Gearbox Oddities
 

Hi Guys,

Never had an issue with my old 2000 FL S8 and the gearbox up to 235K. Just picked up the new one 98 PF S8 and it drove from London fine. Up to Leeds and Back and then Monday on the 12 miles to work I hit the A1 and it reved up high and no power. PNRD4321 on the dash and then power came back but it didn't seem to change gear.

Got to work an put on vagcom 17117 - Gear 3 Incorrect Ratio P0733

Cleared this off and things worked ok.

Driving home and PRND4321 came up just after starting

Cleared the fault again and I could select select things on the dash and vagcom, but the gearbox didn't seem to do much. Tiptronic showed 5 not 1. I could go back and forwards, though pick-up was slow until moving forwards. Seemed like the car can go 0-??? in one gear!

Drove to the supermarket. Parked up. Did stuff. Got back in and no error. Drove home fine.

Yesterday morning it was fine for the first few miles and then again high rev. PRND4321 and similar problems. Clear the code and this time it seems Tiptronic shows 4. The revs are a bit higher at motorway speed, though take off is still very slow until moving.

Vagcom showed
17114 - Incorrect Gear Ratio P0730
17145 - Shift Solenoid 3 (N90) : Open or Short to Ground P0761

Again I cleared them off. Left it a while. But now i get PRND4321 with a bit of a thump when i select D or R

and 17145 keeps returning.

Any ideas where or what Shift Solenoid 3 is ???
BTW I do still have the old S8 at the moment for parts etc!

Lee

Lee

If you mean that all gears light up on the dash, I would suggest the F125 switch might be the culprit (although the scan isn't throwing that error). Not familiar enough with the other codes, but others will be.

I've heard of the F125 switch. In playing with what was doing what I believe that the lights and certainly the mirror was acting as though reverse was selected.

And yeah all the gears on the dash as a bar or [PRND432]

Hi There,

Been doing a bit of net research into this gearbox, solenoids and stuff and gonna put down a bit of a link dumping ground, so A I don't loose them and B it may be useful to someone else doing research into this box

ZF 5HP24A - It seems to also be used in quite a few cars, as such rebuild / diagnostic info on the same box on a BMW / Landy etc is still pertinent and useful while not always being 100% correct, but....

The gearbox assembly seems to consist of two parts. The actual mechanical gears and the Valve body which is the brain / controller. The valve body sits on the bottom of the gearbox and is accessible through the gearbox oil pan with the gearbox still in situ.




Diagnostic PDF - & overview on how things work
http://virtusplatform.com/sam/BMW/e3...P24%20diag.pdf

ZF Valve body maintenance "overhaul"
http://www.bimmerboard.com/forums/posts/527361

Gearbox Rebuilds

BMW
http://forums.bimmerforums.com/forum...e-Walk-through

Audi S8!!!
http://www.motorgeek.com/viewtopic.p...46685&start=25

Landrover based but lots of info/specs
http://forum.landrovernet.com/showth...5HP24-teardown
And he rebuilds for a hoby
http://www.rangerovers.net/forum/6-r...d.html#p298057



Solenoid positions / Names
http://i260.photobucket.com/albums/i...t2008/EDS4.jpg

Solenoid position / Names (official) - Also links to images of parts
http://www.tsgparts.net/index.php?p=...location_5hp24

Solenoid Positions / Diagnostic info
http://www.rangerovers.net/forum/6-r...l-problem.html

Solenoid wiring harness
http://bimmerboard.com/forums/posts/1091413

Solenoid Replacement / Swapping
http://www.rangerovers.net/forum/6-r...tml#post246833


Testing a solenoid
http://www.xoutpost.com/bmw-sav-foru...rror-code.html



Removing the valve body - Youtube video on bench
http://www.youtube.com/watch?v=rJw7RWGl0Qw

Removing the valve body instructions with pics
http://www.rangerovers.net/forum/6-r...tml#post247261


Overhauling the valve body & differences between UPDATED valves
http://www.xoutpost.com/bmw-sav-foru...-question.html


ZF rebuild manual details
http://www.audiforums.com/forum/audi...al-pdf-153014/
http://forums.audiworld.com/showthre...1759363&page=5


----

After having a think and a read and having a spare car, while the fault may be with soilnoid three, debris in the vavle body locking it out or similar. I am tempted to do a full valve body swap as it looks fairly simple.

