Feels like my truck wants to fish tail

Something else to try and this might not appear to have anything to do with it....??

Take the truck to an open parking lot and do some tight 8 circles in both directions. When I mean tight circles...have the steering wheel in full lock in both directions.

What do you experience? Anything unusual? Grumbles? Noises?

This is working your LSD......forcing it to untorque (hard to explain). Again, I don't know if this has anything to do with your symptoms. My thought process is that maybe (and that's a big maybe) something is not functioning properly inside your diff. Anytime I change my diff oils, I always get 'grumbles' on left turns until I put enough friction modifier in it. Weird....just a thought...hunch or whatever.

 

Funny you mention friction modifier, I was getting a groan in the passenger rear after the truck sat for a few hours. Mentioned it at the dealer and they said they added more modifier, and it should go away, which it did. Now that I put the timing together once the grumble/ groan was gone this started. Could this be coincidence?

 

I've have weirder things happen...but you never know. ??

The whole idea with the 'tight 8 circles' is to work the oils/modifiers into the clutch paks of the LSD. I doubt the dealership did that for you when they added the modifier.

It's a good idea to do that and see what happens....

 

interesting on the lsd stuff. . . good points

also, since im now confused on whether you are experiencing body roll, or are sliding, maybe check that the swaybar is in place in the front. maybe the p.o. pulled it off which trust me, makes for a rolly-polly, dippy-divey ride on stock suspension

 

I check the sway bar, everything is tight. It kinda feels like as the body starts to roll, the back end wants to kick out. Really odd feeling, almost like a hydroplane on dry pavement

 

Well, the video disproved my theory. It looks as stiff as stock. I am out of ideas...what tires do you run? My Firestone Destination ATs hold pretty good but will break loose in the rain if i make them.

 

I is can no pay attention.

I don't like those rugged trail tires. They aren't a whole lot better than the dunlops that came on my truck. They were the first thing to go.

 

OP, I may have missed it, skimming through the posts, but have you looked to see if your rear springs have been moving in the perch? If the pin head sheared off near the perch, the spring pack could be moving in the turn and then straightening out again.

If so, a close look at the spring packs would show some signs of it slipping back and forth. Hope you get it figured out soon.

 

Can't see the top of the pin because of the bump stop, But the springs do not look like they are sliding at all. Thanks though I didn't even think of that.

 

I think after spending hours today going over this truck my next step is going to be to have my local shop do an alignment.

 

Ok since there is a lot of talk about tires, what do you all recommend, keep in kind 95% of my driving is highway, but I do go out on the beach and off road on occasion?

 

Where are you from?
Is snow/ice or rain a concern?

 

In central NJ so we have our share of snow/blizzards. It's been two years since the last big snow, but we get our share.

 

I reccomend and all terrain tire no matter what. Just because you never know when you'll need that extra bite.

 

" There is still over 1/4 inch of tread on them, so I shouldn't be into the harder rubber yet, but who knows they could be 6 years old for all I know."

There is a manufacturing code on each tire sidewall, ie YYWW which is year (YY) and week (WW) 01-52 of manufacture. 1303 would be 3rd week of 2013.

 

I found a code P1221BG1 would this be it?
So 21st week of 2012, lands in May, tires are a year and a half.

 

Short update. I went to remove my helper springs, as another trouble shooting experiment. Found all the nuts on the ubolts had no torque on them. I had torqued them to 80ftlbs when I installed them... And yes they have lock washers.

Said to myself, self maybe this could be it, could it be so simple. Damn it! Didn't change anything!