bad shudder driving me mental... can't find the answer

[nado_271]

hey guys.
I've got a pretty bad shudder/vibration in my vn berlina and its driving me nuts because i don't know where it's coming from.

Reco engine about 3 months ago so i'me pretty sure its not engine related.

Whilst cruising at about 2000rpm its a consistant on and off shudder about 1-2 seconds between each vibration.
my mechanic has checked the engine mounts tailshaft bearings and i've double and triple checked the harmonic balancer to make sure i put the right one back on.

can anyone give me any insight??
could it be loose torque converter?? or something else.

only other thing i can think of is about 3000km after driving new engine was on fairly long distance drive and my o2 sensor went at 4am on a sunday so i had to drive another 500 km's home with it running rich and fairly rough. could this have damaged anything e.g. crank?
any feedback would be much appreciated

cheers

[Red Ranger]

Check your exhaust system mate... When i first bought my vn s2 bt1 it had the same sort of shudder, it was the cat vibrating against the under body

[bluvn]

An unbalanced wheel can cause vibration at certain speeds, see if any wheel weights are missing -look for a clean patch on your wheel where a weight might have been. or look for a dent in the rim.

Check tail shaft it tight at uni joints and look for any damage.

As mentioned above check your exhaust.

If you think its coming from the engine check the error codes...cheers

[Denso]

where is the shudder coming from... e.g. through seat, through floor pan, through shifter, through steering wheel, from back or front of vehicle? does it get worse when turning corners? i dont belive running the engine rich is going to damge it unless it was detonating for 500km's lol check the water pump pulley is tight and the water pump is not old/ leaking (i know its a reco engine) i had a supra and the water pump was buggered nd it sent a pulsatiing vibe through the car.

[VPSENATOR5000i]

I had the same frustrations, after the trans company inspecting the trans, then the mechanic suspecting possible worn camshaft lobes. A few months later whilst getting a WOF I had the rear transmission mount replaced (NB: Mechanic & Trans comany thought was old but looked fine), now there's still a small vibration so cam is probally worn as engines done 260K, however the bad shaking that started arond 1500 rpm & just increased disappeared.