Hi and welcome, I'll give you a bit more info which seems to have got confused over on the other side. I can't post on there as I got myself a lifetime ban for advertising this forum (and being critical of the attitude of the mods over there). If you get gearbox fault as soon as you turn the ignition on or start the car, but before selecting a gear, that is a voltage problem. Going into limp mode and either cutting out (especially when hot) or failing to start is quite likely a CPS problem. A gearbox going into limp mode and doing odd things, is likely to be a genuine gearbox fault. Have a read here http://www.ashcroft-transmissions.co.uk/frequently-asked-questions/4hp22/4e-faq-s.html which describes your problems almost exactly. Ashcrofts will do you a recon gearbox or you can take a punt on a secondhand one. The gearbox on a 4.6 is the 4HP24 rather than the 4HP22 fitted to the 4.0 litre and diesel models. The 24 is also longer so you need a gearbox from another 4.6, preferably a later one the same as yours (not sure if there are any differences between gearboxes on the GEMS and Thor but better swap like for like in case there is). If you swap just the gearbox and retain your original transfer box, make sure you change the gearbox output shaft oil seal or you'll be taking the transfer box off again to change it (or dumping ATF all over the floor).
I don't want to speak out of turn, especially not knowing the nature of the problem, but I've known P38s come up with gearbox warnings and shift gear incorrectly when there's been a problem with the throttle position sensor, a problem with the TPS could also cause the engine to cut out...
I appreciate people and firms that know their stuff (including Gilbert, wouldn't want this to read otherwise) and I've just had a look at the Ashcroft website. I have gearbox problems of my own on another type of vehicle, wondered if they might work on my type, they don't but I'm still impressed and found their site interesting.
Simon
Hi guys didnt see this until now as my computer logged me out !
Basicly christmas eve I were at some lights, put my foot down and clonk ! no drive but reved fine then found I had reverse and slight drive (in 3rd) drove home, no kickdown just in 3rd, then she threw the gearbox fault, now start up charge is over 14.3 and 1st selects but nothin g else until you select drive rev her knock and in limp no longer option to select 1st and a whiring sound so have concluded a gearbox failure.
I have found a guarenteed 4.6 thor hse 99' box ancd convertor the same model as mine which I have bought and am planning on fitting.........now
What oil ? where can I buy a new flex plate from ? as seems a shame to refit without it.
Any advice for fitting etc or anyone fancy the job give me a shout !
Flex plate can be got from LRDirect (see https://www.lrdirect.com/FTC4607-Flex-Plate-Auto-New-Rr/). In all honesty if I was doing it, I'd say sod the cost and go for the genuine LR one even though the others will probably all last fine as long as torqued up properly. Oil is standard Dexron 3 auto transmission fluid although some have suggested that you don't use the synthetic stuff so stick with standard. Even Land Rover don't specify a brand, just ATF Dexron 3.
The early HP24 box is longer but the later box is actually the same length as the HP22.
It is a direct swap. A cheap upgrade for the 4.0 and the diesel.
I've always used this http://www.smithandallan.com/products/transport-gear-and-transmission/1840-smith-and-allan-atf-diii-dexron-3-atf-d3-semi-synthetic/ and never had a box issue. Good price if you go for the 20L size as well!