LT40 with Autoclutch - blade never stops?

Dad2FourWI · May 31, 2014, 08:12:45 PM

Yesterday I decided to change the blade... no problems, it almost jumped right on!!

Then I started my LT40 and I noticed that the blade started to spin....

I have autoclutch and it was NOT engaged - yet, the blade was spinning at a slow speed.

I decided to continue and cut some boards for stickers hoping that the blade would eventually stop when not engaged.

When I engaged the saw, the blade sped up and made some beautiful boards out of a bunch of oak scrap destined for the wood shed.... but at the end of each cut, I disengaged... and the blade kept moving (at a much slower speed).

This has not happened before but I have to admit that I have only been using this used LT40 for a short period so I do not have much of a "history" with her yet.....

Thanks for any feedback/ideas,
-Dad2FourWI

POSTON WIDEHEAD · May 31, 2014, 08:18:35 PM

Your brake may not be properly adjusted. With no brake....the vibration and the shaft spinning on the disengaged belt may be making the blade turn slowly.

red oaks lumber · May 31, 2014, 08:53:06 PM

+1

Gary_C · May 31, 2014, 08:57:48 PM

I have a LT40 with the auto clutch and have the same problem. There is an adjustment proceedure in the book and you have to work with it to get it just right. I think the adjustment has been revised a few times so make sure you have the latest version.

POSTON WIDEHEAD · May 31, 2014, 08:59:48 PM

Quote from: Gary_C on May 31, 2014, 08:57:48 PM
I have a LT40 with the auto clutch and have the same problem. There is an adjustment proceedure in the book and you have to work with it to get it just right. I think the adjustment has been revised a few times so make sure you have the latest version.

Gary....are you talking about the adjustment for the auto clutch or the break?

backwoods sawyer · June 01, 2014, 01:39:32 AM

Earlier this week I replaced a missing g-8 bolt on the brake system.
Drive belt had been slipping as well. The auto clutch adjustment and the throttle adjustment affect each other and the break works off the auto clutch. This is a reletivly simple adjustment but a good one to have the manual handy as you don't want to over tighten the drive belt or throttle linkage. (there is more then one style of auto clutch)

Dad2FourWI · June 01, 2014, 04:58:11 PM

Between rain storms and fighting off mosquitoes, I had a chance to dig a bit further and review the manual several times... I am a bit confused!

I took off the Autoclutch cover (managed to break off a bolt! >:( ) and found that someone had made a nest in there!

I cleaned up a bit and noticed the Link Arm... but when I read the manual it said that the upper pivot, middle pivot and lower pivot should all be aligned.... ok but WHEN ??? (engaged or disengaged?)

Here is the Link Arm when the engine is off... and I drew on some lines...

Here is the Link Arm when the engine is just idling...

Here is the Link Arm when the engine is engaged and running...

The blade is still rotating when at idle.... but I am thinking that I may have found out why.... can anyone enlighten me a bit here?

Many thanks,
-Dad2FourWI

Gary_C · June 01, 2014, 05:28:12 PM

Quote from: POSTONLT40HD on May 31, 2014, 08:59:48 PM
Gary....are you talking about the adjustment for the auto clutch or the break?

They both work off the linkage adjustment that is in the picture. It's been a long time since I've been into that adjustment but you have to get both the linkage settings just right for both to work.

drobertson · June 01, 2014, 07:10:54 PM

Quote from: Gary_C on June 01, 2014, 05:28:12 PM
Quote from: POSTONLT40HD on May 31, 2014, 08:59:48 PM
Gary....are you talking about the adjustment for the auto clutch or the break?

They both work off the linkage adjustment that is in the picture. It's been a long time since I've been into that adjustment but you have to get both the linkage settings just right for both to work.

+1 , a very easy adjustment,

Brucer · June 01, 2014, 08:26:28 PM

You need to adjust your brake.

