I searched for other posts about vibration problems but didnt find one like mine.

I was getting some vibration before when going down hills and leaving it in D, when popping it into OD the vibration would go away as soon as it shifted. That problem seems to be getting worse. Now my car will start vibrating at normal speeds and also the transmission seems to be shifting softer. I also notice when changing gears from R to D that it takes a second or two to shift, where before it would do it almost immediately and I could get out of parking lots very quickly. The vibrating seems to be a combination of rpm and speed, because I get no vibration if I accelerate hard until I get to higher speeds; but the shift to OD from D helps reduce the vibration.

Can anyone diagnose these symptoms? Thanks a lot.

-Dave

 

Can anyone take a stab at it?

 

matlock,

this subject has been done to death,although thats not to say your question is not valid.Ive researched into the general vibration problem for years and my car has suffered from it in a minor way in all my 14 years of ownership.See below for what mods ive done and then realise that none of this has made any difference.I think that we have to just accept that vibration in an inbuilt problem of our cars

cheers

PM
·



Below are a list of the modifications carried out over the 14 years of ownership.

Engine Mods
========
Dart Sportsman Heads
Comp Cams cam and roller rockers
Cloyes true roller timing chain
Headman headers
SLP Cold Air Induction kit
SLP T.P.I. throttle body airfoil
Accel Fuel pressure regulator
Hypertech Chip
SLP 3” Stainless Steel Exhaust system(no cat)

Transmission
========
B&M 700R4 and Convertor
B&M Megashifter
Aluminium Propshaft
New Crown wheel and Pinion
New Half Shafts

Brakes
====
Baer Racing Corvette ZR1 brake kit modified for T/A
13”Discs with Z rated pads

Suspension
=======
Koni Adjustable all round
Hotchkiss Panhard Rod,Trailing Arms and Strut Brace
Edelbrock Lowering Spring Kit
PST Polygraphite suspension bushes throughout
South Side Eng.Subframe Connectors


Wheels
======

Image Wheels 10”x18” Rears with Toyo Proxes 275/40x18” Tyres
And 9”x18”Fronts with Toyo Proxes 245/45x18” Tyres

Interior
=====

Cobra UK Seats with rears,door panels,centre console and dash pad and arm rests covered in grey leather and alcantara to match
Centre console plate,Radio surround Plate and Gauge Trim Rings all made from
Billet Aluminium with Billet Aluminium Window Switches
Electric Mirror Switch Hidden
New Headlining and Sun Visors from Year One
Alpine Head Unit,CD Changer and Amp
Plus Six Speakers

 

Thanks for the information on your car.

This can't be normal since it never happened before. I could get my car up to 180km/hr and no vibration. Now it will even do it at 60 and worse at 100. Can worn struts cause this at different speeds? I also notice that when I'm pressing on the gas pedal that it takes away most of the vibration.

 

Two things to check are transmission mount (may be broken), and u-joints (don't have to be "loose", but wear can cause wierd vibrations).

 

Both of those are NEW on my car and it still vibrates...starting right at 75mph and gets back from then on... Feels like it will shake the car loose when I let off at that speed or higher too.

 

Check the tailshaft bushing in your transmission. Once worn, this usually causes vibration on decceleration. You can crawl under the car and see if there is any movement where the driveshaft yoke goes into the tranny. The best way to know if any wear has occurred is to remove the tailshaft and inspect the bushing visually. Hope this helps.

 

Did that too. My busing has only been in for 1,000km's. I got the tool from snap-on which made removal of the busing very easy (just had to remove the driveshaft)