WM up/down chain repair and upgrade

[Jim_Rogers]

On Wednesday of this week, I was sawing and when I went to lift up the saw head to load another log, I heard this loud "snap".

And when I looked to see what it was, it was this:



 

One of my two up/down chains had broken.

And most likely it was my fault.

Last week they were pretty loose. So I took out the bottom bolt that you use to tighten up the chain and cleaned off all the threads and loosened up the jamb nut. When I did this I found the 3/16" roll pin that holds the bottom bracket to the adjustment bolt was broken on one side.

I got a new roll pin and put it all back together with a lot of bluecreeper all over it to keep it lubed up and working.

I then tightened up the adjustment bolt so that the chains were not flopping around when I moved it up and down. It had been "jumping" a link, or trying to jump a tooth on the sprockets, every now and again when lowering down. And I didn't want to damage my gears or sprockets, any more.

Not wanting to wait for UPS to bring a new part in from the dealer, I found the same chain at a local supply house in 10' lengths. I had to replace both as I knew you shouldn't replace one without replace the other due to differences in lengths because of wear.

The tech at WM told me they right size and number to ask for and how to take it apart by starting at the bottom and pull the chains up through to the top.

Taking apart the bottom wasn't hard as I recently had it apart last week. Pulling it up through the machine wasn't hard because one chain was broke. Undoing the top connection was a bit of a challenge as both master links were in the middle. But I did manage to get it apart and took one piece with me to match up with the new ones before I left the supply house.

They did have the correct size chain and $100 later I had the new parts.

Next, I had to get the new ones to be the correct number of links to the old one, regardless of the length.
So I laid out the new chains and the one full length old chain on one of my work benches:



 

Using a pair of needle nose pliers I counted off the links, like this:



 

Even though the links were the same number this was the difference in chain lengths:



 

Then I ground the side of the chain to remove the rivet head:



 

And then using a chisel, I separated the links:



 

Now, I had two new chains of the correct length for my mill.

I attached the top end first:



 

Again this isn't the easiest thing to do as both master link clips are on the inside between the two chain brackets. Putting a rag down under the connection area saved me from dropping a master link clip down into the sawmill several times.

Next I had to feed the chain down through the frame and around the top pair of gears, through the machine and around the "drive" gears.

Well, that meant taking off most of the guards and feeding it through wasn't the easiest thing to do, with a very well oiled or greased pair of chains.

I finally figure out that I could use my framing square tongue as a tray to slide the two chain ends through the small gap between the gear to the sawdust side of the mill:



 

After that it was back through the same gap and around the two bottom sprockets and through the down hole to the cross beam and adjustment bolt at the bottom:



 

By the time I got this done, attaching the two chains to the bottom bracket and putting the adjusting bolt back through the frame cross member it was just about dark here. So I had to stop.

Today, I called the factory and talked to the tech service guy again to understand exactly how to tighten this up so that they will work correctly and not be too loose and not too tight.

He explained to me that with the newer models they have put a small spring below the cross member with the adjustment bolt up through the spring. Washers on both sides of the spring and a spacer to hold the spring in the middle and so that the spring won't touch the threaded part of the adjusting bolt. Once this is all in place to loosen up the top jamb nut way up and tighten the bottom nut up until the spring is collapsed. This spring will hold the chains at the correct tension.

I'm on my way out to the hardware store to see if I can purchase, locally, a spring and a couple of washers and a spacer. Once I have these parts on hand, and it stops raining here, I'll install these and hopefully get back to sawing again.

I wrote this up for anyone who has an older style up/down chain set up, like mine used to be, and wanted to upgrade their's to a better system.

I'll get another photo of the spring in place when I'm done.

Jim Rogers

[Magicman]

Looking good Jim.  Mine uses a double chain, but the challenges are still there. 

Sharing our maintenance items surely will help others, because they will surely have them.   ;D

[Jim_Rogers]

I just got back from the hardware store. I found a spring that's the right size in diameter, but it's too long. I'm going to have to cut it back with a hack saw before I can install it.
And I did get the one with the right wire size, along with two washers for the top and bottom. However the tech guy said I should have a spacer between the spring and the bolt. I guess they must be using a larger spring then the one I've got as there is no space between the bolt and the spring for a spacer.
I hope this works.

