I know the heading says speed but that is obviously relative to what you drive and in my case it is a Blue Marlin Cruiser. I have a weird vibration on my cruiser that happens at three distinct times. when you reach 120km/h, or slack off on the throttle to cruise along basically not accelerating anymore. When I go over a large bump in the road and the suspension extends. The vibration feels like you are driving over rumble strips on the road. I recently fitted new tyres and the vibration was not as pronounced but still there. Propshafts, diffs, shocks, engine mountings have been checked and a castor correction kit ahs been fitted. Any ideas at this stage would help.

Regards
Graeme

How much lift do you have?

Check front panhard bushes.

I would say caster or bad cv's.

Edit... WHoops. I ment to say uni's not cv's.

Also backing off throttle at highway speeds and coasting, could mean worn front diff too. Its more often than not a combination of all things. a little here transfers to a little further down the line.
You say things have been checked. lots of these things look fine and check out ok but they arent their best. these are pretty old vehicles now. I put off doing uni's in my other car because I "checked" them and had comeone else check the ( a pro) and they were fine. Had them done anyway and man, the difference was like night and day

your handbreak could need new return springs.

i know my 80 get some good shakes up when the hand break is left on,
so if you have streached return springs and they are not pulling the shoes away from the drum, it could have a simmilar effect.

just a thought

Quick answer,

Check your spindle bushes on the front axles, I had one spinning in its seat and the other one as dry as a dead fox.

The noise you described was what I was getting, and in the city it scared the crap out of pedestrians.

Changed mine over for the Terrain Tamer needle bearing and bush cap rather than the original sold brass set up for under $80 and have not heard the noise since.

Also gave me the opportunity to check the condition of my axles, CV's and grease levels inside the swivel hubs.

Really need to know what lift you have. how are your wheel bearings, from the replies you got, there is alot that can cause it. One way to check uni's is to drop the front tailshaft out and run with the centre diff lock in and see what it does, you can also remove the drive plates from the front axles and see if it makes a difference.

Andd offtopic, thanks to Baldman for hinting me in a direction of a chattering noise that I have in my 40th. Everything else has been redone and checked, but I reckon you're on the ball there. Sounds like an outer race spinning in its housing, scares the shite out of anyone near it when it does it and puts a grinding feel through the car. Mine will have the needle roller bearings in it as it is a later model, but I reckon they could be dry and are now stuffed.

Cheers
Corry

How dry is a dead fox? What if it was only recently killed, it may not be quite as dry? How about if it had been there for a while and it was raining?

Sorry, I was bored

sounds like driveshaft unis mine has done the same only since i had the lift done!