P38 Gearbox changing woes

Hi,

I've been hunting around for days now and the symptons I'm getting don't really match any of the normal FAQ's. Hopefully someone has had or knows what the solution/problem is from the below:

When I start off and the change is carried out from 1st to 2nd it revs to 2700 then changes, not the normal 2300 or there abouts on normal acceleration. When changing from 2nd to 3rd, sometimes it will drop about 300rpm, go back to where it was, then change to 3rd.

Also if I use kick down from I think 4th to 2nd, this channges, but the revs zoom straight up to 6500rpm and will not move until the accelerator is depressed slightly. This is when going up hill - have not tried it on the flat.

I've checked the gear box oil and this is correct colour and correct level - looks as it should.

When the Landy is hot or cold does not seem to effect it, although does change OK if the accelerator is lifted off just before a change is expected.

The symptons above are what they are now, but before they were as above, only up hill was there any problem. from 2nd to 3rd, the revs would drop about 300rpm and power loss would occour. Then would return to normal and the gear change would occour.

What I have read so far leads me to one of the following problems:

Airflow Sensor needs replacing
New Gear Box
New Torque converter
Not to change oil/filter in gear box

If it is replacement Gear Box - Ashcroft say about £1100 for the whole job with re-con box with a day to complete. If were to ask friend to carry out the change, how long would it take and how hard on a P38. He has already done a manual on a classic RR.

BTW the Landy is a 1995 P38 4.6 Auto with 133k on the clock

Thanks

Gareth

Seems to me the problems may lie in the gearbox valve block with bits and pieces not shuttling around as they should.

The whole caboodle is controlled by hydraulic pressure. The faster the tailshaft turns the higher the pressure goes, so the gearbiox innards knows roughly how fast you are going AND it knows how hard you are stomping on the GO pedal. This enables it to change gears more or less to suit what you want it to do.

The valves that control the gearchanges are pushed by the oil pressure, against light springs which hold them back and return them. The least little bit of dirt can stick them, and then who knows what can happen?

Are you up to taking the box out and cleaning the valve block? If so you could replace the clutch packs and brake bands while you are about it. Easy. The whole thing almost falls apart in your hands. Beautifully designed.

If not, start saving your pennies.

CharlesY

Just tried changing the Airflow meter over as already had a spare and the symptoms are identical.

Something I forgot to mention in the first post, was that before the major problem started, e.g the changing between 1st and 2nd. I was going down a hill and doing 25mph, by accident I manually went to 1st instead of 2nd (it was snow covered hill). Car slowed down a bit before the change was carried out as it normally does. But when the change happened it caused the car to slow down dramatically, more than using the brakes would. I can't remember though if the problems happened directly after or a few days after this event. Could this of had any impact?

I unfortunately ended up in replacing the gearbox. When I phoned up a Land Rover specialist and explained the symptons he said to count how many gears it was using. I did and the box was only using 3 - 1st, 3rd and 4th. Consequently it meant that the gearbox ecu knew there was a problem with 2nd and was skipping it.

After a change of gearbox the problem is no longer there. Now I was lucky and found a garage that carried out the whole thing for £325 including the gearbox as they had one laying around from a low millage P38.