Pinpointing a driveline vibration...

[sillycar chick]

Guys I have a vibration in 51LII thats giving me some greif and proving quite difficult to diagnose. I'll give you the whole run down as this isnt an easy one...

About 3 months after having the W58 in, I hit some problems driving home from work one day. A loud squealing with the clutch pedal in, and then after a while a squeal pretty much constantly. I was pretty certain it was a throwout bearing, but the bearing was only a few months old. I got the car home and let it sit in the shed for about a month and a bit cos I was too busy in the last month of my uni degree and full time work to touch it. So weekend before last I could finally have a look, and found the gearbox bolts had vibrated loose (one of which was missing alltogether), and the lower half of the gearbox had come away from the engine. Ok, not cool. So pulled the box out to see what the damage inside was, and the

clutch and throwout bearing were fine, but the spigot bearing was completely stuffed. I guess the thing got really loaded up with the input shaft hanging on to it for dear life. So it wasnt too expensive to fix and got the gearbox back in. But why did all the bolts vibrate loose?

The only thing I could think of was the tailshaft. I put new uni joints in and marked the sides to line them back up the right way, and figured if it needed balancing i would know about it soon enough and get it done if it needed it. I didnt feel any real vibrations in the car before that bearing went. And the clutch and flywheel were both new and custom jobbies, so it was probable they were already balanced.

So last wed night I finally got the tailshaft back from being balanced, and put it in, and went for a drive for dinner and to wash the celicas. Everything felt good and it drove fine. Same deal thurs morning, but halfway to work it just started

vibrating out of the blue, no real warning, no gradual buildup that i can recall. Since then weve been busy collecting our new toy from Rocky and only just been able to look at the car again last night. There are no weights on the tailshaft that

have dislodged, and i cant find any signs of weights missing off the wheels. I have tried a different set of wheels on the back and still no difference. I cant guarantee the wheels i tried are balanced but I guess I should notice a difference in

the vibrations. I have checked tailshaft bolts, gearbox mount bolts, engine mounts, pinion flange but on the diff, there is no noticeable movement in any wheel bearings, and there is no noise associated with the vibration. Ive also checked the pinion flange for movement and nothing.

The car is up on stands and we have run it a few times in gear. The vibration is noticeable in gear, and dissapears when you take it out of gear. It seems to get worse as the speed picks up, and it was noticeably worse at higher speeds on the road. It makes it hard to diagnose if its a bearing problem, as there is no noise. Normally noises can help you pick where its coming from.

Im reluctant to pull the gearbox back out or pull the diff out unless im sure its the problem, im over gearboxes for this year. But the tailshaft was balanced by a reputable workshop, and seemed fine, and its really odd that this vibration came on so suddenly, but maybe it was there before and I didnt notice it.

So my question is where else should I be looking? Gearbox? Diff? Somewhere I havent thought of yet?

[oldcorollas]

does the vibration happen:
in gear when rear wheels spinning = yes
out of gear with foot on clutch?
in gear with foot on clutch?
in gear with rear wheels spinning, and then clutch in and let engine idle, with wheels still going?

vibration same as engine speed = engine, clutch, flywheel, insput shaft or mainshaft of box.
road speed = output shaft of box, tailshaft, diff, wheels..

has the diff shifted? ie the pinion is pointing at significantly different angle to the gearbox axis? either up/down, or side to side or both?
that would cause the unis to spin at slightly different speeds = vibration..


where the gearbox bolt definitely down up tight before? gearbox mating enough so the input shaft slides into the spigot bearing?

[thechuckster]

phasing of uni joints on tailshaft is correct?


edit: just to add some detail ... when I installed the rebuilt (new bearings in the uni's plus new centre bearing) tail-shaft into the red rocket it came in two bits and I stupidly joined them up out of phase... and I got a novel form of chassis vibration (it felt like bad clutch shudder) that got worse from 80kph upwards.

[wilbo666]

Could it be the clutch? Perhaps the clutch driven plate is 'bent' due to the gearbox hanging off it when the bolts came out...

The fact it was fine for 3months, suggests a lot? Maybe new vibration is a result of the bolts coming undone which was a result of them not being tight enough perhaps? Just throwing out ideas...

Also is the centerbearing correct way up (sounds like you have a 2 piece shaft?)?

And as suggested, uni alignment / phasing


Cheers
Wilbo

[sillycar chick]

Nah nah its a one piece tail shaft....
Wilbo what exactly is the clutch driven plate?

