Top Link Length?

[mantis166]

Anyone notice a problem with proper length of top link with Jinma 284. I bought a new 5 ft. brushhog made by JBar. I believe I assembled it properly. I bought what my dealer said was standard top link that is supposed to fit, but it is a foot too short. It is about 20" in length before screwing out, but even all the way out it isn't even close. I called local Deere store (only tractor supply in area) and he said this is not a common problem and all of his are 20" also. Of course, he added a contented sigh when I said I was setting up a Jinma. Any ideas? I used it anyway without top link and it worked fine. Is that a problem? Thanks again for input.

 

[RonMar]

If the toplink can extend out over the bottom two attach points then it is long enough. The one that came with my 284 can. I test rigged my hog yesterday and my toplink is set at around 23" center to center. It sounds like you are missing something on your Jbar cutter mount. I almost bought one of those Jbar cutters from Ray but decided I would destroy it with the rough ground/heavy brush I am going to be clearing(I need a cross between a box scraper and rotary cutter.

Before I changed my mind about the Jbar, I studied the mechanism it uses to allow the cutter some flexibility when lowered. The upper mount on the cutter is set back behind the two lower mounts. To this upper mount another link is attached, which when angled forward, brings it inline with the two lower mounts. The toplink attaches to this additional link. In tension, when the deck is lifted, these two are in line and lift the rear of the deck(the Rankin cutter I bought uses a 12" chain section at the rear of the mount). When lowered, this link and the toplink fold up or down to allow the rear/wheel of the mower to rise and fall as you ride over rough terrain/drive down into valleys/depressions, instead of trying to lift the rear tractor wheels off the ground/bend the deck/mounts.

Here is a link to a site with a pic of a Jbar cutter attached. It is not a Razor, but I believe it uses the same type mounting scheme. In the top pic, the mower is lowered and you can see the toplink and the link on the cutter are pushed up. this setup lifts the deck tail low but when lowered allows the deck to track the ground as the tactor front end drops down over the other side of a high spot.

http://bamatractorman.com/html/implements.html

You can run without a toplink, you just won't be able to lift the mower over an obstacle. You might scalp on a really abrupt high spot and you might have difficulty turning around in the rough.

 

[JohnS]

I am not familiar with that brand, but believe Ron is correct. King Kutter has a similiar hookup, and I have to have the Jinma toplink at its smallest setting.

 

[greg_g]

Its sad that the dealer had to take an opportunity to cluck at your choice of tractor, rather than deal with the hardware he actually sold to you. On the surface, it sounds like you don't have the mower's TPH yoke perpendicular to the deck. The yoke is the upside down Y shaped piece to which the implement end of the toplink is pinned. Forgetting the toplink bracket for a moment, the yoke should approximate the vertical leg of the letter "L", where the mower deck is the horizontal leg. This should make the diagonal braces line up pretty close with bolt holes on either end.

Once the yoke is vertical, maybe your toplink won't seem so short.

I too am unfamiliar with JBar, but the photo suggests a floating toplink bracket. If it's the type that can rotate 360 degrees on the pin, there's the rest of your toplink gap. Point it toward the tractor before pinning it to the toplink. Once the mower is connected on all three points, then adjust the length of the toplink to permit the mower to float under working conditions. I'd try the underneath position first, where the floating bracket moves inside the yoke - rather than over the top of it. That should keep the toplink moving on a line more parallel to the mowed surface.

//greg//