Lee

Sounds like you may have an open circuit on solenoid 3 (i.e. it’s disconnected). Solenoid 3’s only function in life is to pressurise the opposite face of the reverse gear valve (RG-V) spool - thereby preventing engagement of the C & F clutches - in the event of the gear lever being moved into reverse while the vehicle is travelling forward at speed. Consequently it may never actually be required throughout the whole lifetime of the vehicle (unless the driver has a habit of doing this!)

http://i260.photobucket.com/albums/i...08/RG-VMV3.jpg

However, it is also activated in Neutral, which is presumably why it is being flagged by your controller.

The easiest way to test it (without having to take the sump off) is to check the resistance at the 16-pin connector.

http://i260.photobucket.com/albums/i...ps83905b85.jpg

If you measure between pins 4 & 16 you should get a reading of between 26 and 30 Ohms.

I have loads of (used) spares if you need one.

Phil

Hi Phil,

Given your name, you appear to be the gent up in Lancashire that rebuilds these for a hobby. I recognise you from one of the Landy forums and i've read numerous of your posts. Very glad to have you here. Doubly so given my current niggles.

I actually have 2 S8's one FL and one PF both with the same gearbox (fbg vs ecx but both 5HP's). The facelift one has a dead engine due to timing and throwing pistons into valves (sigh) so I got the second which has developed this gearbox fault.

We did an oil flush and it was not too bad, though the magnets had silver particles.

I was looking at Swapping the valve bodies, but testing sounds good.

However I'm a little confused.....The Code is

17145 - Shift Solenoid 3 (N90) : Open or Short to Ground P0761
Also known as P0761 - Shift Solenoid C

I was thinking from http://i260.photobucket.com/albums/i...t2008/EDS4.jpg

That C was EDS5 ???

However you circle MV3 in red on one drawing and say SV3 on your pin out???

Lee

http://virtusplatform.com/sam/BMW/e3...P24%20diag.pdf

Has mention of Shift Solenoid 3 on Page 17 as MV3 which tallys with what you say. Page 11 however says measure between pins 4 and 12 for 30-34 ohms!!!

What's the difference between 12 & 16 and if someone says 4 ohms :Confused:

Hi Lee,

Sorry about the confusion regarding the correct designation for the shift solenoids.

ZF refer to the shift solenoids as MV1, MV2, MV3 as the German word is ‘Magnetventil’

However, English documents (such as the example below from the Range Rover workshop manual) often ‘translate’ this to SV1, SV2 & SV3.

http://i260.photobucket.com/albums/i...psa774bbc0.jpg

I produced the images in my previous post months, possibly years, apart so I apologise for not being consistent!

The photo you attached is taken out of context. I was answering a query regarding the torque converter lock-up clutch pressure regulator solenoid (black cap) and was advising the OP that they could swap it with any of the other three black cap pressure regulator solenoids as they were all identical. I labelled these as A, B & C on the photo just to help him identify them.

The P0761 code is definitely for the MV3 brown cap solenoid i.e. the one on the end at the opposite side of the valve block to the ‘green cap’ main pressure regulator solenoid

Phil

Pins 12 & 16 are the two power supply wires that service all eight solenoids.

Pin 12 is the power supply for EPRS2, EPRS3 and EPRS5 and pin 16 powers the remaining five solenoids. The ATSG manual has got it wrong. They also have all the connectors identified back to front :

http://i260.photobucket.com/albums/i...ps21b79d4b.jpg

I wrote to them to advise them of this fact and they subsequently corrected it :

http://i260.photobucket.com/albums/i...ps52254046.jpg

Don’t worry about the 4 Ohms, you’re trying to test for an open circuit, but the correct figure is 26 to 30.4 Ohms at 20 deg.C. You’ll have to decide who to believe.

