Steering horn Rebuild??

[Brian2034]

Okay,

I know Lasar sell the steering horn.

My question is the horn something that can be repaired (bushings, bolts)?

I've read somewhere  there's shim washer's that can be used to tighten the side play and believe there's also bushings available??   

Second question

It looks like the newer model Mooney's have an upgraded steering horn will the newer horn fit the C models

[Utah20Gflyer]

I rebuilt my steering horn using new bushings.  Whether that is possible depends on the location of the wear.   I believe the two different steering horns can be interchanged as complete units but the sub assemblies may not be interchangeable.   I.E. can’t take half of one and splice together with half of the other type.  

[Brian2034]

Here are the two steering horns are they interchangeable?

Is one better than the other?

The one I currently have is similar to the first picture which is the older model I believe?

But mine doesn't have a grease fitting

 

[Igor_U]

I believe the upper one is up 1968 model and bottom one is newer, 1969 and up.

It doesn't look interchangeable to me but not sure. I would call LASAR parts department and ask for Dan; he would have more details.

Some 10 years ago I replaced most hardware in the system including that pivoting spherical, IIRC. There was improvement, for sure.

Good luck. 

[Utah20Gflyer]

On 3/7/2024 at 12:06 PM, Brian2034 said:

Here are the two steering horns are they interchangeable?

Is one better than the other?

The one I currently have is similar to the first picture which is the older model I believe?

But mine doesn't have a grease fitting

 

Interesting,  The two horns I’m familiar with both look like the upper one,  so maybe there are three horns?  Or maybe one of the ones I dealt with had been rebuilt with oversized hardware?  They are probably compatible but I can’t say for sure and based on how expensive they tend to be you’ll definitely want to verify with someone with more knowledge on that issue.  
 

The lower one looks like a better design as it has less moving parts and therefore fewer places to wear.   If it worked I would choose that one.  

[47U]

On 3/6/2024 at 1:10 PM, Brian2034 said:

I know Lasar sell the steering horn.

My question is the horn something that can be repaired (bushings, bolts)?

I talked to LASAR about 10 days ago (I’m told Dan is retired, but Heather was knowledgable to my questions).

LASAR doesn’t have any rebuilt steering horns in stock, but will evaluate yours (for .15 amu) and, if it qualifies, overhaul it (another 1.1 amu).  Mooney will make you a new one for north of 2 amu… other MSCs may have different pricing on new manufacture.

The LASAR website shows this as a 1968 and earlier steering horn (what I have on my ‘63C).

LASAR shows this as the ‘69 and later… my understanding is that the older and newer versions are not interchangeable.

So, I sent LASAR my steering horn and am waiting to hear what they say.  I wasn’t on the 7-second ride yet, but there it was pretty sloppy when up on jacks.  I didn’t see any reference in the logbooks where the steering horn had ever been worked on.

 

[cliffy]

When I rebuilt mine I bought all the parts from LASAR and did my own assembly.

IIRC bolts bushings and HEIM joints were all available but its been a few years. 

The worn items were obvious and then the shims come in many thicknesses and you need a variety 

of them to get the slack out. 

[Shadrach]

2 hours ago, 47U said:

I talked to LASAR about 10 days ago (I’m told Dan is retired, but Heather was knowledgable to my questions).

LASAR doesn’t have any rebuilt steering horns in stock, but will evaluate yours (for .15 amu) and, if it qualifies, overhaul it (another 1.1 amu).  Mooney will make you a new one for north of 2 amu… other MSCs may have different pricing on new manufacture.

The LASAR website shows this as a 1968 and earlier steering horn (what I have on my ‘63C).

LASAR shows this as the ‘69 and later… my understanding is that the older and newer versions are not interchangeable.

So, I sent LASAR my steering horn and am waiting to hear what they say.  I wasn’t on the 7-second ride yet, but there it was pretty sloppy when up on jacks.  I didn’t see any reference in the logbooks where the steering horn had ever been worked on.

