While new Jinmas can be had with a spring seat, one wasn't available when I purchased my tractor. I have a Jinma backhoe that requires the seat to swivel 180 degrees. The factory does not have an option for a spring seat that swivels. What follows is how I went about saving my kidneys, and still be able to use the backhoe.
WARNING: These modifications may defeat safety aspects of your tractor. No rollover testing was performed on this.
Spring seat from Tractor Supply Company on the left and original seat on the right. Boat seat swivel in the foreground. I removed the swivel from an old plastic boat seat, I had. I believe swivel base can be purchased separately.
Here is a bottom view of the seats. You can see large swivel mount on the original seat. Mounting the spring seat directly to the original base, will put the seat too high. Seat belt brackets (with slight bending) and bolts fit the TSC spring seat.
Here are the four mounting holes for the seat. The rear casting mounting holes, were not level on my tractor. I added a washer to the lower side, so the base plate fit flat.
Seat mounting base was made from a 6 1/2" X 14" X 3/16" steel plate. A "U" cut-out in the back is needed to clear hydraulic fill plug.
Here the base plate is mounted to tractor. Swivel bracket bolted to that and base plate of spring seat mounted to swivel bracket. All holes in swivel seat base plate needed to be drilled. Yoy need to carefully center swivel onto this base plate. 5/16-1/2L bolts were used.
Here the spring seat base has been rotated about 45 degrees.
Here is a rear shot and can see the base plate, swivel bracket and spring seat base plate. Here you can see that the spring base plate does clear the low-profile hydraulic fill plug.
To clear the spring seat, you must lower the 3pt hook or remove it. I lowered it, by drilling a third hole in the angle bracket.
Here is the seat mounted and in the forward position. It gives a comfortable riding position for my six foot frame. Riding position is higher than stock seat, but can be adjusted by the seat spring tension. Taller people will want to mount the seat slightly more to the rear.
Rotating the seat toward the back.
In the rear facing, backhoe position.
What would I change?
- Make the base plate 3/4" longer (14 3/4")
- mount swivel base 1/2" more to rear
Possible Issues:
- Possible safety concern on roll-over (2 pins + swivel center VS 4 bolts)
- Access to hydraulic filter, will require more time to remove seat
Green is the base plate to tractor mounting. Red is swivel mounting holes and bolts. White is the holes for clevis pins.
Swivel needs to be raised off of the base about 5/16 of an inch to clear the bolt heads of the rear tractor mounting bolts. I used a nut on each corner bolt to raise it up.
Circled in white are the clevis pins to prevent the seat from rotating.
Swivel mounted to base plate. The rear two bolts had very little clearance between the base plate and casting of the tractor. 5/16- 3/4L was used in the rear, while 5/16-1L for front. If you move mounting another 1/2 inch toward the fill plug, should allow more room for bolts.
Corner shot of clevis pin. By sliding the seat forward and back, gives easy acces to the pins. Front pin is a little harder to insert pin in clevis. I may try to reverse clevis, so pin is on top.
The low profile hydaulic fill plug is on the left, with standard on the right. The low profile comes standard on spring seat installed Jinmas. I purchased the low profile from Tommy @ Affordable. Received part in short order.
To save a few bucks, you could modify the existing plug. Cut about 1/2 inch off the top, plug top hole, and cross drill vent hole. If you are going with a standard base, no swivel, you will probably need the low profile plug.
