p38 Diesel Auto Gearbox Grinding and Slow to Take Off

Just changed the fluid and filter in my 97 Diesel Auto p38 in the hope it would aid the current problems I have been experiencing.

Ive recently noticed that as soon as the car hits 70mph there's an audible grinding noise coming from the bell housing area. Also, the car has been very slow to take off in either forward or reverse. Since changing the ATF its much better going forwards but still bad going backwards.

While I was changing the oil I noticed that there is a heavy "sweat" around the gearbox oil cooler and on some of the pipes and also the oil level must have dropped quite low as, before I got the level right , I had to put 2.5 extra litres of ATF in than I drained out.

Any idea what I should be looking out to sort this?

what was old oil like

gravy!

In this situation I think you need to take stock.....

myfirstl322 said:

In this situation I think you need to take stock.....

Click to expand...

Taxi for myfirstl322, please!

Worth trying some of that Lucas transmission fix with another change? Everything crossed and hang sone rosaries from the rear mirror?

Could be a weak torque converter ,In the oil pan ,there is a magnet was there much swarf...metal fragments on it...

Yes, the magnet was covered in a fine metallic paste. The shape of the magnet was barely recognisable under the paste.

Maybe the slow leak from the cooler has reduced the level in the box causing starvation and the box trying to compensate for the issue leading to premature wear Holmes?
What mileage do you have?

120k ish.... not much for one of these.

Ill try a bottle of Lucas in it and see what happens. Its a shame as the car still drives beautifully apart from the whirring grinding noise at high speed.

Maybe I should just slow down a bit.

jimllshiftit said:

Maybe I should just slow down a bit.

Click to expand...

Don't be hasty.

Same thing, innit?

Possibly time for a rebuild. All the metal paste is dust from the clutches I'm guessing 4th clutch plate is goosed. Any zf rebuilder will take one of these on. Alternatively though riskier a used box. Diesels have the cheaper and weaker hp 4/22 variant.

jimllshiftit said:

Just changed the fluid and filter in my 97 Diesel Auto p38 in the hope it would aid the current problems I have been experiencing.

Ive recently noticed that as soon as the car hits 70mph there's an audible grinding noise coming from the bell housing area. Also, the car has been very slow to take off in either forward or reverse. Since changing the ATF its much better going forwards but still bad going backwards.

While I was changing the oil I noticed that there is a heavy "sweat" around the gearbox oil cooler and on some of the pipes and also the oil level must have dropped quite low as, before I got the level right , I had to put 2.5 extra litres of ATF in than I drained out.

Any idea what I should be looking out to sort this?

Click to expand...

another box and torque converter

johnnyb70 said:

Possibly time for a rebuild. All the metal paste is dust from the clutches I'm guessing 4th clutch plate is goosed. Any zf rebuilder will take one of these on. Alternatively though riskier a used box. Diesels have the cheaper and weaker hp 4/22 variant.

Click to expand...

It can be replaced with a HP 24 with bellhousing and torque convertor changed over and also front pump if it an earlier box

Right,

The Lucas fluid made a huge difference, but this week it has started to deteriorate again. So, I guess either a rebuild or a replacement box is in order, so what is the best direction to go in?
If I get a used HP24 is it wise to use my existing torque converter when I refit?
The car is a 97 so will the front pump also have to be swapped?

jimllshiftit said:

Right,

The Lucas fluid made a huge difference, but this week it has started to deteriorate again. So, I guess either a rebuild or a replacement box is in order, so what is the best direction to go in?
If I get a used HP24 is it wise to use my existing torque converter when I refit?
The car is a 97 so will the front pump also have to be swapped?

Click to expand...

@jamesmartin knows these things inside out.

They made quite a lot of changes around '97 and also in '99. Not sure if the pump was one of them but guess checking the part numbers on Microcat might give the game away? I'd be tempted to change the pump anyway in case that was part of the problem.

Does the HP24 have different gearing? As in will it struggle to accelerate without chipping it for a bit more power? I've got a feeling @ovalandrover has either chipped his or has a powerbox on it.

Ive already got a PSI? Supercat chip on but its also on 20" wheels which makes it a bit more sluggish anyway.

Just had a look at Ashcrofts website and I think £725 for a recon unit is more than I would want to spend. I can see im going to end up taking my chances with a used 'box and torque converter so would be grateful to know what im going to need on my shopping list. I did read something about changing the flex plate while the box is out and giving the handbrake a once over too.

If your box has done its clutches then the bits will be in the torque converter so a rebuilt torque converter would be wise The gearing is the same in both boxes Sussex auto parts will supply the front pump but will only supply the pump to the box number so you have to know the number of the later box to get the or order the pump for the HP 22 box Flex plates can crack so check yours out before you refit box. The bellhousing has to be changed over as well.
Datatec checked it out and it might be worth sending him a PM for more info

where about are you I had a guy recon mine about 3 to 4 yeas ago for about 1/2 of the ashcroft price and it has been fantastic since but he is in the midlands near Redditch let me know lf you are interested and I will look up his number