Strange Vibration During Low Speed Turning

I am having trouble trying to figure out what my problem is.

The truck has 56000 miles on it and I am getting some horrible roughness and deep sounding grinding when turning at low speeds forward or reverse. I diagnosed it as rear diff fluid so I went ahead and changed it yesterday with

$30 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 dino oil and the correct additive (thank you for the step by step how to post) and it did not seem to solve the problem. I do not go offroading and the truck spends 90% of the time as my main transportation to and from work, other than that I tow a 2995lb boat and trailer. I would be greatful for any thoughts or advice on this.

Second attempt here looking for some advice.

 

I have the same problem with an 07 sport, I replaced the rear diff. and still have the problem, sorry man I'm still trying to find the problem too!!

 

Im having the same problem in the front when turning left real bad and a little turning right. Dealer told me to get aligned and I did 3 times and still have vibrating when turning. 07 Sport dc lb 51,000 ml

 

I had that and it was fixed after Driver side bearing was replaced.

 

Did you have new tires installed or an alignment recently? If so it could be the tires at a different angle causing the vibes.

 

I did have new tires put on and a alighnment done 3 times. I put the Revo 2's on. The first time I had it alighned it was doing it on left and right turns. So I had it done a 2nd time and it went away for a short period and came back like 2 months later. So I took it to a Taco dealer and they did it again now its more in the left then the right but still get it in the right just not as bad, its at the dealer now and they asked if i had the rear diff fluid changed and I said no and that they were going to take a look at it. In the meen time they found that my timing chain cover gasket was leaking and it was going to take about 6hrs to replace so they are doing that first. Im still under the powertrain warranty. Thank god! Have to wait to hear from them about the vibration.

 

I came across this thread because my 08 sport just started to vibrate a little when turning at low speeds...sounds similar with this thread.

You guys have any luck with figuring out what was going on with yours?!

 

Find a big empty parking lot and do some TIGHT circles (or tight 8's) in both directions. Make NOTE if and when it gets worse - in what direction.
Remembering that, at any given time....the inside tire will be moving LESS than the outside.

This could be a SPORT (pre 2009) issue with those who have the mechanical LSD. Not enough friction modifier can do this.

It could be other things.... You could also jack up front tires, spin them by hand, feel for bad bearings. Turn the wheels to full lock and manually turn the wheels (in both directions). Do you feel anything strange?

Jack up the rear and do the same - manually spin wheels.

What happens when you slip it into 4wd? Does anything change?

Does it do it in TIGHT turns or only on regular turns?

 

Thanks for the reply! Sorry took so long to get back I parked it while traveling...but, I did run through your suggestions and here are the results:

1. I jacked up the front, spun each tire, turned them by hand, pushed, pulled, wiggled...nothing.
2. same results with the rear.
3. It is a 2wd prerunner sport model so...no 4wd test.

In the parking lot I felt the vibration when turning at about a 45deg angle from the speeds of 0-7mph. This is consistent turning both directions, forwards and reverse. The vibration does not occur when going straight OR when cranking the tires all the way for very TIGHT turns.

I went to Pep boys and asked the mechanic if I should change the rear diff oil again, this time using a different brand. He was absolutely zero help...literally...worthless.

So, I may just change it out anyway and switch brands...possibly the Deep Purple? That was on the shelf for $20 compared to the mobile 1 for $11 I used earlier. Thoughts on that?
The Mobil 1 75-90 said it has the LSD additive....but, maybe a brand change would help?

Thank you again for feedback!

I hate driving it with this vibration and don't want to make anything worse