A gs550. I think it's an 81 but not sure on the year. The only difference in the two is suzuki uses a wear ring on the tube so you have to have the tubes turned for the ring. it's about 1 1/2 inch wide and 1/4 mm deep at the bottom end of the tube. seals and everything else is the same. Cost me 10 bucks to have it done. But the forward axle brought my trail back to almost stock.

ONCE-A-NITE