crank (woodruff) keyway trashed -- to braze or not to braze? (1 Viewer)

[mtnphilosopher]

So, I heard/noticed a crank pulley/harmonic balancer wobble, and posted to confirm:

https://forum.ih8mud.com/60-series-wagons/746405-rth-harmonic-balancer-wobble.html

Thanks, Spike for doing so.

I initially thought it would be worn rivits on the HB, but as I began loosening belts, it got REALLY wobbly. Loosen more, HB can move a bit out on the crank shaft. Get mirror, happy to see that rivets look good, but...

Isn't there supposed to be a nut there? A big one, like 46mm that's a PITA to remove?

Still happy -- out come the radiator, fan, etc. I see this:


And out falls this:
[/ATTACH]



Not so happy.

Research on 'Mud shows many have had the same problem, and have addressed it in several different ways. But first, I need to take off timing cover to see the extent of the damage...

 

[Pighead]

Isn't there supposed to be a nut there? A big one, like 46mm that's a PITA to remove?

Um, yes.

 

[mtnphilosopher]

peeling the onion

Timing cover comes off, as well as anything that gets in the way -- e.g., 1/4" of oil grime, the oil cooler hose (now I know why it's called the "hose from hell"), a/c condenser (another question -- I just moved it to the side because I didn't want to undo any connections and create my own private ozone hole. Is there any way to remove without draining the freon or whatever it is?).

This is what I see:



Maybe I can still make it work?



So that's where I am. I've seen some other pics of similar problems, but none quite so bad. The ugly truth:

1) I'm pretty poor for another couple of weeks, but the upside of being off work for another week is that I have a week to work on my truck.

2) It's my DD, but I have the use of a buddy's car until 7/2 (a week).

There seem to be three options (one of which, unfortunately, does not include a diesel swap -- stupid economic "downturn").

In order beginning with the cheapest, fastest, and easiest (wouldn't it be cool if cheapest could be fastest and/or easiest -- just once?):

A) JB Weld or Loctite 660. Many swear by them, but on a keyway with this much damage?

B) Braze the keyway (a la Mark W and others). I'm still reading up on this, but it seems to entail getting a new key (available from local dealer), and building up the damaged area with filler material, then filing/grinding down to match the rest of the crankshaft.

C) Replace the crank. Ugh.

Other pertinent info:

I don't have a garage in which to work, nor the tools that would be in a proper garage (big enough compressor w/air tools, welder, engine jack, etc.).
I haven't welded anything in 30 years (but am hankering to do so).

Oh yeah -- here's my HB/crank pulley. The key slot looks ok to me, other than a bit of damage on the left side (but what do I know):



Should I even consider (option A) JB Weld or Loctite until a more permanent solution is viable? My inclination is to rent an oxy-acetalyne torch, practice a bit, the give option B a shot, but I have a tendency to bite off more than I can chew (like buying a '60 as my DD). When considering option C, I had vision of a "tarp garage," and a rented engine hoist, but I live in an apartment, and the friends in whose driveway it is currently parked and partially dismantled, get back in a week.

Any and all opinions are welcome and appreciated, including "WTF were you thinking being po', living in an apartment, and buying a '60 as your primary means of transpo?"

...need ...

Brad

 

[69rambler]

Using a cape chisel, cut a keyway on the opposite side, file to finish fit and install a new key. The Toyota crank snouts are soft, softer than they probably should be. Surprising considering it's a forged crankshaft which should have been forged, rough milled to size (yes, crank journals are usually milled, not turned), vacuum case hardened then finish ground to size.

I wouldn't put brazing heat to a crank snout in-situ. It's incredibly easy to bend steel with heat.

I would be tempted to install the new key and damper with loctite cylindrical bonding. Since this is a very common failure it might even be a good idea to drill, tap, counterbore the key and install a small cap screw or two holding the key into the crankshaft.

Also, a Woodruff key is completely different. That is a square key, not Woodruff.

 

[Pighead]

Well, you're gonna need a new nut (or used). And LandCruisers do seem to work well with trail fixes for a while anyway...If you promise your 'Cruiser to fix it properly, and soon, you may be able to get away with a JB weld fix for the time being.

 

[southy]

I know you said you have limited tools but are you able to remove that crank?
If I was in the situation id get the key re cut 180 degrees out (so directly opposite this one)..
I would not trust JB weld or any of that on a crank..

 

[mtnphilosopher]

Um, yes.

Silly me, buying a 46mm socket when I don't even need it.

 

[mtnphilosopher]

I know you said you have limited tools but are you able to remove that crank?
If I was in the situation id get the key re cut 180 degrees out (so directly opposite this one)..
I would not trust JB weld or any of that on a crank..

Thanks, Southy -- and that should have been another option. I went through the FSM (late) last night trying to figure out if I can remove the crank without pulling the engine. Couldn't figure it out, so (total Noobie question), "Can I remove the crank without pulling the engine?"

I have all the hand tools (torque wrenches, but no SSTs), and think I see how it may be possible if I dropped the oil pan (something I need to do anyway to replace the gasket/check off one right of passage).

