auto box worries

[ian_s]

the gearbox in my 1995 disco is starting to play up a bit, a few different symptoms all seemed to start around the same time:

when i slow to a stop, then pull away again in D, it feels like its not changing down to 1st gear, meaning it pulls away in 2nd until i give it some throttle and it kicks down.

if i manually shift to 1st it pulls away fine.

if i shift to 1st, and back to D while stationary, it's fine.

changing to neutral, then D feels normal.

the torque converter used to lock in 4th gear at about 52 mph and unlock at about 47 mph, but now it's started locking at 47, and instantly unlocking again. if i have to maintain that speed i keeps locking and unlocking, causing the car lurch and making nasty bangs in the drive train.anything above 50 is fine, anything below 45 is fine.

it seems to change normally between 2nd 3rd and 4th once moving, apart from the TC locking. kick down is working as it should, and the same as it always has done.

when cruising at 50 ish and i put my foot right to the floor, it drops to 2nd and takes off like a scalded cat!

I've checked the fluid level, it's in the right place on the dipstick, but the fluid is looking a bit dis-coloured, more like brown than the red it used to be. could duff fluid be causing problems?

i'm thinking it's time to do an oil and filter change, as I've no idea if its ever been done.

can anyone suggest anything else to try?

[Bowie69]

I would check your kickdown cable isn't broken, this connects to the throttle linkage, though you don't say V8 or TDI...? It can also break inside the box... replacement is tricky but doable with the box in the car, and lots and lots of gloves...

Check the above and if OK, then it is probably time for an oil change given the colouration, as you know it should be red, brown indicates inings burning/breaking up, but this could just be down to the kickdown cable.

Changing the oil will not always cure the issue, may even make it worse... but there's only one way to find out unfortunately.

[ian_s]

i'm pretty sure the cable is fine, as when i hoof it, it kicks down like it always has it's a v8, and it sounds like a v8 should, so i do tend to make it kick down a little too often than my wallet would like!

[Thon]

Brown oil doesn't sound good. ATF is usually a very crisp red. I'd be inclined to change that and its filter first, although i've heard that once the 'box starts playing up it's too late and the damage is already done.

However yours doesn't sound terminal so maybe its redeemable.

Good luck with it either way!

[teabag]

Does this sound something like your problem this is what Ashcroft s say.

Q. I have a 4sp ZF, when I select "D" the vehicle won't move, when I select "1" the vehicle moves off. I can then select "D" and continue to drive normally. If I stop I have to start in first again. Why?

A. 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

[ian_s]

no it's not like that, my dads RRC did that a few years back. when it goes, you just get no drive at all in D from standstill

[teabag]

OK with 'D' selected the vehicle starts in 2nd, RAVE states the possible faults are 1st and 2nd shift valve sticking or Governor sleeve sticking.

[ian_s]

aah, thanks doesnt sound good though filter and oil change ASAP i think

[Boydie]

Firstly I'd be doing a complete auto oil and filter change, the fluid should always be red, never brown, if its brown this indicates that the clutches have worn. Consider a regime of oil and filter changes every 45000 kilometres - Secondly if it still wont drop down into first I'd be looking at the govenor, it can be removed with the auto in position - and then overhauled - but its not a job I'd undertake.