Is this Gearbox / Diff Whine?

[Sammo 2550]

Have had this nasty whine (kind of like a rattly supercharger) in lower gears under heavy load above 3k rpm for some time, seems like it has been getting worse.

Nothing in neutral, easiest heard when the windows are up, sounds like it is coming from in front of me.

Sadly sounds worse than it does in the videos, ugly noise.

Just put on new tensioners and pulleys (which were toast) but no improvement.

Next port of call is to change the MTF and diff oil and then guess I'll be taking it to a pro.

Pretty sure gearbox is ZF310 (car was manual swapped prior to my ownership and has ZF stamped on the box housing).

[B.M.W Ltd 950]

You can't diagnose recorded noises on a computer. It can even be hard when your sitting or driving in the car. A stethoscope, two people and a hoist is often required to locate noises.

[Sammo 2550]

7 minutes ago, B.M.W Ltd said:

You can't diagnose recorded noises on a computer. It can even be hard when your sitting or driving in the car. A stethoscope, two people and a hoist is often required to locate noises.

Thanks, agree; will change the fluids and if that doesn't help get it looked at. 

[B.M.W Ltd 950]

If it's the diff or gearbox it's too late changing the oil. The damage is already done

[Sammo 2550]

Little update in this. 

I spoke to Bellars Motor works about this who recommended talking to the Gearbox Factory in West Auckland. 

Had them do a good road test and then later booked in for a hoist check. 

They think the manual conversion was probably done with a single mass flywheel which is just inherently noisier / transmits more gear noise and didn't seem to think its an issue. 

So comfortable with that I guess. 

[KwS 2429]

My old E36 with single mass flywheel rattled like a bag of bolts at idle in neutral and both that and my M328i rattled/chattered at low rpm when under low. Seemed fairly normal from what I read.

[B.M.W Ltd 950]

Did you have a sprung center plate ?

[Jacko 2158]

Switching to 75w90 penrite progear on my SMF conversion solved the noises when the stock viscosity got warm (with a spring centre clutch)

[KwS 2429]

2 hours ago, B.M.W Ltd said:

Did you have a sprung center plate ?

Unfortunately it's too long ago for me to recall what was in the manual converted car, but its was a hodgepodge of bits thrown together by a specialist at the time. It wouldn't surprise me if the parts were wrong, there was a lot wrong with that conversion.

[Sammo 2550]

2 hours ago, Jacko said:

Switching to 75w90 penrite progear on my SMF conversion solved the noises when the stock viscosity got warm (with a spring centre clutch)

I thought it was best to stick with GL4 for these boxes? 

[Jacko 2158]

Just now, Sammo said:

I thought it was best to stick with GL4 for these boxes? 

This is a GS6-37BZ as in the 130, which is supposed to run the MT2 life time fill GL4 nonsense. Mine just has 75w90 progear, there is a GL4 progear product as well.

Online downside ive seen is its pretty clunky for the first few minutes on real cold mornings.

[Sammo 2550]

2 hours ago, Jacko said:

This is a GS6-37BZ as in the 130, which is supposed to run the MT2 life time fill GL4 nonsense. Mine just has 75w90 progear, there is a GL4 progear product as well.

Online downside ive seen is its pretty clunky for the first few minutes on real cold mornings.

Ill give it a go, does not get too cold in Auckland and I always make sure the car is warm before getting on with it. 

Edited June 12, 2020 by Sammo