3720 hydraulic toplink

   / 3720 hydraulic toplink #1  

greg_g

Super Member
Joined
Dec 18, 2003
Messages
6,086
Location
Western Kentucky
Tractor
JD3720 Cab, 300X loader with 4-in-1 bucket
Lookin' for advice. Am shopping for a HTL for my new 3720, and want to make sure I get the right length. Definitely has to be a Cat 1, there's no room on the tractor bracket to pin a Cat 2.

I thought it would be a simple matter of measuring the OE turnbuckle toplink, but I was wrong. Tried hooking up several of my implements with it, and in doing so extended far more than I'm comfortable with. I'm not new to HTLs, I had a Cat 2 on my previous tractor. It was a hair long, so I'm wanting to do it right the first time on this new 3720.

The OE toplink is 18-3/8" closed (eye to eye). Given what I've seen so far, I know I need at least a 20" HTL. So I guess the question is; should I go to 22", or even 24"? I'm hoping for feedback from some JD3000 series owners that have already been where I'm at now.

//greg//
 
   / 3720 hydraulic toplink
  • Thread Starter
#3  
Thanks, but I crossed that one off my list already, it's even shorter than the OE turnbuckle toplink. But Surplus Center has longer ones. I'm thinkin' the 24" will be too long, but was hopin' for feedback from folks who might have a 20" or a 22"

//greg//
 
   / 3720 hydraulic toplink #4  
Thanks, but I crossed that one off my list already, it's even shorter than the OE turnbuckle toplink. But Surplus Center has longer ones. I'm thinkin' the 24" will be too long, but was hopin' for feedback from folks who might have a 20" or a 22"

//greg//

I have used mine for over a year. If I had to do it all over again I would buy the same one, and certainly not one any longer. The size is perfect for my box blade, my brush hog, and my tiller.

On my side link I bought a 6 inch stroke job, it I had to do that one over I would buy the 4 inch.
 
   / 3720 hydraulic toplink #5  
My factory hydraulic top link measures 19.5" retracted and 25.5" extended. Seems to work fine with brush hog, back and box blades, and tiller. Not saying you have to go OEM, just wanted to give you the measurements.
 
   / 3720 hydraulic toplink #6  
Here's the best one I found:
HYDRAULIC TOP LINK CATEGORY 1 - Agri Supply

It started out in use on a 2520, but I kept it when trading tractors and then installed it on my 3720. So its probably 4 years old now, and has been used extensively. Works great, plenty of range, plenty of power. Very reasonable price and comes with the ball-joint ends and proper length. Before you ask, I am not sure what its range is, although I could measure it this weekend. And, I don't miss the load-handling check valve thing. In actual practice, I change the setting often enough to be able to ignore whatever slight settling might occur.

Good luck...
 
   / 3720 hydraulic toplink #7  
Lookin' for advice. Am shopping for a HTL for my new 3720, and want to make sure I get the right length. Definitely has to be a Cat 1, there's no room on the tractor bracket to pin a Cat 2.

I thought it would be a simple matter of measuring the OE turnbuckle toplink, but I was wrong. Tried hooking up several of my implements with it, and in doing so extended far more than I'm comfortable with. I'm not new to HTLs, I had a Cat 2 on my previous tractor. It was a hair long, so I'm wanting to do it right the first time on this new 3720.

The OE toplink is 18-3/8" closed (eye to eye). Given what I've seen so far, I know I need at least a 20" HTL. So I guess the question is; should I go to 22", or even 24"? I'm hoping for feedback from some JD3000 series owners that have already been where I'm at now.

//greg//

I am having trouble understanding when you say your OEM extended "far more than I'm comfortable with" yet you want a top link cylinder that starts out longer than your OEM is closed. The HTL cylinders only get longer when extended. :confused:

Or are the 20", 22" or 24" extended lengths? :confused:

I would start with collapsed and extended length of OEM top link and make sure I could cover that with a cylinder. As to whether you need to be able to go shorter or longer I don't know. :confused:

Someone with more insight may be able to address the need to be able to go longer or shorter than the OEM top link :)
 
   / 3720 hydraulic toplink #8  
Lots of range in both directions (longer and shorter) can be usefull. Examples: If using a box blade, being able to lift the front way up makes it more of a trowel than a digger, making it possible to smooth the surface without gathering much soil. When I am working with a landscape rake in the woods trails, the elevational differences change dramatically from moment to moment. Like when crossing a ditch, sometimes it helps to be able to lift and then tilt the rake way up to help clearance. Other times I have to be able to drop and tilt it way down to follow a water break feature in a trail as I am traveling downhill over it. Another use for long range tilt is to extend a single box blade tooth, pull the bb tooth thru the ground up to a small stump, and then tilt the bb back as far as it will go, then retract again while pulling forward, and repeat. the stump will be pried from the ground by the tooth working against the bb cutting edge, powered by the hyd top link.
Ultimately, I think a guy would like to get a toplink that had a range of at least 6 inches, and its range should be centered where the ball end of the top link is extended to directly above the draft arm balls, 16 inches above them (cat 1). Hopefully that makes sense.
 
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   / 3720 hydraulic toplink
  • Thread Starter
#9  
I'm actually quite familiar with HTLs, I had a Cat 2 for quite a few years on one of the tractors I traded in against the 3720.

Anyway. The toplink that came with my 3720 is 18-3/8" closed (eye to eye). Toplinks of any kind are strongest when closed (screwed in all the way), and get progressively weaker as they're lengthened. And as a general rule, I transport my implements with the TL "closed". The OE toplink that came with the tractor is too short for that. Then once it's lengthened (screwed out) far enough to get my implements into their respective working positions, there's too much thread showing. Increasing length = progressive weakness.

The solution (for me) is a longer toplink. And yes, I've found Cat 1 HTLs as long as 24" closed. I'm trying to strike a compromise for a decent transport length closed, but not lose strength by having to open it too far to obtain working positions. I already determined that anything <19" closed is too short, but I'm sorta thinkin 24" may be too long. So I think feedback from the 20" and 22" folks would likely help me most.

I like the AgriSupply HTL as the rod is of a larger diameter than that Yugoslavian thing at Surplus Center. Larger diameter = greater strength. And 20" closed/28" extended sounds like a good range. I also like the extended tractor end. My other HTL had the ball end welded too close to the cylinder body, which caused the cylinder body to strike the tractor bracket in tight turns and high lifts.

That 19.5" factory HTL; John Deere factory? Frontier? The 6" extension seems a bit short. I typically extend up to 8" for some boxblade tasks. I've even found some Cat 1 HTLs that extend 10".

Gonna get a plumb line and test that idea about determining ideal toplink length based upon lower ball location. Thanks. Given previous experience though, I'm not sure 50/50 would work for me. My previous HTL usage never required more than 3" of retraction from full vertical for any implement in my inventory. It was a 10" Cat 2 cylinder, which I guess was split pretty much 30/70 (retract/extend). On an 8" Cat 1 cylinder, I'm thinking maybe 35/65 (?)

I'm presently leaning towards that 20" AgriSupply HTL, but hate to make a move without hearing from someone that may have experience with a 24"

//greg//
 
   / 3720 hydraulic toplink #10  
I have new cat 1 hydraulic top links that go from 19"-29". 2" bore with 1 1/4" rod or 2 1/2" bore with 1 1/2" rod. Center line of pin is 2" off of the hydraulic.
 
 
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