Whinning Diff

[jmspec]

After 10 years of building, i've just taken the super spec for a quick run around some work units (Private land).

To me the diff sounds like an old London bus.

I was told when I bought the kit from Robin Hood that this part was the only used bit but was reconditioned.

If it was reconditioned and not just repainted, what could the noise be and can this be easily fixed or is it a case of giving it to a specialist.

Jez

 

[Guest peter2b2002]

mm mm sounds like no oil in there

peter2b

[Guest zerorace]

might have oil but is it the right oil

[speedtripledan]

Recon by rh 10yrs ago, doubt it they gave me a similar bull snot story when i bought my factory built 2b in 2006 they said engine and gearbox were in good condition both were knackered! Company went bust days later

Edited August 19, 2015 by DanE

[Guest 2b cruising]

If oil level and condition ok, have you got all your sound proofing in place.

The weakest point to pick up transmission noise is through the gear change hole.

Put a good thick rubber gaiter on the gearstick and trap it under the floor.

You can always cover the rubber with a nice looking leather one to keep it looking nice.

Try this before you start thinking about changing transmission parts as any noise at all is transmitted right through the transmission.

On this same note, you should also be very weary about where the noise is actually coming from.

Diff wines usually alter massively as to what is going on.

ie, noise on over run might not be there when under load or visa versa.

My first tip about sound proofing is the best to start with before despair about cost, effort and extra time sets in.

Even a good thick coat of under seal inside the tunnel makes a big difference. Unless of course you are presenting in pristine show competitions.

Have someone else drive it passed you at the same speed you here the noise when driving yourself. You can then see if it sounds noisy from outside the car. If the diff is worn you will hear it then. If it is not worn, you won't hear it. Simple as that.

But I would still go ahead with sound proofing.

EDIT:- If the work units are on private land, but are open to the public 24 hrs a day, ie not gated and locked, normal road regulations apply.

Watch for the boyo's in blue mate.

Info only.

Edited August 19, 2015 by 2b cruising

[Guest 2b cruising]

Recon by rh 10yrs ago, doubt it they gave me a similar bull snot story when i bought my factory built 2b in 2006 they said engine and gearbox were in good condition both were knackered! Company went bust days later

There work ethic has not really changed even now Dan.

Still got problems with the dash they fitted.

Same ship but with a different coloured funnel.

[Longboarder]

 

There work ethic has not really changed even now Dan.

Still got problems with the dash they fitted.

Same ship but with a different coloured funnel.

If you are having problems with this then talk it over with GBS. At least initially. No one gets it right all the time.

 

As far as the initial post is concerned diff noise is a problem in our cars. The diff is solid mounted and its noise resonates through the car panels. Mine was fairly loud for the 20,000 miles my car did but was quiet in the donor sierra which I did a few hundred miles in. When I switched to an LSD it has been much the same. I don't know how loud your diff is or if you filled it with oil. Perhaps ride in another hood to see how it compares. Sierra diffs are pretty tough and don't break easily.

 

Nigel

[jmspec]

Thanks for all the suggestions.

The noise is still there when I'm stood outside the car

I will check the oil as it's been so long since I filled it I can't remember what type I used

I'm just assuming diff noise

It's a general whining noise that seemed to be behind me when driving

Jez

[jmspec]

The car was moving about 20mph

The only reason I thought it might be the diff is because when I drove it the noise seemed to be behind me more then next to me

[alanrichey]

It certainly sounded OK when we just started her up in neutral to check for the infamous Superspec 'rattle', so I guess the diff maybe the cause. Having said that, my Superspec makes so much noise and has so many rattles I don't think I would hear a whinning diff

[Guest Ian & Carole]

Don't forget the diff when in the Sierra was 8 foot behind you under a floor with sound deadening material, a back seat and a padded tunnel, soft mounted on the Sierra shell.

 

In the kit it is just behind you bolted solid to your chassis with little or no sound deadening.

[Guest peter2b2002]

If you can hear the dif your exhaust isn't loud enough

Peter2b

[jmspec]

Ive checked the oil today and the level is good.

The oil that I used was EP 80W/90 GL-5

I don't think its a sound proofing problem as I can hear it 50ft away.

I know RH told me it was reconditioned, but they also told me it was a limited slip diff.

Im starting to doubt both.

I jacked up one side of the car and could turn the wheel easily.

Im not sure if this is normal for a LSD.

Im starting to think that I should replace the diff but there's no guarantee that the next one will be any better.

Jez

[Bob Tucker]

Jack up both wheels.

Turn one.

If the other one turns the same way its an LSD

If it turns the opposite way, it aint.

[Guest 2b cruising]

Standard Sierra LSD were a hydraulic type and don't lock until under pressure.

I made this mistake on this matter on the forum some time ago.

I bought a second hand LSD to fit into mine to replace what I thought was a open diff on my car.

Like yourself I could spin one wheel without effort.

The new one I got will not spin one sided so I assumed all were like that.

I think it is only the plate type that lock both sides when not under effort.