Loaded no vibes empty slight vibes "Why"

When I am alone in the truck I have a slight vibe when coming to a stop 35-15 mph. but when my dad (300)lb's myself (285)lb's and the bed with about 150-200 lb's it is smooth as can be. I put the 5100's on it at 1.75 to level out the truck but it had this slight vibe before the lift. Any answers.

 

its your drive shaft angles...you can try a set of axle shims

 

I did not do any type of lift to the back would that make a difference?

 

oh no.....

 

"Oh no" is that good or bad?

 

IH NO MY BAD ....i thought u did an aal
bring it back to dealer....

 

I thought it could be the tires, I am running 35psi all around. Could it b getting road vibes because to much air? But with the weight in it would that make a difference.

 

do the chalk test
http://www.tacomaworld.com/forum/wheels-tires/51690-what-psi-should-i-run.html#post921497

 

I'll give that a try. Then take it to the dealership I guess

 

What else could it be? little things like this realy bug the sh*t out of me!

 

Has anyone else have this problem? I even had the drive shaft tested to see if it was out of balance but it was perfect.

 

If the truck is an automatic I think this is one of "they all do that" things. Mine does it and my last 05 which was a stick didn't and neither does my brother in laws which is also a stick. Something to do with the transmission downshifting I believe. Put it in neutral before slowing down and see if it does it. Mine has a bit of a shake slowing down from like 35 to 20 or so in gear. In neutral nothing.

 

It's an automatic. Did you ever have it checked out to see if anything could be done about it. Or it is what it is and live with it?

 

I bought this truck used with 113k on it. When I test drove it I thought it might have had warped rotors. After realizing the pedal wasn't pulsing when it did it I searched some old forum threads and apparently it's very common on automatics. So is a slight driveline resonance right around 1800 RPM in overdrive. That one goes away if you drop it into 4th. So it's RPM related and not speed related. Both rather annoying but not the end of the world. Had I bought the truck new I may have made a stink about it. But as a used truck after learning they are common issues I'm not overly concerned. It's not hurting anything, and it's a truck after all not a lexus. The 05 4 cylinder 4x4 I bought new was completely trouble free until it was out of warranty. Afterwards was another story.

 

Thanks for the info I'll keep in mind but it still sux to feel it when slowing down but I'll get over it. I still love the truck.