Oil from the MT propeller

[astaib]

Hello,

For those who have also a MT Propeller, do you ever had this kind of leak that sprays oil inside the spinner and on the blade?
Now every 15hrs of flight I have to remove the spinner and clean because especially one blade is leaking.
It is very limited but I’m asking myself if it is serious.

Thanks

[jwx96]

Yes I have had this, on a MTV-12-B. It could be grease and not oil. Mine started only after an overhaul in 2021 at a local prop shop (MT authorized), but got pretty bad so after about 75 hrs they took it back and did a repair, also in 2021. They referenced service letter SL 23 C. It didn't leak after that but this year I noticed that one of the blades was a little loose. I sent it to the USA MT service center in Florida and they repaired it and now after about 15 hrs I am getting a little leak like you are describing. I think that's normal because they pack a lot of grease in at the reassembly, but it should eventually stop. Your leak might be different because you didn't say you had any prop work done recently. I've talked to mechanics, Savvy, and 2 prop shops over the last year and a half. The people at MT in Florida were the most knowledgable and helpful. Can you call MT in Germany or the service center in France for an opinion? There are other posts about my experience, with photos, in another thread in this section.

[Rich]

Most likely grease leaking past the seal. If you haven't had work done recently and this is new, it probably indicates seal wear. There is a fixed amount of grease in there. No way to replenish without opening the hub. When was the last overhaul on this prop?

[Steve]

I agree with the other commenters, this appears to be grease. I had (a smaller leak) like this when my aircraft was new, but nothing after each of two overhauls. Arnaud, I know your airplane is a 2001, like mine. Has your prop had the service bulletin to insert steel sleeves into the hub? This seemed to make the difference on mine, as it was done as part of the first overhaul (required that the hub be shipped to Germany and back to TX for that work).

[astaib]

Yes I have had this, on a MTV-12-B. It could be grease and not oil. Mine started only after an overhaul in 2021 at a local prop shop (MT authorized), but got pretty bad so after about 75 hrs they took it back and did a repair, also in 2021. They referenced service letter SL 23 C. It didn't leak after that but this year I noticed that one of the blades was a little loose. I sent it to the USA MT service center in Florida and they repaired it and now after about 15 hrs I am getting a little leak like you are describing. I think that's normal because they pack a lot of grease in at the reassembly, but it should eventually stop. Your leak might be different because you didn't say you had any prop work done recently. I've talked to mechanics, Savvy, and 2 prop shops over the last year and a half. The people at MT in Florida were the most knowledgable and helpful. Can you call MT in Germany or the service center in France for an opinion? There are other posts about my experience, with photos, in another thread in this section.

Hello,

I have an overhaul in 02/2019 and this phenomena appears from this overhaul. But I have the feeling that the delay to see the grease out of the spinner gets shorter, maybe I'm wrong.

I just sent piuctures to MT in Germany, and I will let you know about theire feedback.

Thanks.

Arnaud.

[astaib]

Most likely grease leaking past the seal. If you haven't had work done recently and this is new, it probably indicates seal wear. There is a fixed amount of grease in there. No way to replenish without opening the hub. When was the last overhaul on this prop?

Hi Rich,

The lastest OH was in 02/2019 and this is "leaking" till that date and not before.

I have the feeling thatthe delay to see the grease sweating out of the spinner gets shorter. At the beginning 45hrs, then 30 now 15...

Arnaud.

[astaib]

I agree with the other commenters, this appears to be grease. I had (a smaller leak) like this when my aircraft was new, but nothing after each of two overhauls. Arnaud, I know your airplane is a 2001, like mine. Has your prop had the service bulletin to insert steel sleeves into the hub? This seemed to make the difference on mine, as it was done as part of the first overhaul (required that the hub be shipped to Germany and back to TX for that work).

Hi Steve,

I have no idea about the SB, but as it was overhauled in 02/2019, maybe it has been done in the same time?

Arnaud.

[astaib]

Hi,

MT Prop engineer answered me with an extract of the installation manual:

Grease Leakages:
The first run-up of a new or overhauled propeller may leave
grease on the blades and inner surface of the spinner dome. This is normal and do not mean that it will be a continuing grease leakage.
Remove any grease on the blades or inner surface of the spinner dome by using a mild solvent.
Minor grease leak which can be seen on one or all blade root(s) and spinner should be monitored if it gets worse.
If the grease leak does not spray more than 7 inches (18 cm) on the blade surface from the blade root outside the blade ferrule in 5 hours of operation, it is defined as minor and should be only monitored!
Continued grease leakage after 20 hours of operation from first leakage requires repair at an authorized service repair facility within 5 operating hours.
In case of doubt contact manufacturer!

[Steve]

I agree with the other commenters, this appears to be grease. I had (a smaller leak) like this when my aircraft was new, but nothing after each of two overhauls. Arnaud, I know your airplane is a 2001, like mine. Has your prop had the service bulletin to insert steel sleeves into the hub? This seemed to make the difference on mine, as it was done as part of the first overhaul (required that the hub be shipped to Germany and back to TX for that work).

Hi Steve,

I have no idea about the SB, but as it was overhauled in 02/2019, maybe it has been done in the same time?

Arnaud.

It should be noted in the itemized work order for the overhaul. That portion on mine was about $600 in 2014 plus shipping to Germany, over the cost of the standard overhaul. It took about 30 days to get the hub to Germany, modified and back to TX. Here is the applicable service letter:

https://www.mt-propeller.com/pdf/sls/sl23c.pdf

[astaib]

I agree with the other commenters, this appears to be grease. I had (a smaller leak) like this when my aircraft was new, but nothing after each of two overhauls. Arnaud, I know your airplane is a 2001, like mine. Has your prop had the service bulletin to insert steel sleeves into the hub? This seemed to make the difference on mine, as it was done as part of the first overhaul (required that the hub be shipped to Germany and back to TX for that work).

Hi Steve,

I have no idea about the SB, but as it was overhauled in 02/2019, maybe it has been done in the same time?

Arnaud.

It should be noted in the itemized work order for the overhaul. That portion on mine was about $600 in 2014 plus shipping to Germany, over the cost of the standard overhaul. It took about 30 days to get the hub to Germany, modified and back to TX. Here is the applicable service letter:

https://www.mt-propeller.com/pdf/sls/sl23c.pdf

I wasn’t the owner at that time, I will check if I can get information.