Accidentally bent drive pulley when trying to remove...

[Alrashid2 310]

Ugh... feel like an idiot. Quick backstory: I noticed that my drive belt was ever so slightly rubbing the brake rod on my 1985 312-8 with a Kohler K301 engine. Looking at the engine belt from above, I could see that the drive pulley was just a hair too close to the engine, skewing the belt inward and thus pushing the belt into the brake rod. I was originally thinking I could just dremel off a bit of the brake rod surface to give some clearance, but then I was looking over the parts diagrams and saw that the drive pulley on the engine had a set screw! Sweet, I should be able to just pull it out a hair and that would move the belt away from the brake rod. Or so I thought...

 

Well, I take off the PTO and clutch assemblies and get to the pulley. Parts diagram says 2 set screws. Take out both. Pulley won't budge. Heated and sprayed PB Blaster. Still not moving. I eventually took a pry by behind it and slowly tried to shift it off the crankshaft... I thought I was making progress and then saw I was bending the pulley V from the engine side... ugh!!

 

Looking at it from 45 degrees (as close as I could get my head in to the engine) I could see it was slightly bent. Freaking out, I took a block of wood and a dead blow hammer, and put it into the V to bend the V back toward the engine. Hit it with a few blows, and it appeared straight again.... Straight enough at least that after I turned the pulley a few times I forgot where I had bent it... I then ran the tractor for 10 minutes and she ran fine, then I watched it idle from the front and I couldn't see any bumping or inconsistency in the blur of the pulley spinning... My thought was that if the pulley was bent the "blur" of it moving at thousands of RPMs would look inconsistent, or the belt would be bumping up and down, but I couldn't see anything. She seems to be running fine. 

 

Think I am in the clear? Any issue with just running her? That's what I get for tinkering... Thanks guys.

Edited Thursday at 08:02 PM by Alrashid2

[ri702bill 8,507]

Pictures from several angles of the part would be of help to assist you in fixing it......

[Alrashid2 310]

Hey @ri702bill. I assembled everything together again and test ran it to check for any issues. 

 

I'd take pictures but they won't show anything to you guys. Like I said, I couldn't even tell where the bend was after hammering it back down

[Alrashid2 310]

Scratch that - I found the spot. With a bright light I can see the stress mark on the inside of the V where i bent it outward.

 

I'll admit, looking at the edge and feeling it, the pulley doesnt feel out of alignment. Maybe I can just lightly sand down the stress mark?

Edited Thursday at 08:50 PM by Alrashid2

[Alrashid2 310]

Update. Sanded it down with 400 and 600 grit sand paper. Feels smooth to the finger. Also checked and it doesn't seem to be affecting the position/seat of the V belt.

 

However, now its starting to look very crack like to me... Seems like a stress fracture.

 

I'm hoping I can just keep running her. In nearly 50 years I'd think this isn't the only little crack on the horse... What do you guys think? Really hoping I don't need to replace the pulley as #1, I can't get it off and don't have the tools or skill to do so, and #2 it seems like it's very difficult to find an exact match pulley... 

 

So upset with myself now. I need to learn my lesson that sometimes trying to be overly proactive can just cause more problems. Hoping to get your opinions one way or another... Thanks guys 

 

P.S. @ebinmaine @SylvanLakeWH@Ed Kennell @peter lena @Bar Nuthin @oliver2-44 Sorry if I'm being a nuisance but calling out a few of you who have really helped me with some sage advice so far. Ive really appreciated your input so far and would love to hear from you on this as I'm real stressed out about it... thanks guys. 

Edited Thursday at 09:16 PM by Alrashid2

[SylvanLakeWH 25,965]

Run it for a while and see if it changes... hard to say from the pictures...

 

Again, these things are 40+ years old and well used... they will run under a lot less then ideal conditions... 

 

[Alrashid2 310]

Thanks @SylvanLakeWH. Will make a note of it's location in relation to the set screws so I know where it is. Thanks again for a bit of peace of mind...

[Bar Nuthin 542]

Another case where if it's a problem, it will make itself known at some point.

 

I must say, I feel like you've taken my signature quote to a whole new level! 

Edited Thursday at 09:38 PM by Bar Nuthin

[Alrashid2 310]

@Bar Nuthin so funny you said that - when I first saw your sig, I said to myself, "Wow, that's the story of my life right there!" 

 

Another one that I'm infamous for regretting soon later is "What's the worst that could happen?" 

Edited Thursday at 09:55 PM by Alrashid2

[Alrashid2 310]

Tried to get a little pocket mirror behind the pulley, though hard to get behind it (hence why I was trying to pull it!) but from what I could see, no damage or crack there. I also took a straight edge to the little 2" section I could fit it on and it sat flush. So I think the pulley shape is fine - just a question if the crack will eventually break. I wouldn't think the pressure of the belt would be enough force to break it outward, but who knows? Honestly, if I bought it like this I would have never noticed if it was cracked. There could very well be other cracks on my pulleys I haven't even noticed! 

[ebinmaine 68,406]

1 hour ago, SylvanLakeWH said:

Run it for a while and see if it changes... hard to say from the pictures...

 

Again, these things are 40+ years old and well used... they will run under a lot less then ideal conditions... 

 

 

 

Seconded. 

Runnitt.  

Checkkit. 

If/when it breaks and you invent new words be sure to share them by PM.  

 

That might be fine for YYEEEAARRSSS like that.  

[SylvanLakeWH 25,965]

1 hour ago, Alrashid2 said:

Thanks @SylvanLakeWH. Will make a note of it's location in relation to the set screws so I know where it is. Thanks again for a bit of peace of mind...

Oh man... if you have a bit of my mind you are in trouble... 

