ZF tranny info

[greenjag03]

Max_Torque said:

And 03 car is getting on for 15 years old. Cars are designed for 10 years and 150k miles.

No excuse. Bad engineering by ZF when it was new is still bad engineering when it's 15 years old.

I like my 03 S type 3.0L SE. Sure I could buy another later model, but I like this particular one for personal reasons. It's my fourth Jag and will be my last, probably outliving me.

Edited by greenjag03 on Thursday 26th October 17:03

[eliot]

E-bmw said:

+1 for the above statements.

You could always grease the threads and the bolt flange.

Some one told me many years ago & I have done it ever since.

"Just imagine you may be the next person to take it off again".

I take a pot of copperslip to the tyre place and get them to put a dab on the threads and hub face - they told me that nobody does it (apart from staff)

[anonymous-user]

greenjag03 said:

Max_Torque said:

And 03 car is getting on for 15 years old. Cars are designed for 10 years and 150k miles.

No excuse. Bad engineering by ZF when it was new is still bad engineering when it's 15 years old.

I like my 03 S type 3.0L SE. Sure I could buy another later model, but I like this particular one for personal reasons. It's my fourth and this one will be my last, probably outliving me.

it's not "bad" engineering.

Engineering is a compromise, between cost, capability and durability.

You cannot have all three.

ZF made an engineering decision, probably based on objective test data (like salt spray tests) that told them the fastener system used was sufficient to last the design life of the car. And they were right, it did.

[greenjag03]

eliot said:

I take a pot of copperslip to the tyre place and get them to put a dab on the threads and hub face - they told me that nobody does it (apart from staff)

I had a mate once who had front pads done at a tyre place, they put too much copper-ease on his hubs which got to the discs, not nice.

Putting that stuff on steel to steel threads like wheel studs is fine, but personally I've found it seems to dry to a cack when used on steel - aluminium. Don't know why

Edited by greenjag03 on Monday 23 October 22:30

Edited by greenjag03 on Monday 23 October 22:33

[greenjag03]

Max_Torque said:

it's not "bad" engineering.

Engineering is a compromise, between cost, capability and durability.

You cannot have all three.

ZF made an engineering decision, probably based on objective test data (like salt spray tests) that told them the fastener system used was sufficient to last the design life of the car. And they were right, it did.

Thank you for suggesting it was deliberate.

Though I might suggest you're missing the point slightly - what defines the design life in an example like this? is it the self-corroding fasteners, or the fact that the sealed for life box leaks at some random time ? Yes, many a ZF 6 leaked during warranty.

As for cost capability and durability, I also have a 15 yo Suzuki Swift with more mileage than the Jag, which I've had from new. So far in 15 years all it's ever needed was tyres, oil, brakes, plugs, distributor cap, wipers, a couple of track rod ends, and the occasional bulb. It's only a 1L 3-pot runabout but by heck you couldn't get an easier car to service, and no dirty design life tricks anywhere. Also runs on a whiff of petrol :-)

On the other hand I have a Mercedes van, guess what----the gearbox synchro's kaput. Not really bothered to look as van SORN, but wouldn't be surprised if that box is made by ZF as well. Shame as it's still got a cracking engine after 176,000 miles.

So, to a point I have to agree with you, however my sentiment would be along the lines of perhaps this day and age big business is using factored 'design life' as a price we pay for luxury / hi tech products.

Brings to mind a well documented comment made by a certain CEO of a very big software company....."don't give 'em what they want cos they won't come back and buy another one".

Mugs aint we. Though I maintain old stuff that keeps on going is better than new stuff which dies when someone else says it dies.

Thank you for a stimulating exchange of sentiment.
Regards

[helix402]

I serviced an 8 speed ZF box with a ZF kit. It came with new modified sump bolts, can’t remember what material they were.

[greenjag03]

helix402 said:

I serviced an 8 speed ZF box with a ZF kit. It came with new modified sump bolts, can’t remember what material they were.

They'd be zinc passivated steel, just like the originals, but with larger torx drive. It was the only acknowledgement ZF ever gave to the problem.

[It's fixable...]

