I can't say when it started but I have an annoying problem. When I come to a sudden stop my seat rocks forward about 2 inches or so and falls back when I stop. I was riding with my Dad in the passenger seat and he mentioned his seat doing the same thing! Is something not locked down like it's supposed to be?

 

Have a look under the seat at the seat rails. Two inches is a lot of travel. If it's rocking sounds like your seat rail bolts either broke off or came loose and are almost all the way out.
Look under the seat in the back with the seat all the way forward.
Should be two goldish hex bolts on each rail. If the seats were pulled by previous owner locktite may not have been put back on the bolts. If they look stripped order new bolts before you mess with it.

 

Three on each rail!

 

Told him slide the seat all the way forward and check the Two in the back.
He said his seat rocks forwRd when he stops. Which lead me to believe the back bolts are loose or missing.
Anything else?

 

Does it move around when just pushing on it? Either the bolts aren't secured properly or I have seen the metal support break on several 964's requiring weld repair.

 

The bolts are all secure and I should say it doesn't move 2 inches. More like 1.

 

When you say the seat rocks, can you tell if its the seat bottom or the seat back that's moving? Trying to isolate where the problem is.

 

Sounds like the metal subframe has broken. Check the areas circled in blue they can sometimes break free and cause the seat to rock.

 

The seat slides forward on the rails with the inertia of a sudden stop then slides back. The rails are secure. The seat slides back and forth on the rails.

 

The rails would still work if the supports gave way.

 

can I check that without removing the seat?

 

It is best to remove it but if you can rock the seat back and forth then you know you have a problem in either case it is best to check everything out I would hate to see it happen worse under acceleration and you loose control. Try lifting on the front and rear by reaching under the seat and lifting if you have movement I would start there.

 

Just ran out to the garage. Tried to lift from the front and rear. No movement.

 

Then it sounds like you have no choice but to remove the seat and investigate. Sorry I can't be of further help.

 

Thanks for helping me eliminate some things. Now I have a project for this weekend.