Thread: Auto box locking early?

Hi all, our 2000 TD5 auto got a replacement box for its birthday. Not a reco one but one known to be in reasonable serviceable condition. The old one was suffering badly with jolts on up and down shifts and quick burning smell and blackening to Transmax Z fluid.

I learnt lots in removal and insertion of the box with car on ramps in the driveway using a low clearance jack with box adaptor from underneath and an engine hoist with block and tackle from above doing the hard yards. Tedious but not onerous stuff.

Anyway, it's all back together and I took it for a drive. Was running beautifully in high range and not sport mode. I then went to low range and again it performed well. I then stayed low range and M mode and it was holding gears happily. It also dropped to first when I had it in M 3rd low and let it slow down a bit (all on flat black top road). I went back to high range on the Transfer and selected S mode. Seemed to be working well holding gear longer (road speed not ever over 60 and revs not over 3000 in this testing). I then went back to normal no S in high range and problems struck ....

It was hunting gears trying to choose 2nd or 3rd. I made it back home ok with no over revimg but it was still hunting (less than 900m from home at all times). I thought it might be low fluid despite careful filling process. I put it back on the ramps and while running in P climbed under to remove the fill plug. Oil came out at far more than the usual 2mm trickle down front of box. So not under filled!

I took it for one more drive to see what it was doing. It seems to be trying to hunt up the gears quickly to then get into TC lock up. It was locking in 4th at en 35kph and not wanting to drop out unless I pulled the shift back to third the. It would hunt again.

My current theory is it is over filled and maybe this is over pressuring systems causing hunting and early lock up??? I'm going to drop fluid to back to the 2mm trickle state coming out the fill hole and try again.

Anyone got ideas or suggestions or experience?

Oh the simple things ..... seems I'd not fully tightened the locking ring that secures the main wiring connector to the transmission. Have been away but got under the car today and found the ring loose (connector still engaged but clearly not enough). SOme judicious use of finger force and appropriate encouragement words later and the ring tightened up with a satisfying silent click.

Car driving just fine now. Fingers crossed I've got it sorted.

Thanks the Dave Ashcroft for his reassurance unlikely to be mechanical and more likely the loom/shorts/connection.