Another brush hog mower question

[JimR]

I took the blade assembly off the mower again yesterday. The splined shaft is in fact worn. I can feel a wear step on it at the top where the blade attachment stops. I also tried pushing it further up on the drive unit. It still rocks, but not as much. This unit has seen better days. I will try one more thing before just saying the heck with this unit. I am going to lift up the mower again with my bucket and try to drill the center of the shaft. If I can drill it, I can tap it and save it. If it is hardened, that would be out of the question. If not, Ill be buying a like new or brand new mower. I have put $100.00 into this one. With that, I made $300.00 mowing their fields and trees and got to do about 4 acres of my hilltop already. I also found that the two blades were bent upwards and turned up at the cutting ends. I bought a new set yesterday and tried them out hoping that the bolts would stop breaking. The unit still breaks the bolts. Here's the grade 5 5/16" bolt that I had in it the other day. You can see that it is stretched downward in two spots. This has got to be related to the looseness of the blade adapter and the shaft fit just pounding the daylights out of the bolt. I'll let you know how the drilling goes if the rain stops.

 

[SPYDERLK]

I took the blade assembly off the mower again yesterday. The splined shaft is in fact worn. I can feel a wear step on it at the top where the blade attachment stops. I also tried pushing it further up on the drive unit. It still rocks, but not as much. This unit has seen better days. I will try one more thing before just saying the heck with this unit. I am going to lift up the mower again with my bucket and try to drill the center of the shaft. If I can drill it, I can tap it and save it. If it is hardened, that would be out of the question. If not, Ill be buying a like new or brand new mower. I have put $100.00 into this one. With that, I made $300.00 mowing their fields and trees and got to do about 4 acres of my hilltop already. I also found that the two blades were bent upwards and turned up at the cutting ends. I bought a new set yesterday and tried them out hoping that the bolts would stop breaking. The unit still breaks the bolts. Here's the grade 5 5/16" bolt that I had in it the other day. You can see that it is stretched downward in two spots. This has got to be related to the looseness of the blade adapter and the shaft fit just pounding the daylights out of the bolt. I'll let you know how the drilling goes if the rain stops.

Jim, try the loctite retaining compound suggested in #15. Its a cheap experiment and may cure the problem. Yould be surprised how much stiffness this adds in a joint that has significant overlapping components. I did a 1-1/2 X 2" smooth joint on a 5" JD bushog blade drive yoke. I cut a bunch of stuff, trees and rocks included, before I broke it loose - - and the loctite was the only thing holding it! You have the splines. Filling the joint to immobilize the yoke should do wonders.
Larry

 

[JimR]

I suppose I could give the Loc-Tite a shot. I do have a few bottles of it kicking around. There is nothing to lose and lots to gain if it works. I'll have to clean all the grease off the splines and yoke to make it work right. I'll also have to plug the bottom of the hole in the center of the yoke, it is hollow.

 

[SPYDERLK]

Jim, what loctites do you have?? Some are not appropriate. #638 will be about the best, but if you tell me what you have, I will tell you how they rate.
Larry

 

[JimR]

I'll check tomorrow on which ones I have. I believe that I have 4 bottles. Two red, one blue and one yellow. Oh ****, I'll go look now. Here is what I have
222MS for small fasteners (forget that one)
271 adhesive/sealant
290 Threadlocker
326 Adhesive speedbonder

How about this product. Loctite-Application Assistance

 

[SPYDERLK]

I'll check tomorrow on which ones I have. I believe that I have 4 bottles. Two red, one blue and one yellow. Oh ****, I'll go look now. Here is what I have
222MS for small fasteners (forget that one)
271 adhesive/sealant
290 Threadlocker
326 Adhesive speedbonder

How about this product. Loctite-Application Assistance

Jim, Very neat product. Thanks! Several years ago another fellow and I spent considerable time charting Loctite test info taken from their spec sheets. In doing this we perused the info very carefully and took up questionable areas with Loctite Corp. We found errors in some areas and discrepancies in uniform application of their test procedures elsewhere. We were pests. There is still probably some name recognition at Loctite.

When I saw your post I looked at my chart and chose Retaining Compound #s 620, 635, 638. I noted 680 as a contender, but too weak @2800psi.
Then I saw your product and went thru the selection process coming up with #680 - - Huh?. I then modified the search parameters a little and came up with #s 620, 638, 648. I looked at my chart - - 648 @3.3K is still weak compared with 620-4K, 635-4.5K, 638-4k. ?????? Some of the problem is that the automated selection will sometimes force you into a partially correct choice. Some more of the problem is that some how it does not always choose from the same strength numbers that are reported on the Data Sheet for the specific product. Example - In the Auto select, if you key on #680 it says strength to 4000, but if you look on the DS it says 2800 like my chart - - thats a relief - I thot chart was wrong even after all that effort we spent to verify.
So, my word about using their "select" product in the blind is -"DANGER".
I recommend #638. It is among the very stongest and is good for cyclic loading and will fill a gap and set up well. Nuances, that we looked deep to find, affect this recommendation. 620,635 cure slowly - 620 has TRUE hot strength (up to about 400F). You may not ever be able to get it off without heating the shaft to the point where you ruin the seals. Product #638 was recommended to me many years ago by a Loctite guy that knew what he was talking about - at least according to a hard look at the data sheets.
It sounds like you know about preparation and joint filling. Give it a day to set then put a lightbulb on it for a few days to assure cure. Quite warm to the touch is good. Do not use the primers or accelerants. They produce a weaker joint.
Luck, Larry
Dont use the ones you named. All of the threadlockers, even 270Studlocker Green, suffer in the nuance department for use as a retaining compound.

 

[JimR]

Thanks Larry, I think that the 638 is the one to use also. I just found Loctite's website today and found that they had the applications list for their products. I'll be picking up a bottle of 638 tomorrow.

 

[sandman2234]

And the verdict is....

can you salvage it, or are we now looking for some new or used parts?
David from jax

 

[JimR]

And the verdict is....can you salvage it, or are we now looking for some new or used parts?
David from jax

That project is on hold. I started a big roof job last week. This mower deck will have to wait. I also ordered the Loctite and it has not arrived yet. I will try the Loctite first sometime this week if I get a chance. I do have a backup plan if it fails. I just recently bought an engine lathe. I can knurl the output shaft to enlarge the metal. That should take up the slop in between the shaft and mower assembly. Loctite on them with very little clearance should hold it. Worse case scenario would be to drill and tap the end of the output shaft. Right now my mind is on getting this roof done. I still have the rest of the roof to finish on the building to the right side and the rear of the left roof behind the chimney to re-rafter and shingle.

 

[SPYDERLK]

And the verdict is....can you salvage it, or are we now looking for some new or used parts?
David from jax

That project is on hold. I started a big roof job last week. This mower deck will have to wait. I also ordered the Loctite and it has not arrived yet. I will try the Loctite first sometime this week if I get a chance. I do have a backup plan if it fails. I just recently bought an engine lathe. I can knurl the output shaft to enlarge the metal. That should take up the slop in between the shaft and mower assembly. Loctite on them with very little clearance should hold it. Worse case scenario would be to drill and tap the end of the output shaft. Right now my mind is on getting this roof done. I still have the rest of the roof to finish on the building to the right side and the rear of the left roof behind the chimney to re-rafter and shingle.

Hey Jim. Ever get to this? I never saw any follow up. The Loctite seemed like a good solution. Knurling could have helped too, but splines are usually HARD and may not take a knurl.
larry