Electric trim fail… again

[BravoWhiskey]

An on going issue I have is my electric trim failing.  I have had my Bravo just under 2 years and this is the 2nd time this has happened.  Prior log book entries suggest this was repaired a number of times over the years.  I am thinking about leaving it inoperable and just using the trim wheel.  That trim wheel does get very tight and I am assuming that is why the elec trim keeps drawing excess current and popping.  I have had that adjusted and lubricated but it doesn’t stay “loose” for very long.  I will have the whole thing examined again at annual but curious if anyone else has had this as an ongoing issue and what a reasonable solution might be.  

[ArtVandelay]

I would disconnect trim motor and then check for resistance


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[LANCECASPER]

On 7/27/2022 at 6:41 AM, BravoWhiskey said:

An on going issue I have is my electric trim failing.  I have had my Bravo just under 2 years and this is the 2nd time this has happened.  Prior log book entries suggest this was repaired a number of times over the years.  I am thinking about leaving it inoperable and just using the trim wheel.  That trim wheel does get very tight and I am assuming that is why the elec trim keeps drawing excess current and popping.  I have had that adjusted and lubricated but it doesn’t stay “loose” for very long.  I will have the whole thing examined again at annual but curious if anyone else has had this as an ongoing issue and what a reasonable solution might be.  

When you say you've had it adjusted and lubricated do you mean the wheel up front or the jack screw in the back of the airplane? The grease back there may be old and need to be cleaned out and re-greased. If the trim is very tight your airplane is speaking to you.

[BravoWhiskey]

2 minutes ago, LANCECASPER said:

When you say you've had it adjusted and lubricated do you mean the wheel up front or the jack screw i t the back of the airplane? The grease back there may be old and need to be cleaned out and re-greased. If the trim is very tight your airplane is speaking to you.

last time there was no grease on the jack screw.  Not dirty, or old… just nothing! So that was addressed.  It was also adjusted so the trim moved more freely.  Now I don’t know exactly what was done to make it move more freely But it feels tight again.  It is not stuck on anything,  just feels like there is more restriction in its movement.  This is something that has been reoccurring in this plane so I am wondering if the trim assembly is a problem.  

[N201MKTurbo]

I agree with lance. the trim shouldn't be stiff. The only way to effectively lube the jackscrew is to remove it, disassemble it, clean it and work in new grease. It isn't that hard, especially at annual when everything is opened up.

[Shadrach]

22 minutes ago, BravoWhiskey said:

last time there was no grease on the jack screw.  Not dirty, or old… just nothing! So that was addressed.  It was also adjusted so the trim moved more freely.  Now I don’t know exactly what was done to make it move more freely But it feels tight again.  It is not stuck on anything,  just feels like there is more restriction in its movement.  This is something that has been reoccurring in this plane so I am wondering if the trim assembly is a problem.  

No lubrication? Did you see it? I find it hard to believe that it would function at all under air loads with no lubrication.

[Fly Boomer]

3 hours ago, BravoWhiskey said:

An on going issue I have is my electric trim failing.

If you have TKS, you may need to lubricate everything in the tail more frequently.  And "more frequently" may be every 50 hours, or every oil change, or every time you pump the TKS.  It is apparently well distributed inside the tail during use, and it strips lubrication from everything it touches.  Love my TKS, but it's kind of a mess.

[BravoWhiskey]

8 hours ago, Fly Boomer said:

If you have TKS, you may need to lubricate everything in the tail more frequently.  And "more frequently" may be every 50 hours, or every oil change, or every time you pump the TKS.  It is apparently well distributed inside the tail during use, and it strips lubrication from everything it touches.  Love my TKS, but it's kind of a mess.

And I did have quite the leak of TKS fluid that was recently fixed.  Well either way I go in for annual next month.  Hopefully they uncover something.

[LANCECASPER]

34 minutes ago, BravoWhiskey said:

And I did have quite the leak of TKS fluid that was recently fixed.  Well either way I go in for annual next month.  Hopefully they uncover something.

Specifically tell them that you want the jackscrew removed, cleaned up, lubricated and reinstalled. Otherwise most shops will miss this. 

[ArtVandelay]

I agree with lance. the trim shouldn't be stiff. The only way to effectively lube the jackscrew is to remove it, disassemble it, clean it and work in new grease. It isn't that hard, especially at annual when everything is opened up.

How many hours do you expect it would take? Is there any Mooney specialized skills or tools required?

[N201MKTurbo]

34 minutes ago, ArtVandelay said:

How many hours do you expect it would take? Is there any Mooney specialized skills or tools required?

I wrote up the whole procedure on here somewhere. I would look it up. 
 

if the plane is opened up, it will take about 4 hours. If not it will take 6. If you are figuring things out along the way add two more.

[Fly Boomer]

2 hours ago, BravoWhiskey said:

And I did have quite the leak of TKS fluid that was recently fixed.

The phenomenon to which I refer has no connection to leaks.  When the system is working correctly, the fluid finds its way from the tail surfaces inside the empennage and washes off all lubrication from everything.

