F935, pulley removal - sheared bolt removal

[Big Wave D]

I am dealing with part 7.

I went online to Deere parts and it labels it as a tapered fit pulley. So it seems that I should be able to use a standard puller for removing it. Not going so well at the moment. Will heat help much? How 'rough' can I get with it in trying to remove it?

After getting it off, the second problem is removing the remainder of the bolt that is sheared off in one of the 3 thread cups. I haven't really tried anything since I've not gotten the part off; however, I am wonder about what other options I might have other than drilling and using an extractor. It is an M8 sized metric bolt, so not overly large, but I am wondering if it is possible to do the welding technique? If so, how? Am I literally trying to use the bolt as my "rod"? Don't want to screw up the threads.

Thanks for any tips or advice.

 

[Big Wave D]

Okay, as an update. I was able to use some 'gentle' heat and get the pulley to come free from the front of the crankshaft.

Now only 1 problem left, removing the old sheared bolt.

Is drilling and trying to use a bolt extractor my best or maybe, should I say, my only option?

I'd like someone to weigh in on the welding method. Is this to small a bolt to try this with? It's only an M8.

Thanks

 

[Zebrafive]

Is the bolt broken off above or below the pulley?
Blind hole or go all the way thru?

 

[Big Wave D]

The bolt is broken off just a few threads below the lip of the blind hole.

Have decided to go with the drill and extractor route. The bolt size just doesn't allow enough room to try and weld a smaller bolt to the remainder and not mess up the threads.

I know of PB Blaster or Kroil, but is there any other tricks for trying to get the remainder of the bolt to let loose?

I have heard of somehow using candle wax, but don't remember how it was explained to be used to help unsieze the stuck part.

 

[zzvyb6]

Now that the pulley is off, is the remaining bolt stub loose enough that a small dental pic or chisel can work it out? The conditions of the other bolts should give you a hint. A small sharp center punch usually works for me. Can you get a hold of a reverse direction drill bit so that if it bites on the bolt it will unscrew it?

If you unbolt the motor mounts, you might be able to tip the engine upward enough to get a better working position view.

 

[zzvyb6]

Since the pulley is off, no need to tip the motor. Manual indicates there is Loc-Tite on the threads, so heat it up to release the thread lock. A center punch then ought to back out the bolt fragment. If you can cut, grind or chop a slot in the stub, a screw driver ought to be able back it out, too.

 

[Big Wave D]

I saw that to, about the thread lock. It says medium body, so I hope I don't have to heat it up to cherry red or anything to have it let loose.

I have tried the pick and also an old nail set. Kind of had a little corner to work on, but it seems like it was only going to mess up the threads, so I stopped.

I did get and extractor to finally 'bite', but could tell it was only going to snap if I tried to force it any more. I have not added the heat yet and will today. I do hope that it will finally play nice and let loose so I can back the rest out.

Some one had already replaced one bolt with a substandard, 8.8. So, I am wondering it that is what got broke off. The did not use Lock-Tite for the other, so I am hopeful that the broke one doesn't have any either.

We'll see.

 

[moored4]

Now that the pulley is off, is the remaining bolt stub loose enough that a small dental pic or chisel can work it out? The conditions of the other bolts should give you a hint. A small sharp center punch usually works for me. Can you get a hold of a reverse direction drill bit so that if it bites on the bolt it will unscrew it?

Since the pulley is off, no need to tip the motor. Manual indicates there is Loc-Tite on the threads, so heat it up to release the thread lock. A center punch then ought to back out the bolt fragment. If you can cut, grind or chop a slot in the stub, a screw driver ought to be able back it out, too.

I would start reverse drilling just enough to get a hole started and then heat it up, then while its hot from the heating prosses then finishing drilling and cross your fingers that it will back out whill drilling it! GOOD LUCK! :thumbsup:

 

[Big Wave D]

moored4,

I just bought some reverse drill bits yesterday. Had to put the project on hold because of already made plans for Friday evening.

I am going to use heat and see if the extractor that is 'anchored' in the remaining bolt will do anything. If it doesn't, then I will give your heat and l.h. drilling a try next.

Thanks to all for the advice and well wishes. :thumbsup:

 

[canucklehead]

I have exact same issue. Haven't removed pully yet...was going to use a puller. How was the sheared bolt to remove?

 

[Big Wave D]

The left handed drill bit worked with a bit of heat.

 

[canucklehead]

my son was trying to help me. I suggested the LH drill but but he insisted on his method. He didn't center the punch very well before drilling hole. He drilled 5/32" hole and then hammered in a T-25 torx bit. It got a great bite, but wouldn't turn the broken bolt. May have stripped hole a bit. So then we applied oxy/acetylene and got it red. tried the same torx bit and managed to completely mangle the torx bit. tried a LH extractor, wouldn't touch it, but by this time I could see the hole was pretty buggered up and probably wouldn't re-tap. Also noticed when I used puller to remove it, I may have overtightened puller (really hard to pound puller with hammer from that angle/geometry). anyways, the puller also pinched the top and bottom of pulley enough that I decided that would wear belt funny, plus mangled hole= new pulley.

also bought a new rubber spacer/isolator. WOW... expensive parts IMHO. I also bought JD bolts at $2.40 each. I'm told they're grade 8. woulda thot maybe softer grade bolt might prevent other damage but I suppose rubber isolator will still be the first to go before bolt would shear.

any idea what these torque to on driveshaft, and on pulley? Loctite as well?, or are the ny-lock nuts good enough?

 

[Big Wave D]

That was the cause of my problem also. Some used lower grade bolts and they snapped.

That area is a nasty venue for access. It SEEMS like it should have more than enough to get done what you want, but as you said, the angles are all wrong.

I don't own the mower, just do repair work for the nonprofit that does. I too have experienced the sticker shock of JD parts. They sure are proud of their paint.

I had the left side axle bearing go out and needing replacement. There was some gouging done to the axle shaft. When I inquired about that 16" long shaft by about 1" diameter for pricing, even the JD parts guy said it must be gold plated, $350+.

I found a machine shop that could build it back up and ground it back to size, $45. I told the parts man I'd take 2, not really.

 

[canucklehead]

I too have experienced the sticker shock of JD parts. They sure are proud of their paint.

haha, very well put. it's disgusting. It isn't justified. All about paying off all the layers of distribution so they all make copious hoards of $$.

and when there is a weak link, they should cut you a break to make it right. Instead, you get to feel their wrath of greed. to clarify, not knocking JD products, but when they discover recurrent weak spot costing loyal owner downtime, repair cost, etc... wouldn't in be nice to cut owner a break on parts to stop the bleeding? Instead, it feels like someone stepping on your throat when you're down. Ice the cake with snotty attitude from parts guys (with no prompting or whining from me).

Once China clones all their parts and marketing, they'll be hurting.

 

[pat32rf]

The pricing guy works for Polaris on his spare time.....
An axle shaft made by Neepco that looks identical to one for a Mazda is twice the Mazda price....which is twice the Chevy price!!

 

[canucklehead]

I just replaced Grizzly rear axle for $125, a place from Ontario.... It is bigger/stronger/better (allegedly). look an ebay, that's where i found them.