Still raining a bit here, and I left my piece of cardboard that I lay down on out and it got all wet, bumper >:(
I'll have to find my spare..... I never liked laying down in wet sawdust....

Jim Rogers

[Magicman]

You may have to use a side grinder with a cut off wheel instead of your hacksaw.   :-\

[POSTON WIDEHEAD]

Good Pics Jim! 

[Jim_Rogers]

You may have to use a side grinder with a cut off wheel instead of your hacksaw.   :-\

You don't think my hack saw will cut it ;D :D

Jim Rogers

PS sun's out got to go.....

[Chuck White]

Nice step-by-step Jim.

I'm sure it'll help out some others!

[beenthere]

You don't think my hack saw will cut it ;D :D

Make a video of it Jim. That'll show how it is done. ;)

[Peter Drouin]

Im glad you got all back together ok

[Jim_Rogers]

So, my hack saw could cut it. But holding on to a spring to be able to use a hack saw to cut it proved to be a challenge, for sure. But a bench vice did it.

When I got out to the mill the ground was wet so I took my tarp and put it down with the wet side down and laid down on that to install the new spring.

Well the tech at WM told me to get a 1" long spring and two 1/2" flat washers. After undoing the nut and attempting to put all these things back onto the bolt hanging down there just wasn't enough threads for everything.
So I had to go with just the nut and the spring.

Like this:



 

And I tried it up and down and the chains didn't have any slop in them at all. I was very happy with this upgrade.

I figure when I do see some slop in the chain, later on, I'll take the nut off and put the two washers in and put it all back together again.

After putting all the guards back on, I loaded up this 18' hemlock.



 

Not one of the straightest ones I've ever seen for sure.

But I just got to make some 2x10x16's for a foundation guy to use a footing forms, so it shouldn't matter much.

Jim Rogers

PS. no time for video, but thanks for the idea.

[terrifictimbersllc]

Jim, helpful post, thank you.  Isn't the head hanging on the chain and at risk of falling if the chain breaks? Maybe I missed it but didn't see mention of how you dealt with this.

[Jim_Rogers]

Sorry about that.
Well the tech guy said to lower the head down till it was about 4 or 5" off the bed.
I didn't want it that low, as I didn't want to have to bend over to look in and line up the new chains over the sprockets and gears down there. So I found a stick and put it between the saw head and the battery box/fuse box. And then lowered the head down onto the 2x2 stick. This prevented the head from falling on me while I worked on it.

I think my stick was at least 18" long maybe even 24" long, so that all the gears and everything was up high so I could easily see it and work on it to put all the new things in.

It also helps with the guards to have the head up high, in order to see the bolt holes when you replace the guard bolts.
The guard I have the most trouble with installing is the one that goes behind the small 45° belt guard. This guard has two bolts up through the bottom of the heavy steel beam and then into a nut welded to the guard. I found that if you use a standard round pencil to put into one of the two holes the cone of the tip of the pencil helps line up the holes and make it easier for the second bolt to line up to the thread in the welded in nut. In the past I used a round tip metal punch but I was always worried that I mess up the threads of the welded in nut. So using a wooden round pencil tip worked great. Once you get one bolt started the other one lines up pretty easy.

Having the machine up high helps to see all these things.
I hate to have to bend over when there is an easier way to do it.

I hope this has helped you some more.

Jim Rogers

[Dave Shepard]

I do believe there are instructions in the manual for supporting the head. I remember something about 5/16" chain around the top of the mast.

[Peter Drouin]

ya chain it up  :D :D that's what I do when I'm working on it

[terrifictimbersllc]

I do that for safety but don't like putting weight on it fraid it will distort top bracket/ pads. Jim's method but backup with 5/16 chain sounds good.

[Nomad]

     I've had to replace the chain on my LT50 twice now.  Due, as I found, to operator error. :  I found the easiest way to do it was to connect the old chain and the new one with a master link and feed it through the sprockets.  I didn't have the nerve to use power to do it, so I put a ratchet extension through the drive pulley and used it as a handle to spin the pulley.  Only took a few minutes to feed the new chain in.

