Yet another gearbox thread

[slklite]

Hello guys, as you might know, I recently bought an Audi RS6.

The car has a gearbox problem that's not very common I think. I found this thread in which the owner (sheffielder)had similar symptoms.

viewtopic.php?f=2&t=107180&start=0

But he didn't explain what fixed it, except the amount of money he'd spent.

Here is what I experience.

The car drives fine when you don't push it too hard. When you push it hard, the gearbox gets confused on which gear it should choose...

For example, if you go slowly after a stop and then decide to push it, the car downshifts all the way to first gear and immediatly puts second gear (assuming it was in 3rd gear). It's like it didn't know it shouldn't have gone to 1st gear, but went anyway ...

When I'd get the car out of the garage, (pretty agressive uphill), if I don't do it in one shot, it's like the transimission disangages. Sometimes, it goes into limp mode (all letters illuminated) and sometimes it doesn't ...

Here are the codes the transmission throws :

17125 - Torque Converter Clutch
P0741 - 35-00 - Stuck OFF / No Power being transferred
17114 - Gear Ratio Monitoring
P0730 - 35-10 - Incorrect Gear Ratio - Intermittent

I can hear a whining noise at low revs. I thought this was the transmission oil pump starving oil. I decided to buy some oil and check the level follwing this procedure :

http://www.thectsc.com/5hp24a-transmiss ... procedures

I opened arround 36° and no oil came from the transmission, so I thought that it was missing some oil. I shut down the car so theat the oil doesn't warm up and goes above 40°. Problem is that when I did this, some oil started to come out. I immiediatly started the engine again and put the fil cap back on. I shut the car again to prepare myself to fill oil in. Then when ready, I started the car again, opened the fill plug, (noil came out) and filled about 1 litre, until overflow (engine still runing). Then I put the fill plug back in. I took the car down, and went for a test drive. Garage uphill, no limp mode, but the geard disangaged. I'd say I felt a slight change, but I don't know really ...

Anyway, I drove the car arround for a bit, and when I got home, I checked the transmission's fault codes. Surprise !!! Nothing !!!

I have to let you know that I have an ABS problem as well :

00283 - ABS Wheel Speed Sensor; Front Left (G47)
30-00 - Open or Short to Plus
01435 - Brake Pressure Sensor 1 (G201)
48-00 - Supply voltage
01119 - Gear Recognition Signal
35-10 - - - Intermittent

In ECU :

16885 - Vehicle Speed Sensor
P0501 - 004 - Implausible Signal - MIL ON
17535 - Fuel Trim; Bank 1 (Mult)
P1127 - 002 - System too Rich - Intermittent
17537 - Fuel Trim; Bank 2 (Mult)
P1129 - 002 - System too Rich - Intermittent
17482 - Mass Air Flow Sensor 2 (G246)
P1074 - 001 - Signal too High - Intermittent

These are the codes that come back. I don't have access to some modules in the car, like central locks, navi, HVAC ...

About the ABS, I didn't do anything. I thought about cleaning the ABS sensor and maybe switch it with the one on the other side. To be honest I don't want to buy a sensor, if I'm not sure, the problem comes from it, they are soooo expensive !!! Plus I've read many times, that it could be a ABS module problem !!!

About the sensor, the original reference is 4B0927803E Cheapest I could find is this one : https://www.fcpeuro.com/products/audi-a ... 4b0927803e

This one looks similar but has another part number : http://www.ebay.de/itm/ABS-Sensor-Drehz ... Sw5ZBWKcZq

What about this one ?

http://www.ebay.de/itm/ABS-SENSOR-VORNE ... dFhDvwCNEA

Seems to be the same as the previous one, but with different connectors, even though it's listed for the same cars ...

I don't mind taking one with different connectors and swap them, as long as I save a lot of money !!!

Thank you guys for helpin me out !!!

[Shoppinit]

Bad mixture and bad speed information will confuse the gearbox.

Sort out those first, then do an ATF and filter change and hope that the filter that is in there is the wrong one that is causing the gearbox to be starved of oil.

[Mɐʇʇ]

Has anyone done a howto on identifying the correct filter unambiguously? I've not seen one.

Bad mixture and bad speed information will confuse the gearbox.

Sort out those first, then do an ATF and filter change and hope that the filter that is in there is the wrong one that is causing the gearbox to be starved of oil.

[Gripper1]

There is a thread with pictures of it but it's difficult to find now with the milllions of threads about gearboxes.

But if the pictures can be found they deserve their own thread and put in the FAQ post in huge letters

After my own experience I think because of the complex nature of the gearbox you can get different codes masking what could be the same problem, namely oil starvation. Run for too long like this and it's bye bye gearbox and all attention is on getting the box out and a new one in without making a note what filter was in the original box.

Of course that doesn't stop garages offering the £4.5K gearbox change service when it could be something much simpler and cheaper to sort. Again I found this from experience!

[mavada]

http://audisrs.com/about62126.html

[lswing]

So you bought a car with failing torque converter, and failed or worn clutches in the trans from the slipping TC...my guess at least. Replace both and you'll be good! Give it 50-100 miles for the TC code to show back up.

[Gripper1]

Don't you think it's jumping to conclusions at a rather early stage?

All of the symptoms you mention could be a by product of insufficient oil pressure and flow, wouldn't you agree? The clutch packs rely on hydraulic pressure to maintain pressure between the plates. No pressure and there is nothing to hold the clutch packs tight against each other and you get slip and the symptoms and codes mentioned.

Funnily enough if you replace the gearbox and TC you get a gearbox with the correct oil filter pickup and correct amount of oil in it and amazingly it works. Something that can be done to an already fitted gearbox and can result in solving their symptoms for a lot less money. I worked in hydraulics during my airforce years, hydraulics are incredibly reliable but if you starve it of oil through whatever means, the system will not work.

