above the blend door actuator... The climate control uses 4x of the same actuator for front mode, left blend door, right blend door, rear mode. Most internet tutorials cover the blend door actuators, but not the mode door actuators. The front mode door actuator is right above the left blend door actuator... but none of the tutorials say that. The rear mode actuator is not co-located with the right temp actuator, but I haven't noticed a problem with the rear mode (probably because I've never ridden in the back seat. Hah!)

Anyway... may be able to get the mode door fixed this weekend.

[The Dark Side of Will]

I had my dad's trusted shop do front suspension work on the Jeep.

The lower ball joints were in unknown condition, but probably original. The bushings were also probably original and the vehicle had driveline shakes and other signs of worn out front diff bushings. The lower control arm rear pivot bushings are mounted in a pillow-block style casting, which is secured by two bolts through the subframe. On each side, one of those bolts was broken. I had previously taken it in to have it aligned, and the tech said that he couldn't get bolts loose, and didn't want to break one and have the vehicle stuck in the shop.

I had the lower ball joints, lower control arm to body bushings, shock to lower control arm bushings and differential mounting bushings replaced.
Apparently it was hell getting everything apart, as the shop owner said they had to burn out all the old bushings and cut off all the old bolts. My dad may have been able to help, as he has access to a 60 ton press at the shop, but they didn't ask. Anyway, it's done and we didn't have to mess with it.

The effect is subtle, but definitely perceptible. The front end used to squirm when crossing gutters in intersections diagonally and doesn't do that now. It's less wander-y and more stable at speed. The sway-bar links are still worn out and still clunk... I'm looking at what I can do for disconnectable links to replace the stockers. That might be my very very first modification--Err... Actually the adjustable upper ball joints were my first mod, with the front 2" spacer lift already in place when I bought the vehicle.

Now that the front end is stable, I can tell that the rear end steers sometimes on drop-throttle events, particularly noticeable at speed. I guess I need to do a bunch of work to the rear suspension, now. I'm thinking a spherical bearing Panhard bar, but not sure what I might do about the 4-link parts. The rear diff whines on overrun, so it already needs new bearings...

I like my women like I like my Jeeps... 20 years old with lots of problems?

So it needs:
-Unknown rear suspension work

-Rear diff rebuild... I'll include the Quadra-Drive II clutch pack along with bearings and seals

-Engine oil cooler o-ring replacement. This requires removing *EVERYTHING* from the valley of the engine, as the oil cooler is the very item installed in the valley. Benz apparently cheaped out on those, as they're a common failure point. I can install some viton o-rings and it'll be fixed forever, but first I have to get there. Having the intake manifolds out is also a great time to do the swirl flap delete, which is a common way to deal with the failure of the difficult-to-access swirl flap motor.

-Bunch of nickel & dime stuff like parking proximity sensor, airbag sensor, infotainment capacitor replacement and, because it's fundamentally a Mopar, lots of non-functioning switches.

If I'd known this about it when I was looking at buying it, I might have thought differently... but maybe not.

[The Dark Side of Will]

Update: I asked (trust but verify) if the shop had put anti-seized on the bolts or put weight on wheels before tightening the bolts. They had not done either. Guess what I have to devote time to doing this weekend?

At least I didn't have to mess with the bushing replacement.

[The Dark Side of Will]

Hah! Oy vey.

The four vertical bolts securing the pillow block bushings for the front lower control arm rear pivots were easy enough. I removed them, applied anti-seize and reinstalled one at a time. I then use a paint marker to mark the locations of the bushing shells and sleeves relative to each other.

I previously installed my adjustable upper ball joint baseplates so that the adjustment was purely fore/aft, so the adjustment would only change caster. The shop knocked them out and put them back at 45 degree angle to get caster and camber to come in to spec. I noticed that at full droop the back of the knuckle was rubbing on the rubber spring seat, and might even hit the spring perch with a little bushing compression.

Left side first
The bushing bolt connecting the shock to the control arm was tight, but I broke it loose with a long breaker bar. In trying to remove it, I found there was still tension on the spring. Bleh. That was difficult to worry out but I did get it out. After looking at all the problems in the suspension, I decided that they were all caused by the spacer lift and that $#!+ needed to go... so I removed the shock assembly and removed the spacer, and everything went back together easy-peasy lemon squeezy.

