cjr09

New Member
Hey gents,

So my recently purchased disco has an issue with its box...

Under light partial throttle only it changes through 1St - 2 nd nice but then on its change from 2 nd to 3 rd when it gets To about 1800 rpm it surges or free revs like it has hit neutral jumping about 500-750 rpm momentarily lasting for as long as half a second to several seconds until it decides to hit 3 rd

This only happens on the shift from 2 nd to 3rd so I am hoping that there is some adjustment on the box somewhere to firm up the gear change?

I have Video of this but am having trouble up loading from my phone will Post it as soon as I can

Any help very much appreciated - hopefully an easy fix!

Cheers, cjr
 
Anyone any thoughts on this?

Adjustments on box?
clutch pack fekked?
solenoids?
fluid?


seems weird to me that it happens only on that change from 2nd-3rd at about the 1800rpm mark under light-med throttle position...
 
so i finally got round to checking the fluids and it seems that the trans fluid whilst vehicle/trans is cold at idle the fluid reads 2-3 times above the top marker - as in the gap between the hi/lo marks on the dip stick the level is approx 2-3 times that distance above the top/hi marker.

so the question is are the symptoms that represent symbolic of an overfilled auto transmission?

what are the repercussions of an overfilled auto transmission gearbox?

if the symptoms are not symbolic of an over filled box then where to next?

is it worth changing the fluid and filter? it had good colour?

I can provide photo if necessary...

many thanks!
 
No I didn't - when you say cycle through the gears do you mean to take it for a spin around the block or just throw it in drive then back to park/neutral?
 
I had a very similar issue in an EDC auto, there is a small blue plug for the fly by wire throttle from memory hanging off the bulkhead just to the right of the fuel filter, this was hanging down and making contact with the engine block, I can only guess it was getting hot and being contaminated with oil and giving a false signal to the potentiometer???

Anyway cleaned it and tied it back and never had a problem since
 
I had a very similar issue in an EDC auto, there is a small blue plug for the fly by wire throttle from memory hanging off the bulkhead just to the right of the fuel filter, this was hanging down and making contact with the engine block, I can only guess it was getting hot and being contaminated with oil and giving a false signal to the potentiometer???

Anyway cleaned it and tied it back and never had a problem since

Thanks for the heads-up will look into this also...

So this is what the dip-stick is reading:





Simply way overfilled or something else going on perhaps?

Might just drop it all replace filter and oil for new...
 
According to the difference between the max/min marks, if you have checked the oil correctly and this is the proper measurement you would be roughtly 1.5ltr above the max level, surely that would of went bang by now.

If you have any trouble finding that connector I mentioned let me know and Ill get a picture
 
just to remind the correct way of checking your autobox level.
When cold,
1. Keep engine running
2. cycle through all gears.
3 lever in neutral, engine running.
4. carefully check oil level, should be between the two holes.

this is the method to use.
Let us know how you get on

cheers

Jim A.
------------------
1996 300Tdi auto(Jap reimport)
 
just to remind the correct way of checking your autobox level.
When cold,
1. Keep engine running
2. cycle through all gears.
3 lever in neutral, engine running.
4. carefully check oil level, should be between the two holes.

this is the method to use.
Let us know how you get on

cheers

Jim A.
------------------
1996 300Tdi auto(Jap reimport)

Was just about to say needs to be in neutral. If i was you do that if still getting that reading, drain it and see how much is actually in there ATF isn't all that expensive
 
Yes thanks guys, initially was doing it as per instruction on dip stick - cold in park at idle, then did it in park at idle after a spin around block to cycle the gears, and have now done it in neutral at idle after spin around block to cycle gears - all readings have been similar with the last correct reading being the lowest with the level sitting at the "C" of "check when cold"

so will proceed to drain it as soon as i can...

Is this likely to be the cause of the slip from 2nd-3rd? why does it happen only with that change and not all the time? Although when I think about it maybe it has been slipping more than what I was aware as it has been going through a little more juice but I had assumed due to the fact I was driving around the prob - ie dialing up 2500rpm in second to get a positive change from the 2nd-3rd?

thanks for the help, much appreciated!
 
If you have any trouble finding that connector I mentioned let me know and Ill get a picture



If you could get a pic that would be great mate, the only blue connector I can find was up near the battery - not sure what that one is for and it has been disconnected and left for some reason?
 
According to the difference between the max/min marks, if you have checked the oil correctly and this is the proper measurement you would be roughtly 1.5ltr above the max level, surely that would of went bang by now.

If you have any trouble finding that connector I mentioned let me know and Ill get a picture




So I drained the Box - 6L came out but only about 3.75L went back in, will continue to check the level over the next day or so - its sitting just above the min mark at the mo so might take another cup full yet...



Bad news is it hasnt cured the slippage happening on that 2nd-3rd gear change, whilst perhaps it is not quite as bad revving maybe 400-500rpm
 
Following on from Jim's post and adding a little detail just for clarity:

1. Commence procedure on a cold engine, with auto gear selector in P;

2. Start engine, then select each gear position in turn, allowing 2-3 secs delay each time (position) to take up drive;

3. P-N-R-D-3-2-1, then back to P - LEAVE THE ENGINE RUNNING !!
4. Now remove the dipstick, clean it and then dip the oil level.


That is the correct procedure for this HP24 auto bow oil level check.

Hope it's clear enough for you,

Good luck

Dave

PS what was the colour of the oil that came out? Red? Reddish brown? Brown? Did it smell burnt?
 
If you could get a pic that would be great mate, the only blue connector I can find was up near the battery - not sure what that one is for and it has been disconnected and left for some reason?

Here you go mate, gave this a clean and tied it out the way, might not be blue on yours though but you should have it somewhere in that area
 

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Following on from Jim's post and adding a little detail just for clarity:

1. Commence procedure on a cold engine, with auto gear selector in P;

2. Start engine, then select each gear position in turn, allowing 2-3 secs delay each time (position) to take up drive;

3. P-N-R-D-3-2-1, then back to P - LEAVE THE ENGINE RUNNING !!
4. Now remove the dipstick, clean it and then dip the oil level.


That is the correct procedure for this HP24 auto bow oil level check.

Hope it's clear enough for you,

Good luck

Dave

PS what was the colour of the oil that came out? Red? Reddish brown? Brown? Did it smell burnt?


Thanks for clarification - yes that is the procedure I ended up on

As for the oil that came out, yes in my opinion it had a brownish hue to it, looked ok on the stick but in the pan had a hue to it - it has been replaced with fresh oil - castrol transmax? its dexronII, same oil that goes into my old Ford pan fill C4.

Is there a better oil for these about? pretty clear I don't know much about these...

Anyway at this stage the problem persists!
 
Thanks for clarification - yes that is the procedure I ended up on

As for the oil that came out, yes in my opinion it had a brownish hue to it, looked ok on the stick but in the pan had a hue to it - it has been replaced with fresh oil - castrol transmax? its dexronII, same oil that goes into my old Ford pan fill C4.

Is there a better oil for these about? pretty clear I don't know much about these...

Anyway at this stage the problem persists!

When the car was first produced Dexron IID was the recommended atf. However this standard of oil is way old. Everything takes a minimum of Dexron III and preferably Dexron IIIH or Dexron VI, nowadays

The Dexron thing is just a series of stds propsed by GM and generally accepted by the autobox manufacturers, the latest is VI is supposedly more stable at a wider set of temps and being the thing oil type is meant to give smoother changes and better fuel economy.

What should you use? Depends on your pocket depth really, a fully synth to Dexron IIIH would do nicely.
 

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