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!

[Magicman]

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?

Yes to what Chuck just said.  Drop it down and firm it up. 

[WELumberjack]

Thank you Chuck @Chuck White & Lynn @Magicman. When I get my replacement part from WM and get it all back together sometime this next week, I'll try that out and be more aware of how much I use the down lever to make sure the sawhead is barely resting on the "stops" and make sure that I have some slack in the lower part (and upper part) of the chains.  I wasn't aware of the stops before this week/I hadn't read that part of the manual.  Initially when I got my sawmill, my habit was to lower the sawhead to rest on the travel pin. Then during a trip to my local WM shop they said to put it down further, so the left side would go down until it stopped, and I started to do that. But I was not aware of/they did not mention the "stops" on the left side.

Here's what I think happened (which Lynn described in reply #22) - when I was putting the sawhead down, I likely kept engaging the motor after the sawhead had contacted 1) the pin on the right and 2) the stops on the left, and thereafter was pulling on the bottom chain connection while the sawhead was restricted by the stops. I did that enough times and/or the up/down motor was strong enough, and the chain-link fatigued/broke from that strain.

Is it recommended/mandatory to replace "master links" on both chains, or just the side that broke?

[Magicman]

Everything is the same age, so I would play it safe.  The cost is minimal especially when you consider if it breaks.

[WELumberjack]

I figure that since I have it all apart and the covers/guards all off, I'll fix what needs to be done. The master-links I got come in a 4-pack. I don't think I need all new chains like Jim showed above with replacing both of his chains. It looks like at the time his chain broke in the middle. Mine broke on the end link. It's a 30-year old sawmill and I assume the chains are original given the mill has ~850 hours on it.  

[Magicman]

@850 hours, I agree, but I would replace the master links, etc. since you are already there and have it apart.  Give that chain a regular soaking with ATF.  Mine gets it at the beginning of every saw day. 

[WELumberjack]

To apply my ATF I use a 2-gallon handheld pump sprayer with a wand to coat the felt runner of the carriage track that runs on the top rail, along the top rail, as well as run the wand along the chain that the power feed runs on. I may have neglected the up/down chains and the mast rails by comparison as those are harder to get to. I also find it difficult to easily lube the bottom rail. Maybe others have suggestions of what they do.

I initially tried to use a handheld spray bottle to "spray" on the ATF, but had to fill that too often and in a winter environment like WI, the viscosity of the ATF was too thick to get it to spray in droplets and the mechanism would fail easily.  In the south, viscosity probably isn't an issue. Not sure if anyone else uses other methods. 

[Magicman]

I do not lube the bottom rail because it is an electrical contact point for the hydraulics.

[WELumberjack]

Good point. I hadn't thought of that. That would be counterproductive. I haven't lubricated the bottom rail on my mill so far, because it would be a difficult thing to do from a maintenance standpoint.

So for understanding, let me ask if I got this right for the purpose of maintaining the top and bottom rails and proper lubrication. If you don't lube the bottom rail because it is an electrical contact point for the hydraulics, what should I do to maintain it? Should I treat it similar to the 6' copper strip on the left side of my mill that also helps run the hydraulics when the sawhead is back toward the hitch?

Is the top rail mainly designed for wear and due to gravity/friction and being exposed to the elements, I need to lubricate it and the felt wiper pad with ATF to keep it lubricated and to avoid rust? And I'm using ATF (compared to grease) because the sawdust doesn't stick to ATF as much as it would to grease.

Is the bottom rail used only for the electrical contact?  But roller bearings also run on that rail as the sawmill moves forward with the power feed.

What do I need to do to maintain/lubricate the track roller bearings that run along the top and bottom rails?  Do I use grease for those using a grease gun? How often?

[Magicman]

The cam followers that are on my sawmill top and bottom are sealed and I don't do anything with them until they need replacing.  I only use ATF on the chains and wiper felt that lubes/cleans the top rail.  It's purpose is to prevent sawdust buildup that will get under the cam followers.  They need to roll clean and smooth.  I have never had a buildup problem with the bottom rail.

