Fluid does expand, but not that much. Also so does the transmission housing itself, that is it expands. Oil expansion is about 0.00039% per degree F. At 175 degrees you are talking about 7% expansion. There are 10 quarts of oil in the ZF trans for the LR3. (it take 6 or 7 to refill because of the fluid stuck in the TC). Can a half quart spread over the area of the transmission body make that big a difference? I know with my BMW ZF trans this would not be an issue.

 

That may be true, but the fill procedure specifically mentions a temp to reach before plugging.

Why mention if it didn't matter?

Unless the temp is not for volume, but some other reason: Like torquing the drain plug on a heat-expanded pan and not a cold one?
I just assumed it was for correct volume I guess.

 

"everything look solid" What were the actual readings? Does his tool actually display them while driving? Have you recorded them?
It's a 300K mile ZF transmission. You cannot expect another mile out of this transmission, highway miles or not. Bushings wearing, bearings spinning, valves opening and closing, clutches wearing, etc, etc still happen even on the highway.
This truck is driven by electronic modules... EVERYWHERE and they all talk to each other. If one sensor isn't happy, it'll broadcast to many other modules that may show up as completely different issues than the original. If you can't/won't get a tool (specific designed for the LR3 software) to help yourself diagnose your particular situation you are going to be in for a rough time trying to repair your LR3.
Here is a sample of the transmission solenoid readings. They change while you drive and the transmission shifts. I would suggest you record them as they change and what they are in different gears and come back with the info so we compare with what's known to be "normal".

 

Hi, completely new to any forums, so sorry if Im In the wrong place or talking about something that has already been talked about etc....

have some diff and transmission questions/queries please.
if anyone with very good 1st hand experience is willing to have a chat please get in touch.
kind regs

w

disco 3 2.7tdv6
3 td5’s before.

 

Very wrong place, start a new thread with any question you have please and thanks.

 

Well fellas, looks like the fluid/filter change knocked out the problem. Not as soon as I did it, but after driving about two hundred miles I am having no more throttle hunting/surging/whatever you want to call it no matter what mode or gear I'm in. Maybe it will go another 300K miles. I'll get an IID tool, but thats third on the list after a new alternator and hunting down the exhaust leak from where I chopped up the exhaust while changing the pan/filter. I suppose I'm pretty lucky that as of now it was a reasonably simple fix, we'll see if it lasts. In the meantime, I think after those three things are done I'll raise it up a few inches and get another set of rims I can slap some decent off road tires on.

 

Hopefully you get many more miles out of it.