Help - Squealing Sound

[MarkBzero]

Well another Stoneleigh missed, kit car has broken down on M6/M42 junction.

Horrendous squealing noise, sounds like metal on metal, not 100% sure where from but somewhere at the rear. Thinking diff rather than wheel bearings, no humming or play when tested. I supposed it could be driveshafts.

Doesnt happen on local roads, only high speed roads so heat and expansion must be at play some where. Also on rolling road yesterday and no squealing noise, although couldnt hear anything over rollers and engine revving. So maybe straight line driving is OK, maybe the extra weight in the car, beer and camping gear.

Lot of ideas at this stage, I would welcome any ideas!

Still going to Stoneleigh in tin top tomorrow.

[jaimo]

Sorry to hear mark i am not there yet till tomorow so keep fingers crossed not let me down yet even though all probs had

Are you taking ur laptop tomorow incase cant get mine to work just want to check megajolt working

[nelmo]

Sorry to hear that mate - hope it's sorted soon.

 

But this is why I have no interest in getting my car on a RR - I've just read too many people having problems during or after a RR session.

[theduck]

Honestly, you are more likely to have a problem with a car that needs setting up by not going to a dyno then you are tonhave a problem caused by a dyno!

[Longboarder]

 

I've just read too many people having problems during or after a RR session.

A rolling road session stresses a car but only within parameters it should be built to cope with. Certainly overheating has to be watched out for and is likely to occur and need to be managed. However if a car can't safely manage a RR session it probably can't reliably manage being on the road at all.

Mark, tough on the 'breakdown' and disappointment but the RR session is probably innocent and it's the weight of the beer + tent.

Edited May 5, 2018 by Longboarder

[kevin the chicken]

I always said if my car couldn't manage a rolling road session I wouldn't be confident using it on the road. Mine has been on the rollers twice without problem. I would rather find out a problem when it was in a shed off the highway than 100 miles from home on a motorway. It ran better afterwards both times and last time gained a big chunk of power that I would never have found. Don't be scared, get it on the rollers.

[MarkBzero]

Well plan A did not work. I stripped the hubs and noticed a rubbing mark on the driveshaft as suggested by Steve. I made the hub carriers slightly larger to eliminate any chance of contact.

 

On the test drive wit and without weight loaded everything was OK.

 

On my way to Coventry motorfest the squealing sound returned, had a passenger onboard and he believes the noise was coming from the diff.

 

So going to replace diff (I was going to during winter anyway), current have 7 3.36 diff and MT75 gearbox.

I have a post somewhere about the pros and cons of lsd but at this stage not interested in upgrading driveshafts and brakes yet.

So should I;

1. Get the diff refurbished, new bearings and seals,

2. Upgrade to suitable lsd,

3. change diff ratio during both above, whats the best diff ratio?

Thank you in advance.

[jaimo]

Dont fit the lsd mark give it to me

seriously lsd all the way

[tractor]

LSD every time I can now do perfect doughnuts

[Bob Tucker]

The only perfect doughnuts come from Crispy Creme...

[DeanRudkin]

+1 for lsd

[Andi]

+2 for LSD maaaaaaan

[Longboarder]

3.62 LSD. ST170 will pull it easily (mine does). 3.9 will leave you overgeared and a 3.14 will take the sparkle away too much.

Are you sure you have diagnosed the problem and got the right answer?

[MarkBzero]

3.62 LSD. ST170 will pull it easily (mine does). 3.9 will leave you overgeared and a 3.14 will take the sparkle away too much.

Are you sure you have diagnosed the problem and got the right answer?

Honestly I am not sure, I have checked bearings, enlarged hub carriers so only diff or shafts left. I have never heard of driveshafts squealing, clicking yes but not squealing. Tempted to throw in a cheap second hand Sierra diff.

[MarkBzero]

LSD looking like the preferred option. Any good places/recommendations in Midlands that could fit it?