Syncro noises? I bloomin knew it!!!!

Post by **toomanytoys** » 20 Jul 2006, 08:46

Now I have heard the term "hum in the bum" and the propshaft rattle/zing. But whats normal?

I seem to have a hum/whine/ring, in 2nd and 3rd and to start with in 4th.. but by the time 85mh (50mph ish) it seems to disapear (and not coz its too fast to hear..) on over run down hill, it does a similar noise but touch the brakes gently and it goes away..
cant feel any vibrations and the oil levels are ok (box has fresh oil) although the mag sump plug did have a hairy metal particle "wig" but no
lumps! but who knows how long the oil had been in there!!
The propshaft will rattle and zing loudly if I change up a bit too soon.. ie 1st to 2nd and the revs drop to 1700 ish.. so I dont...

Was planning on the drive to Belgie and across to the uk and back home with a load of gear, 1500k; all motorway, so was gonna drop the propshaft as I know the VC is a little stiff (tight 1st gear turns are not easy) so would see if its the propshaft making/accentuating the noise..
Oh and thats on road tyres.. not my "tube train" offroaders.

Post by **HarryMann** » 20 Jul 2006, 08:55

Diff hum/whine and that ringing are two different things... and from the sound of it

neither usually a problem, just a nuisance. Prop-off will remove ringing, maybe not diff whine.

Diff whine usually centres around 50-55mph on a 5.43, louder on overrrun, bit higher speed with higher diff ratio I imagine. Like most noisy diffs, they'll usually whine their way to 100,00 miles and beyond but if its the transaxle's diff, maybe another matter

Post by **toomanytoys** » 20 Jul 2006, 09:41

Mmm.. as you said before...
It didnt get worse in the 900km I did at the weekend, if anything it seemed quieter on the return road trip... (but the locker was stuffed full of camping gear)

To me it sounds like a diff whine, not, bad just its there and making me worried..
Its got 143k km.. nearly the 100k miles.. it also has a fresher "green" gasket on one part of the box, so I assume it may have been apart for something in the past.. It changes smoothly and easily. Will drop the prop later and see what changes.
Might change the box oil again.. but what an a*** with the protection bars in place.. I found some fully synth to G52 spec, supposed to be the updated version!! to see if much "hair" has grown on the sump plug.

Post by **HarryMann** » 20 Jul 2006, 11:14

You mean the transaxle diff, so ifits got oil in it, then not much else you can do. If its a really dry sound in 1st and 2nd (like an big lorry in ultra low gear, winding its way up a hill?) to me, thats not too good. Diff whine will generally just be in 3rd or top and often sounds like a 'Whah, whah, whah) a constant speed and notices most when lifting off and coming down through the 50's... graunchy dry sound in lower gears - maybe not so good

Post by **Aidan** » 20 Jul 2006, 14:33

don't worry, a little whine is fine, in first and second and third, even some noise in top. Could be anywhere on the drive train, 2 uj's, 8cv joints and two diffs. If it changes ok and stays in gear don't panic. Service and inspect all the joints as and when you can, but if vc is tight then prop out is good plan, enjoy.

Post by **toomanytoys** » 21 Jul 2006, 07:29

Cheers
It isnt a dry sound to me.. just a whine.. chnges smoothly with no crunching.
Will drop the prop and change the oils again.. and see how it goes.. maybe you can have a listen when we meet up Beaker?

I am trying to get a price for a health check from the french syncro box specialist, better to do it before it eats/breaks something.. but maybe it has!!!

Oh and its a 1992 model.. so one of the last, so ought to have all the little mods done anyway!!

Post by **Diamond Hell** » 21 Jul 2006, 07:37

Blimey, this is better than a Rolf Harris cartoon.

Have ya gissed what it is yit?

Post by **jen** » 21 Jul 2006, 18:47

Seriously Si - if anyone can judge from a written account of an unknown noise, hats off to em for being a complete genius, or just happening to use the same version of onomatopoeia as you.....

I find the Syncro to be incredibly noisier than a 2wd van, but find the numbers 18-22 helpful, especially when choosing something like Feeder or The Automatic. Avoid wishy washy pop, by all accounts it'll never drown it out....

Post by **toomanytoys** » 22 Jul 2006, 09:16

I realise that Jen.. but as you say.. its a lot noisier than a 2wd.. thats the kind of answer I was looking for, then maybe mine is alright.. wont know until Aidan has a drive of it.. or it breaks something!!!

Post by **HarryMann** » 24 Jul 2006, 22:58

Bet its just a front diff howl.. pretty sure of that... with the overtones still ringing in my ears after 250 miles of it today, yuk its a racket, but that's all it is.

Post by **toomanytoys** » 25 Jul 2006, 10:25

Jeez.. must be loud if its that annoying!!

Post by **HarryMann** » 25 Jul 2006, 11:59

It is loud, like as loud as a loud diff howl, quite common... below 40 its OK, but at 55-65 orrible, starts to go away at 75, but she overheats oil and buzzes held up ther too long - had the buzzer coming on yesterday when revs dropping below 3100 at one point - in fact the revs at which the buzzer starts when slowing down is a very good oil-temperature gauge

Anything below 2100 and she's a relatively cool baby!

Post by **toomanytoys** » 25 Jul 2006, 16:20

you nutter!!

Post by **toomanytoys** » 26 Jul 2006, 14:41

Dropped the prop..
No scrubbing in tight turns..
Noise still there on accel and seems to be a little more pronounced in 4th and noisy for longer, ie still hear it even at 65-70 whren it had gone quiet after 55 ish..
No noise at all on over run.. where it did whine a bit before..

A well, suppose it will either get worse. or go bang.. the next 3 weeks and 3000km, will test/break it.
Thanks for your help.

Post by **toomanytoys** » 31 Jul 2006, 16:13

Drove the 650 km at a nice 90-100kmh bloomin traffic and accidents turned it into a 9 hour trek... box seemed ok for the first 400 odd km, then a gradual extra noise crept in..

This morn after a nights rest and cool down.. it didnt seem too bad until I got to 85-90kmh.. noisey...... I think it has eaten itself....... Still quiet on overrun, so prob the pinion bearing given up.. gonna check the oil again, may get some fresh and change it, but I think damage already done..

So gonna need a box and pretty quick as i'd rather not blow it completely so it can at least be rebiult..

pretty much any working box would do at this time.. will it last another 400km till I get somewhere I can change it though!!!