Playing with the IID tool and getting to know my vehicle's operating parameters better ... Noticed the gearbox temp on the high (118C) side the other day. So today I took her for a 50km drive to my folks, logging some health data along the way.



Apparently she doesn't like start-stop traffic situations very much (who does anyway?)

Ambient temperature was 20-23C during today's drive. Took at least 15 km for the gearbox to warm up to 100C.

I suppose gearbox temp is going to be through the roof in heavy traffic on a hot day...

Last edited by vs322 on 5th Sep 2021 8:24pm. Edited 1 time in total

Anything over 100c and you are damaging the ATF fluid, I expect your transmission oil thermostat is worn out and maybe the main rad is blocked at the bottom where the gearbox cooler takes it's supply... Very common on yours and it will reduce the life of the box if not sorted... Pete

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2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Funny thing the radiator, transmission thermostat, connecting manifold of oil cooler to the radiator (or whatever they call it) and oil cooler itself are new! (Less than 2 years old)! Actually some of the very first things I replaced on the vehicle.
Curious to know what the normal operating temp is for the gearbox. Values seem to vary and so do opinions...
Transmission fluid and filter changed 35K km ago... Gear changes are smooth as ever and no messages on the dash. Had it not been for the IID tool I would have had no clue.

Should run around 80c as I said over 100 and the oil begins to deteriorate...

If all that has been changed then it is more than likely the car radiator, they work fine to cool the engine but the bottom gets sludged up.... Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Thanks Pete

I just can’t see how the radiator could be sludged up within less than 2 years. Especially after so many changes of the coolant, over this period due to various leaks and repairs thereof.
I mean, with all parts changed, it has absolutely no reason to be overheating like that. Yet the fact remains, that it does. So I should take it apart and find out what the hell is going on the soonest. ATF is scheduled for a change this month as well.

Here's some more data from today's drive to work. Some moderate traffic encountered. Ambient temperature began at 20C and reached 24C at destination.

So, had a word with ZF representatives over the phone. As per their procedures for new installations testing, the ATF temperature should not exceed 120C during performance testing.
Also, LR could have set another consistent 10C on top of that i.e. 130C before going into cooling strategy mode and further up before giving a warning message. Oil changes are recommended at 150K Km. I'd never follow that with the road and climate conditions here in Greece of course...
115C and 118C are pretty close to 120 so I'll definitely be taking the thing apart during next service just for peace of mind.
Also, a brand new 5HP24 is not insanely expensive to procure at 3,5K Euros. I'd definitely consider this over say 1,5K for an uncertain overhaul here should I ever needed to.

They can sludge up pretty quick but not so much if you are changing the fluid often...

Fit one of the lower temp thermostats that are available now, the only reason they are so hot was to reduce emissions on part throttle to get it below the newer emissions they were up against, it really doesn't do anything to help and they run so much better when cooler...

Lowering the engine water temp obviously reduces the gearbox temp... I had an 86c one on fatty offroader and everything was much cooler...

If you google or eBay M62 lower thermostat temp you will find loads just make sure the hose attachment is the same as the RR one as some models have normal ends on..

IIRC the overheat comes on somewhere around 130c but it's like the engine water temp, the damage is usually done before the warning comes on..!!! Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Unnecessary quote removed

Hey Pete,

Thanks again

Unfortunately my thermostat was replaced wirh stock, last February, so other things are being prioritized now unless...

1. With all these hose, valley pan and expansion tank jobs, the coolant has been changed several times already. It just refuses to stay put for any reasonable length of time Actually, the only real problems I've ever had with my car are hose and rubber gasket related.

2. Like most things Land Rover

And that's because it's running so hot, get it changed and everything will be a lot better...  Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Mine was particularly susceptible to this kind of failures as it had been sitting for 4 years! I did my best inspecting all things of major concern before purchasing and doing the necessary fluid changes afterwards. So far she hasn't let me down considering the acquisition price as she was exactly what I had been looking for; a solid foundation to work on and use as a tool vehicle.