PT-425 dented lifting arm

[Incline]

I'm wondering if any other 425 owners experience this not - The front horizontal tube on the lifting arm assembly is developing a fairly deep dent/crease (see pics). It appears to be from making contact with link rod of the Quick attach assembly though I am not aware of it as it's happening.

I'm guessing it's occurring while using the mini-hoe during full extension but not sure. Only about 100 hours on the machine so far.

Either I need to correct something that I'm doing wrong, or I may need to weld on an additional piece of steel to shore up the dent. It's not all the way through the tube but I'm afraid it might be getting close and then I presume it loses structural integrity.

Any thoughts?

 

[MossRoad]

I haven't experienced that. I recall years ago people having problems with the roll-over tube cracking, and PT coming up with a beefier solution, but that damage you show isn't on the roll-over tube. I did bend my top-link. But that was from extreme abuse. Next time I see my machine I'll look at it. I have a 2001 model year, so my lift arms may be different.

What year is your machine?

 

[agjones]

I think you nailed the cause... An stroke limiter will help. Send the picture to Keith (to print for terry.).

 

[Incline]

Thanks guys. Moss, I took delivery July 2018 - presume it was made same year.

I see now where contact is being made. The front knuckle of the control arm makes contact when the lifting arm is lowered to floor level. That would be the general position when pushing a bucket into dirt.

I notice that there's about 1/2" of free play in the QA plate (front to back) and that's just enough wiggle to drive the knuckle into the cross tube.

Weird, since it seems like that would be a pretty standard and well used position when using a bucket.

I'll talk to the Power Trac folks.

Thanks again

 

[MossRoad]

That is weird. I'm trying to remember the configuration in my head....

So that knuckle you speak of is where the rear of the QA top link attaches to the top arms on the roll-over bar? At that point, the dump/curl cylinder is retracted all the way, correct?

That knuckle clears that cross-brace through most of the raise/lower cycle of the FEL arms, but at the lowest point the knuckle starts hitting that cross-brace?

Sounds like the geometry is off a bit.

Find someone that has a similar year model, and measure the length of the link arms on the top and bottom of the roll-over tube. See if yours are the same length as everyone else's top and bottom. If they are the same, then never mind my thought process. However, if the top and bottom arms are different lengths, and your measurements of top and bottom are different, maybe your roll-over tube got installed upside down? Just a thought. Most likely NOT THE CASE.

Another thing would be to measure the dump/curl cylinder and see if it's the same as everyone else's. Could be wrong cylinder.

Do the same for lift/lower cylinders. Be safe and don't get under the FEL, of course, without blocking it up.

And measure the QA top link rod length, too, while you're at it.

Then you'd have to look at cylinder and FEL mounting tabs to make sure they are located in the correct positions, etc....

Something in the geometry is off.

As someone mentioned, you could put a collar around the dump/curl rod to restrict retraction. That would keep it from hitting, but also lose you some range of motion.

Good luck in your investigation and hopefully PT will have an easy solution.

 

[MossRoad]

Or you could put restrictors on the raise/lower cylinders, too, to keep it from dropping all the way, but again, you'd lose range of motion.

 

[ponytug]

Yikes! Yes the geometry is off, and it is not the plate, though that sounds like a lot of slop.
Talk to Terry.
If he does not send you a replacement link, I would shorten that tube before that dent gets any deeper. (Might cut it out and weld a patch onto the other tube while I was in there.)
I hear plasma cutters do a great job of cutting tubing...
All the best,
Peter

 

[coolconnection]

Mine did something like this when i first got my tractor. The only fix was to replace the entire control arm assembly. Even bent my quick attach so it wasnt flat anymore. On mine the center control link arm (don't know it's name) was on backwards.it made my curl to extreme. It is a pain to replace and really heavy to work with. they replaced it free because it was manufactures defect.

 

[MossRoad]

Mine did something like this when i first got my tractor. The only fix was to replace the entire control arm assembly. Even bent my quick attach so it wasnt flat anymore. On mine the center control link arm (don't know it's name) was on backwards.it made my curl to extreme. It is a pain to replace and really heavy to work with. they replaced it free because it was manufactures defect.

I think that center control link arm is the same thing as the roll-over bar that I'm speaking of. It's the pivoting tube in the center of the FEL arms that connects the dump/curl cylinder on the lower side and the QA top link on the upper side. It has two grease zerks.

 

[Incline]

Thanks for the feedback. Geometry seems to be in the lead.

I added another pic of the arm position when contact is made but Moss, yes, you understood the position exactly! Based on coolconnection's experience, this is not a unique problem so I've sent off some pics to Terry for comment. Funny, these days you tend not to think in terms of hand made equipment and the possibility for human errors in the build process. We'll see if that's the case or not.