Gear oil is good for 40k miles or so. If the last change is unknown to you, go ahead with that and save the receipts and make notes. Check it every 6-8 months and top off if necessary. If you find you are losing diff oil, replace axle seals. You also want to do a flush and fill anytime you wade high water, for obvious reasons. I hold you in high regards for taking maint/repairs seriously.

Before you go dropping the engine sump, get the VC gaskets replaced, get the engine cleaned, then look for signs of other leaks. A bad VC leak will cover everything all the way back to transfer case. You don't want to remove sump for just a gasket. Save that for when you do oil-pump and timing chain, if possible.

 

Not sure if the problem is air spring or some other normal issue. While I was working on the ABS, I disconnected ECU one by one plugs. I dont know if there is any relations with pumping the Air Springs.

I have the truck sitting in the drive way for 6 hours now and no loss of air.

So, it's a good news that I may not have to deal with the Air Spring. These may be some other fault and any changes will trigger.

any help?

 

'Non return valve'

Tip: when removing any alectrical connections firstly photograph them if they are a complex array but spray them with electrical contact spray before plugging them back in.

The SLS is very robust but fairly complicated in lots of separate parts. Things to watch are the air intake filter behind the rear, drivers side, light cluster, the air drier immediately before the compressor unit, the compressor piston ring which is ABS or similar and obviously the air suspension bags. Don't ever go buying a used compressor unit as they are often already knackered, just rebuild your own. When rebuilding the compressor unit you must keep everything spotlessly clean (kitchen table electrical rebuild style) as the internals are susceptible to dust and dirt.

 

the best help that I can be is to advise ditching the air bags and getting a coil-conversion kit. I believe the air springs are operated through the BCU, not the ECU. The section in RAVE will tell you for sure, but I'm pretty sure its BCU-controlled.

 

So the Truck has been sitting on the drive way over night. Air Spring holding up ok.
I still don't know why i lost all the Air in the garage while I was working on the Truck with my never ending Tres Amigos.

 

I have a set off my Disco that worked great.

*edit....sorry just read the whole thread.

 

How do you figure that Chubbs? having owned mine from new (13 years) I've had no problems. For driving on highways and towing they are great and are self levelling as they state unlike springs etc and you can raise or lower the rear for offroading or towing. If you own a plip it's easier as it can be done from externally. You are correct, the BCU (Body control unit) does control the air suspension. My RRS is totally air suspension and I wouldn't want anything else.

PS if I was going to ditch anything it would defo be the V8 petrol engine first, the TD5 is far more useful as is the TDV6