The later P38"s and the Disco II don"t have dipsticks on the autobox, instead on the front face of the sump they have a filler level plug, The fill proceedure is first to put the transfer case in neutral so theres no load, fill with oil until the oil overflows, autobox in N, start the engine, it will suck all the oil up so you need to pump like crazy to top it back up until it overflows again, put the transfer case in high and move the shifter up and down the gate a few times, a few seconds in each position, check level, the engine revs should now drop when you shift from N to D as it takes up load, plug in, test drive, check level, engine running in N.

there is a good guide to oil temps here

One of the one way clutchs has failed which causes the loss of drive in D, it will sometimes pull off in 3rd as the ECU recognises a fault and puts it in 3rd which is "limp home mode", It needs a rebuild.

Your A clutch (forward drive) has failed and you will require a replacment autobox.

Check the setting of the kick down cable, if it is too tight the gearbox will think you have more throttle applied than is the case. Check and adjust the gearbox accordingly. As a guide the looser the cable, the earlier it will shift, visa versa the tighter the cable, the later it will shift.

It sounds like the torque converter sprag clutch is slipping. Two common symptoms are 1) as you describe sluggish pulling away; sprag clutch is slipping which effectively means no torque multiplication; and 2) the sprag clutch has seized. In this case the car pulls away fine but at 2,000-RPM ish it feels like the brakes are jammed on. Solution – replace the Torque Converter.

We recommend you use AFT Dextron 2/3.

The first thing to do is to remove the oil cooler pipe from the bottom of the gearbox (put a container under the open end to catch the oil) and start the engine. You should get a good flow of oil. If not the pump has been broken during installation and will need replacing/rebuilding. The torque convertor must be fitted to the gearbox, located correctly on the pump and locked into postion before the gearbox is offered to the engine, otherwise damage will occur to the pump, resulting in no oil flow and subsequent to other parts of the autobox.

It sounds like you need to change the filter! In the cold weather, i.e when the oil is cold and more viscous, if the filter is partially blocked it will take some time for the pump to draw oil through it. Once the oil becomes warm it flows more freely and can pass through the filter more easily. Hence the problem only occurs when the oil is cold. To remedy this problem your filter needs to be changed. This should be done sooner rather later to reduce the possibility of damage to the autobox, by the clutches “slipping” during this slow engagement.

It sounds like you need to change the filter! In the cold weather, i.e when the oil is cold and more viscous, if the filter is partially blocked it will take some time for the pump to draw oil through it. Once the oil becomes warm it flows more freely and can pass through the filter more easily. Hence the problem only occurs when the oil is cold. To remedy this problem your filter needs to be changed. This should be done sooner rather later to reduce the possibility of damage to the autobox, by the clutches “slipping” during this slow engagement.

A sprag clutch has "inverted" and will need replacing. No further damage will occur if you continue to drive but you will need to select "1" every time to start moving. A rebuild is required to correct this.

The governor valve is sticking, which can be caused by contamination. i.e. clutch plates or other parts disintegrating. The fine debris finds its way past the filter and tends to accumulate in the governor, causing it to stick. A temporary solution is to remove and clean the governor. The problem will often recur as debris from damaged parts continues to build up in the governor. If the problem continues after cleaning the governor then it may be necessary it replace your Autobox.

We have noticed many customers reporting this fault starting a few days after an oil and filter change and after researching this using our experience and the expertise of others in the trade we have come to the conclusion that as ATF oil is a detergent type oil, when the oil is changed this will dislodge and stir up settled debris in the autobox which in turn jams the governor valve. In light of this although it sounds controversial it is debateable if changing the oil and filter is a good idea, some say if the box it going to fail it will fail if the oil is good or bad and their advice is leave it alone. I am still undecided but the truth is I get a lot of calls from customers thinking they are looking after the autobox by servicing it and a few days later this fault occurs.

We can supply rebuilt exchange autoboxes and offer a sameday fitting service, with free use of a courtesy car. Please call for details.