Phil

Hey Phil,

Talk about an authority when you are correcting the trade! +++

I didn't doubt your advice, I just come from a background of research and double checking and like to get my head arround what is going on!

Since i've got the spare dead car, I'm going to pull the valve body out of that one to work out what is what. It'll also give me spare parts etc. I don't know if it is wise just to swap the bodies then play with the problematic one or fix the problematic one. There is about a hundered thousand less miles on the problematic one and I know there wasn't much (if any) maintinance on the working one, though its an 02 model vs 98 so I don't know if there were any updates etc - I see that there is a Valve mod that ZF do if refurbing!

Thanks for all the help,
Lee

Yes, your ECX (1058 020 011) model was the last one to use the ‘old’ design for the upper valve body

http://i260.photobucket.com/albums/i...ps704590c5.jpg

but you can exchange the shift solenoids between it and your FBG (1058 020 030) model without a problem.

http://i260.photobucket.com/albums/i...1058427059.jpg

http://i260.photobucket.com/albums/i...1058427068.jpg

Phil

Hi Phil,

Ah....So you can't just swap the FBG (newer and working) with the ECX one (older, solenoid) ???

Would it fit, would it work, would it be an improvement ???

At one point I was contemplating a whole box swap!!!

Lee

Just for reference Late model Facelift S8's have extra bars across where there gearbox is, that and those last two obscured bolts are bloody tricky. I now have the gearbox sump loose. Just need to remove those bars with some ground down bolts (thanks speed bumps) and i'll have her open!

Interesting the ATF is a reddy brown. Don't know what the origional fluid is ?

Lee

LT71141 starts life with a light brown colour. Let’s hope no one has tried adding Dexron to your transmission........

http://i260.photobucket.com/albums/i...ps730f95b3.jpg

Phil

Glad to see you on here Phil!
Where is the best place to get the correct ATF and what is the part number I tried TPS and the guy was useless and tried to supply me with EP90 gear oil
Cheers Dave

I usually get mine from ‘theappledorn’ on eBay. It’s currently priced at £11.49/litre with free postage. The only alternative to Mobil ATF LT71141 is ZF Lifeguard Fluid 5 which is manufactured for ZF by Pentosin in Germany, but it’s hard to get hold of in the UK anyway.

http://i260.photobucket.com/albums/i...uardFluid5.jpg

These are the only fluids you should use in your 5HP24A. Never use fluids that claim to be ‘equivalent’ or ‘recommended’ or similar wording. The friction modifier pack used in the fluid has been developed specifically to give the necessary static to dynamic friction characteristics required for the correct operation of the torque converter lock-up clutch when operating in its ‘continuous slip’ mode

http://i260.photobucket.com/albums/i...ficientLUC.jpg

The ZF document TE-ML11 provides other car manufacturer part numbers for LT71141/Lifeguard Fluid 5 but I expect that all of these will be more expensive than £11.49/litre

http://i260.photobucket.com/albums/i...-ML1101_12.jpg

http://i260.photobucket.com/albums/i...-ML1110_04.jpg

Phil

The cheapest place I found Mobil ATF LT71141 was Opie oils. Worked out to about £9/litre when I purchased 12.

Hi Phil,

Brown would make sense. It also means that no one has serviced that gearbox in it's lifetime! About 230K on the box!

Any idea on what swapping the bodies would do or if it is possible ?

Lee

I don't know of any reason you can't put the newer valve block assembly on the older transmission. The differences between them are internal so the interface should be identical. I guess it's possible that the ECU runs a different calibration, but I doubt it.

Phil

Old oil
http://farm6.staticflickr.com/5475/1...6b402178_b.jpg
I swirled it arround the barrel up the sides to give an idea of colour

Sump removed - Oil filter still in place
http://farm6.staticflickr.com/5493/1...2faf7688_b.jpg

Valve Body still in place
http://farm8.staticflickr.com/7412/1...94517bfd_b.jpg

And the valve body is out!!!

