Noise in 4th

• 
  Hi everyone,
• 
  
• This is my first RR so im a bit out of my comfort-zone here. The car is a 2001 2.5 with the 4HP22 tranny that I just changed the ATF and filter on straight after bying it. Have driven it about 200 miles after the change and suddenly on the way home from work last night it started making a squealing / chirping noise that follows the rews.
• Tried to lock it in to 2 and 3 and the noise disappears, but as soon as its back in 4th around 17-1800 rpm the noise comes back. As mentioned it follows the rews so its not the brakes (even though they are on the way to be changed) and it also comes back in lower gears under heavy load, like a steep uphill.
  First idea the guy down the street had that the ATF may have been overfilled so i put the car level and opened up the fillhole, and let some of it out to barely dripling and then turned it closed again but the noise only seemed to get worse.
  Its exactly the same noise as in the video on youtube named "knackered diff noise range rover p38 broken squeeling"

• Any ideas what to to next?
  Fill more ATF? Change UJs? (But why would the noise follow the rpm and not the roadspeed if it was those) Bad converter?

Btw, this ONLY happends when its warmed up, when its cold it drives fine for the first few miles.

Not enough oil in the box, it should be filled cold with the engine running move slowly through all gears continue filling until oil dribbles out of the hole then put the plug back and shut off engine. with luck you may not have knackered the box. Did you fit the O ring on the pick up pipe from the filter?

Changed all the o-rings and filled it up while it was running and the gearbox in park.

EdinM said:

Changed all the o-rings and filled it up while it was running and the gearbox in park.

Click to expand...

But did you run through the gears?

Several times actually.

Could it have gotten to warm during everything? The car has an auxilliary heater that gets it up to temperature in just Minutes.

Will try to fill up more later tonight but im hoping the box isnt screwed as it was parked 3/4 miles after it started making noise.

The gearbox should be checked with the fluid cold. Engine idle needs to be stable so the engine will start to warm up.
The gearbox must be run through the gears whilst filling as it allows the pump in the box to distribute the fluid. If you don't there will be insufficient fluid in the box.
Many odd noises from the ZF are due to low fluid and/or blocked filter screen & that's highlighted in the LR workshop manual troubleshooting section. Any chance you displaced one of the pick-up tube 'O' rings whilst fitting the screen?

There's a 'how to' here:
https://www.landyzone.co.uk/land-rover/p38-auto-gearbox-filter-change.136345/
& Ashcroft say for those with the level plug on the front of the sump:
put transfer case in neutral remove oil filler level plug, front face of oil sump, fill until it overflows, start engine, quickly pump more oil in until it overflows move the gear stick up and down a few seconds in each gear whilst topping the oil level up, once level has stabilised, test drive and recheck oil level,
https://www.ashcroft-transmissions.co.uk/automatic-gearboxes/zf4hp22eh.html

Hopefully it will just be a low fluid issue.

Thanks!

I belive I did just like the description (actually read that post before I got at it) but I may have been to quick calling it success.
Will try to fill it up further when i get back later tonight and cross my fingers that its all it takes, hopefully the few miles it went after the noise appeared didn`t shatter the box. The strange thing is that it went as far as close to 200 miles after the change without as much as a blipp and ran perfectly, smooth changes, no surging of rpm or any usual signs of low ATF-levels.

As stated before, its my first RR, or brit for that matter as I`m used to Alfa Romeos (whole different story there).

So time for an update,

To my unbelivable surprise there was allmost 2,5 liters of ATF "missing". After a testdrive everything seemes to be just fine so after the count of bottles that were emptied i started checking around the box to look after leaks.
Dry as dessertsand!

So a fair warning to everyone whos about to do the oilchange - watch out for airpockets.

Well done. And thank you for letting us know the problem is sorted.

When draining fluids as part of a routine service check the level & if OK measure what comes out which will then give you an idea of how much you should expect to be put back in.