Vibration when towing w/'98 Suburban

When towing my Miata to an autocross a few months ago, I had a very bad vibration in the front end. The vibration started at speeds as low as 45mph. The strange thing is that the severity of the vibration would "fluctuate" while maintaining a steady speed (say, 70 mph).

After dropping the Miata off, I made a run down the interstate with just the trailer (an open, tandem axle, probably about 1500#s.) There was a slight vibration, but nothing like what was present with the Miata on board (an additional 2300#s.)

Any ideas?

A Miata ??? Ain't That A Chick Car ?????

Sorry, I Couldnt Help Myself......

I Would Start Looking At The Front Suspention And Tires. If The Weight On The
Trailor Was Not Even And You Had To Much Weight On The Tounge And Not Enough On The
Trailor Axels You May Have "unloaded" The Front Suspention To Much...

Just A Thought, I Hope It Helps...

Dave

Sure, chicks dig it! (And so does my wife, the only "chick" that matters.)
:)

Thanks for the reply. The whole combo was fairly even, although I did try to position the car further back on the trailer when coming home from the autocross. That did not seem to make any difference.

David