Telescoping lift arm won't stay locked in new holland 4630

[seanndiane]

I have a low hour 4630 that lets the left "telescoping end" pop loose and extend when pulling an implement (not the stabilizer, the lift arm itself that telescopes to help you hook up easier) I tried bending the spring on the latch down so it applies more pressure but that didn't work. The latch doesn't seem to have any more play in it than the right. I can use a piece of wire to hold down the latch but it is only somewhat effective. I've seen parts to rebuild it but the tracto only has 300 hours so it seems a little too new to be worn out already. Any advice? Is it the notch in the end where the latch catches vs the latch itself that's the problem?

 

[SPYDERLK]

I would guess that the angle of the engaging "dog" is wrong when its in the notch. Load and jiggling works it out and it lets go ... ? It seems like it would be a warranty issue. ... But if not its probably one you can fix by a small adjustment you can do using a grind wheel to relieve the root of the notch and the dog.
,,,,,This way loading will tend to pull the parts more firmly into engagement.

 

[seanndiane]

It's a 1996 tractor so warranty is probably not gonna happen. By dog do you mean the "latch" that moves up and down or the "business end where you hook the attachment to"? Do you just drive the pin out to release the whole sliding assembly from the arm?

 

[SPYDERLK]

OH. I saw 300hrs so i thought "young". I dont know the specifics of your extendable link design so Im basing it on what Iv seen generally. ... But yes I am referring to latching -- your latch to business end engagement. A dog on the latch lever falling into a notch on the slider (probably). It seems the pin you mention is probably what keeps the slider from coming all the way out. You may have some damage to the dog or the notch or the latch lever bent a little.

Lots of things to imagine w/o seeing the design. Comparing to the right side may give you insight.

 

[seanndiane]

The right and left seem to function identically, except the left comes unlatched. The spring tension seems the same

 

[SPYDERLK]

View attachment 480612
The right and left seem to function identically, except the left comes unlatched. The spring tension seems the same

Its not apparent to me how those parts work together. Where does part 4-4 pivot. How is it released to extend the link? Is the one on the left damaged?

 

[ch1ch2]

I am wondering if the arm is fully returning to the retracted position to where it can properly lock.
I have had dirt get behind the arm so it could not close all the way.

 

[seanndiane]

I am wondering if the arm is fully returning to the retracted position to where it can properly lock.
I have had dirt get behind the arm so it could not close all the way.

The arm works completely normal.....except after pulling a disk or plow 20-30 feet, the left arm will break loose and extend 10 inches. With implements removed, I can't get it to duplicate the problem. The spring that holds the latch down into the notch on the arm it the same tension left and right (on both sides the spring sits 1/4 inch above the latch. I tried bending the left one down to make contact with the latch, but it looks like it's really not designed to touch it unless you lift up on the latch.) I don't mind buying new pins, spring, or whatever but I hate to spend $20 on each pin and $6 for a spring and it NOT fix the problem.... I've done that on too many things already.

 

[CADplans]

My arms are similar,,,

Once in the 20 years I have owned the tractor, the arm came unlatched,,,
I was pulling a 7 foot grader blade, and overloaded it,,

Is it possible, that you overloaded the tractor?

 

[seanndiane]

I hope not. It's a 55hp tractor, class 2 hitch, pulling a 16 blade disk harrow (5ft) in previously tilled soil.