Hi all, 

 

I have a pulsing humming noise coming from the car. It has increasingly got louder over the last 3/4 months. Originally I thought it was wheel bearing but managed to get these changed for free via the dealer (they couldnt road test it after as it was wet to check for noise!). So, secondary inspection suggests noise coming from the rear diff. You can hear it when coasting too and it increases in pitch the faster you go. I took it to another specialist and they have also spent some time trying to diagnose and concur its not wheel bearings but it could be rear diff - the "query" is when they approached the specialist they use for rebuilding differentials, this company said they had never heard of a bearing going in the diff. Before I go and commit to having it taken out, stripped and rebuilt looking for a cracked or worn bearing, has anyone had any similar experience and has it turned out to be this? Thanks, Ryan

This might be completely irrelevant, but have you checked the rear tyres for sawtoothing on the inside shoulders?  I had this problem and the noise coming from the rear got gradually worse, I mentioned this at it's first service and after only 4000 miles the inside shoulders were badly worn.  A 4 wheel alignment improved the noise a little and the wear didn't get any worse.  When I eventually replaced the tyres I made sure to get the tracking checked again just to be sure, with the new tyres the car was transformed.

 

 

Edited 21 June, 20197 yr by shrikep15

Thanks - Tyres are new last November and I had tracking and balancing checked two weeks ago no difference. Garage had it up on ramp / tested on road and could hear something using stethoscope that was more noticeable on one side to the other so they are erring on a bearing in the diff being the culprit- the problem is you have to commit to taking it out and apart to prove or disprove...

I have had a yeti with rear diff problems nothing else.

Has it had a haldex oil change?

They could just drop the oil see what that looks like maybe change it. You could be hard pushed to see anything with a stripped down diff.

Also disable the rear end check its not transferring from the front (on ramp)

I take it the noise on ramp is the same as while test driving?

The Haldex oil is fine, had that checked too. The noise isn’t as noticeable on ramp because there is no weighting on the chassis. I found this last night and the noise is pretty much the same in my limited opinion, so I’m going to ask them to check as it directly points to a pinion bearing - https://youtu.be/hORUAwDRSCg 

 

My Vrs 4x4 also whines slightly from the rear diff and it varies with speed. It also gets more noticeable with increased wear on the rear tyres. The rears wear slightly faster than the front which means they have slightly less circumference so rotate quicker than the front axle and wind up the transmission everso slightly from rear to front. In theory the rear axle should be disconnected at speed but there will always be a slight resistance there which drags in the driveline either positively or negatively.

Tread depths side to side are equal, No sawtoothing of the tyre treads.

 

If you have deeper tread on the fronts, Swap the tyres front to back and there should be a drop in the amount of noise heard.

 

Its a Octy 4x4 thing. Less NVH over the posher VW Audi siblings means more noise in the cabin. Sudden loss of rear diff noise means 4x4 function is not available...!

Edited 22 June, 20197 yr by BigEjit

Thanks, I’ll get my indie to check but main dealer also tried swapping wheels with another Octy and still had noise. This particular noise was not present 3 months ago. If it is present on a different set of wheels, isn’t tyres or wheel bearings we do seem to be eliminating things but unfortunately it’s a slow process! 

On 22/06/2019 at 09:14, MacmillanSkoda said:

Thanks, I’ll get my indie to check but main dealer also tried swapping wheels with another Octy and still had noise. This particular noise was not present 3 months ago. If it is present on a different set of wheels, isn’t tyres or wheel bearings we do seem to be eliminating things but unfortunately it’s a slow process! 

Hi, 

I have a "bearing like" noise aswell on the back, changed the tires and the bearings but no luck. Thing is that it comes from the differential now, which 2-3 weeks ago didn't, really new noise. 

Did you manage to sort out your problem? 

Turned out it was exactly what I thought but each mechanic wanted to try other things first (to try and save money!) ... It was two bearings in the rear differential. Had it stripped out and rebuilt. If you've ever had a wheel bearing or tyre problem before you know how it feels and sounds. This was something that got worse over time and the pitch changed depending on speed so I always 'knew' it was going to end with £££! Still, wheel bearings done (garage never charged me) and haldex oil done (got that done free too as it ended up being done twice!) and diff rebuilt so should be good for another 100k!! 

I used this video to highlight to mechanic what it was sounding like to me - https://youtu.be/hORUAwDRSCg they even took a stethoscope to the car when driving and up on lift to try and identify but got there in the end... 

With mine the noise it's a lot more noticeable round 20-30 mph( need to do the alignment aswell, today or tomorrow). But last night at the mechanic, we had the car on the elevator and even at low speeds you could hear it badly. He checked if it has oil in it and it does. I don't know what to do now. Is it worth it going back to Skoda to tell them as it's 14 k miles after the service? Will they do anything about it or is it just my own problem ? 

On 09/02/2020 at 09:40, MacmillanSkoda said:

Turned out it was exactly what I thought but each mechanic wanted to try other things first (to try and save money!) ... It was two bearings in the rear differential. Had it stripped out and rebuilt. If you've ever had a wheel bearing or tyre problem before you know how it feels and sounds. This was something that got worse over time and the pitch changed depending on speed so I always 'knew' it was going to end with £££! Still, wheel bearings done (garage never charged me) and haldex oil done (got that done free too as it ended up being done twice!) and diff rebuilt so should be good for another 100k!! 

Hi, 

How much did itncost to recondition the differential? 

Thanks!

If memory serves it was about £700 (after spending money on first haldex oil change for initial diagnostic which didn't show anything, rear wheel bearing changes which I got for free and some other coupling which was about £450)