I could see where road salt would play havoc with the bottom rail. 

[Ben Cut-wright]

I do not lube the bottom rail because it is an electrical contact point for the hydraulics.

Good point. I hadn't thought of that. That would be counterproductive. I haven't lubricated the bottom rail on my mill so far, because it would be a difficult thing to do from a maintenance standpoint.

So for understanding, let me ask if I got this right for the purpose of maintaining the top and bottom rails and proper lubrication. If you don't lube the bottom rail because it is an electrical contact point for the hydraulics, what should I do to maintain it? Should I treat it similar to the 6' copper strip on the left side of my mill that also helps run the hydraulics when the sawhead is back toward the hitch?

Is the top rail mainly designed for wear and due to gravity/friction and being exposed to the elements, I need to lubricate it and the felt wiper pad with ATF to keep it lubricated and to avoid rust? And I'm using ATF (compared to grease) because the sawdust doesn't stick to ATF as much as it would to grease.

Is the bottom rail used only for the electrical contact?  But roller bearings also run on that rail as the sawmill moves forward with the power feed.

What do I need to do to maintain/lubricate the track roller bearings that run along the top and bottom rails?  Do I use grease for those using a grease gun? How often?

The bottom "rail" should be lubricated.  It appears there is confusion between rail and electrical contact strip.

[Magicman]

I know the difference between the copper contact strip and the bottom round rail.  

The copper strip is the positive contact and the bottom rail is the negative contact.  The cam follower (s) ride the sides of the bottom rail and the spring loaded negative contactor rides on the bottom of the bottom rail.  I am assuming that the LT35 is the same as my LT40 in that regard.

[WELumberjack]

It likely is the same. I'll be at my sawmill hopefully this Thursday and take a detailed look. Lynn, my LT30HDG24 is a 1993, so a little older than your '98 LT40 super HD, but is basically a 4' shorter version of WoodMizer's LT40's of that era.  I'll also check what my manual says in the meantime and look to see if my cam followers are sealed or not or if they have a grease fitting.

Summarizing to see if I got this right:
So the bottom rail is the negative. And in order to run any of the 4 hydraulic functions, the sawhead has to be in contact with the left-sided copper strip (+) near the hitch. And in order to run the 3 electrical functions along the length of the sawmill (up/down motor, forward/reverse power feed, and in/out guide roller), the spring-loaded negative contact rides along the bottom (6 O'clock position) of the bottom rail.

Greasing the cam follower bearings (if mine have a zerk fitting) will keep those rolling smoothly (internally), but keeping the bottom rail free of rust and technically I don't want to put any lubricant on the bottom of the bottom rail in the path the spring-loaded negative contactor rides to keep good electrical contact with the bottom rail. If I wanted to, I technically could rub some type of lubricant (ATF) on the bottom rail in the path that the cam follower runs to avoid friction between the metal-metal contact of the cam followers and the bottom rail, but not in the path the negative contactor runs.  I'm not sure if both those paths are the same.  I will have to take a look.

And keeping the top rail cleaned with the felt wiper pad that's soaked with ATF will help keep my cuts smooth, prevent sawdust buildup on the top rail, and will minimize rust formation due to the top rail being exposed to moisture/the weather.

I think I got it!

[Ben Cut-wright]

I'll also check what my manual says in the meantime and look to see if my cam followers are sealed or not or if they have a grease fitting.



Greasing the cam follower bearings (if mine have a zerk fitting) will keep those rolling smoothly (internally), but keeping the bottom rail free of rust and technically I don't want to put any lubricant on the bottom of the bottom rail in the path the spring-loaded negative contactor rides to keep good electrical contact with the bottom rail. If I wanted to, I technically could rub some type of lubricant (ATF) on the bottom rail in the path that the cam follower runs to avoid friction between the metal-metal contact of the cam followers and the bottom rail, but not in the path the negative contactor runs.  I'm not sure if both those paths are the same.  I will have to take a look.

