Hello guys!

this is my first post here,i have an skoda octavia 2012 2.0 4x4 manual 103kw

almost 400.000km pased

but i have a problem with 4x4

 

when i drive my car,after 10/15 minutes of driving,more than 60/70kmh i start hearing a noise from the back and it looks like comming from rear diff,i have changed haldex oil, rear diff oil 2 times,filter but its still the same

when im more than 100kmh the noise its pretty high

 

I also checked the wheel bearing but they are in good condition
 

here below is the video (100kmh plus)

because the forum does not allow to upload more than 10mb

https://files.fm/u/y94cjuubm5

https://files.fm/u/f47dmdu2d6

Edited 4 August, 20241 yr by Argjenddre

Have you checked the rear propshaft doughnut coupling? 

2 minutes ago, skomaz said:

Have you checked the rear propshaft doughnut coupling? 

Yes,i have changed it but the noise is the same

What did the oil look like that came out of the Haldex and the diff?

 

Has the haldex and diff had previous maintenance?

.

6 hours ago, SuperbTWM said:

What did the oil look like that came out of the Haldex and the diff?

 

Has the haldex and diff had previous maintenance?

Im not sure because the car service history its in sweeden and i do not understand nothing

but both oils very pretty dark and the filter not in good condition

Edited 5 August, 20241 yr by Argjenddre

Can you tell it’s definitely coming from the rear?

 

The car also has a transfer box which transmits the power 90 degrees down the propshaft, if you know it’s not that I would maybe look for a second hand or recon rear drive unit (Haldex & diff). 
 

Also might be worth changing the oil in the front transfer box as a preventative measure if you can. 

9 hours ago, SuperbTWM said:

Can you tell it’s definitely coming from the rear?

 

The car also has a transfer box which transmits the power 90 degrees down the propshaft, if you know it’s not that I would maybe look for a second hand or recon rear drive unit (Haldex & diff). 
 

Also might be worth changing the oil in the front transfer box as a preventative measure if you can. 

Yes definitley its comming from the rear down,you can hear also in the video

Yea, it sounds quite bad on the video, I think you know what needs to be done!

It will be the left hand (smaller) differential output shaft bearing, its a standard bearing but apparently the oil seal is unobtanium, I think I may have found a source but the description makes me wonder if it could be the pinion oil seal or the one for the RH shaft, here is a link.

 

https://www.trodo.fr/bague-d-etancheite-differentiel-corteco-01033862b

 

The job is relatively simple if you are old school and have rebuilt differentials before, easy in fact as its unlikely you will need to play around with the CW&P meshing or pinion pre-load but after decades of manuals saying that gearboxes and final drives cannot be repaired without special tooling and expertise most have swallowed it and there are only a few people worldwide who will work on these units despite their ridiculous replacement cost.

 

I will replace mine within the next few years, its noisy after my mistake draining the wrong oil but has remained constant, if I knew the oil seal was correct I would bite the bullet and do the job to benefit earlier from a quieter ride?