Transmission Flush

[mgroeger]

We all know the 8 speed tranny in the JL is sealed. I'm one of those guys who changes my tranny fluid every 60k. Has anyone figured out how to do this yet?

We could do the cooler line flush but you need a machine since you can't do the pump out and refill on your own. So that would mean u$$$ing a dealer.
We can drop the pan and change our own filters but then how you you get the fluid back in? There has got to be a way since it's very possible someone would gouge a whole in their pan offroading and you would need to add trans fluid on that repair.

Oh, and don't buy into that "lifetime" transmission fluid or any other lifetime fluid crap. Lifetime means 100k to the manufacturer.

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[BillyHW]

We all know the 8 speed tranny in the JL is sealed. I'm one of those guys who changes my tranny fluid every 60k. Has anyone figured out how to do this yet?

We could do the cooler line flush but you need a machine since you can't do the pump out and refill on your own. So that would mean u$$$ing a dealer.
We can drop the pan and change our own filters but then how you you get the fluid back in? There has got to be a way since it's very possible someone would gouge a whole in their pan offroading and you would need to add trans fluid on that repair.

Oh, and don't buy into that "lifetime" transmission fluid or any other lifetime fluid crap. Lifetime means 100k to the manufacturer.

There's a few videos on YouTube of people changing their own fluid in the ZF8 (and similar transmissions). There is a fill hole near the top of the pan (as opposed to the drain plug at the bottom of the pan.) The procedure is a bit of a pain, and technically to do it right you need to be monitoring temperatures and follow all the recommended steps. (I suppose another hack way would be to carefully capture and measure all the fluid you took out and place back exactly the same amount of fluid, assuming they originally filled it up with the right amount and you don't see any leaks.) You need to get a kit with a new pan (which includes the filter), and about 7 liters of ZF8/Mopar Lifeguard 8/9 speed ATF. (Very $$$.) You won't be able to change all of the fluid, only about 2/3rds to 3/4rs of it.

I have another thread on this somewhere with some linked videos.

 

[Rockreid]

You change the oil from the bottom of the pan. There is a fluid bucket you hang from the engine hood or place on top of the engine with hose and special fitting with a nozzle bent down about 45deg that fills the transmission from the very bottom. Inside the trans pan is a shelf that holds the proper amount of fluid. Once fluid starts running out of the bottom of the pan it is filled. The dealer uses their diag tool to monitor the temp while the engine is running to do this the right way.

 

[kyleguy101]

-- Jeep says their automatic transmission fluid is good for the Lifetime of the warranty, which is 60k. OEM transmission fluid Mopar 68218925AB must be used until warranty expires -- It's NOT a Chrysler or FCA tranny. It's made by ZF out of Germany. ZF reccomends fluid and filter to be changed every 50k -- After warranty expires, then most any fluid that meets Dexron VI or ATF+4 specs will work, because those fluids meet ZF specs -- I changed mine at 50k. Magnets were covered in metal particles and pan covered in black soot. It definitely needed changed -- Remove tranny pan to change fluid and filter. Fill plug is on right, rear, lower side of tranny. Buy a 5' piece of 3/4" hose. Put a 90 degree fitting on one end and a funnel on other end. Feed it down from engine compartment to the tranny side fill hole. Add 6 quarts of fluid. Install plug. Preform the check transmission fluid level procedure. Undo plug and let excess fluid drain out of tranny. Re-install plug -- Jacking tranny up 1/4", before removing pan helps sneak pan by the exhaust pipe. It comes out the rear right corner.

 

[Engmoreau]

-- Jeep says their automatic transmission fluid is good for the Lifetime of the warranty, which is 60k. OEM transmission fluid Mopar 68218925AB must be used until warranty expires -- It's NOT a Chrysler or FCA tranny. It's made by ZF out of Germany. ZF reccomends fluid and filter to be changed every 50k -- After warranty expires, then most any fluid that meets Dexron VI or ATF+4 specs will work, because those fluids meet ZF specs -- I changed mine at 50k. Magnets were covered in metal particles and pan covered in black soot. It definitely needed changed -- Remove tranny pan to change fluid and filter. Fill plug is on right, rear, lower side of tranny. Buy a 5' piece of 3/4" hose. Put a 90 degree fitting on one end and a funnel on other end. Feed it down from engine compartment to the tranny side fill hole. Add 6 quarts of fluid. Install plug. Preform the check transmission fluid level procedure. Undo plug and let excess fluid drain out of tranny. Re-install plug -- Jacking tranny up 1/4", before removing pan helps sneak pan by the exhaust pipe. It comes out the rear right corner.

great post, what torque values did you use for the plug and oil pan?

 

[Ron ap Rhys]

Did this yesterday and it wasn't too bad. One thing I noticed is that my transmission seemed to be very over-filled. When I opened the drain plug more than a quart came out. Even following the established "warm it up and fill process" that techs use I still couldn't get that much fluid back in. I even tried jacking the rear end up a few inches.

The initial fluid that came out was very thin (I'm at 80k miles). Didn't smell burnt or anything, just thin. Normal metal bits on the magnet - nothing large, just that normal schmultz you get on magnets near gears. I didn't change the gasket this time, will do that next time. I'd also suggest that I need to get an in-lb torque wrench. That 10N-M torque value isn't easy to do on an old clicker-style.

Replaced it with Royal Purple Max ATF.

 

[Ron ap Rhys]

Update for anyone doing this - I didn't realize that I needed to have the vehicle running to get the last bit of fluid in there. This weekend I warmed the tranny up to the recommended range, kept it running, popped of the drain/fill plug, and was able to pump the rest of the needed fluid in.

Easy-peasy, lemon-squeezy.

 

[JINO]

Sorry for the resurrection, seeing if things got better for people doing their own drain and fill.

 

[Jeeps2Little]

@JINO In case you haven't seen the stickied thread yet.

 

[Grayhound]

@JINO In case you haven't seen the stickied thread yet.

1 of the best threads. up there with torque spec thread, and locker sensor potting thread!

 

[mgroeger]

I'm really curious to know how @kyleguy101 is doing after using the Valvoline stuff and not ZF specific fluid.

 

[Grayhound]

I'm really curious to know how @kyleguy101 is doing after using the Valvoline stuff and not ZF specific fluid.

Same. Did the zf8 hold on for long, or did that cause issues?

 

[mgroeger]

Same. Did the zf8 hold on for long, or did that cause issues?

Almost every forum (BMW, JEEP, etc... ) that uses this tranny says use ZF specific fluid. One guy ran liquimoly and it was good but he said he then ran ZF and he could feel a diff in the shifting... way smoother.

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