And keeping the top rail cleaned with the felt wiper pad that's soaked with ATF will help keep my cuts smooth, prevent sawdust buildup on the top rail, and will minimize rust formation due to the top rail being exposed to moisture/the weather.

I think I got it!

Section 3, page 3.5, paragraph 1: "Lubricate the lower track rail by wiping it with Dexron III ATF."

[Magicman]

And in order to run the 3 electrical functions along the length of the sawmill (up/down motor, forward/reverse power feed, and in/out guide roller), the spring-loaded negative contact rides along the bottom (6 O'clock position) of the bottom rail.

Not really.  All of the functions other than the hydraulics should be wired directly to your battery.  The bottom rail only comes into play with the hydraulics, but certainly it is always supplying supplemental grounding.  It rides the entire length of the sawmill head travel.  If the bottom rail is not making full contact you would/could be drawing some hydraulic pump current through the cam followers which would probably heat them up and .....

To address the bottom rail lube, yes I occasionally take an ATF wet rag and give it a good wipe down, but I am more interested in keeping it clean rather than lubricating.  Thankfully my sawmill has never seen salt and it does not rust. 

Ben's statement above is correct.

[NaySawyer]

To clarify, if only for me .. the old mills used a piece of threaded rod with a roll pin through the top to attach to the lower double chain bracket.  The bottom of that rod passes through the gantry's lower cross beam.

Typically when one side of the roll pin breaks, the other may pull out or fail too.  Woodmizer has an upgrade kit for this that replaces the anchoring rod/roll pin with a bolt and a flatter lower bracket.   Although there is no weight on the roll pin or rod the bolt head is allot more secure than the roll pin.  

hope this helps

[WELumberjack]

@NaySawyer,
 Yes, you are correct. When I ordered the replacement kit from Woodmizer for my '93 LT-30 last week, it came with the long bolt with a bolt head that fit snuggly inside the lower bracket such that when I installed it, I did not need to put a wrench on the top of the bolt; just tighten the nut on the bottom. (No more threaded rod with a roll pin). With the sawhead raised all the way to the top, the recommended deflection of the up/down chains pushing in the middle was 1-1.5" deflection from vertical with 5 pounds of force (using a standard belt tension gauge).  The chains are not supposed to be rigid/taut. Also, for my replacement kit, it did not come with a spring as Jim showed a picture of in reply #9, as may be on newer mills.

Either way, I got everything back together last week and am back to sawing.  Similar to what Jim described above, my experience in putting the 2 master links together with that new bracket was it was a bit tricky to fit the master link clips right next to each other. Not sure it really matters, but one slider clip was on the inside and one was on the outside of the bracket. All that matters to me is that it's clipped together and holds.  It's not like roller chain on a bike that has a single direction of force.  This is an anchor point.

To my knowledge, just replacing things as I did, did not change the accuracy of the measurement of my blade height on the sawmill bed compared to the main height gauge/ruler. Although if someone has to replace both chains, that measurement may change due to old chains being stretched and new chains being tighter.

And to solve/avoid the issue of having this happen again, when I'm done sawing for the day I just leave the sawhead suspended by the chains; I'll put it down on the travel pin, only when I'm travelling (and I'll make sure the bottom chains are not overtight!)

Lastly, I checked my mill & my upper cam followers have a zerk fitting for grease as well as the felt pad for ATF over the top rail. The cam followers on the bottom rail are sealed. The spring-loaded negative contactor rides on the 6 O'clock position under the bottom rail, and the cam followers on the bottom rail ride on the 4:30 & 7:30 position.

Being in WI, my sawmill has the potential if moved in the winter, to being exposed to salt.

[Chuck White]

The replacement is definitely an improvement over the threaded rod and roll pin that was the original on the LT40 I used to have!

I upgraded mine a couple of years before I ended up selling the mill, much easier than the earlier setup!