Servicing the ZF 8HP box for the first time at 100k miles.

[housemouse]

Recently acquired an F31 330D ( see Readers Car post here). Car has about 100k, no indication of the 8HP having been serviced. I read that it can actually be problematic to service it for the first time once the mileage is this high.

What is the consensus, if any on doing a first gearbox service at this kind of mileage? The ZF specialist service center seems to think it is fine to do it, but then they are incentivised to do the work. Thanks in advance.

[Glasgowrob]

i'd be servicing it tbh

especially if your doing it with a ZF agent. they'll no the correct process/procedure wont be powerflushing it and are probably best place to suggest if any further preventative or remedial work is required once the pans off.


also worth doing the transfer box/diff oils at the same time as i'd imagine of the box has never seen a service neither has the rest of the drive train.

[Dannbodge]

Normally they get done around 60k.

BMW say sealed for life, ZF say 60k (iirc)

Most BMW specialists have the knowhow to do it.

[danb79]

housemouse said:

Recently acquired an F31 330D ( see Readers Car post here). Car has about 100k, no indication of the 8HP having been serviced. I read that it can actually be problematic to service it for the first time once the mileage is this high.

What is the consensus, if any on doing a first gearbox service at this kind of mileage? The ZF specialist service center seems to think it is fine to do it, but then they are incentivised to do the work. Thanks in advance.

Get it serviced; this is the kit you need: https://www.amazon.co.uk/ZF-1087-298-365-Oil-Filte...

Same kit I used on our F31 earlier this year - just need a decent mechanic to do it with the right code reader to read box temps; or find a local autobox specialist

[E92_325]

I did my ZF6 at 80k miles and when the fluid was almost 20 years old. I was hesitant at first but glad I did it. Zero issues. As long as your transmission is working fine, then it shouldn’t cause any issues.

[housemouse]

I did a service on a ZF6 in an Audi that had 195k miles and it was fine. But I had not read about potential problems servicing a box at very high miles, so ignorance was bliss! And then car wasn't worth much and was pretty knackered, so would not have been that upset if it had killed it.

This one is so nice (probably too nice for the remit, if honest), so it would be upsetting if servicing the box caused problems. It seems fine as it is, though this is my first ZF8 car and I don't know exactly how it should perform. There are absolutely no clunks or error codes from the box. In certain situations, you can slightly feel the shifts, but absolutely nothing remotely clunky or jarring. Again, I'm not super familiar with the ZF8 and don't know if the shifts should be virtually imperceptible at all times.

[Pica-Pica]

housemouse said:

I did a service on a ZF6 in an Audi that had 195k miles and it was fine. But I had not read about potential problems servicing a box at very high miles, so ignorance was bliss! And then car wasn't worth much and was pretty knackered, so would not have been that upset if it had killed it.

This one is so nice (probably too nice for the remit, if honest), so it would be upsetting if servicing the box caused problems. It seems fine as it is, though this is my first ZF8 car and I don't know exactly how it should perform. There are absolutely no clunks or error codes from the box. In certain situations, you can slightly feel the shifts, but absolutely nothing remotely clunky or jarring. Again, I'm not super familiar with the ZF8 and don't know if the shifts should be virtually imperceptible at all times.

Having had mine from new (F30 335d), and at 70k miles, I have now felt the occasionally 'woolly' shift change, nothing worrying, but certainly slightly less imperceptible than a few year ago. I plan mine for next year.

[Jakg]

housemouse said:

I read that it can actually be problematic to service it for the first time once the mileage is this high.

Supposedly, when the clutches are worn out the friction material ends up in the oil and helps stop it slipping. Hence new fluid "causes" slippage. But really the transmission was already shot at that point.

I would, and have, changed.

[housemouse]

Jakg said:

Supposedly, when the clutches are worn out the friction material ends up in the oil and helps stop it slipping. Hence new fluid "causes" slippage. But really the transmission was already shot at that point.

I would, and have, changed.

Yes, that it what I have read. I may be over thinking this, but how does one ascertain whether the box is best left alone or not?

[Jakg]

housemouse said:

Yes, that it what I have read. I may be over thinking this, but how does one ascertain whether the box is best left alone or not?

You'll be able to get an idea on general transmission health by reading the adaptations.

[danb79]

housemouse said:

Jakg said:

Supposedly, when the clutches are worn out the friction material ends up in the oil and helps stop it slipping. Hence new fluid "causes" slippage. But really the transmission was already shot at that point.

I would, and have, changed.

Yes, that it what I have read. I may be over thinking this, but how does one ascertain whether the box is best left alone or not?

100k mileage isn't high; 170k upwards is

Ours was on 109k miles when I got it serviced; zero issues. But smoother changes, and a lot sharper

If it were my car and not my wife's now; I'd have got the xHP map done to the box as well

You're overthinking; get it serviced, it'll do it a world of good

[housemouse]

It's already booked in for later this week. I'm just sense checking before it goes in.

[Cheddarbang]

housemouse said:

Jakg said:

Supposedly, when the clutches are worn out the friction material ends up in the oil and helps stop it slipping. Hence new fluid "causes" slippage. But really the transmission was already shot at that point.

I would, and have, changed.

Yes, that it what I have read. I may be over thinking this, but how does one ascertain whether the box is best left alone or not?

That is an old wives tale from 1970s crappy GM autos.

No auto enjoys ancient crappy oil in it's bowels. Get it changed. At 100K, I would be resetting the adaptations as well, but you'll need ISTA for that.

If the oil pan has a green sticker on it, it's the original one.