I have a D6C, 1968 that I put in the shop (Caterpillar) and had a couple rollers and the spring track tensioner replaced.  After about an hour after getting it back on the job it started have issues turning to the side with the new parts.  Now it will not turn in that direction at all.  Other side that had no work,    works fine.  Do you think it is the clutch or something else?

Replacing those parts shouldn't have anything to do with steering trouble. Whats with the C frame hitch at the top back of the blade??????

Thanks for your message but I'm not sure what you are asking about. The C frame is attached to the blade with a 3 or 4" diameter pin that was also replaced. The pin allows the blade to pivot manually. You think that might have something to do with it? But it turns fine in the other direction. Cat dealer tells me it's the clutch but would take $3-400.

Total coincedence is all. Going to need to do a steering clutch. Better look at the other side also while there. Hate to have to haul it in again.

The hitch on the back of the blade for the center pin should be down at the bottom, not at the top, so all the force is near the cutting edge and to the C frame. 

steering troubles would most likely be steering brakes or steering clutches. does it drive properly forward and reverse in a straight line?  a broken track spring will affect the tracks but it should still turn. the track wont be driving properly as it wont have correct tension. the way the steering works is by skid steering when you apply the brake and clutch to the right track the left keeps driving and thus the machine pivots on the right track and turns to the right the reverse is true to turn to the left.

its possible you have more than one problem but fix the track tensioner first as its the obvious fault and see what happens. maybe the steering clutches and brakes are out of adjustment have that checked when you get the spring done. it can be worth while doing it at the same time as your not paying for 2 lots of transport fees. they may also be able to do the job at your place ask the question and find out the cost.

those springs are under huge tension when in working order and replacing them is a job to be done with the right tools and great care. if you have never done it before best to get it done by a experienced crawler mechanic.

I also owned a '68 D6C it was 10K373 (I purchased it in 1977). The first problem I had with it was steering. The problem was the Teflon seals that actuate the steering clutches, the clutches were okay. I would recommend you replace the cross-shaft bearings while you are having it done.
Craig 
 

Thanks for your message, it took me a while to find this link again and see your blade. The C frame is attached to the blade with a 3 or 4" diameter pin that was also replaced. You think that might have something to do with it? But it turns fine in the other direction. The pin broke and had a pretty significant repair job. It attaches to the bottom of the blade but the photo is right after it broke and the C frame was raised.

Thanks for response, you take it to a Cat dealer to have it repaired?  I've been told $4-5000 per side to replace clutches.  Pretty expensive for such an old dozer.   

Steering seemed to work fine until I had the spring tensioner replaced.  Was in shops for a few months getting the spring and some weld jobs completed on C frame.  Didn't notice a steering issue when I first got it back but went bad to worse in just a few days/hour of work.