I did my metal transmission pan conversion yesterday - but I was only able to get about 5.25 liters of fluid back in. This is after warming up the truck, cycling slowly several times R to D to park, lifting the truck back up while running and finishing the service. Seem abnormal?
I was actually considering raising the **** end by backing up on my ramps in the hopes of getting that last 3/4 of a liter in...but I had good run over out of the fill hole at 5.25...
Did the mech sleeve too - it all went back together a treat, and zero leaks!

 

Define "warming up the truck". If the transmission is up to full operating temperature, it is too hot to fill and will be underfilled.

 

^ thank you. Had a debate about this the other day. I left it with "OK, you know what you are doing".

 

Any time I have pulled a fill/level plug on a hot trans, it always gushed out. These units must me checked cold. Service procedure is 30-50 degrees C (86-122 F).

LR_ATF_Check.png

 

Just in case someone reads the attachment in the above post and sees a temperature range of 30 to 50 for the tranny oil fill measuring temperature, recall that the ZF tranny is not exactly a Made in USA product, nor are their instructions written solely for the US market.

30C is about 85F, and 50C is about 120F, where C refers to degrees Celsius and F to degrees Fahrenheit.

Below are a couple of BMW links where they talk about oil temp for their ZF trannys. There are some interesting comments re oil fill quantity, factory new fill and refill. In other words, you have to do the temperature measuring thing re correct oil quantity - it is an art, not a science.

I also found a link for ZF transit bus trannys. They require about 50 liters of oil; not exactly in our league. They also regard 90C, (190F) as a nice operational idle oil temperature to check the tranny fluid level - but they still have a dip stick like GM and Ford used to have.

Transmission Oil Temperature VERY HOT!! - Bimmerfest - BMW Forums

https://5series.net/forums/diy-do-yo...-refill-88129/

 

By up to temp, I mean I idled the truck until the temp needle on the dash just started to move - about 3 or 4 mins. Nothing gushed out when I pulled the fill plug.
That is some very good information, and thank you. I appreciate all the feedback. It makes sense, I'm guessing the heat that is creating pressure within the system? I thought the fluid is engineered to not expand or have viscosity changes at temp.
So I need to get the truck back on the lift - gauge temp...with a heat gun(?) and top it off when it is in the correct range?

 

Yes, a heat gun aimed at the pan is what many guys use to determine approximate oil temperature. All you have to do it get it in the range.

Below is a link to about twenty files related to our ZF 6HP26 tranny.
Some of them have coloured pdf showing fluid paths; other relate to the metal pan change out and others, the fluid change.

DISCO3.CO.UK Photo Gallery - ZF 6HP26 Automatic Transmission in LR3

 

Or if you happen to have an IID tool or similar, you can read the transmission fluid temp directly. I'm not going to lie... it was pretty nice to be able to read the fluid temp on my iphone while I was laying underneath the car, drain plug in my hand and towel wrapped around my forearm (to prevent burning it on the cat)... well, it was as nice as that sort of experience would allow.

I would imagine that there is some sort of temp lag when trying to measure the temperature of the pan vs. the fluid itself (especially considering it's not a metal pan), so I would shoot for the lower end of the temp spectrum if you do it that way.

 

The fluid reaches, at least, the minimum temperature prettty quickly. Fill approx 3/4 gallon while not running, start the vehicle and top off. By the time the bug sprayer is getting enough fluid in the trans, it has reached the temp range.

Of course this could be because I'm in so ca, in a garage.

 

I would agree that shooting the pan termperature, plastic in particular, is not exactly a science, and would be on the low side, however I am surprised that your GAP reads tranny oil temperature at all.

I have a BlackBox but never looked for tranny oil temperature - guess I should as it must be available as well.

I also have a ScanGaugeII and for certain, tranny oil temperature is not available; coolant temperature is as are some air temperatures, but not tranny oil temperataure.