Vibration between 55 & 60MPH

[graham_fuller]

Any suggestions.
At 55-60,65 MPH the car gets a vibration which remains even when you take the car out of gear.The vibration is much more severe when the car is going down hill decelerating.Under load going uphill it is less severe.You can't feel it coming through the steering wheel.
Cheers,
Graham

[HARKO]

I would almost be certain your tailshaft either needs balancing or new uni joints, Get under and physicaly have a geek and see if there are any dents knocks or scrapes to the little bugger and see what you come up with .
The vibration you feel is coming through the seat right ? If you dont feel it in the steering its normaly rear tyres which would slowly increase and be consistent or wheel bearings which should be noisy around a corner or the T shaft. Good luck - let the mission begin  

[nicko]

also check tyres for deformed tread from separation and if tailshaft all looks good then check that all bolts on clutch pressure plate and flywheel,are tight

[normd]

Hi Graham
       I'd have to agree with Harko (hard to believe  ) I remember as a kid , my dads car had exactly the same problem , "Tailshaft out of Balance" , but don't do what he did , "sold the car & bought the next model  :-/ .

  Norm

[gp]

Graham,
For quick tailshaft removal techniques, ask Tailshaft_Tim for instructions. I've seen him remove his tailshaft in 2 seconds flat while doing about 80mph!!  

Cheers,

Graham Pryce

[nicko]

first FC i ever owned had exactly same problem when i went to chop springs down i found one was 1 inch lower than the other,but been young i cut shorter of them  two coils and the other 3 coils,could not remove jack so had to drive it off and found sump could only clear coke can if i turned it on its side,but remarkedly the vibration at 55 to 60mph went away,very unlikely that your car has this problem though, loose bolts will usually show at certain revs not mph so would expect them to do it in each gear,but the tyre problems can and do show up in funny places making it hard to tell where problem is.

[customFC]

Hey Graham.
I had the same prob once. Turned out to be uni joint. That's where I'd start. If it is a uni, change them both, as they are probably of the same age.
Regards
Alex

[craiga]

Graham,

I'm with Alex. Mine was exactly the same, especially noticeable when you backed off from around 60 MPH. Replaced both uni's and all fixed.

Cheers,

Craig.

[RET]

Graham,

There's some sort of harmonic that kicks in at around 100kph - I remember driving down to the '91 Adelaide Nats in Faecal and the car would vibrate like a bastard at around that speed.  Tony Tobin fixed me up with a replacement tail-shaft and it was smooth 120kph sailing home.

Like the others say, check the unis first, but have a look at the tailshaft if they don't turn out to be the cause.

cheers
RET

[gp]

Hi guys,
Also in Tailshaft_Tim's repertoire is a little number called "How to get the back wheels 8 inches off the ground without using a jack". Ask him about his experiences, and I'm sure he'll share them with you. Replacement uni joints (and quite a few other bits!!) also fixed Tim's problem.

Cheers,

Graham Pryce

[Spinner]

My FC Van (sold years ago) had that same problem - at 110 mph indicated (5700rpm on the tacho) the tailshaft broke, catapaulting the car so tat I could look across the rooff of the car (XD) we were overtaking.  Mate who was driving kept his foot in it even then, I had to tell him to let it idle as we stopped bouncing and braked to a smooth but shaken stop.

What was left?  The two bolt on uni caps on the diff yolk and a series of tears punched through the floor across to the right.  The gearbox stayed in the car because the linkages & speedo cable held it there.  The gearbox sheared off at the front input bearing as did the main input shaft.

The car was towed home and a replacement box & tailshaft from an EK Sedan at Dollar Wally's (Milperra) was fitted (by me) to get me going again. Two new uni joints featured.

[Sarge]

Graham
           5 will get you 10 that it s your tailshaft or uni joint more than likely the front one or you could have a look at rear wheel bearings they dont alway make a noise when on the way out. They have be know to cause the said problem. Also have your wheel balance checked all these thing could be it or a combination of these. Happy hunting and good luck. Oh also rear shocks but the vibration should back off under deaccleration with them.

Regards
Mark

[Al]

Good old Dollar Wally, I used to work with one of his sons and I only paid 50 cents for parts. Lucky Me!!!!!

  Cheers Al

[zulu]

A lot of older trucks & cars used to have a simple bracket up the front that would catch the tail shaft if the front uni packed it in.
Got many a rare part at dollar wallys,   is he still there?
or gone to the great wrecking yard in the sky  
Gary

[normd]

Smiling here  
    Already got a tailshaft strap , Part of the Reg's for racing . Anyone who's got a bit more power than usual "Should Put One On" . Saves a lot of Heartache , worry AND Final expence , doesn't have to be big or expensive. Breaking a front uni would be an "Exciting Ride" , but I wouldn't like it  
    Graham , Let us know how you get on.
   Cheers
   Norm

[2brite]

Have you tried  looking at your nuts  

Wheel nuts that is  :-/

Are they tight ,also i agree with the tailshaft and uni;s

Cheers  2brite

[nicko]

Hi,its been a week since you first asked what and why,have you had a chance to trace vibration?
very keen to find out what it was.
reguards Nick

[graham_fuller]

Nicko,
I have started.I replaced the front Uni on Saturday and it seems better but still there.The next is to replace the rear Uni.Will keep you posted.
Cheers,
Graham

[nicko]

carefull ,dont get carried away changing everything unless there is an obvious fault as it can end up costing a small fortune,by the way How long since car had a front end alighnment as any and all front end faults can cause vibration and its also money well spent every couple of years or 5000 km

[ACE]

Graham,
I'm just wondering why did you only replace the front uni .
While the tailshaft was out i would have replaced both !
ACE