Allegedly impossible - KL Cherokee diff fluid change

[HoosierJeeper]

Been reading up on the Cherokee forum about changing the rear diff/PTU fluid on my 15 Cherokee. There's two fill plugs (one on each side) but no drain plugs. One guy has tried to suck it out but failed - has anyone here been done one? I think this place is a little more technical so that's why I ask here! Not ready to give into the "lifetime fill" argument yet...
Thanks!

 

[RamFan]

Full disclosure, I have no experience with your Cherokee. But, if there's a fill plug, that means there's some form of channel from the plug to the "sump". Maybe there's some weird angles going on, but I can't see how a diff wouldn't be able to be sucked dry.

 

[buck91]

Sounds similar to the Explorer PTU service issues. Some packages did include a drain plug- maybe there is the same variability in the KL? People had also had success drilling and tapping a drain on the Explorers.

 

[nascarnation]

Interesting...two fills...no drain.

In the modern era, components like this are usually built as a module sub-assembly and pre-filled with fluid then delivered to the final assembly line.
The assembly people have done everything they can to do fluid fills off line for efficiency and cleanliness purposes.

But I have to wonder why two fill ports?

 

[double vanos]

I'll be joining the "how do I service PTU club" as the wife just bought a Lincoln Nautilus with AWD. Ford tech makuloko shows how too mityvac the fluid out then replace it. Should be done every 15-20k according to him. Can't wait to tackle it......

 

[cpayne5]

Originally Posted by double vanos
I'll be joining the "how do I service PTU club" as the wife just bought a Lincoln Nautilus with AWD. Ford tech makuloko shows how too mityvac the fluid out then replace it. Should be done every 15-20k according to him. Can't wait to tackle it......


I did a PTU on a 2013 Explorer two weeks ago. Family member bought one used and I did some quick research and discovered the issues with the PTU's "lifetime" fluid.

It's a tight spot for sure. I have a lift and it was still hard to finagle a way in through the fill hole. I had to try a few times, but eventually got a hose down in far enough to suck out a bit of fluid. I pumped about a pint of Mobil1 75w-140 back into it. I didn't measure how much I extracted.

At 85k miles, the fluid didn't look nearly as bad as the ones on YouTube. Could have been changed by a previous owner.

 

[bdcardinal]

Originally Posted by double vanos
I'll be joining the "how do I service PTU club" as the wife just bought a Lincoln Nautilus with AWD. Ford tech makuloko shows how too mityvac the fluid out then replace it. Should be done every 15-20k according to him. Can't wait to tackle it......


If it has the 2.0EB you have drain and fill plugs. If it is the 2.7EB you remove the PTU cooler to drain the fluid.

 

[Astro14]

Impossible to change the rear differential fluid on the 2002 Volvo XC.

No drain plug. Factory "fill for life". No space inside the differential housing to fit a hose to siphon out the fluid. You can't feed a hose, even a small one, down inside the housing.

So, here's what I have had to do:

Cut a 2 foot piece of Mercedes hard vacuum line (4mm)
Connect to Mityvac reservoir with adapters
Drive the car to warm up the fluid (very important)
Put car up on ramps and while still warm, remove fill plug.
Slide line in past internal components to reach bottom of differential
Suck out old fluid.

It takes at least 10 minutes due to the small size of the line, but no other hose fits. They're all too big. If you don't warm up the fluid, it takes half an hour.

Refill with your choice of quality fluid.

 

[BMWTurboDzl]

Not that differentials need service these days, but why not just pop off the cover?

 

[HoosierJeeper]

I might have to try the Mercedes vacuum line. Thanks for the tip!
And wish I could pop the cover off...can do that on my 96 but not my 15!

 

[littlehulkster]

Couldn't you just keep squeezing oil in until it comes out clean?

Alternatively, you could always drill a hole and thread it for a plug.

 

[threeputtpar]

Drill and tap is likely the best course of action. Had to do the same in my former 2008 Ford Taurus X when I first bought it used. Had never been changes and was no longer fluid but black sludge. It was actually really easy. Bought the Demming drill bits from Harbor Freight and used my 1/2" cordless drill. Bought the size tap to match the hole I drilled and installed a hex cap plug.
Side note - I used Schaeffer's 75W-140 made for Harley gear cases.

 

[Sunnyinhollister]

If you change the fluid, take pics. I've been wondoring about this as well.

 

[littlehulkster]

Originally Posted by threeputtpar
Drill and tap is likely the best course of action. Had to do the same in my former 2008 Ford Taurus X when I first bought it used. Had never been changes and was no longer fluid but black sludge. It was actually really easy. Bought the Demming drill bits from Harbor Freight and used my 1/2" cordless drill. Bought the size tap to match the hole I drilled and installed a hex cap plug.
Side note - I used Schaeffer's 75W-140 made for Harley gear cases.


Drilling and tapping would work, but given how he's described the thing I have to wonder if you couldn't just keep squeezing in oil until it comes out clean. It'd be a lot less work.

 

[Arctic388]

if it has two fill holes i would drive that thing on a long trip to really get fluid up to temp and then just open both holes and flood one with new fluid and let the thermal laws float the hot fluid up and out while the new cool fluid is sinking to the bottom.

 

[cos]

Arctic388,

Good idea!