[carusoam]

Typical Mooney tail gear boxes are mostly maintenance free… until the grease turns into stones…. Over the decades….

It would be odd to have no grease in the box…. And to have to service it twice in your lifetime…

Use caution when servicing the gear box… there may be specific spacers as part of the sealing system…

Cleaning the rocks of the Jack screw is a good idea as well… then re-lube with fresh grease…

Stuff I have read around here only, I haven’t seen any long bodies discussing gear box / Jack screw lube…. Yet.

 

Best regards,

-a-

[N252MK]

We have that problem but if we reset the trim circuit breaker it starts to work again for awhile.


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[LANCECASPER]

8 hours ago, N252MK said:

We have that problem but if we reset the trim circuit breaker it starts to work again for awhile.


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It's working too hard against the old hardened grease. You will burn out the trim motor. Your circuit breaker is telling you something.

[BravoWhiskey]

Well I did not see this one coming!

annual is complete.  Hats off to Weber Aircraft and Lancaster Avionics again.  The 7 weeks wasn’t their fault because the AP and elec trim was serviced… again!  But this time they may have finally found the bug that has been plaguing this system for years.  Apparently the computer in the STEC55x was actually for a Cirrus.  So now I have an Autopilot and servo that is specific to my airframe… how nice.

I did notice some differences in the reaction time and direction today.  On the prior system the aircraft would sometimes start the turn in the wrong direction for about 5-10 degrees then correct itself. I’ll play around more tomorrow when I have time to fully test everything out.  
 

oh… and about those v-bend clamps… not cheap!

Edited November 4, 2022 by BravoWhiskey

[LANCECASPER]

31 minutes ago, BravoWhiskey said:

oh… and about those v-bend clamps… not cheap!

Did they remove the turbo or the exhaust?  How much did they charge you for the v-clamps?

[BravoWhiskey]

The clamp had a large crack in it and was hanging on by a hair.  1950 from Lycoming.  

[LANCECASPER]

6 hours ago, BravoWhiskey said:

The clamp had a large crack in it and was hanging on by a hair.  1950 from Lycoming.  

Great news that they found that before it let go.

Aeroquip makes that clamp for Lycoming and when Lycoming gets the part they use their own part number 40D23255-340M  and list it for $2000 , a little less through vendors (https://www.aircraftspruce.com/catalog/pnpages/07-03199.php).

Piper sells the Aeroquip version for less than 1/3 the price. https://www.aircraftspruce.com/catalog/eppages/engineclamps.php

Picture of Lycoming version with Aeroquip number on it: https://www.dropbox.com/s/ujezkp00d8r32fd/Lycoming vs aeroquip.png?dl=0

Same exact clamp and both part numbers on the clamp - also both part numbers mentioned in the Mooney Service Bulletin addressing this.

 

 

[BravoWhiskey]

49 minutes ago, LANCECASPER said:

Great news that they found that before it let go.

Aeroquip makes that clamp for Lycoming and when Lycoming gets the part they use their own part number 40D23255-340M  and list it for $2000 , a little less through vendors (https://www.aircraftspruce.com/catalog/pnpages/07-03199.php).

Piper sells the Aeroquip version for less than 1/3 the price. https://www.aircraftspruce.com/catalog/eppages/engineclamps.php

Picture of Lycoming version with Aeroquip number on it: https://www.dropbox.com/s/ujezkp00d8r32fd/Lycoming vs aeroquip.png?dl=0

Same exact clamp and both part numbers on the clamp - also both part numbers mentioned in the Mooney Service Bulletin addressing this.

 

 

I was fortunate that Lycoming had the part.  Weber tried a number of suppliers.   But after learning about the AP computer issue I was less concerned about the clamp cost and more concerned with whether they were going to be able to fix that.

[LANCECASPER]

Once I learned about the less expensive route ($550ish), I bought one and kept it on hand so that later on I wasn't having to pay the full price ($1700ish). Having one on hand almost ensures that you'll never need it.

[affricate]

On 11/5/2022 at 7:36 PM, LANCECASPER said:

Once I learned about the less expensive route ($550ish), I bought one and kept it on hand so that later on I wasn't having to pay the full price ($1700ish). Having one on hand almost ensures that you'll never need it.

Good catch on the V Bands, don't want to be playing around with that exhaust. Last thing we need is a blow torch in our lap!

[affricate]

On 11/5/2022 at 5:35 AM, BravoWhiskey said:

The clamp had a large crack in it and was hanging on by a hair.  1950 from Lycoming.  

Good catch!

[PhateX1337]

On 11/5/2022 at 9:36 PM, LANCECASPER said:

Once I learned about the less expensive route ($550ish), I bought one and kept it on hand so that later on I wasn't having to pay the full price ($1700ish). Having one on hand almost ensures that you'll never need it.

So @LANCECASPER the piper part you listed works for our Bravos? I may just do the same order now and hope you never need it approach too … markup seems crazy

[LANCECASPER]

1 hour ago, PhateX1337 said:

So @LANCECASPER the piper part you listed works for our Bravos? I may just do the same order now and hope you never need it approach too … markup seems crazy

It is the same part if you read the service bulletin.