There is a big circlip on the electrical connection which meant i had to slightly modify my pliers to open wider, but success.

The valve body from the top
http://farm6.staticflickr.com/5497/1...92805c33_b.jpg

Different angle
http://farm8.staticflickr.com/7354/1...c1329a9f_b.jpg

And the gearbox sans valve, just for interest
http://farm8.staticflickr.com/7363/1...eb752a3f_b.jpg

It's worth noting that there are differences between this box and the others i've seen online. Particularly that sensor and the wiring. You don't need to disconnect speed sensors as I guess it is all in the one that is sticking out the valve body!

Lee

This brings back memories from when I was refitting my valve block over Christmas. How did you find the process ulfilias? Did you carry out the work at home or on a ramp?

Hi There,

I run a small manufacturing company and we are pretty quiet at the moment, so I have it at work. Bought a pair of decent axel stands, though I also have jacks under and a couple of other saftey precautions. Would kill for ramps at the moment.....I did almost contemplat fitting a two post one in our loading bay, but they tend to run to about a grand and they would possibly get in the way of the forklift and the like

This morning I now have the PF car to the same point with the valve body out. This was easier to do as you don't have two bars crossing under the sump.

The oil is pretty clean, though it has only done about a thousand miles since it got changed and all in 4th or reverse!

The magnets have a bit of sludge, but no metal. However after removing the valve body, whatever that sensor is on the top jutting up (I'm guessing speed related) had 4-5 bits of 3-4mm metal stuck to it!!!

While I know the error is with Solenoid 3. That can't be helping

I will have a look better at what i can see inside the box after lunch!

Lee

OK.....I want to cry!

Spent the past few days removing a valve body and then today the big day, removed "faulty one" and fitted the "working one" and i've just tested things and NO CHANGE!!!

Still got Solenoid 3 Error :Confused:

So all that work for nothing:(

Well.. not for nothing.. have you checked the solenoid itself?

Could be that it's not the solenoid and there's something not happy further up the hydraulics (or a wiring problem)

Psyche - Changing the valve body, changed all the solenoids, and a lot of the pathways that could be blocked/problematic and a slug of the wiring loom (inside the gearbox)!

Basically from what I think I know about bits, it's not the gearbox at all. Could be TCU or wiring......Or there is something else causing the fault not registering or comming up as a symtom (though i'd expect more)

Lee

That is electrical fault.

Are you saying you did all that work without checking solenoid resistance at the plug first?

Hi ainarssems,

Alas not.....I guess that should have been done way back in the begining, before even the oil change. However I didn't know about it then! And due to circumstances - ie having the old car about and working on that first to see what was involved and speaking to gear box pro's saying it really needed a rebuild as they thought debris had fouled the sensor, it made sense to change the valve body, changing sensor, part of the wiring and any potential debris path!

Since I have the old car albeit a newer model, I just tried changing the TCU (gearbox ecu). Alas it faults with a couple of software errors, so is incompatible. It doesn't throw the solenoid error, but it exhibits all the same symptoms, so i'm not sure!

Interestingly while having a play (testing) I had my had on the gear selector and just turning the ignition from 0 to 1st position, before the car starts but electrics are on, there is a thump on the gear leaver and that's when the dashboard also errors, ie from clear, PRND432 to reded out, [PRND432].
This is before you go into reverse, neutral or anything!

Hi There

Well i used a long probe and a multimeter to trace out pin4 and pin16 on the TCM interface cable header

http://i734.photobucket.com/albums/w...31/Section.jpg

It looks like this and middle rown 4 sockets in from the left is pin4 and the 3rd from the right is pin16.

Testing the two together and I get resistance of about 27!

This means it must be the TCU then!

Shame I get 18249 & 18263 on my new model one DG vs BL :(

So it looks that solenoid and wiring to TCU are OK. I would crack open TCU and look for dry solder joints.

Hi There,

I opened the box up and couldn't see anything particularly obvious. It's all surface mounted and riveted into the box so you can only get to one side.