That looonnng hex nut that looks like a turnbuckle (vertical in photo 3, at an angle in photos 1 & 2) slides on one of the links. When the autoclutch is engaged, the link is vertical (photo 3) and maintains upward pressure on the motor mount. You adjust the link to get proper belt tension.

When the autoclutch is disengaged (photos 1 & 2) the link is at an angle and should not be applying any pressure. The bottom link should have slid out of the hex nut about 1/8" to 1/4". From the pictures, that doesn't appear to be the case.

In the disengaged position, the weight of the engine and motor mount is carried by the brake band pressing down on the brake drum. The top mount of the brake band has a long slot with two carriage bolts through it. You can see the tops of the carriage bolts in the upper part of the photos. Take off the outside cover and you can get at the nuts.

You need to slack these two nuts off and slide the top of the brake band downward. This will cause the motor to sit a little higher, which in turn will cause the brake band to press more firmly on the brake drum.

The adjustment is kind of trial-and-error. I engage the autoclutch (with the engine off) to adjust the brake band. That way there's no pressure on the band and it's easy to make the adjustment. To check my adjustment I make sure the two nuts are tight and disengage the clutch. You should see the bottom link slide out of the long hex nut a little, which is what you want.

Before I start messing with the brake adjustment I put a mark on the brake band mounting to show me where the original setting was.

Dad2FourWI · June 01, 2014, 08:54:52 PM

Brucer,

Thanks for the feedback!

It has been a long day here and I have printed out your reply to re-read with a strong "cup of joe" tomorrow AM!

I will take off the outside cover tomorrow or Tuesday (it looks like Monday is going to be raining all day.... we really do NOT need any more rain!) and will take some more pics and see if we can make some sense of this...

Again, thank you for the info. This LT40 is new to us... but the more I look "under the hood" I can see that it has been around the block!

-Dad2FourWI

Ga Mtn Man · June 01, 2014, 09:16:02 PM

D24WI, do you have a manual for your mill? If not, you really should bite the bullet and get one from WM. You will need it.

Dad2FourWI · June 01, 2014, 10:09:51 PM

I have a "Safety, Setup, Operation & Maintenance Manual LT40HD" and I have the "Autoclutch Option Safety, Installation, Operation & Parts Manual".... but I have to admit, I have read over a lot of manuals and I seen better manuals!

For instance, in this case, the manual says that the three pivots needed to be aligned...

Well that is great... aligned when the engine is engaged or when the engine is at idle?

It may be me, but I did not see that small point in there... and maybe I could have used some more coffee too but as I stand there, it would be nice to know when this "alignment" was suppose to happen (in what state)...

If you have any suggestions for a manual or whatever, I am all ears or eyes or well, you understand!!

Thanks,
-Dad2FourWI

Magicman · June 01, 2014, 10:27:43 PM

On my sawmill, it would be impossible to align the pivot points when the clutch is disengaged. The picture in the manual is obvious that the clutch is engaged.

Ga Mtn Man · June 01, 2014, 11:29:22 PM

My apologies D24WI. I missed the line in your previous post where you said you had the manuals.

Section 3.3, Step 2 in the auto clutch manual tells you to push the auto clutch toggle switch up to engage the drive belts.

You may not have the same version of the manual as I have.

Brucer · June 02, 2014, 12:03:55 AM

I think the manuals could have been a little clearer. I installed my autoclutch as an add-on so I got to know it pretty thoroughly.

As the brake band wears, the motor mount sinks down a little further in the disengaged position. That closes the gap in the link until there isn't a gap any longer. Then the linkage is taking the weight of the motor and the brake is no longer effective.

I have to re-adjust my brake band every 500 hours or so.

