I`am going to buy a cat d4 6u7401 but how old is it

MY info shows a 1953 production date.
Good luck with your purchase:D

I`am really excited it has a bucket on the front and a winch on the rear ,I will be using it to do some logging ,Hey how hard is it to un-freeze th steering clutches

Bucket on the front.........sounds like you have an HT-4 loader unless we're talking something home built.
Stuck steering clutches can make a grown man cry:)
Are they stuck open or closed? Sometimes fiddling with the adjustment will help, soaking in kerosene will sometimes help, pushing up against something solid will sometimes break them loose, really bad ones will require disassembly.

That would be a 1952 model 6U7131-6U8255 = 1952

The HT4 is based on the 7U D4. Maybe it is one of those Balderson units. Please post pictures.

As for stuck steering clutches, tighten the adjustment as far as you can and run the tractor and ride the brakes to heat the drums. I have had success with this method.

Wouldn't be the first time a 6U motor wound up on a 7U. Got a 6U/7U conversion myself. Pictures would help solve the question.

On the back above the drawbar is the tractor SN too so look there for a plate on the rear housing or if it,s gone you should see where it was riveted on & it would be stamped in the casting where the plate was between where the rivets were drove in. Shocktower, a 6U is a narrow gauge tractor & the tracks are close to tractor where the 7U is wide gauge & you,d be able to move between the tracks & engine fairly easy where the 6U is too close in that area.

It has a winch on it so there is no reading the back tag. The gauge measure will help determine whether it is 6U or 7U. If it's 7U there is a good chance it is a HT-4 or if it is in fact a 6U chassis a picture would still be best to identify the bucket arrangement.

You have me so thrilled BTW the front has a plate that said Tractavator or some thing I will get some pics today:D