ANOTHER Vibration!

[6G74]

So of late we've heard of a few people with vibrations, im up their with puttin in my 2c with the general stuff but now im in the same boat

About 2 years i noticed a slight vibration at 90kph only, above and below and it didnt exist, its slowly gotten worst with time, now it there between 75 - 105 or thereabouts. It seems to be a traditional tailshaft type thing, 4 to 1 of wheel speed sorta thing etc.

I put 2 new (genuine) unis in, i had it balanced, made no diff, then i removed it again, put a plug in the back of tfc, locked the centre diff and drove it, vibration completely gone, silky smooth. Convinced its still the tailshaft i had it rebalanced, it came back fine again (different place).

So its diff related or transfercase related - the slip joint in the transfer has a bush in the extension housing to support the output shaft etc, it seems to have a little clearance with the tailshaft in, can be moved about 2-3mm in all directions - so im told this is insignificant enough to cause my problem. So be screwed if i know....

Any surgestions?

[bounceferret]

sounds like the problems I had

If not the tailshaft balance and not the uni's, I'd say either check your transmission and tfc mounts or possibly tires.

[Lambie]

Had a problem in our other car - the falcon (EL station wagon) thought it was tail shaft etc - turns out (after a lot of stuffing around) and after thinking about gear box mounts etc - I'm convinced that it is the tyres fault - BUT - I had them balance by another mob because they were nearly new, but the vibration was still there.

Tried high tyre pressures (re out of round?) at 45 PSI - no difference.

After rotating tyres front to back - the vibration has gone ????

We may have a warped rim (?) but the location of individual tyres/rims seems to make a difference.

This may not add alot to the discusssion - but I'm extremely surprised by our outcome - I'd almost have bet the crown jewels that the tail shaft was our problem ( how wrong I am!)

Cheers
Lambie

[6G74]

But my issue is that if i drive the car with the shaft out there is no vibration at all - this to me rules out tyres and means driveline, which only leaves diff or tfc...???? maybe???

[Loco]

search for post "VVV Vibration" that should cover my findings on this

[marquis]

Not the tires?

I have driven vehicles with dodgy tires (ie out of round or tires that you cannot balance) and it feels like a massage chair.

[6G74]

Not the tires?

I have driven vehicles with dodgy tires (ie out of round or tires that you cannot balance) and it feels like a massage chair.

If this was the case though, wouldnt the vibration be there all the time??

[marquis]

No it seems to kick in at >70-90kph (ie at a particular speed).

I remember Goodyear tyres on a Falcon - hit 103kph and you could see the bonnet vibrating up and down.

Travelled in a lux ute with recycled tyres (retreads) and over 60-70kph it was like sitting in a massage chair on "high".

[mr_grumble]

Not the tires?

I have driven vehicles with dodgy tires (ie out of round or tires that you cannot balance) and it feels like a massage chair.

I can back these claims up with personal experience with two different vehicles.

I purchased some 'cheap' tyres, Simme from memory for both the Paj and our Starlet at the time. Both within 20,000km developed a noticable shake, Starlet more so. Went through the same diagnostics, bent rims, tailshafts etc and had given up the fight to find the problem.

Changed tyres in due course for a more reputable units and wholaa, vibrations in both vehicles gone.

The vibration was a very strange vibration only occuring at low (<20km/h) and at high speeds (100-125km/h) and felt like it was a side-to-side wobble more than anything. Soon before I replaced the tyres I took them off the vehicles and slowly rolled them on a flat surface and watched them wobble from side to side due to the deformations

[6G74]

No it seems to kick in at >70-90kph (ie at a particular speed).

I remember Goodyear tyres on a Falcon - hit 103kph and you could see the bonnet vibrating up and down.

Travelled in a lux ute with recycled tyres (retreads) and over 60-70kph it was like sitting in a massage chair on "high".

I dont mean all the time as in through the speed range - when the tailshaft is removed, and the car is drivin in 4hcl there is no vibration at all, anywhere, not at 90, or anything... if it were tyres, removing the tailshaft should have no effect i woulda thought?

[CRH]

Mate, this is exactly the same as mine except the speed range was 90-105.

I did the same thing, removed the tailshaft, plugged the t/c and the vibration was gone. And how good did it feel! Felt like I was getting somewhere.

It seems the bush in the t/c can wear. It cannot be sourced separately. You have to buy the rear extension from Mits. There are none in the country, takes 3 weeks to come from Japan and costs about $295.

You could try and have the bush pressed out and a new bush made, this would be far cheaper, but what if you don't get it right. This would only lead you to think that wasn't the problem.

I think I'll be getting the housing, after all the stuffing around, I want it right.

[6G74]

I wouldnt have throught the diff could create my issue, which leaves as you say the bush in the extenstion housing or something with the center diff in the tfc.

With the shaft in i have about 3mm clearance in the slip joint moving it in all directions - i thought it seemed excessive but have been told its not significant enough. Im fairly sure i can cut the old bush out and press a new one in on the car without removing the extension housing - if i go down this path, and its successfull, i can have another bush machined up for you if your interested?

I put different wheels and tyres on today just to eliminate that possibility, made no difference.

Im going to remove the front shaft tomorra, and put in 4hlc with hope of eliminating the tfc...

[Loco]

With the shaft in i have about 3mm clearance in the slip joint moving it in all directions - i thought it seemed excessive but have been told its not significant enough.

It's supposed to have nil movement, a snug fit, thats why it's a bush, it has a lube hole in the top and grooved to the front and rear and the transfer case chain throws oil up in to it,( do you have movement in a big end? No.) so if it moves replace it, it's gone, the hardening has worn away, Check my remedy in the post title vvv vibrations, do a search ($20 fix).

[CRH]

I have bee told that the play in mine is normal as well.

This makes no sense to me. Something spinning at probably 4+ times wheel speed is not going to need much play to cause a problem.

Mine can vibrate under hard accelerartion too. Like a buzz through the drivetrain that disappears once you are through the torque peak.

I would have thought the extension would need to come off to get the size right for the bush. Local CBC thought it would be about $20 for a bronze replacement.

6G74, I would love to know if you get it sorted. Let me know how you go.
Where abouts are you? I'm in Sydney.

[pagerow]

Gees I'm dumb, can anyone tell me how to find loco's vibration thread?