[Alrashid2 310]

Thank you all so much for the help and advice here! Saved me

[Handy Don 12,467]

8 minutes ago, SylvanLakeWH said:

Oh man... if you have a bit of my mind you are in trouble... 

Because you cannot afford to lose any more?

 

Note that that engine pulley looks like a machined casting (many are). They do not take kindly to bending so keep an eye and ear out. Vibration and heat are not your friends in this situation.

[8ntruck 7,093]

Another thing you could do is to get a dye checking kit.  The kit has a spray can of cleaner, a spray can of dye penetrant, and a spray can of developer.  Not sure how much or where to get the stuff- Mc Master Carr maybe?  We would use it in the test lab on durability tests we ran on wheels.

 

You clean the suspected area of the part with the cleaner and wipe it off.  Then you spray the suspected area with the dye penetrant and wait 5 minutes or so.  The area is then cleaned of penetrant with a rag soaked with the cleaner.  Finally, the developer is sprayed on to the suspect area.  It will dry to a flat white coating.  If there is a crack, it will show up as a red line.

 

If this was not a drive pulley, I'd suggest using transmission fluid and talcum powder to do the same thing, but oil on a drive pulley is not a good idea.

[Alrashid2 310]

@Handy Don thank you sir, yes I was shocked how little effort it took to bend. Wish I never picked up the crowbar! 

 

@8ntruck thanks for the advice! Part of me wants to but part of me feels like ultimately it won't change much for me, though it is quite interesting...

 

I guess I better plan ahead just in case. How hard/expensive is it to get a new drive pulley for one of these? 

[lynnmor 7,354]

I would get a new pulley and toss that cracked thing in the recycle bin. 

[Alrashid2 310]

1 minute ago, lynnmor said:

I would get a new pulley and toss that cracked thing in the recycle bin. 

If I can find one relatively cheap then I'm not opposed to it... what I'm worried about is:

 

1. Getting this old one off. I'm mechanically inclined, but not interested in using pullers and torches and such to remove it. I've done more harm than good when I do that sort of stuff

2. Nervous I won't be able to find the right replacement pulley. Looking online I was getting all sorts of different model/part numbers and have no clue how I'd find the right one

3. The few people I did see discussing getting a new one said it cost hundreds of dollars - I paid $500 for the whole tractor!

[ebinmaine 68,406]

3 minutes ago, Alrashid2 said:

How hard/expensive is it to get a new drive pulley for one of these? 

New. Not likely or cheap. 

Good used. Definitely.  

 

As always contact our Redsquare vendors.  

 

 

Just now, Alrashid2 said:

Looking online

Just get outta that habit. Immediately.  

There's a plethora of good used parts available.  

 

1 minute ago, Alrashid2 said:

The few people I did see discussing getting a new one said it cost hundreds of dollars

 

This is ..... with all due respect.... just ridiculous people.  

 

 

[ebinmaine 68,406]

2 minutes ago, Alrashid2 said:

1. Getting this old one off. I'm mechanically inclined, but not interested in using pullers and torches and such to remove it. I've done more harm than good when I do that sort of stuff

 

YOU WILL LIKELY NEED A PROPER PULLER. 

@Pullstart recently posted a video to his own channel. He may be able to offer advice.  

 

 

 

 

[lynnmor 7,354]

6 minutes ago, Alrashid2 said:

If I can find one relatively cheap then I'm not opposed to it... what I'm worried about is:

 

1. Getting this old one off. I'm mechanically inclined, but not interested in using pullers and torches and such to remove it. I've done more harm than good when I do that sort of stuff

2. Nervous I won't be able to find the right replacement pulley. Looking online I was getting all sorts of different model/part numbers and have no clue how I'd find the right one

3. The few people I did see discussing getting a new one said it cost hundreds of dollars - I paid $500 for the whole tractor!

 

1. Go ahead and use a puller, breaking it more is a non issue.

 

2. There should be a part number cast in the pulley that you will see once it is off.

 

3. Quit prying against the engine, all you need is to crack it as well.

 

4. I bought a pulley from A-Z Tractor for a reasonable price.

Edited Friday at 12:02 AM by lynnmor

[Alrashid2 310]

Had an idea just to get a better view of the pulley installed. Grabbed my rifle bore scope camera and slipped it in there! I'm not super knowledgable (and maybe just being hopeful here) but it looks more like a "stress fracture" in the metal than a full on crack through. I put the bore scope on the back end of the pulley between the pulley and engine block - couldn't get in there quite well but from what I could see, no crack on the back side, so that makes me hopeful it's just a small fissure on the V side of the pulley only. Photos attached if youre curious and want to weigh in

[953 nut 55,827]

16 minutes ago, Alrashid2 said:

torches and such to remove it

DO NOT USE A TORCH or you will end up needing to replace the crankshaft seal or worse.

If you don't have the proper puller for this job your local auto parts store probably loans this type of tool for free, just have to leave a refundable deposit.

Call Lincoln at A-Z for a good used pulley.    https://www.a-ztractor.com/

 

[8ntruck 7,093]

Yup.  That does look like a crack.  Might be OK, might not.  The only way to tell is to keep track of the size of the crack - both length and width.

 

Being a cast pulley, I'd expect that the crack will grow.

 

A co worker was a helicopter pilot in the Air Calvary in the middle east.  Before each flight, he would look at the maintenance log of whatever machine he was going to fly.  The entry he really hated to see was "Unable to recreate reported problem.  Fly and watch."

 

One option for you is to "fly and watch".  Just keep in mind that you will be seated in the rotation plane of a damaged pulley with a rim speed of around 3000 feet per minute.

[Bar Nuthin 542]

48 minutes ago, Alrashid2 said:

Grabbed my rifle bore scope camera

My God! ? They trust you with weapons?