Timberwolf Fins and flywheel bearings

[Dean Lofthouse]

Got my mates Timberwolf 150 in which decided to throw the ali fins off the flywheel and up the spout. Whilst wI had it stripped I advised to replace the flywheel bearings at the same time.

 

Started by stripping off the hopper and roller housing, then undid the flywheel cover bolts and took the flywheel shaft centre bolt off. The rear flywheel bearing cup or housing is nearly always seized so I drew the cover plate complete with bearing housing off the shaft with bearing pullers. After taking off the drive pulley, I undid the four bolts securing the front bearing housing and withdrew the flywheel.

 

I then spent a good hour cleaning all the mating surfaces and bearing contact areas up then lightly sandblasted the flywheel shafts to clean off all the gunge, you can see the use of a three legged puller to take off the main front bearing which was then knocked out of the housing. You can also see where some animal had previously knocked out the bearings last time they were done and dinted all the housing.

 

The new flywheel fins were fitted after lighly sandblasting the mating surface of the flywheel to ensure a flat fit, the holes were slightly out of line but drilling the holes to a half a milimeter bigger helped align them.

 

Once the fins were fitted I proceeded to fit the main front bearing, this is where things get tricky, bearing alignment is vital on refitting to avoid end loading them which will cause premature failure and getting the gap right between anvil and blade.

 

The main front bearing is a slack fit in it's housing and a tight fit on the shaft, I fitted the bearing into the housing then only started it on the shaft, I then fitted one of the blades on the flywheel for a reference point.

 

I then put the flywheel to one side and refitted the flywheel housing cover and tightened it up. I then took a steel rule and measured the distance fron the back of the flywheel housing (as close to the bearing mount as possible) to the front edge of the side anvil which was say for arguments sake 122mm, if I take off 2mm from this measurement it gives me the measurement I need from the blade cutting edge to the foremost surface of the main front bearing housing which mates to the front of the flywheel housing.

 

As you can see in one of the photo's, I then pressed on the front bearing pressing on the inner race until I had that measurement less the 2mm for the clearance gap between the blade and anvil.

 

I then refitted the flywheel and bolted the front bearing and housing back in with the four bolts through the engine bay side, then refitted the flywheel housing cover. If everything is right you should have a 2mm clearance from the blade to the anvil.

 

Next is to clean up the rear bearing cup and push in the two bearings, they should be a nice push fit in with your fingers. I then put a small peice of wood between the flywheel and front cover to hold it in place so the shft was in the centre of the hole it protrudes through.

 

This is the important part, the rear bearing must be shimmed correctly, it is this bearing job to maintain the flywheel position and therefore anvil gap. If you press in the bearing cup complete with bearings over the shaft and into it's socket in the plate and press it home it may or may not have a gap behind it between the flywheel and bearing inner race. You can if you are competent measure with depth guages and vernier to find out but the easiest way is this.

 

Pull the bearing cup back out and fit a few shims (shims will be available from timberwolf) then push the bearing cup back onto the shaft and fully home, if theere are too many shims it will push hom and the bearings will push out of the bearing cup (you could measure how far they push out and reduce the shims by this amount) remove the smallest shim repeat the process untill the bearing and cup push home with the bearing pushing out. This is the correct shimming.

 

To check you have it correct, replace the bearing cup retaining cover and centre bolt and then leaving just one blade on turn it to 9 oclock and the weight of the blade should fall slowly to 6 oclock if it doesn't then there is a little side load on the bearing. First of all try slacken all the bearing housings off then retighten.

 

If this doesn't help line everything up you could try just giving the bearing housing a tap from either side with a rubber mallet, if still not sinking to six oclock then you will need to change the shimming to take off a few thou at a time till it does.

 

As a final check you should run the chipper with hydraulic belt removed to prevent the feedwheels turning for at least ten minutes and keep feeling the rear bearing housing to make sure it doesn't get hot. You should be able to hold onto the housing quite easily

 

Timberwolf did tell me a different way of doing it but being an engineer I had to do it my way

 

Picture also show removing a broken stud and the broken rear fins

[Mr Ed]

Dean, absolute quality job. I would be happy to entrust anything mechanical to your tender care.

Your skills as a fitter are underutilised!

[skyhuck]

Do you do Unimogs???????

 

And if so what do you charge?????????

[Dean Lofthouse]

Dean, absolute quality job. I would be happy to entrust anything mechanical to your tender care.

Your skills as a fitter are underutilised!

 

From you Ed I take that as a great compliment, you are a very skilled man yourself

 

 

Dave, I spent many years crawling underneath muddy all terrain vehicles and squeezing into tank engine bays, I run a mile at the site of anything remotely similar

[Mr Ed]

From you Ed I take that as a great compliment, you are a very skilled man yourself

 

No mate, I am very Knowledgable, and have a good idea of engineering and mechanics, but skilled I'm not. Compared to you I am a fumbling bodger.

[Mozza]

i REALLY wish i had your knowledge Dean, Im useless at mechanics but its the one things ive got most interest in, Awesome job you've done there mate :thumbup1:

[Ian C]

Good job there Dean, properly done, i had forgotten how lightly those things are built. looks like a toy in your pics..........

[Tree Man Tom]

I would be very happy if i only had half of the knowledge you have dean Any idea why the fins sheared off?

[Ian C]

Any idea why the fins sheared off?

 

cos there cheap alloy and not steel, heard of a few doing this and the fins aint cheap either.

[Tree Man Tom]

Any idea why the fins sheared off?

 

cos there cheap alloy and not steel, heard of a few doing this and the fins aint cheap either.

 

I see, makes you wonder why timberwolfs are so popular sometimes.