The thing to remember about any galvanic couple ie any metal to metal interface is that the less noble material will rot first.

As other posters have stated ali to stainless is a "worse" galvanic couple where the ali is most likely to corrode.

Ali to passivated steel is also bad but the ali will corrode slower.

Copperslip can be bad as it can cause additional acids to be generated depending on the salinity of the water sluicing the interface between metals.

Look up sacrificial anodes on the interporn to better understand the concept.

[greenjag03]

It's fixable... said:

The thing to remember about any galvanic couple ie any metal to metal interface is that the less noble material will rot first.

As other posters have stated ali to stainless is a "worse" galvanic couple where the ali is most likely to corrode.

Ali to passivated steel is also bad but the ali will corrode slower.

Copperslip can be bad as it can cause additional acids to be generated depending on the salinity of the water sluicing the interface between metals.

Look up sacrificial anodes on the interporn to better understand the concept.

Thanks for that info, but, I'm sticking with stainless with a good dosing of waxoyl. It worked for me on bikes ridden through numerous winters over a 30 year period....never got a corroded fastener.

Re passivated steel: I suspect galvanic action between the fastener and casing is largely dependent on what the fastener is passivated with i.e. Zn, Cd etc. I suppose in effect you could say stainless is passivated with chromium...which doesn't rust. Then again I always coat threads on weather exposed parts with waxoyl, so I guess I'm keeping the electrolyte i.e. salty road water out. perhaps this is why I don't get corroded fasteners.

Copper-eaze / slip........yeah can't stand the stuff, shouldn't really be needed.
Cheers

Edited by greenjag03 on Thursday 26th October 17:01

[helix402]

Agree re Copperslip, ‘‘tis horrible stuff. It was banned from the BMW dealer I worked at a few years ago. Now alloy grease, that’s lovely for stopping alloys corroding onto hubs:

[greenjag03]

As a point of interest, I once heard the Japanese don't salt their roads. Maybe thats why an MX5 I had a few years ago exponentially rotted out on me big time.

Salty water makes a good electrolyte.

[helix402]

That why you can import a rust free Japanese car and have it rusting happily away in England a few years later.

[VYT]

Having just completed a similar task on my 2008 Range Rover Sport I have the following to add, (apologies if already noted above).

Its not possible to remove the sump from an RRS / Disco3 without removing chassis cross members and jacking the engine / transmission. However it is possible to buy a two piece filter / sump assembly to replace the OEM one piece. If replacing with the two piece sump then the one piece can be removed without disassembling chassis cross members and jacking the transmission because the oil pickup tube on the one piece sum can be "carefully" sawn off making it possible to swivel the sump out.

I imagine all of the ZF trannies are similar, so, if you are going to the trouble of removing the sump then make sure you also replace the connector sleeve, (at the right rear on the RRS just above the fill plug) These leak and can only be removed once the sump pan is removed. The sleeve itself is fine of course it just the O Rings that need replacing but the complete sleeve is cheap. Murphy states that the sleeve will leak one week after you do the trannie service.

I used ZF fluid to refill as it was bundled with the 2 piece sump but I know that the same trannie is used in the Ford Falcon here in OZ so there must be a Ford fluid that is suitable.

[Mr2Mike]

greenjag03 said:

Actually it wouldn't have fixed the issue....a set screw doesn't have a head, so clearly wouldn't hold the sump pan on.

A blind set screw (AKA grub screw) doesn't, but equally a set screw can have a head. My apprenticeship was better than yours

[melhookv12]

Sealed for the life of the warranty.

I've changed the gearbox oil on my S type R 6 speed. My dad's xkr 5 speed.
On mine I put the torx bit on the bolt and hammered it a few times shocking it loose.
Did the same on my dad's. Box gearboxes were hot, and I applied more heat to the bolts on the XKR as thevsump is metal.
Changed the oil and filter on my e class, very similar gearbox to the xkr. I applied the same tactics no problems.

When working for jaguar we were told not to apply copper grease to the hubs. Not sure why?
Vaguely remember them saying the nuts could come loose.

Now working in the rail industry and everything must be torque tightened using calibrated gagues and clean, dry, grease and paint free fixings.