Thanks again,

Brad

 

[Pighead]

"Can I remove the crank without pulling the engine?"

I think so, yes. Though I've never tried it myself. Assume you'd have to drop the transmission too.

 

[mtnphilosopher]

Using a cape chisel, cut a keyway on the opposite side, file to finish fit and install a new key. The Toyota crank snouts are soft, softer than they probably should be. Surprising considering it's a forged crankshaft which should have been forged, rough milled to size (yes, crank journals are usually milled, not turned), vacuum case hardened then finish ground to size.

I meant to include this one as well. I saw your reply to another post making the same suggestion, but then couldn't find it, and couldn't remember the correct term ("cape chisel"). Thanks for the reminder, and it sounds like a viable "home machine shop" possibility. Any suggestions or directions on which cape chisel, precautions, etc.? I'll search here and google it as well.

 

[mtnphilosopher]

I think so, yes. Though I've never tried it myself. Assume you'd have to drop the transmission too.

No transmission jack, but could probably fashion and/or rent one. My concerns are the "can o' worms" and "while I'm here" kind, particularly given time and budget, but, again, it may be the only/best option.

 

[augirthedude]

That would be impressive to make a new keyway in the crank with stone knives and axes while it is still installed in the truck.
I would use this product to fill the void and maybe even tap some small screws into the damaged area so the putty has something to anchor to. I have used this product with success ! but not quite in this application.

http://www.devcon.com/products/products.cfm?brand=Devcon&family=Plastic Steel® Putty (A)

 

[mtnphilosopher]

Well, you're gonna need a new nut (or used). And LandCruisers do seem to work well with trail fixes for a while anyway...If you promise your 'Cruiser to fix it properly, and soon, you may be able to get away with a JB weld fix for the time being.

Yeah -- that was my rationale as well. It's my rig's 28th birthday in July, so I'd have to have the proper fix by the end of the month, latest.

Still, I don't wanna drain and pull the rad, shroud (yes, I'm splitting it), etc., again in a couple of weeks.

 

[mtnphilosopher]

That would be impressive to make a new keyway in the crank with stone knives and axes while it is still installed in the truck.
I would use this product to fill the void and maybe even tap some small screws into the damaged area so the putty has something to anchor to. I have used this product with success ! but not quite in this application.

http://www.devcon.com/products/products.cfm?brand=Devcon&family=Plastic%20Steel%C2%AE%20Putty%20%28A%29

Now, now -- I did request any and all suggestions; however, after reading this:
http://toolmonger.com/2009/09/10/get-out-of-a-bind-with-a-cape-chisel/

and this:
http://www.practicalmachinist.com/vb/general/cape-chisels-keyways-hows-done-242227/
I realized it was way beyond my pay-grade.

I did check out the Devcon Plastic Steel Putty, and it seems stout. Anyone else care to chime-in on the de/merits of JB Weld vs. Loctite vs. Devcon?

Any of the "pro-brazing" crowd care to chime in?

Also, if I cut/have cut a new keyway (180 degrees from original) don't I need to fill the original?

Thanks for all the help.

 

[69rambler]

If the pulley is not sloppy on the crank I wouldn't bother trying to fill the old keyway.

JB weld and epoxy aren't very durable, they are very soft compared to ferrous metals. They make very poor wear surfaces. Being soft, they allow particles of harder material to embed themselves and actually wear out the other part sometimes.

Cape chisels may be stone age tools, but they are still current and will never go away. They are a tool, just like a cutter in a mill or lathe, just used by hand. I think you would be very surprised how quickly you can rough the keyway out with one. My WAG would be you'll have the keyway roughed in about 30 minutes then spend the next couple hours doing the final fitting with the chisel resharpened and a small file or two.

I have used cape chisels to completely remove rusted solid and sheared off bolts as small as 5/16" from down inside machinery where nothing else could reach without harming the existing threads. They are a very capable tool with just a little patience.

Use a small hammer, it does not require much force to push the chisel's cutting edge into steel. You want a small chisel, 1/8" or 3/16" wide cutting edge and small hammer so you can control it easy and not tire your hands out too fast.

There are lots of videos on Youtube showing people engraving metal with hand tools. They can give you a good example of how to hold the tools and how little of a hammer tap it takes to drive the tool.

 

[Trollhole]

My advice. Do it the right way and replace the crank or find another motor.

Or do it the wrong way and put it all back together and weld the nut to the crank and pulley while keeping the sealing surface cool and know that if you have a problem your going to have to do it the right way.

 

[TobyB]

Buy the chisel, practice on a couple of other soft pieces of metal, and when you realize how easy and
controllable it is to do, cut another keyway.

It'll take an hour (less time than it takes to get the oil pan off)
and work for the remaining life of the motor. When you rebuild, you can
braze up the damaged keyway- or not, as you decide then.

Check the inside face of that balancer/pulley- it may have a great big groove chowed into it.
Or it might not, if the nut suddenly decided to leave, rather than slowly loosening over months.

Good luck!

t