Zf4hp22 gearbox oil change

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lvdxd00

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I’m in the process of changing the oil in the auto box on my 90.
I’ve dropped the crossmember and dropped the oil and replaced the filter.
What I would like to do is give the box a flush through.
What I would like to know is there a best practice.
My plan was to disconnect the gearbox from the oil cooler somewhere in the middle and try and get the box to pull the fresh oil in whilst pushing to old out.
Which line is the out and which is the return?
Cheers
Dave
 
In my OPINION.

I wouldn't bother, just run some cheap oil through it, and do a few changes from the sump..
finishing off with a good quality fluid - Millers Millermatic for eggsample.
 
Best practice is to avoid the risk of running the box dry in any way shape or form. This will spoil your day :eek:

Thus, unless you have the right powerflush type equipment, then just change it twice and be done with it - 25K miles later, do it again - repeat as required. :)

I use Castrol oils, because I reckon they are worth the extra, AND because they have technical folk who are available should you need them. :):)

I'm not disagreeing with the use of Millers ( for example ), but I wouldn't use cheap oil for anything - not worth it IMHo_O_O

FYI, the flow of oil through the cooler changes direction at TQ lockup - and IIRC, flow to the cooler is thermostatically controlled - so not really as simple as flow and return ....
 
Thanks for the reply’s
Easier to change the oil twice, I guess.
25k between changes might be a problem, I only do a few hundred mile in a year in it.
 
Dirt is your enemy so the less time its open to contamination the better. Is there any reason to beleive it needs a flush? Unless its done really well you may just move stuff about. I also drive older Mercs, typically the auto box is fine for 150k before an oil change - so long as no water or dirt get in.
 
lvdxd00 said:
Thanks for the reply’s
Easier to change the oil twice, I guess.
25k between changes might be a problem, I only do a few hundred mile in a year in it.
Click to expand...

Personally I wouldn't be too concerned, my 32 year old Classic has probably never had the fluid changed. I bought the car eleven years ago with only 40k on the clock so it's unlikely to have seen a change in that mileage & I've never carried out the task since. The car has now done 59k, the fluid on the stick is slightly discoloured but the 'box performs perfectly.
I've recently had the fluid changed on my old 5 series BMW at 149k & the garage saved a small quantity in a clean glass jar for my inspection ... yes the fluid was dark but not black.
 
Last edited:
lvdxd00 said:
I just felt it needed doing, the oil did look a little old, but not burnt.
Click to expand...

In that case, I'd recommend three years as a max life span on the oil - Oil is cheap compared to the hassle and expense of changing a clutch pack in the box....:)
 
Yes, I did read that right, an auto defender 90! A rare beast!

I’ve just changed the fluid on my D2 auto and it came out almost black... I’m guessing it may we’ll be the first time in its 170k Miles... As said above, change the fluid, if you feel it needs it do a couple hundred miles or more and change it again. I may even do it a third or fourth time depending on the colour of what comes out next time. When I’m happy then I’ll do the filter. I’ve already found an improvement in the gear changes and am glad I did the change. Regardless of the stated interval, I will be changing the fluid much more often than every 100k plus!
 
It is recommended to change the fluid every 25k..
i myself have never understood the Ain't broke attitude towards drivetain maintenance, why not apply the "it's fine" thought to the engine, and never change the oil?

I pulled this out of a 4hp22 that hadn't seen a service in it's life and 180k

U9gNCq7l.jpg


This was out of my autobox it was changed at 57k according to the service bootlet 28/09/2005


9PWnYIpl.jpg


J2mSKCMl.jpg


so that is 124k on 15yr old ATF, never towed by all accounts.

my P38 had towed, for most of it's life and the fluid was black..

I changed it and the shift improved drastically..

Also worth noting oil does have a "best before" i doubt many would drop a litre of engine oil or ATF into their cars that was sat in a shed and was 20+ years old!! ;)
 
Disco1BFG said:
25K miles later, do it again
Click to expand...

Henry_b said:
It is recommended to change the fluid every 25k..
Click to expand...

There's a pattern here - probably 'cos we've both read the ZF technical blurb... :)

norseman said:
Personally I wouldn't be too concerned, my 32 year old Classic has probably never had the fluid changed. I bought the car eleven years ago with only 40k on the clock so it's unlikely to have seen a change in that mileage & I've never carried out the task since. The car has now done 59k, the fluid on the stick is slightly discoloured but the 'box performs perfectly.
I've recently had the fluid changed on my old 5 series BMW at 149k & the garage saved a small quantity in a clean glass jar for my inspection ... yes the fluid was dark but not black.
Click to expand...

