Truck Wiggle

Not shocks. Shocks only provide up/down damping but add no lateral stability.

Springs, bushings and their connection points are probably to blame.

Have you asked a Nissan forum if this is common? Maybe they all wiggle.

Not necessarilly true. If one strut or a shock goes bad it can cause all kinds of instability.

Shocks can be visually inspected for leaking fluid and manually tested by lifting and pushing down on the corner of the vehicle and see if it bounces.

Best to have the vehicle checked to see what the root cause is.

Maybe, maybe not.

Drew K will find the cause and report back, I'm sure.

I will do what I can to find the root cause and check back!

I did look at the shocks and did not see any seepage, but given the age I might just go ahead and change them. I did the bounce test and it was not definitave.

I am not a member of any of the nissan forums, perhaps I will browse around (but I don't have enough time for learning a new forum right now).

Does anyone know of any good way to test the bushings (I wish I was in England and had could just take it in for an MOT, but I am stuck here for an unknown amount of time).

Drew K

Grab the bed from the side, at the rear of the vehicle and shake it back and forth.

Maybe you can lie under it while somebody else shakes it and listen/look?

I will check that out. I know from watching them do MOT inspections in the UK that they stand under the car (usually in a pit) and will jack and pry against the suspension parts looking for play. Perhaps I will see it if someone else does the shaking.

Drew K

as well as tire wear issues...

Sounds like rear axle bushings are worn out.....here's a 'how to' video....

https://www.youtube.com/watch?v=LUaM2tagIX4

Could be a resonance condition caused by something loose, worn or out of balance. You can drive at any speed and everything is fine, then you hit a bump and the rear vibrates and then the vibration goes away if you change your speed sufficiently.

I once traced that to a tire that had thrown a balance weight and lost some air pressure relative to the other ones. You might also try jacking up the rear and see what has too much play. How much is too much? 0.003 vertically, any horizontally unless it has an independent rear suspension.

A commonly overlooked cause of rear end sway is due to weak sidewalls on the tires.

Even when inflated to their maximum ratings many tires will have fatigued sidewall belting/renforcement that lets them flex side to side making the back end seem loose no matter how good the suspension is.

Lots of valid suggestions offered. If all them do not resolve I suggest letting someone else drive it over your favorite bumps and you follow along to get different view. Could be what we might call "crabbing" . That's where it will appear to be traveling side ways and hitting the bumps causes the truck to try and correct it self. Causes can be different diameter tires on same axle ( forget sidewall label , measure the circumference). Also check that tires can be very over inflated causing rock hard bounce. Also since this was used truck, check for bent frame by alignment shop.

At 110k miles,the rear spring bushings are due for replacement. You don;t say where you are but here in the US, many of the parts houses will either loan or rent the specialized tools to do a job like this. With the right tools it;s not all that difficult to change them. If you decide to DIY, dish detergent makes an excellent assembly lube.

In Europe, many vehicle testing stations have a special machine to check out the suspension. It gives a clear report of which side(s) have a problem and when the engineer watches as the test is made, he can usually tell you where to start changing parts.

I am sure that the USA has the same or similar equipment!!!

Due to the fact that worn or damaged suspension parts, if not replaced as soon as problems are apparent, can cause a serious accident, do address it immediately..

I think it was Lyn who had a good idea, which was to lie under the truck and get friends to push the vehicle from side to side and watch for movement where there should be no movement in the suspension, is a cheaper alternative.

Whichever side the problems are found (usually the nearside in my experience), do replace the same parts on the other side as well to keep everything "parallel"....

Even simply jacking the car up and undoing a few parts will often show where the wear and tear is.....it's not Rocket science!!!

I am of course assuming that you have good tyres all round, at least of the same type/manufacturer on the same axle, though I prefer the same ones all round myself. Also they must be ones correct for the vehicle and that correct, or slightly higher (fully loaded) air pressures are in the tyres.

Badly worn tyres can also cause instability too....

I'm thinking its a tire problem

Block the front wheels, and separately jack up each rear wheel. Run the vehicle up to the speed where you have the wiggle, and check the wheel for out-of-round tire, balance, etc. Keep in mind with one wheel down, the speed will be half(or double, not sure) what the speedo is registering.

Make absolutely positively sure the vehicle cannot get into four wheel drive!

Seldom thought of but can cause your problems:

Low tire pressure.

Are the lug nut/bolts tight? This would probably be accompanied with a metal to metal noise but not necessarily a loud one.

Good Luck, Old Salt

Bad dampers do not always show leakage - many are gas-filled. A stiff damper will affect ride, but not show with a static test.

I have also had a damper go bad due to the internal flow adjuster not being tightened correctly in the factory.

"...the rear end seems to wiggle"

Maybe it's just flirting with the vehicle behind it!

All 4 tires were new when I bought the truck, no apparent damage to the rims, tires and weights appear ok (my old truck had a slightly bent rim that always needed extra weights to ballance).

I will try to crawl underneath today and have a look.

.

On another note, I observed an odd bounce in the miss's Suv over the weekend. It is smooth riding and seems to not have excessive rebound after hitting dips and bumps except one wheel feels like it bounces when hitting a large crack or small pothole (the width of a spray can or so?) I haven't had a chance to watch from another vehicle to see if it is indeed bouncing.

Can a shock fail so there is no short stroke dampening but long stroke still works?

Drew K

Yes, a shock can develop a condition where it is still firm as it gets closer to the ends of travel, but looses its ability to dampen in the center area, where it spends most of its life.

You went from a small truck to a big truck. I have seen this when the truck does not have enough weight in it. Try hitting the same bump when you have weight in it. Suspension may be to stiff, meant to carry more weight.

You should be able to check for worn rear suspension bushings by standing firmly on the foot brake, and placing the transmission in reverse. If the bushing you are checking is worn, you should be able to see the end of the spring move, while the shackle or frame mount does not. You may need to bring the engine slightly above idle while doing this test.

WARNING! only look from the sides of the truck, and me absolutely sure the truck will not run into anything if the brakes allow it to roll. Keep a hand on the key and do not hesitate to turn it if there is any movement from the car at all/ This test needs a minimum of two intelligent people to perform.

If the transmission is a manual, you should not try this.

Good luck.

Manual transmission...this is going to be fun. I don't have anyone at home with my level of manual experience or mechanical experience...I might have to hunt around and use a camera.

I think I am going to replace the rear shocks to eliminate them as a possible culprit. I will have a good look around while in there.

Drew K

Hold on there partner.

There may still be hope for this. Stick the truck in first gear. Now lay under the truck, and have one of your talented friends push and pull the truck back and forth. While the truck is loading and then unloading the drivetrain, any play in the suspension bushings should show up. Good luck.