I had noticed throughout this process that even though I'd moved every piece of the suspension, the paint marks on the shell and sleeve for the lower control arm forward pivot had not moved relative to each other. When the time came to pull that bolt out to anti-seize it, it was... not tight. It was more than hand tight, but not nearly as tight as it should have been. Sigh.

Right side to follow...

[The Dark Side of Will]

Doing the right side was much easier, since I already knew I had to take it apart and get the spring/shock assembly out. The shock-to-control arm bolt was even more munged up than the one on the left. It's a M16x2.0... so dies are hard to come by. A lathe at the shop had a 13/16" hex collet which was able to grab the 21mm head of the bolt and let me spin the bolt to make good use of the thread file. I was able to save the bolt. Once the spacer was out, it went back together as easily as the left side had.

I put it back down at stock ride height, bounced the suspension and popped it back up on ramps, then tightened the forward pivot bolts and the shock-to-control arm bolts.

Even with the alignment messed up after taking the suspension apart, it steers and drives better than it did with the spacers. It also stops much more level... it used to pitch forward a good bit more than it does now. The concept of the SRT8 and TrackHawk start to make more sense based on the way it drives now.

Also, in looking at the subframe and front suspension, a 4 inch "subframe lift" may actually end up being cheaper, simpler and more easily implemented than the SuperLift style 4 inch lift that only moves the lower suspension pivots and the diff. I'll have to look at the rear end to see how hard it would be to lift 4 or more inches while turning the current lower control arm pickup on the body into an upper control arm pickup, and fabricating a new lower control arm pickup lower and further forward than the current one.

[The Dark Side of Will]

Couple of pics from the job:





FUCK. THAT. SHIT.
Too many problems



Also, I noticed this connector without wires coming off it at a branch off a harness that wraps around the bellhousing... It's just below center in this photo



And just to the left of center in this photo



Gotta figure out what that is and whether or not its a problem

[The Dark Side of Will]

Had the vehicle aligned last week, along with adding washers in between the big bolt heads & nuts and the subframe because the subframe was showing some wear from having the bolts tightened up on it over the years. It drives much better, although the wheel isn't perfectly straight.

The A/C leaked down over the winter via the damaged valve on top of the receiver/dryer. I have a new unit, but need to have an actual A/C shop install it and refill the system by weight to get to best performance. The cheap shop in town no longer does A/C work, so I have to go to the shop just out of town and recharging the A/C is a $240 or so service.

[The Dark Side of Will]

The climate control mode selection (which vents the air comes out of) hadn't been working for a while... maybe not since I've owned the vehicle. The WK's have stepper motor type actuators that operate front mode selection, rear mode selection and left and right temperature blend doors... Four actuators total. Thankfully Mopar used four of the same actuator.

All the YouTube tutorials cover the blend door actuators, but no one talks about the mode selector actuators. The blend door actuators are symmetrical on either side of the HVAC system, just above the driver's right knee or the passenger's left knee. Both of them are easy and quick to change.

Flipping through the 7,190 pages of the .PDF service manual I downloaded eventually showed me that the front mode actuator is ABOVE the left blend door actuator while the rear seat mode actuator is below the right blend door actuator. Ok, doesn't sound heinous.

The closeout panel below the steering column pops off by hand... I'm loving this design trend. The closeout panel above the pedals comes out with just two screws. That's easy enough. The blend door actuator is right above that and super easy to deal with, but that's not what I'm after. The mode actuator is right above that. Two screws come right out and... Hey... where's the third screw? Just to make up for everything being super easy up to this point, the third screw is outright impossible. It's at the top of the actuator body, but tucked behind the steering column and the structural component supporting the steering column such that there's only room for a bare torx bit, reaching AROUND the actuator body. Since the steering column supporting structure was the obstruction, lowering the column would not have helped. The screw is only visible if you put your phone/flashlight exactly where your tool needs to go to drive the screw. I was able to use a Chapman ratchet on the bare bit to get the screw most of the way out by feel. That worked until the screw was far enough out that there was no longer enough friction in the threads to operate the ratchet mechanism. I was not able to get a good enough grip on the bare bit or the screw head itself to turn it out the last two turns. I ended up just having to pull on the actuator to break the last thread or two that the screw still engaged out of the plastic HVAC housing structure.

Guess which screw did not get reinstalled?