I have a 'new' one comming from A8Parts with the right code. BL It should be a plug and drive part +++

Will see what happens when it arrives

Lee

Hi There,

10 minutes work this morning to swap the Gearbox ECU and it seems I have gears again. Haven't taken her for a test ride yet, but I believe I am up an running!

Lee

Hope its a good result. I have learnt a lot from this thread though I hope I dont have to use it. +++

Fingers crossed for you fella, I do love a happy ending +++

Take the positives from all of the unnecessary work, in future you'll tackle gearbox problems with no fear at all ;)

Well done Lee thats excellent news! :respekt::yippee:

Hi There,

Well I went home with the novelty of working gears last night. I've noticed a bit of pulsing with things, but that could be down to having low oil as doing the filling procedure on axel stands, even at a fairly low level will result in it being out. Will be getting it topped and checked tomorrow on a ramp.

In doing this I've learnt a lot and cleared some debris from the gearbox and changed the oil which are all good things. I think if I was in a similar situation, i'd trace the box out first, however I didn't know that info until later.

I think If I had given it to Audi they would have charged a couple of hundered diagnostics and then a lot for the TCU, so i've come out pretty reasonable!

Thanks,
Lee

Hi there,

AND.......More bad news. Drove down to London on Saturday night and almost got to mys destination, slight over rev and [PRND432] comes up. Limp mode and 5th gear only. Parked up at destination. Came back and it had cleared. Pull away and limp mode after a brief bit of driving. Got home in 5th *SIGH*

Vagcom just gives me a 17114 - Incorrect Gear Ratio P0730.
I did also notice an engine speed sensor error intermitant, but cleared it.

Having a search and read i found this http://forums.audiworld.com/showthread.php?t=1755643

Now doing a quick bit of testing with vagcom.

state Eng Spd Input Spd Output Spd Gear
Idle 750 0 0 1M
1st brake 800 768 0 1M

Scoping while trying reverse and forwards, gets *VERY* little in the output speed regardless of input. You get 25-100rpm maybe. And when the input speed reaches 1500-2000 it hits limp mode.

I'm thinking that output sensor is out of whack as if you were getting slippage i'd expect to get more spiky readings of the output and a larger reading???

So.....Where is the output sensor on the S8 as it isn't inside the gearbox as per the BMW/LANDY

Lee

The transmission output speed is taken from a target wheel on the Torsen unit carrier by an inductive sensor.

http://i260.photobucket.com/albums/i...pse7104ab4.jpg

http://i260.photobucket.com/albums/i...ps05a5204d.jpg


There’s also an output speed sensor on the LH front driveshaft but I assume that’s for the speedo.

http://i260.photobucket.com/albums/i...ps45598539.jpg

http://i260.photobucket.com/albums/i...ps2ce05d8c.jpg

Unlike the 5HP24, the wiring for the output speed sensor of the 5HP24A is separate to the main transmission wiring loom i.e. it doesn’t pass through the 16-pin connector.


The input (turbine) speed sensor sits on top of the valve block assembly, of course.

http://i260.photobucket.com/albums/i...ps24b7b5ae.jpg

Phil

Phil,

Much useful information yet again :D

However having an extensive play with VCDS last night in the carpark i'm less convinced it is a speed sensor, though quite what is happening I am not quite sure!

After clearing errors and starting the car, limp mode is not engaged and everything looks fine.

You can get reverse nice and smooth, monitoring the sensors and input is high (800+) output is low (0/25rpm).

Changing to 1st with the brake and it's fine. Releasing the brake, no problems, but you don't really creep forwards like normal. Input is still high and out low. Adding gas very slowly and you get to 1200-1500 with still almost nothing on the output and then it hits limp mode. It's like it never even trys to engage 1st or actually move out of 5th!

Driving home in 5th last night I carried on monitoring and the input and output speed were both fine, which then says to me that it is not the speed sensor (in fact the output was often higher than input, which I guess is gearing).

I can check the solinoids and the power to them with the software if anyone has any ideas ???

Lee

Have you checked the oil level yet?

That would be the first place to start before you go digging deeper.