I got a wheel balance and rotate on Sat morning and drove it fine sat arvo, sunday and monday, but today the vibrations are back again. To answer OC's questions, it seems to be there pretty much regardless of whether clutch is on or off, in gear or out of gear. It does seem to dampen the vibration a little when you put the clutch in or take it out of gear but its still there.... and it seems to be a lot worse when decellerating, braking or using the gearbox to slow it down, it pretty bad accelerating also, and cruising in 4th gear in particular, but I have felt it in pretty much all gears..... and its pretty bad, I can feel it through the floor and the gear shifter. I dont want to drive it like this it almost feels like its straining at some times, it almost makes ya feel sick driving it!

This is so frustrating if only i knew what it was I could FIX it, but I cant figure it out and havent had very much time at all to play with it lately

[oldcorollas]

but is the vibration correlated to road speed, or engine speed?
ie speeds up and slows down as you go thru the gears, or just continues to increase with road speed?

[sillycar chick]

its really hard to tell but i reckon its more related to road speed than engine speed, cos it doesnt matter what rpm im doing the vibrations are there, they seem to get a little worse wtih road speed but are particularly bad accelerating and decelerating (independantly of rpm), and moreso than cruising at a particular speed....

[wilbo666]

Nah nah its a one piece tail shaft....
Wilbo what exactly is the clutch driven plate?

Just a way of saying the friction plate part of the clutch system. The bit that the gearbox input shaft does in

Cheers
Wilbo

[oldcorollas]

are the driveshaft bolts to the diff loose?

[sheepers]

some things to try,
replace the bush that the splined spigot on the end of the driveshaft goes into, in the back of the gearbox (i don't know what this is called) the drive spline runs inside it. i had one that was really worn and it would vibrate like you say, started really suddenly too.
TBH i don't even know if W series boxes have these.....(the one i did was an auto)

the other thing you could try is borrow a gearbox and stick it in, try a different one??
bit of a bastard i know but might help to eliminate/pinpoint a problem??

sheepers.

P.S there is a place down the road called the gearbox factory, they know their shit, I'm going to be going past today so i could stop in and ask them???

[Cuzzo]

Is the throwout/bearing/clutch and everything a factory item?

Or are they parts from different cars?

[sheepers]

i stopped in at the gearbox factory.
the rear input shaft bush is indeed a replaceable part and has the ability to cause vibration if its worn.
you need to take the rear housing off the gearbox (PITA because of the gear linkage) or you can use a internal puller to remove the old one.
he told me that toyota A40 auto's have the exact same bush if you have trouble finding one and he sells them for 13$+gst.
sheepers

[Turdinator]

Subscribed.

I have a similar vibration at the moment. Has been there since i replaced the following items...
1. Tailshaft
2. Diff center
3. Head Gasket

However i believe i have multiple problems. I think my timing chains are worn and causing vibrations on engine braking. I think the diff might need a look. And the tailshaft i have has been powder coated and i've been told this can lead to bending. These are all areas i will be investigating or replacing anyway. I'm curious to see what else you guys come up with.

[sillycar chick]

Wilbo:
I couldnt visually tell if the clutch friction plate was bent, but i didnt run a straight edge over it. The clutch operates fine, thats about all i can say about it really. Thanks for the link you sent me too.

Sheepers:
Yeah my dad mentioned a bush on the output side could be there and could be worn, hence why I asked wilbo for a w58 manual Im going to have a look in the manual tonight. I have another 2 gearboxes in the shed one of which is a spare anyway, im just over pulling gearboxes in and out for the time being, and im not 100% the spare gearbox is ok because it was in a car that ate a power pole and had locked up as a result (we did get it free before we stripped the car though, before the crash it was working fine). Thanks heaps for going to speak to the gearbox shop hey I really appreciate it.

Cuzzo:
Throwout bearing was supplied with the clutch kit, which is an exedy kit which I bought from a reputable clutch shop who are the qld agent for exedy. When i installed the w58 about 3 months ago i put in new clutch, flywheel, throwout and spigot bearings. I think i mentioned that in the first post but yeah its a long post to read

Thanks guys for all your help!

[allencr]

drove it fine sat arvo, sunday and monday, but today the vibrations are back again.(

Is this only happening on one particular road? Weather change from dry to hot & humid, or something else?
Bad & broken & worn mechanical parts don't usually get unfucked after they've gotten fucked up and they aren't going to work intermittently for very a long time if any time at all, while some electrical parts will.
Otherwise I'd only think it is something electrical or placebo effect or from different road harmonics & surfaces.


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Edited for assholeness.