Shuddering in the steering when going reverse / U-Turns (1 Viewer)

[VAPny54]

Hey all - recently I've noticed when I back out of parking spaces (when cold) with the steering wheel in full-driver / left, there is a bit of shuddering when I hit the throttle. I notice it also going left on u-turns. It goes away once the truck is warmed up.

Last year, the dealer but dextron power steering fluid instead of ATF so I've had 2 power steering flushes to clear it out. It smoothes out but then the shuddering returns so I'm now considering flushing out and replacing the transmission and DIFF fluids as well. Should I be looking elsewhere?

Maybe someone here has experienced this before so any guidance would be great!

 

[TimCFJ40]

A few different ideas...
1) Drive belt and tensioners? Is the noise a whine, a squeal, or what? Does it change with engine RPM? Does it start on startup and get worse when stressing the steering system (ie when turned full lock) or does it not even appear until you turn full lock? If it starts on startup (with the wheels straight-ish) and gets worse when the steering pump is under load, you may just need a new serpentine belt and tensioners. If it is silent on cold start, but only happens when turning, I'd look elsewhere. If it's been over 100k since this has been done, it isn't a bad Idea for PM either way...

2) Are you running stock tires/rims or something larger/more aggressive? The only turning hard left makes me think you've got a tire rub somewhere. Not sure why that would change as the car warms up, but maybe you just don't notice....?

3) LX or Land Cruiser? Shouldn't matter, but suspension behavior and clearance is a little different between the two.

4) Is there any evidence of leakage from the power steering pump, power steering hoses, or rack and pinion?

 

[doru]

No experience w/ this on LX but on Outback there are two issues that can cause it: air getting into the high pressure side of the power steering circuit due to worn o rings at the pump hoses, or pump that needs replacement.

 

[VAPny54]

Thank you both for your responses - my truck is a 2013 Land Cuiser with approximately 127,000 miles.

1) there is no whining or sounds when I start the engine, there is no evidence anything is wrong until I turn the steering wheel full left and hit the throttle in reverse - noticed it DOES NOT shudder when I just release the brake and allow the car to roll back in reverse without throttle

2) I run standard Michelin Defenders - I think 285/70/18s

3) Land Cruiser

4) No - engine is dry and park in same place, no evidence of leaks.

Looking at if air is in the hose in an option however I understood that would create some whining or a noise if I'm correct?

 

[Trukk]

Since you have larger tires (not sure if you are lifted), and it's only happening in one direction, are you rubbing at full lock on that one side?

Mine will kiss the KDSS at full lock in reverse.

 

[VAPny54]

Since you have larger tires (not sure if you are lifted), and it's only happening in one direction, are you rubbing at full lock on that one side?

Mine will kiss the KDSS at full lock in reverse.

Not lifted however I believe these are standard tires. It's only when I go full left no when I turn right.

 

[TeCKis300]

If you can check the actual size of tires on your car, that may help. 285/70R18 as you stated above are not stock, and actually a pretty aggressive 33.7" tire.

That said, this is a full time 4WD truck. So some binding of the drivetrain would not be unexpected in severe maneuvers. The center diff is a torsen limited slip (helical gear type) differential. In a reversing with full steering dialed in situation, there would be some center differential action necessary. Torsen LSDs can tend to load up and ratchet in their action, especially when cold. This is probably what you're experincing.

Fortunately, it's normal. If you really want to try something, you can refresh the transfer case fluids.

 

[OregonLC]

That it goes away when warm indicates its something with either the pump or the rack. My guess is something got damaged or partially blocked with the DEX. When the system warms, the lower fluid viscosity makes the problem appear to go away. At full lock when cold a restriction is blocking the fluid relief path back to the reservoir to the point that you feel that as a shudder. This is pronounced as RPM increases. Nothing suspension or tire related would change with engine temp. If it weren't for the statement that engine temp relieves the issue I would say you likely had a bad CV. Those typically express themselves the worst when turning in reverse. But again, that isn't a function of engine temp.

I would go back to the dealer that added the wrong fluid and allow them to keep it overnight so they could experience the cold-start condition and diagnose themselves. My guess is they owe you a pump, rack, or both.

At least this is my theory.

 

[doru]

The power no power rolling diff can be accounted by the different pressure the pump has. The pump is directly belted with the engine so change in rpm means change in pressure.
The point made above about the central diff is also valid. My tuck has some action depending on steering angle and surface grip in thigh maneuvers at low speed including parking all normal.

 

[VAPny54]

The power no power rolling diff can be accounted by the different pressure the pump has. The pump is directly belted with the engine so change in rpm means change in pressure.
The point made above about the central diff is also valid. My tuck has some action depending on steering angle and surface grip in thigh maneuvers at low speed including parking all normal.

Thanks all - this is super helpful. I just changed the diff fluid and power steering again and the shuddering remains. Regarding air on the hose, my mechanic didn't find any bubbling in the reservoir or any changes so they're ruling that out as well.

Will keep looking!

 

[sixsixnine]

Following.

My '13 with 170k just started doing something similar after a ~1k mile round trip drive.

Weird shuddering feeling when reversing. Steering angle doesn't seem to make any difference, though.

Happens when going straight, partial turn, and full lock.

 

[sixsixnine]

Update on my situation.

Ended up throwing a P0303 code while I was out running errands, which helped immensely to diagnose the issue.

Started by troubleshooting items that could potentially cause a misfire (spark plug, ignition coil, wiring, etc.) but the shuddering persisted.

Next item on my list was injectors, but I didn’t have time to pull and replace them so I decided to throw a bottle of injector cleaner in there and hope for the best.

To my surprise, it cleaned out whatever funk was in there, and the engine is now running smoothly. Guessing I dumped a dirty tank of fuel in there during my recent trip.