OutdoorKing Repair Forum Forums Collectors Corner Cylinder Alroh Rear Roller - Will Not Reverse

Morning all

Picked up an Alroh 20 inch with split rear roller, didn't notice until I went to put in the shed that the mower wont pull backwards, it only rolls forward. Has anyone struck this before ?

Cheers
wce

Hi wce
You need to isolate the problem issue.

Is the problem within the roller assembly or within the landroll clutch?

Remove the final chain in the chaincase and see if you can rotate the
final drive sprocket. It should engage anticlockwise, but freewheel
clockwise {for LH chaincases].

Hope this helps.
--------------------------------
Jack

Thanks Jack

Will have a look into this area.

Cheers
wce

G'day wce,
Did you get any joy with this?

I have also just (yesterday!) bought an Alroh 20" split roller mower. I haven't tried running it yet because the fuel tank looks grubby/rusty(?) and I want to clean it thoroughly before use. When simply pushing it the right section will only roll forwards but locks up when trying to pull it back. I'm new to these mowers so if you have gained some understanding of what is going on it will probably help me. Cheers,... in anticipation!

Good evening Beammeup and Jack

I didn't end up doing anything about it as it was not a big issue to me. I conferred with the chap who does my blade sharpening and set as he is knowledgeable about cylinder mowers, his comment was the same as Jack's about having to diagnose the cause but was reasonably sure the rear roller would have to come out and be dismantled. His other other comment was how much time is the mower going to be used in reverse ? it's not going to effect it's mowing performance and being a 20 inch you would be using it on a larger area not requiring it to be stopped and pulled backwards to get around tight corners and you can tilt up on the front roller if required but they are pretty heavy. It's mainly maneuvering in the shed but if you can walk it in and face it forward then you don't have to pull it backwards at all.
It sounds like your mower has been sitting for a fair period of time which will always contribute to things becoming stuck, the fuel tank issue shouldn't be an issue to sort out unless rusted through.
Lastly but importantly, I applaud you for doing the right thing and picking up the mower as agreed after you made the offer sight unseen. I've done this on many occasions and it's a case of sometimes it works out well and others not so good.

Cheers
wce

G'day wce and Beammeup
I have had this experience before too.
Many thanks for saving another Alroh.

I would like to comment on wce's blade sharpening guy who said,
"...how much time is the mower going to be used in reverse?"
I don't get that view at all!

That view may disguise the real issue and real problem.
If the machine can't reverse then it will effect differential action,
important to all split roller reel mowers, and crucial to mowing.

In other words, it can effect how mowers turn going forward!
One, or both, rollers will lack differential capacity.

The best advise is to diagnose the problem.
Possibilities ... clutch, seized pawl(s) or seized shaft to roller(s).

Cheers
----------------------------
Jack

Morning Jack

With the unit I had, everything worked fine when going forward, turning wasn't a problem and it mowed great. Yes, there was definitely a problem there, but wasn't causing me concern enough to rectify.

Cheers
wce

G'day wce
Fair enough and I understand your thinking there.
Many thanks.

I would like to add a simple test and background to
my thoughts here. It is an indulgence, I know ...

I have always favoured split rollers on reel mowers because
they permit less scuffing to grass on turns.

Sure, split rollers made no sense on some of the very small
reel-roller mowers of the late 19th and early 20th century.
[Here, I'm talking about tiny 6, 8, and 10 inch roller mowers].

But 12" and above roller mowers require split rollers for quality
grass cutting [in my view]. The Scott Bonnar Model 30, for
example, has four rear rollers!

Here is a simple test that shows that a mower that cannot travel
backwards must affect differential action and induce scuffing.

If you were to stand behind a reel-roller mower and turn it
with ZTR (zero turn radius] then the outside roller will turn in the
same direction as the turn; the inside roller will turn away from the
turn direction.

If only one roller fails to turn backwards then that roller is the
problem [either seized bearings or pawls]. If both rollers fail
to respond then the issue may be both rollers seized or the
problem may lie with the landroll clutch holding both rollers.

Interesting discussion!

-----------------------------
Jack

Interesting discussion indeed Jack. Thanks.

In my case, since the mower rolls forward freely making a (quite loud) 'ratcheting' sound, can I eliminate seized bearings and pawls in diagnosing the problem?

Hello Beammeup
Not without the second test: -

Remove the final chain (or belt) to the rear roller.
With one hand turn the roller sprocket/pulley.
It should freely turn when rotated backwards but
engage the pawls and lock when rotated forward.

If it passes this test, the likely cause will be a clutch not
fully dis-engaging and providing enough 'drag' to stop
free-wheeling of the rollers backwards.

I don't have an Alroh parts list, so this is the best
answer that I can give today.

Hope this helps
-----------------------------------
Jack

Thanks Jack. I'll give it a go tomorrow.

I did what you said Jack.
I should say that the roller was on a couple of blocks of wood to keep it off the ground.

When I turned the roller sprocket, the roller turned freely with it in both directions. Surmising that the friction of dried grease from lack of use over a long period might have caused the rollers to turn forward together I applied a little resistance with the palm of my hand on the roller and turned the sprocket again. This time it did turn backwards relatively freely but engaged the pawls (made a ratcheting sound) in the forward direction. I take this as 'passing your test'.

However, after reassembly I played with the clutch to the point of being able to turn the motor side of the clutch freely without any discernible drag to the other side of the clutch and was back to the same problem that I originally had: locked up roller when pulling it backward. I'm scratching my head...

Hello Beammeup

The rollers should be on the ground.
Otherwise, Place your other hand on each roller (to eliminate frictional drag).

The rollers should engage when the sprocket is rotated forward.
The rollers should freewheel the other way. You should be able
to turn the sprocket easily when rotated towards the back with
no movement of the rollers.

--------------------------------
Jack

Thanks so much Jack!
I followed your advice, cleaned up dry grease etc between the collars on the shaft and the outer bearings... and voila!
All good now.