I have to replace the front only frame, (sub-frame), are the bolts metric & are the struts attached to it?

All the bolts on a Hyundai are metric.

There was a recall on the 2000 for problems with the sub frame rusting out .Do you know if yours have ever been replaced under the recall. Some of them were removed and had larger holes drilled in them to increase drainage. The bolts are metric and the shocks are attached to the wheels.

If you are the original owner check with your local dealer about the recall. There is lots of information about your problem.

I just replaced my sub frame last week. 2000 sonata. all bolts are metric, rangeing from 10mm to 22mm. you dont have to remove struts. but motor mounts ( front and back ) tranny lines on frame and power steering shaft from back side of sub frame then 6 bolts for frame. I removed frame with control arms attached, I removed exhaust prior to frame work. this job took me 4 days...by myself. not really too bad. used all hand tools. If you need replacement bolts...go to dealer. surpriseingly cheap. and I found the sub frame at a salvage yard for $135.00 total cost for me $150.00 and my free labor

the rear motor mount must be removed from frame ( 3 bolts ) front one from engine. so the front mount stays on frame and rear one stays attached to engine. these motor mount bolts next to firewall are a bear to get to....but it can be done !!! just so you know, I am not a mechanic, just someone with mechanical ability and a tight wallet !!!!