VEVOR 37.77cc Gas-Powered T Post Driver, 4-Stroke Engine Gasoline Fence Piling Pounder, with 3 Post Driving Head(45/55/88 mm) , 1000W Portable Piledriver For Farm, Ranch Fencing, Road Improvements

I did not find any information about replacement parts availability in the product description or customer reviews.

While the product description doesn't mention anything about hard rocky soil, customers mostly have positive things to say about using it in various soil conditions. One customer says it works fine in mud, while another comments that it's not strong enough for dry, hard Alabama clay.

I don’t know but this works really well for driving t post.

This pile driver can't drive such large pillars. The largest sleeve that comes with this product is only 88mm, so it might not have enough power to drive larger pillars.

This machine can cut steel pipes up to 88 cm in size. Please calculate it yourself.