From what I see on here there are way too many people who simply jump on the bandwagon and say take your car to MRC or Unit20 for a new gearbox along with the million of other things that need replacing 'whilst it is out sir' without the slightest amount of fault diagnosis. Then said owners post on here about how their last visit cost them more than the value of their car and they now need to sell

[blm70]

I also had the 'torque converter/clutch', 'no power being transferred' and 'checksum error' fault codes brought up by the AA then confirmed later on by the gearbox specialist I used. As I have already posted in other threads, the gearbox chap said to initially ignore the 'box and instead validate the codes i.e. they are supplied by the TCU which could be faulty. Turned out mine was. Replacing it resolved the checksum issue although the 'box & TC still required rebuilding - the TC being completely knackered.

FYI, I paid about £350 for a used genuine TCU with a guarantee which in theory could have saved me the cost of a full rebuild - this being suggested by the gearbox specialists - and is something I would not have considered, having resigned myself to the rebuild.

I didn't go to MRC/Unit 20 as so I understand they outsource the work anyway. I was almost ready to entrust the work to AmD (Essex) although I did a bit of digging and found the company that they use for the rebuilds. Saved a few hundred £ too.

[chunky79]

Don't you think it's jumping to conclusions at a rather early stage?

All of the symptoms you mention could be a by product of insufficient oil pressure and flow, wouldn't you agree? The clutch packs rely on hydraulic pressure to maintain pressure between the plates. No pressure and there is nothing to hold the clutch packs tight against each other and you get slip and the symptoms and codes mentioned.

Funnily enough if you replace the gearbox and TC you get a gearbox with the correct oil filter pickup and correct amount of oil in it and amazingly it works. Something that can be done to an already fitted gearbox and can result in solving their symptoms for a lot less money. I worked in hydraulics during my airforce years, hydraulics are incredibly reliable but if you starve it of oil through whatever means, the system will not work.

From what I see on here there are way too many people who simply jump on the bandwagon and say take your car to MRC or Unit20 for a new gearbox along with the million of other things that need replacing 'whilst it is out sir' without the slightest amount of fault diagnosis. Then said owners post on here about how their last visit cost them more than the value of their car and they now need to sell

Most people say take your car to either mrc/unit20 so they can look at it. I'd be very VERY suprised if they'd say you need a gearbox without any diagnostic work first.

[slklite]

Has anyone done a howto on identifying the correct filter unambiguously? I've not seen one.

Bad mixture and bad speed information will confuse the gearbox.

Sort out those first, then do an ATF and filter change and hope that the filter that is in there is the wrong one that is causing the gearbox to be starved of oil.

Hello, you can check here : viewtopic.php?f=2&t=104077&start=45

Thank you guys for your input. I'll try to sort the ABS problems first, and then a gearbox oil service... I'll let you know when I have some more info !!!

[slklite]

Hello, guys, I'm in the process of ordering parts for the geaborx service.

Does anyone know which parts should be replaced on the valve body when opened to be checked ?

I've seen on some posts, that ZF dortmund, changes the marbles inside the valve body and other parts depending on how used they are. I'd like to do something similar, but also change the pressure piston, and any other seal inside the valve body.

The best would be a valve body seal kit or rebuild kit.

Can anyone help me with this ?

Last time I drove the car, it was after I topped up the oil level in the gearbox. I noticed an improvement, but it's still not good ... I also noticed now that the gearbox gives a clunk / bang when engaging a gear. It's the same for reverse or drive. Before it was very smooth, I could only hear the change in engine idle speed ... I'm afraid something got worse. Do you guys know anything about this ?

Thank you.

[Mɐʇʇ]

Unfortunately not - I'm afraid the innards of an auto gearbox are rocket science to me.

[RichB888]

Don't you think it's jumping to conclusions at a rather early stage?

All of the symptoms you mention could be a by product of insufficient oil pressure and flow, wouldn't you agree? The clutch packs rely on hydraulic pressure to maintain pressure between the plates. No pressure and there is nothing to hold the clutch packs tight against each other and you get slip and the symptoms and codes mentioned.

Funnily enough if you replace the gearbox and TC you get a gearbox with the correct oil filter pickup and correct amount of oil in it and amazingly it works. Something that can be done to an already fitted gearbox and can result in solving their symptoms for a lot less money. I worked in hydraulics during my airforce years, hydraulics are incredibly reliable but if you starve it of oil through whatever means, the system will not work.

From what I see on here there are way too many people who simply jump on the bandwagon and say take your car to MRC or Unit20 for a new gearbox along with the million of other things that need replacing 'whilst it is out sir' without the slightest amount of fault diagnosis. Then said owners post on here about how their last visit cost them more than the value of their car and they now need to sell

Most people say take your car to either mrc/unit20 so they can look at it. I'd be very VERY suprised if they'd say you need a gearbox without any diagnostic work first.

and just how do you propose they could do that Chunky without removing the box and inspecting its internals? Worn bands or incorrect hydraulic pressure both result in the same symptoms. Kind of reminds me of a question I asked quite recently for this very reason hey. Which is why it would be advisable to take it to a gearbox specialist as opposed to just a very well respected Audi RS specialist

[chunky79]

Yey, I have my very own stalker, hope you're a pretty young thing.
How many cars have worked worked on? How many do you think either the above specialists have? They will be able to give you a good indication of what's up with the car. Both of the above could rebuild a box, I've done getting onto around 100 so they wouldn't have any problem at all.
If the box needs stripping, the box needs stripping, but it could just be low oil level or blocked filter, or incorrect filter.
Do you buy presents or just stalk on the internet, keyboard warrior style as you put it?

[Mɐʇʇ]

Fight! Fight!