Vibration problems!

[gadgets]

So here is the problem, I tow a trailer 90% of the time for work, all works well. The rare occasion I unhook the trailer and go for a drive I get really bad vibrations/ shaking movement through the whole car at 80kph.
Its almost like driving from 0 to 80kph on a new freeway and then from 80 to 90kph it feels like Im on a badly corrugated road( not exaggerating). Only happens without the trailer,
05 d22 with 265000ks on it.

 

[Old.Tony]

My gut instinct is to put the bloody trailer back on!

That's a strange one. I wonder if it's a bad uni or a drive shaft that's slightly out of balance, but the suspension with the extra weight of the tow on it is enough to smooth it out ...

How about dropping a couple of bags of cement in the back and go for a drive?

 

[gadgets]

My gut instinct is to put the bloody trailer back on!

That's a strange one. I wonder if it's a bad uni or a drive shaft that's slightly out of balance, but the suspension with the extra weight of the tow on it is enough to smooth it out ...

How about dropping a couple of bags of cement in the back and go for a drive?

Haha, I said the same to my self, put the trailer back on haha!
Your idea about putting some weight in the back, Im not sure there is any room! its got a fridge, 2 extra batteries and any remaining space has various tools etc.
The canopy has a steel roof rack that is usually loaded too.( Im guessing
by now you can tell the car has had a hard life)!
Its still been a faultless car, nothings ever broken, only ever had oil and filter changes,not bad considering the life its had.
Thanks for the suggestion though.

 

[ShortyNavros]

Gadgets you have a 2" suspension lift installed? I dont have one myself but from reading a couple of other threads it seems some people get vibations at certain RPMs and to correct that they use a castor wedge to correct the pinion angle or something? See here http://www.superiorengineering.com.au/product_info.php?cPath=31_3119_51_345&products_id=5059

Sorry mate this is only a guess.

 

[fourocker]

Generally speed related vibrations come from tyres, wheels or hubs. If it's drive line related it would usually show up at certain revs through each gear, maybe more pronounced in some gears more than others, I'm saying usually but not always but this is the theory I would start with, oh and even a failed shock could start to behave better with a trailer on.

 

[Lawry]

Putting the trailer back should lower the rear end.. depending on what leafs you have. Lower rear end means less tailshaft angle/uni joint angle. Go under the nav and give each uni joint a good shake on both planes.

my 2cents

 

[Saitek]

Drop the tailshaft it only 6 bolts by memory and check the unis off the car as you can get a better feel through the angle of motion on them. You could also while you have the tail shaft out tape up the end of the extension housing with a plastic bag and take it for a quick drive in 4 wd to see if the vibration is still there.

 

[unkn0wn]

when i had my 2inch lift installed, the guy told me the HD leavs would cause driveshaft vibration at slow speeds if the ute is unloaded.
dosent really help you at all.

but i would also check the uni's on the tailshaft, and your rubber center bearing is not warn, as alot are.
but id also sugest getting your wheels re-ballanced, or at least checked.