another whining gearbox

[340 Nate]

hi all, having a issue with my volvo, ive done the search already and cant find anything related to temporary whining.

went out yesterday for a little drive, a hour into the drive i was in 5th gear and de-accelerated and could hear a whine, never had this before by the ways, drove carefully trying to force the car to make the noise again as it had dissapeared???.

went out today and it seems when im violent with initiating gears it wants to whine but its not making this noise all the time? , if you drive it gentle after it whining it will stop which seems funny to me, would low diff oil make it temporarily whine?.

when it does whine, no matter what gear you put it in it will still make same whine which makes me think it could be diff related?, it does leak aswell btw.

cheers

Nathan

[Speedy88]

Low oil and/or old box. Change the oil or top it up if you've already done that recently. If it leaks from between the box and diff it might be worth taking them out one day and putting a new gasket in.

[volvosneverdie]

Do you only hear the whine when youve got a woman in the car?
I used to hear whines from the passenger seat area at high speeds, but only when I had the GF in the car.

Hope this helps.

[pettaw]

If the diff is leaking you can bet it'll be low on oil level so check and top up asap and then get a gasket kit from Mac when you get a chance, but top up first, because the diff doesn't hold much oil, 2 iitres approx, it doesn't have to leak much to get dangerously low.

[340 Nate]

my car got a little excited by the looks












just walked outside now and huge puddle of diff oil, this proves that welded diffs wont hold out forever, i bought the volvo years ago with it from bennett so i cant garentee the weld, something inside has blown part of the cast casing underneath out though, about 2-3mm hole!!.

[340 Nate]

forgot to ask, does the gearbox and diff share same oil or can you separate the units without draining them?

cheers

nathan

[Speedy88]

No they have different types of oil and your gearbox will spill everywhere when you try and take it out - drain that first. It's a real bitch of a job but you should only have to do it once ever again if you do it right.

[340 Nate]

ah nice one, will crack on with that hopefully soon, have another volvo to revive really so i should do that and use that for a while, need fuel lines doing anyways so time for her to come off the road for a little while me thinks and get many other bits fitted too

cheers

Nathan

[SteveP]

Ooops! Ali's did something similar to that too... Chemical metal?

[pettaw]

lol @SteveP. Nah you'll have to find a new diff mate. I bet one of the weld blobs has separated from the spider gear, gone whizzing round the casing and destroyed half the stuff in there, and even if it hasn't the fact that one weld blob has come off means that the others won't be far behind.

[340 Nate]

i think pettaw may have it correct, i drove it today and thought the diff was not locked properly, felt like a mild bit of play but i only think that because it was not scrubbing that much on full lock.
glad it went on my driveway rather than me driving it and locking up on me!.

cheers

nathan

[Ride_on]

Seems you have the cause but make sure you use the right thickness of gasket between diff+gearbox on rebuild. A slow down whine can be caused by incorrect clearances in the gearbox bearing that stick out of the gearbox and rests on the diff housing. The gasket is part of the calculation for the shim clearance, its all in the manual.

I once repaired a 340 which the dealer had given up on, they could not figure out what was wrong and decided it was a 'characteristic'. Neither could I until I reassembled it with a new gasket kit and realised they'd used the wrong one (for the front of the box) when the diff had been replaced. I made a nice little profit on that car.

[Speedy88]

Interesting, so gasket paste would be no good really? Just woundering as the gaskets are now NLA at Volvo. (I had the last 2, sorry)