# Stub guard adjustments



## DSLinc1017 (Sep 27, 2009)

I'm in the process of installing new stub guards on a NH 1465. After reading the manual, (RTFM). It says to adjust the hold down clips 0 to .015 clearance. I've been using a feeler gage of .008. Its very difficult to shim these clips just right especially from one to the next. Some of the guards don't sit perfectly flat from one to the next as well, even after taking a wire brush to the mounting steel. 
I do have a bunch of all the shim's as well. 
So my question is, how critical is the gap? Should I go a little tight less than .ooo or give the hold down clips a bit of gap?

Thanks all for the advice.


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## mike10 (May 29, 2011)

First thing. When shimming for stub guards always use a new knife or a knife with new sections. IF you shim with a knife with worn sections you will get the shimming too tight. Also the tips of sections can be bent and will give you the problem you are describing. Before inserting the knife into the machine stand it on edge and eye down the length of the knife to make sure it is straight. You can straighten the knife by laying it flat and hitting it with a hammer on the high spot. A straight knife will make the shimming go a lot easier and you will have a better job.

Second. When I install stub guards I first install and tighten three guards, the two end guards and one in the center. No clips at this point. I then lay the knife in place on the guards. I then install the rest of the guards with clips and shims, but leave the bolts and nuts loose.

Now with the knife in place check how much clearance you have between the first guard and the first section. The first section needs to be in contact with the first guard. Loosen the knife head bushing clamp bolt and raise or lower the knife head until the section contacts the first guard. Before tightening the clamp bolt rotate the wobble drive until the knife is in the center of the stroke, section in between two guards, and then tighten. This step on tightening is not so important for your machine, but for other machines, like the 488, it is necessary.

Now you are ready to start shimming the clips to the guards. Turn the wobble drive until the sections are over the guards. I start on the wobble side of the machine and only shim one guard hold down clip at a time. Install the necessary shims so the clip is not pinching the section you are working on. If you are using NH guards and clips, the first three high clips will take a pile of shims. Install enough shims until you have a gap between the section and clip. NH has two thickness of shims. I use the thinner shim as a gauge. If I can get the thin shim in between the section and the clip, I will remove shims until I can't but still the knife is not pinched. You will find that one tip of the clip will be just right and the other tip either higher or tight on the section. In situations like that, cut one the shims, it will look like a square with a slot, and install so the cut shim will be on only the one bolt where the clip needs to be higher. Do this until you get the clearance just right. Time consuming, yes, but worth the effort. Continue down the bar.

Some tricks; The clips can be bent in case you have one that is way off. Clamp the clip in a well anchored vice and take a large hammer and hit the tips of the clip.

The only thing I use to judge the clearance is the thin shim. When I remove or add shims I will take the shim and see if it can be slipped in between the section and clip. If it can not, then I grab the section and see if I can slide the knife front to back or vice versa. If you can move the knife you should be good, if not add shims.

On the 488's, and I think on your machine, I then grab the reel and pull towards me, If the knife is free it should rotate the wobble drive and move the knife back and forth. I watch the tips of the clips as I do this, If I see one moving up and down I know it is too tight, re-shim. To rotate be sure the front pto shaft is supported so it can rotate freely. You know you are good if when you are done you can still move the knife by pulling on the reel.

If you have guards that are significantly lower, do not shim the clips to push the knife down. I made a tool which I can bend the guard mounting plate of the machine. Since you do not have a tool, you can do as I do on combine heads. Cut a shim like I mentioned before so you have that square with a slot. Now cut the legs at the half way point. Usually the guards will be too low. In that case loosen the guard and slip the shim from the rear between the guard and the cutterbar. This will tip the guard up in front.

Under no circumstance use the clips to excessively force the section down. You will not be able to remove or install the knife from the machine and you are likely to cause wobble drive or knife failure depending on machine.

Place a floor jack under the cutter bar and raise the head as high as possible.

Always rotate the knife so the same section is over the same guard when shimming. You will drive your self crazy if you are shimming a section to two different guards.

An impact wrench helps a lot.

All this seems like a lot of work, but goes quite quickly, just be patient.


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## DSLinc1017 (Sep 27, 2009)

Mike10, 
Thanks so much! 
I should have mentioned that I am using a band new cutter bar with serrated knives. 
I did start exactly as you pointed out, installed the end guards and a center guard with out the clips. Slid the new bar in then started from the center, not the end as you pointed out.
I did NOT adjust the head bushing. Fortunately I only have a quarter installed. A small step back to adjust the head bushing. 
Now that I know that's ok to cut a shim, a sigh of relief has swept over the process. As well as knowing that a small shim gap is desirable. Along with all the rest of your detailed instructions. I feel like I can fine tune this 1465 and feel good about it. 
I don't touch jobs like this without my cordless impact wrench!

I think I'm going to have to print out your instructions to proceed.

Thank you for the detailed response, the time you have taken is priceless and deeply appreciated. 
I am humbled 
With great respect, Michael


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## mike10 (May 29, 2011)

Glad to help. There are a couple of other items I should have mentioned but forgot, old timers I think. I always remove the paint from the flat surfaces of the guards and from the tips of the hold down clips. This only makes a few thousanth's difference but it is something I do.

If this is the first time the machine is getting stub guards then the reel tines will probably hit the hold down clips. There are shims under each end of the reel and there should be some spares bolted to the left side sheet. If there is only one or two tines hitting, I will cut or grind the tips of the tines so they clear the clips.


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## DSLinc1017 (Sep 27, 2009)

I've noticed the spare shims, will defiantly take look. 
Thanks again!


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## DSLinc1017 (Sep 27, 2009)

Done!! It took a good long day to get it right. Ended up running out of shims near the end of the process but found that washers work well. I did have two guards that for some reason were lower than the others. It wasn't the guard as I swapped them out for others. Took a file to the mounting bar but that didn't help much. Ended up grinding down the clip where the carrage bolt goes through on the surface with the bar. Little by little got the guard to match the others. In a few places I ended up with a small shim gap under the knife instead on top. I went with it as I could easily push the knife down and get the gap on top.

Replace the chain a bit of grease and oil and I'm good to go.

Again thanks much for the advice. If I come away with anything from this process. I would say.... I'm going with a disk mower before I ever change out another haybine guard!

Cheers,
Michael


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