Little Help: Surging / Vibrating

[Necrum_McDirk]

I've just had some body work done after a close encounter with a light pole.

The commodore now seems to have developed a Vibration/Hum at 80km/h and to be surging at 20km/h and 40km/h?

In my limited knowledge I beleive this is probably going to be the gear box or drive shaft.

Was wondering if any one had either, a clue as to what it could be?
or a way of finding out that will not require the loss of to much cash?

any help would be much appreciated.

[Boonz]

the vibration/hum could be a bent rim or off balance tyre...did you slide into anything going sideways??

[Necrum_McDirk]

Did come in side ways, but she's sitting on four new rims, and had the allignment done.

I had the same thought, but figured that if it was anything to do with the tires them selves it'd show up constantly.

[sircruisealotVS]

is this vibration/hum only felt/heard at and above 80k's/hr? try getting your car up to a little over 80 going up a slight incline, not a big hill, just preferable not flat, then back off with your foot still lightly on the throttle...if the vibration gets worse as your doing this its probably your torque converter slipping.

[Hillerus]

Did they balance they tyres and rims.....? They might be new, but that doesnt necessarily mean shit

[Scooter79]

Could also be damaged engine mounts. I got hit from behind really hard and it actually broke the engine mounts even though the drive gear was untouched. Engine was left sitting on the cross member.

[Boonz]

what model is it??? you could of bent an axle also

[vl rb30]

conver slipping i bet

[5speedcalais]

might be able to eliminate the converter being the problem by asking u a simple question. is it auto or manual lol u did say it was manual didnt u that means cant be the converter

[andynogo]

I know I probably shouldn't admit to this...but...I had a turbo RX7 which may have 'kissed' a kerb once and developed an annoying hum at certain speeds. I replaced the rear axle bearing on that side and it was fixed.

Jack your car up and lift one wheel at a time, preferably starting with the side that hit first. Turn the wheel by hand- you may notice a rumbling noise from the bearing.

If it's not that then it'll be any of the other things mentioned- out of true rims, gearbox/engine mounts stuffed, bent propshaft.

In fact, for that matter, could even be the centre bearing /CV on the shaft. I'd still be looking at wheel bearings first- much cheaper! Good luck.