Rear diff/haldex

[antonws3]

Had a reconditioned rear diff fitted to my car in January under warranty from where I purchased my 57 plate s3. Ive recently been told it needs replacing by my local garage after hearing whining noises. They have now sourced me one of a tt I believe with 59k. I was wondering could there be another issue that would cause the rear diff to get damaged or just seriously bad luck?

 

[paddy]

My diff went at 55k miles, i just bought a new one for £3600, many people said buy reconditioned or used but i cant see a lot of point fitting a 50k miles used diff, i just took one off... there was no obvious reason for the bearing failing but since i had mine replaced i have seen more and more posts like yours with the same problem.

 

[Jps3290]

The key is regular oil changes of the diff not just the haldex unit/box. I do both at the same time every 20k along with haldex filter.

 

[HHS3]

The key is regular oil changes of the diff not just the haldex unit/box. I do both at the same time every 20k along with haldex filter.

The does diff oil get changed during services or major service intervals like every 30/60K?

 

[paddy]

My diff had 3 oil changes in 50k miles, bottom line is you have a naff bearing with poor tolerances from start no amount of oil changes will help it. Audi buy in diffs and Haldex from the same people that make them for Skoda and Ford so just because its Audi doesnt mean its any better than some cooking models.

 

[antonws3]

The garage where my car is have sourced me one for £700 with 59k supposedly. Can't afford a new one so taking a chance and thinking of just selling the car now

 

[ch1z64]

Now is there any truth in the Generation 4 haldex meant to be serviced every 20,000 miles as it only has a strainer where the Gen 2 has a filter and it would be every 40,000 miles .Just my mechanic mentioned the 20,000 as i have a 59 plate S3 and the Gen 4 in it

 

[Jps3290]

Gen 4 has a filter. I changed mine about 8 months back. Change oil & filter every 20k.
Most people don't bother changing Haldex and diff oil.

You can buy it from here: https://www.haldexrepairs.co.uk/shop/filters/generation-gen-4-filter-kit-vw-audi-seat-skoda/

Audi don't list them.

 

[ch1z64]

I recently had the dreaded 00448 fault so popped it to the mechanic who drained the oil changed it out and the checked the strainer gauze for any Sh*t but nothing there and oil looked good for doing over 30,000 but now be getting it changed out every 20,000 .

 

[Jps3290]

Mines a 2011 170 TDI and had the filter in i provided link for above.

You run the risk of clogging up the fine filter on the pre charge pump if the haldex filter clogs up with gunk and it burns out. You won't get any warning light on the dash it usually noticeable as you are then only running in FWD mode.and traction light will flash in the wet when pulling away hard.

VCDS will show the error code though. By keeping oil changes with filter every 20k it should prevent pump burning out which costs about £280 for the part.

 

[ch1z64]

Mines a 2011 170 TDI and had the filter in i provided link for above.

You run the risk of clogging up the fine filter on the pre charge pump if the haldex filter clogs up with gunk and it burns out. You won't get any warning light on the dash it usually noticeable as you are then only running in FWD mode.and traction light will flash in the wet when pulling away hard.

VCDS will show the error code though. By keeping oil changes with filter every 20k it should prevent pump burning out which costs about £280 for the part.

Thanks for the info and i will be keeping on top off it and watch out for that flashing light but so far nothing .
The fault we think could be a mass off different things so will do a scan once or twice a month just to see if it keeps coming back if so then look at the filter .

 

[Jps3290]

448 fault code is a pre charge pump fault. You .might have been lucky and fixed it with new filter and oil. Sometimes it can also be the connector has corroded but usually is a the pump is knackered.

If u have vcds you can run a pre charge pump test and should hear it start and stop.

 

[ch1z64]

that will be the next thing i will do once i put her back together . it could be a few things after doing some researching due to it being a intermitted signal fault it could be some oil or greasey stuff on my wheels and showing when i pull away or might even be something to do with a greasey road or wet road

 

[Jps3290]

If your front wheels spin in the wet with a 448 fault.it will be the pump. It lots ad 'intermittent fault but is logged each time the haldex clutch tries to engage when the front wheels loose grip and can't engage as the pump is running and pressuring the rear oil up.

 

[ch1z64]

If your front wheels spin in the wet with a 448 fault.it will be the pump. It lots ad 'intermittent fault but is logged each time the haldex clutch tries to engage when the front wheels loose grip and can't engage as the pump is running and pressuring the rear oil up.

Thanks for all the info , as i am new to the Vcd's could you do a step by step for me so i can test to see if pump works . i gather it would still be ok to do without having the Calipers on as there away getting refurbed . Thanks

 

[Jps3290]

At work right now but can do. Yea can do it while stationary and engine doesn't need to be running as it's an eletric pump, Just need the ignition on.

 

[ch1z64]

cheers beers just give me a shout when you can thanks again

 

[Jps3290]

You need to go to module 22 (AWD) within VCDS and you will see a drop down list called Output Tests. Within that will be one labelled something similar to 'Pre charge pump'. I cant remember exact name. If I remember correctly it will perform 4 tests, clutch engagement/release and pre charge pump etc. When it does the pre charge pump you should hear a buzzing/electrical noise as the pump runs. If you hear nothing or just a clunk the pump will be knackered. If it is you most likely wont' hear the haldex clutch engage because it won't have the oil pressure with the pump being knackered.

http://www.ross-tech.com/vcds/tour/out_test.php This link shows the output tests for module 1. Just basically follow the guide but connect to Mod 22.

 

[ch1z64]

You need to go to module 22 (AWD) within VCDS and you will see a drop down list called Output Tests. Within that will be one labelled something similar to 'Pre charge pump'. I cant remember exact name. If I remember correctly it will perform 4 tests, clutch engagement/release and pre charge pump etc. When it does the pre charge pump you should hear a buzzing/electrical noise as the pump runs. If you hear nothing or just a clunk the pump will be knackered. If it is you most likely wont' hear the haldex clutch engage because it won't have the oil pressure with the pump being knackered.

http://www.ross-tech.com/vcds/tour/out_test.php This link shows the output tests for module 1. Just basically follow the guide but connect to Mod 22.

thanks man will do today and lets hope i hear that buzzing noise