1998 E150 conversion. Shimmys/shakes at 65-75 mph. Balenced tires. No change. Bought new tires, no change. Re balenced. No change. Rotated tires back to front, no change. Its in the rear as no shake in stearing. There was some change in speeds affected during all the tire rebalencing and swapping.

 

Rear axle bearings? How many miles do you have? have you ever re-build the rear end?

 

U-joints?

Sixto
93 E150 Chateau 5.8 190K miles

 

second on the u joints

 

Pep boys said drive train was tight.
126,000 miles. Just aquired from my father. Driven gently whole life.

 

Get a second opinion from a shop that works mainly on trucks.

Sixto
93 E150 Chateau 5.8 191K miles

 

Is it the steering wheel that shakes or the whole vehicle?

 

The steering does not shake.

 

Where can I get a second opinion that wont charge me $100?

 

I don't know what they charge but on the surface I'd trust their diagnosis over Pep Boys:

Home - liskeysaut1004826-107180-sml-1

Jerry's Automotive - expert auto repair - Lansing, MI 48911

O?Donnell?s Auto & Truck Repair | Lansing, Michigan

http://www.chucksgaragelansing.com/

Tuffy Auto Service Center Lansing,Michigan Auto Repair Shop

Your profile says MI so I went for the middle

FWIW, a pair of Moog brand u-joints won't cost you $50 delivered. I don't know what standard rates and times are but a proper shop shouldn't need more than an hour on a lift, if you're not the DIY sort.

Sixto
93 E150 Chateau 5.8 191K miles