5quarter · June 02, 2014, 12:49:53 AM

You're drinking the wrong coffee. Have Bruce send you some of his special blend. after a couple cups, you will be able to rewrite the LT-40 manual. ;)

MartyParsons · June 02, 2014, 06:40:07 AM

Hello,
Brake is not adjusted correctly. On your photo # 2 you have a circle around the drive belt adjustment link. The bottom of the link has two nuts and the top of the link has one nut. When the brake is adjusted correctly there should be space between the two nuts and the barrel of the adjuster. The barrel is about 3" long and has six sides. Remove the cover under the water and fuel tanks. You can see the adjustment bolts on the brake in your pictures, there are two bolts with lock nuts on them. Mark where the link is now before you move the adjustment. Engage the auto clutch, loosen the nuts and slide the brake down. This will make the brake come on before the link is out of travel. Disengage the auto clutch and check the bottom of the link you should have about 1/8" between the barrel and the nuts at the bottom.
If you have the brake coming on to soon the drive belt will not be loose enough and it will smoke and squeal at idle, if it is too loose the band will spin at idle.
The bolts break on the cover often, you can drill out with a left hand bit, put never seize on the bolts when you put the cover back on.
This picture is for a gas engine the diesel mills will have a heavy ring above the two nuts it is use as a spacer to increase engine lift.
This would be a good time to grease the lower pivot point. It is behind the up and down gear box and it often missed.
Hope this helps.
Marty

Dad2FourWI · June 03, 2014, 10:09:38 PM

I am back up and running again!

Many thanks Brucer and Marty - your detailed instructions were _very_ helpful !

It is always a bit frightening on trying something like this the very first time !!!! The idea with marking the current location with a sharpie was awesome! I will have to lower it again since I still do not have enough space on the AutoClutch turnbuckle... but that will be easy now!!

MagicMan, yes.... now that I have studied this over and have made the adjustments, I can see that it is obvious that the picture in the manual is shown with the clutch engaged... :-[

I think that 5quarter was correct.... I need some better coffee!!

! :D and I think I am going to look into some more up-to-date manuals too (good idea Ga Mtn Man!)

Just in case another "newbie" is searching this forum in the future, I am going to add in a few more pics that might help them become a bit more "familiar" with this adjustment!!!

Thanks again everyone !!!!!

-Dad2FourWI

Remove belt cover

Albeit, a bit dirty, this is the break strap bracket needing adjustment... clean it and then place a mark on the bottom of the bracket where it is currently...

After a bit of cleaning and lowering the bracket 1/8" down (as you can see from the sharpie mark)

The Autoclutch turnbuckle now has a "tiny" amount of space between the bottom two nuts and the barrel... not enough, so I have to adjust the break strap bracket down a bit more to finally have 1/16"-1/4" of space

Magicman · June 03, 2014, 10:29:29 PM

Thanks for the update. Your are very correct in keeping the thread continuity flowing which will help others with a similar problem to find their solution. We all help each other.

Brucer · June 04, 2014, 12:43:15 AM

Even a "tiny" space will stop your blade from moving at idle, because all the engine weight is now on the brakeband. However, the band will wear and close the gap. You're better off setting it to the maximum recommended gap while you've got the covers off and right tools at hand.

If you ever have to adjust your drive belt tension, be sure to check the brake setting afterwards.

Nice followup. Thanks for taking the time to do it.

caveman · May 14, 2022, 10:24:11 PM

John and I were sawing cedar and oak for a customer who drove quite a ways for us to saw for him. On the third cedar log, the autoclutch would cycle and not disengage. We called wood mizer and they suggested that it was not the switch. We pulled the five sided cover between the engine and the front vertical rail of the monobeam. After using a meter, John determined that one of the Parker sensors was not working.

We temporarily installed a switch that would bypass the sensor so we could finish the job. WM's computer system was down today so we'll find out Monday if they have the part in stock. Ironically, the part from WM was $55 and on the net it was $120-$150.

We sawed mostly cedar and a few oaks today. Some of the oaks were firewood, in my opinion.

This is the magnetic sensor that failed without notice. The additional switch takes a little getting used to. I only used it when flipping the cant or when loading another log, otherwise, the blade kept moving.

Some may also notice the oak box on top of the accuset II. It holds a couple of commonly used wrenches, tape measure, chalk/crayon and has some magnetic clips above to hold cut lists. It has magnets epoxied to the bottom to keep it in place.