Well, it's about time it had a change then - what ever is in your AT now is not ATF any longer - the additive packs and the base oil will have degraded to hell, and whilst the box may still work ... wear will be exponentially above where is would be with oil in.
 
Thanks again for the reply’s, I will run it for a while and drop the oil again. I do have a spare box if needed, but changing it would be a massive hassle.
It drives ok at the moment, but when I got it the throttle valve cable was loose. I have adjusted that now.
I also have a spare 3.9 to go in at some point. Fancy doing a megasquirt conversation as well
Jobs for the future
 
Well, it's about time it had a change then - what ever is in your AT now is not ATF any longer - the additive packs and the base oil will have degraded to hell, and whilst the box may still work ... wear will be exponentially above where is would be with oil in.[/QUOTE]

I take your point, but with a lot of fluid remaining in the TC it's going to require more than one change to get all the old fluid out. I can't do this work myself & what with the X member having to be dropped each time the cost of materials & labour will be heavy.
If the 'box has suffered exponential wear as a result of long term usage of old fluid over 59k would it not be preferable to plough that cost saving into a replacement 'box when problems occur?
 
Not wishing to sound rude but why can’t you do this yourself? You don’t need to remove the cross member to drop the fluid. That’s only needed to remove the sump to change the filter which is not needed to just change the fluid. It’s just two different size hex keys, one for drain, one for fill. You’ll need something to catch the old fluid and I used a 5 litre garden sprayer (£10-£15 from B&Q and the likes) with the lance cut down to refill the ‘box. I did mine on my drive the other day.

Undo the fill plug (so you know you can refill it) then the drain plug, leave it a few minutes to drain out. Replace the drain plug and fill until the fluid runs out of the fill hole, start the engine and go through the gears, pausing a couple of seconds in each, I went through them twice for the hell of it, leave the engine running with the ‘box in park and fill the ‘box again until the fluid runs out the fill hole again and replace the plug. Job done.
 
Spot1 said:
Not wishing to sound rude but why can’t you do this yourself? You don’t need to remove the cross member to drop the fluid. That’s only needed to remove the sump to change the filter which is not needed to just change the fluid. It’s just two different size hex keys, one for drain, one for fill. You’ll need something to catch the old fluid and I used a 5 litre garden sprayer (£10-£15 from B&Q and the likes) with the lance cut down to refill the ‘box. I did mine on my drive the other day. .
Click to expand...

You are not being rude, just curious I guess.
Answers >
Old age / bad back / poor eyesight / arthritis in hands / no ramp = no inclination :(
nb. your description makes the work sound less labour intensive than I thought, so maybe I'll speak to my local garage as they have recently done a fluid change on my old BMW … thank you.
 
norseman said:
You are not being rude, just curious I guess.
Answers >
Old age / bad back / poor eyesight / arthritis in hands / no ramp = no inclination :(
nb. your description makes the work sound less labour intensive than I thought, so maybe I'll speak to my local garage as they have recently done a fluid change on my old BMW … thank you.
Click to expand...
Fortunately I suffer none of the above so do able to do all the fluid changes, but with the auto box fluid and filter change, so I let a LR indi do the removal the cross member and drop the exhaust Y pipe from the manifolds, £150.00 including parts &VAT, the last time it was around eight years ago so twice in the life of my disco.

I may have a go at the ATF fluid only change this year as it’s simples, no B&Q garden sprayer required, as my gearbox like yours doesn’t have a fill plug, and will be done when I’m doing an engine oil/ filter change due later this year which is done every two years, last year was axels and T box fluid change done every three years, antifreeze change is every five years so have two or three years to go for that. Fuel, air filter and spark plugs are done as required.:)
My main car goes in to a Jaguar main dealer for a service once a year, best way with modern vehicles I think. :D
 
@norseman thats quite understandable.

I’d be surprised if the labour took an hour, with a ramp it’s probably a 20-30 minute job to change the fluid and an hour to do the filter. Just the first fluid change has made a huge difference in the changes in my ‘box. It’s well worth doing.
 
I’m not entirely sure you will even need to remove a cross member... when I was under my late D2 the other day I was looking at it for when I drop the auto ‘box sump and couldn’t see why I would need to remove a cross member. There is one under the t’box and one under the engine but none under the auto ‘box... I don’t know if they changed the design but I’m fairly sure that there isn’t one missing on my truck... when you look at this pic, it doesn’t show a cross member blocking the auto ‘box sump either...

13456771-A67F-4FE0-892A-92172470A942.png
 
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