[Peter Drouin]

Run the chain around the head and up over the place where the lift chain connects.you have to do that when you change the up down belt

[JustinW_NZ]

Good instructions there 

One question, how much slop is there meant to be or is allowable in the chain?
Mine has a fair bit of deflection underneath the head, but I haven't seen any issue?

Cheers
Justin

[Jim_Rogers]

With the spring I have in there now, there isn't any slop at all.
If you have some slop you may want to upgrade your machine with a spring.

I like the way it works now.

Jim Rogers

[WELumberjack]

Thanks @Jim_Rogers for your detailed post. Yesterday I encountered the same issue with my 1992 WM LT-30 hydraulic where the master link broke at the bottom by the up/down chain tensioner bracket and bent the bracket. It will help me a lot in getting things back together.
Ben

[WELumberjack]

This is what my up/down chain tensioner bracket looked like once I removed the tensioning bolt. It may have been reusable if I bent the V back together, but the sides of the "F" on the broken side that engage the 2 cross links on the chain were bent upwards, different from the opposite side. I have a replacement kit from WoodMizer on order for $32.28 + shipping for the "Up/down chain tension assembly."

[WELumberjack]

This is the 5/16" G70 chain (as referenced by Dave Shepard above) I used to take tension off the up/down chain by putting a chain over the crossmember of the mast head vertical and underneath the sawhead. It was recommended by the WM tech rep I spoke with on the phone, and better than a stump of wood on the ground. That allows you to keep the sawhead up higher and be able to work on things at the sprockets at a higher height.

[Magicman]

Just as a matter of information, if you pull the head down too tightly in the travel mode, you are putting an enormous strain on that lower chain connection.

[WELumberjack]

@Magicman, thanks for the information.  Each evening/when I'm done sawing for the day, I have the habit of resting the sawhead on the travel pin, rather than have it up in the air (sometimes it's a couple weeks between my sawing opportunities since I don't saw full-time). What do you suggest doing to not "pull the head down too tightly" onto the pin? What do you do in your daily regimen to avoid that? What do I need to check to know I'm not putting strain on that lower anchor point/chain tensioner bracket & bolt? I'm trying to avoid repeated issues. You have much more experience than me and likely do this daily.I researched my owner's manual on WoodMizer's website.  I can only find reading WM's manual for my '92 LT-30HD in the section "Preparing the sawmill for towing" (Section 2.20), the following text:"6. Lower the saw head until it is seated firmly on the rest pin. 7. Continue lowering the head 3/4" (19mm). until it contacts the stop blocks on the mast rails.CAUTION! Failure to properly secure the saw head can result in severe machine damage. Lower the saw head onto the rest pin until it contacts the rest pin collar, then lower the saw head 3/4" (19mm) further to insure that the saw head cannot be dislocated from the rest pin.8. If necessary, adjust the two stops (Figure 2-20) located at the bottom of the mast so the saw head contacts them after it is lowered 3/4" (19mm) past where it contacts the rest pin."I didn't know that these 2 stop blocks existed.  Would adjusting the height of those to the correct height, avoid "pulling the head down too tightly" and take pressure off lower chain tensioner bracket?  When looking from the hitch, the travel pin is on the right side of the sawhead; these 2 "stop blocks" are on the left side of the sawhead at the bottom of the mast.I also found a reference for how tight/how much deflection my up/down chain should have for my LT-30 when properly tensioned (Page 3-19). "Measure chain tension with the head all the way to the top of the vertical mast. Secure the carriage with a chain (at least 5/16") at the top. Find the chain adjusting bolt at the bottom of the mast, behind the battery box. Adjust the nuts on the bolt until you can get about 1.5" (3.8 cm) total deflection in the center of the chain with a 5 lb. (2.3 Kg) deflection force.

[Chuck White]

When you're lowering the head on an LT40 and it gets near the bottom, listen for a clunk, as soon as you hear it STOP and you'll still have some slack in the lower part of the chain!