p38 4.6 auto kickdown prob

got a prob with the kickdown
when i floor it it drops down like it should, but if i keep it floored untill it tryes to change up it seems to flick from the currant gear into nutral then back again like it cant get the next gear. it wont change up unless i back off the accelerator a little.
somone said it could be the gear oil?
how often should it be changed or is this something more serious
other than this the box works fine up and down

gfromleeds said:

got a prob with the kickdown
when i floor it it drops down like it should, but if i keep it floored untill it tryes to change up it seems to flick from the currant gear into nutral then back again like it cant get the next gear. it wont change up unless i back off the accelerator a little.
somone said it could be the gear oil?
how often should it be changed or is this something more serious
other than this the box works fine up and down

Click to expand...

Every 48,000 miles i think with a new filter.

Be careful about changing it as drainning and changing thr filter can pull **** through the box and **** it up.

juiceyv8 said:

Be careful about changing it as drainning and changing thr filter can pull **** through the box and **** it up.

Click to expand...

Yes that is true, but leaving it in with a blocked filter will also f**k it up.

wammers said:

Yes that is true, but leaving it in with a blocked filter will also f**k it up.

Click to expand...

see point.

Take the dipstick out and what colour is the ATF??

juiceyv8 said:

see point.

Take the dipstick out and what colour is the atf??

Click to expand...

pic dont realy shown its a pink/peachy colour

ive had the car for 30,000 miles and the previous said its just had a major service but he also said "its got a good engine" and the head gasket blew after 300 miles

Anybody ever tried a gearbox megaflush for auto problems such as these??

I'd not heard of it before but then out of nowhere loads of D3 owners started having it done to cure gearchange problems, juddering etc. They swore by it. Its like a gearbox dialysis from what i read and far better than just changing the oil. Anybody had it on a P38 successfully. From memory it was just short of £200.

gfromleeds said:

View attachment 22646
pic dont realy shown its a pink/peachy colour

ive had the car for 30,000 miles and the previous said its just had a major service but he also said "its got a good engine" and the head gasket blew after 300 miles

Click to expand...

Should be pinky and smell "cherry aidy".......if black then it means trouble.


I could see how the dialysis could would if its pushed and sucked through quick enough not to leave any crap in the box.

juiceyv8 said:

Should be pinky and smell "cherry aidy".......if black then it means trouble.


I could see how the dialysis could would if its pushed and sucked through quick enough not to leave any crap in the box.

Click to expand...

It is pinky in colour
Does this mean its not the oil?

the problem with autos and oil changing is that atf has high detergent qualities get it on your hands and it cleans all the crap of them better than hand cleaner ,there should never be alot of crap in autos unless there om their way out in which case only short term fix ,but with slighlty worn valves in block fresh oil can sometimes alter their shifting qualities ,but is well worth a try with a box with these problems there are one way clutches that when worn dont allways grab on during erratic torque apllications ie sudden gear change ,eventually if this is the case the box wont want to drive, so will then heed to be changed they wont hurt the box in any way not like a brg breaking up ,change oil as std and do twice to clean t/c with a run in between,one way clutches (sprag clutch free wheel clutch same thing different name depending on person ,company)can easily be checked as are all other clutch pack with box stripped ,oil pressure test with box in vehicle to test valve block