Exchange of Alternator Belt

Abstract:  Two weeks ago my alternator belt has broken in flight. I had no harm. Just the red light switched on and the battery voltage has fallen down indicating that it was time to shorten the trip and goto home base.

Subject: Exchange of the alternator belt
From: "prg55100" <pierrot.greff
Date: 8/25/08 10:54 AM
To: G109_Pilots@yahoogroups.com

Bonjour to all,
This is an information I hope to help.Two weeks ago my alternator belt has broken in flight. I had no harm.Just the red light switched on and the battery voltage has fallen down indicating that it was time to shorten the trip and goto home base. Grob sent the belt fast and explained that it was easy to replace via the mag hole. And in fact it was as easy as they said.  Now why has it broken?

The broken belt was greasy and has given no indication of wear out at last 50H check. My guesses are that I'm in fault. I lubricated to generously the mag which lubrication hole is located a few centimeters from the belt. Instead of putting a few drops of oil in the mag hole, I used a spray for convenience. Forget it. Lubricate the mag with drops of oil, nothing else... The spray lubricates also the alternator
belt.

Fly safely
Pierrot

Subject: Re: Exchange of the alternator belt
From: "Stu Ostrander" <saberraider24
Date: 8/25/08 5:33 PM
To: G109_Pilots@yahoogroups.com

Pierrot,
I had planned to change my alternator belt in the near future. It looked like it might be somewhat involved as it does not appear readily accessible. When you say it is replaced via the mag hole, do you mean that you removed the mag to insert it through that opening?
I just posted the engine repair manual but there is no detail in it on the bell housing and mag.
Stu

Subject: Re: Exchange of the alternator belt
From: "williamberson" <whodunit@BZxKQaMYlgYdq8lU7KkSKEa1x07bwgDE-HK4qvCDilQ4JpsXmzU47CnQLwltVwDoiem6wY-YQybVcHQ.yahoo.invalid>
Date: 8/26/08 8:17 AM
To: G109_Pilots@yahoogroups.com

L2000

I had to split the back case from the main crankcase to install the belt. This takes about three
hours and requires an engine hoist to suspend the engine so the mount bolts can be
removed.
This was the method used by the previous owner, he was changing the belts every couple of
hours... quite a hassle. He was unable to determine the cause of rapid belt failure. He was
using Dayton brand belts that did not last and shed rubber dust. I tried a premium Gates belt
and it has lasted over ten years. I use only Gates rubber belts now for everything I own.

If the belt could go through the magneto hole, that would be great news. Please advise if
that is possible.
Bill

Subject: Re: [G109_Pilots] Re: Exchange of the alternator belt
From: "Ackerman Capt. Ron" <ronackerman@_VLvPggIg1p8ExiSJ5n98U1KQHN56esgS9kHXbLylu7FVvHsQw0JkBJZnm_Oo13YrXuNqy2Xz_zQkne7Qbs4-1JO.yahoo.invalid>
Date: 8/26/08 11:25 AM
To: G109_Pilots@yahoogroups.com

Sorry guys, I don't have the L2000, I have the Grob version. However, on the 2500 the belts can be accessed by removing a plate that the mags (I have two) are mounted on. This gives good access to the pulleys and belts. There are 6 bolts that hold the plate to the engine. However, again, this is for the G2500 engine with dual ignition and I don't know if anything is common between us. Good Luck!

Capt. Ron

Subject: Re: Exchange of the alternator belt
From: "prg55100" <pierrot.greff@Qsmq1a-WN_0gUcq9I9eklAorR7ZMnMPPhFEmrqSD2tUbgau2RPgC2E6rU_WoW0BgRqqxcTk8nEnFXIFbVvY1FBs.yahoo.invalid>
Date: 8/26/08 11:36 AM
To: G109_Pilots@yahoogroups.com

Hi Bill,
My experience concerned the Grob 2500 engine. I don't know about the
Limbach engine. As already said it was pretty easy to replace the belt
via the mag hole as recommended by Grob.
Cheers
Pierrot

Subject: Re: Exchange of the alternator belt
From: Ray
Date: 8/26/08 7:26 AM
To: G109_Pilots@yahoogroups.com

On an L2000, since the belt goes on the pully on the flywheel, you have to remove the Mag in order to let the belt go around onto the pulley.

I expect that it would be done from the opening at the alternator although since you have to remove the Mag perhaps it can be pushed through there as well, but I don't think that really would be any easier.

Better make sure the Mag shaft orientation is preserved just the way you removed it otherwise the timing could be off?
I would make a mark on the mag shaft just to avoid any potential hassles.

Ray

Subject: Re: Exchange of the alternator belt
From: "prg55100" <pierrot.greff@tvA56tDP7EcI_CViN7nlJGwcm7gxLBIlElpkF-T1WvaAI4nzsGhiv70H7Cq0_VL_ZlA0oonC4AVgpFKH1ZmkE58K.yahoo.invalid>
Date: 8/27/08 12:43 PM
To: G109_Pilots@yahoogroups.com

Bonjour to all,
I just noticed a possible confusion of which oil inlet should be used
to lubricate the mag head. The inlet is located on the engine casing
NOT on the mag body. A photo is posted in the photo galery.
A second photo shows the interior of the mag hole when the mag is
removed. Note that the engine is a single mag engine.
Cheers
Pierrot