Rotax drive gear?

Kevin_Richey

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I need a good Rotax drive gear (to replace the one I have that has chips worn off of the gear teeth.

This is the small gear that fits on the taper at the end of the Rotax crankshaft, and is held on with a bolt into the end of the CS. Whew! I almost typed "eccentric" shaft, which is the rotary engine's name for the piston engine's crankshaft) Would prefer a used one instead of buying new at Rotax's prices.

Not sure if all are the same, but apparently the "A" and "B" gear box drive gears are the same.

The one I have that is bad came off a Rotax 532 with an "A" box.

I want to get going on my gyro rotary engine project...hence the request!

Kevin
 
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Hey Kevin..

Hey Kevin..

That's not for your lightning is it?
Hope all is well with you and the rig.
I went for an 1.5 hour flight today! Perfect flying conditions!
Take care
Ben S
 
Hey Kevin, do you have an A box on a Lightning?

A box and B box might have the same gears, is it 2.0 to 1, 2.58 to 1 or ?

You need to change oil in the box every 50 hours.
 
The A and B box guts are the same, unless you have one of the early 3:00 to 1 boxes.
Check with CPS. They sometimes sell used parts for 1/2 the cost of new.
But You might just want to get a set of new gears instead of running an old gear on a new gear. You should also check and make sure that the gearbox has been updated to the 12 spring washers.
Rotax A Gear box updates:
Article:

Updated - Rotax gear, dog hub, washers, shaft.

Aircraft: All ultralight aircraft using the Rotax reduction drive.

Incident report:

We have several reported problems from pilots using the Rotax reduction drive.


1. a hard to start engine, or an engine that will start but has a hard time coming off an idle or runs very erratic at idle.

2. the gears inside the gear box disintegrating, especially on engines using large radius propellers.

3. the gear box retaining bolts vibrating loose and or breaking allowing the gear box to in one case come right off the back of the engine.

4. the output shafts on the gear box especially on the 65 hp engines, severing, or the prop shaft hub cracking.

5. the oil slinger located on the end of the output shaft breaking and then getting messed into the gears.

6. the loss of reduction drive gear oil during flight.

7. the stripping of the bolts used to attach the prop to the hub of the gear drive.

Suggestions:

1. There was a problem on early Rotax gear drives where a series of spring washers inside the gear box, over a period of time lost their tension.

This in turn caused the engine to become hard to start, and would not come off an idle. Rotax has an update kit which replaces the eight spring washes, and spacers found in the old style gear drives with a new 12 spring washer system.

It is recommended that these spring washers be replaced every 150 to 200 hours and that the gear drive oil be checked periodically, and replaced every 100 hours or yearly which ever comes first.

2. The problem with the gears shattering was also an early problem, and there is also a retrofit kit, which replaces the gear with a stronger gear.

3. The problem with the retaining bolts backing off was more common on the 3 bolt pattern adapter plates, the new engines are 4 bolt. This problem was also caused by pilots who were reinstalling the gear box for whatever reason.

In reinstalling the bolts on the 3 bolt system, there are two different lengths of bolts. Both bolts will go in and appear to tighten the plate against the housings. In fact the longer bolt is bottoming out in the crankcase housing and is NOT tightening up on the adapter plate.

4. The aluminum hub cracking hub cracking problem were also corrected on later model Rotax reduction drives, I am not however aware of a retrofit kit for this at this time. The only suggestion would be to update to the new style steel output shaft and hub.

5. The oil slinger problem has been eliminated by the removal of the slinger completely. New model engines do not come with the oil slinger, and the removal of them is recommended on older style gear drives.

6. The stripping of the prop bolts seems to occur when pilots have taken off and reinstalled their props several times. Some pilot have reported drilling out the holds using larger bolts, with locking nuts, and safety wire.

Other pilots have simply gone to larger bolts and used the other bolt pattern on the redrive. This problem is caused by the pilot over torquing the prop bolts on installation. The recommended torque is 100 INCH LBS.

7. The gear oil existing problem can be cured simply by installing a very small gas line filter on the top of the reduction drive vent cap using a small piece of gas line and some clamps. It is caused by the prop creating a low pressure area above the vent, siphoning the oil out of the gear drive.
 
That's not for your lightning is it?
Hope all is well with you and the rig.
I went for an 1.5 hour flight today! Perfect flying conditions!
Take care
Ben S

Not off the Lightning. It has the R-503.

This drive gear came off a R-532 engine. I didn't fly that engine.
It used the "A" box. I'm guessing the 532/582 at some 64 ponies is too much power/torque for the "A" or "B" gearbox, and should be using at least the "C" box.

The two gyro pilots that flew this engine/gearbox combo were what I'd say conservative fliers. So I doubt they were hard on it...the original owner (a light-sport type of fixed wing plane over in Idaho) replaced the 532 with a 582 on his plane.

I'm very jealous about you getting in your almost-daily flights!!!!!!!! The weather and my days off haven't coincided hardly at all since early October. Flew once in Oct. and once in Nov.!

Yuma sounds wonderful this time of year...
 
Hey Kevin, do you have an A box on a Lightning?

A box and B box might have the same gears, is it 2.0 to 1, 2.58 to 1 or ?

You need to change oil in the box every 50 hours.

Thanks Dave! I do have the "B" box on the Lightning, with the R-503 engine.

The drive gear came off of a 532 that passed through my hands.

Maybe I'm incorrect about it being a "drive gear". It is the small gear that is attached to the Rotax tapered crankshaft, and held on with the bolt onto the end of the crankshaft. It then fits into the gearbox into one of the gears inside the GB, which in turn turns the larger, final output gear.
 
The A and B box guts are the same, unless you have one of the early 3:00 to 1 boxes.
Check with CPS. They sometimes sell used parts for 1/2 the cost of new.
But You might just want to get a set of new gears instead of running an old gear on a new gear. You should also check and make sure that the gearbox has been updated to the 12 spring washers....

Scott: Thanks for all the GB problems report. I learned a lot from that!
And, for the CPS suggestion, too!
 
I have a set of 2.00 - 1. I will sell the pair. They came out of a working "B" box. I had a repair station switch them over to 2.58 for me to match the engine and prop I have. New from LEAF is $494.09. I'll let it go for $200, shipping included. Let me know...

BTW - Rotax gearbox
2.00 - gears have 20 & 40 teeth
2.24 - gears have 21 & 47 teeth
2.58 - gears have 19 & 49 teeth
 
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