 

So $1250 all in to replace a heim joint, re-bush, shim and paint an existing horn?

Does not seem like a great value... It seems both Mooney and Lasar have the same plan to minimize sales volume. I guess if you’re going to lose money, might as well do as little work as possible.

[47U]

11 hours ago, Shadrach said:

Does not seem like a great value...

No disagreement.  

Part of the issue with rebuilding the steering horn in the field (in my opinion) is the lack of the blue-line drawing listing the individual joints, bearings, shims, bushings, etc. that makes the rebuild both functional and compliant.

As the resources to keep our airplanes airworthy dwindle, those resources that remain available will likely command a premium price.  I can’t refute your pessimism, it’s just the way it is.  

If an owner/pilot is experiencing the 7-second ride, 1.25 amu in parts to get it fixed might be economical compared to the costs associated with repairs due to a runway excursion, or the increase in insurance premiums.

I wish I had a better solution, but I guess I’ll support the resources that are currently available and hope the resources are still there when I need their support in the future.   

[ArtVandelay]

So $1250 all in to replace a heim joint, re-bush, shim and paint an existing horn?
Does not seem like a great value... It seems both Mooney and Lasar have the same plan to minimize sales volume. I guess if you’re going to lose money, might as well do as little work as possible.

How many hours do you think it should take? 8-10 doesn’t seem too bad.

At 10 hours that’s $125/hour, for California that’s sounds about right.

[Shadrach]

10 hours ago, ArtVandelay said:

How many hours do you think it should take? 8-10 doesn’t seem too bad.

At 10 hours that’s $125/hour, for California that’s sounds about right.

8 to 10 hrs on this to replace a bushing, heim joint and shim? I think it likely that I could have all of the wear items fabricated and installed locally for <$400..  I understand charging what the market will bear. I believe we are nearing a place where it is easier and less expensive to OPP. 

[N201MKTurbo]

The only reason the two steering horns are not interchangeable is the pivot point. The early models had a small tube to put a bolt through and the newer airplanes have a welded on pin. LASAR did have a pin you could bolt into the older models so you could use the newer horns. If they don’t have it anymore, anybody with a lathe could make one in a few minutes.

[65MooneyPilot]

5 years ago I installed LASAR mod 148 for the steering horn mod. The website says they are not available. To bad because it was another option. Once you install that mod you can’t go back. 

[Ragsf15e]

Wait, isn’t “sloppiness” from a different issue than the 8” ride?  The slopiness issue is pretty easily resolved with new bolts bushings or heim joints depending on what’s causing it (my IA needed to replace a small joint).  The 8” ride is from misalignment (vertically) of the nosewheel causing it not to seek neutral steering on its own.  Do either require the steering horn rebuild?

[PT20J]

1 hour ago, Ragsf15e said:

Wait, isn’t “sloppiness” from a different issue than the 8” ride?  The slopiness issue is pretty easily resolved with new bolts bushings or heim joints depending on what’s causing it (my IA needed to replace a small joint).  The 8” ride is from misalignment (vertically) of the nosewheel causing it not to seek neutral steering on its own.  Do either require the steering horn rebuild?

Worn steering parts just make taxiing straight take a lot if pedal work, but it’s not dangerous. If the gear is properly set up, there is enough caster to keep it going straight at landing speeds.

I’ve been told by a couple of well known MSC owners that the Mooney steering is kind of sloppy even when new. There are lots of places that wear and cause slop as you noted. In my case, replacing a rod end and shimming the steering horn took out most of it. One problem with the newer horns is that they are hollow and it takes a lot of grease to get it to the bushings and the bushings will wear if not lubed. 

MSCs have access to more parts info than is in the IPC. They can get the correct bushings if that’s what you need. 

[N201MKTurbo]

In my experience the only thing a worn steering horn will do is give you a dead spot in the steering response and if bad enough, it can allow steering shimmy.

In my old M20F, it was very worn and it would shimmy some times. A quick rudder kick would stop the shimmy. Shimming up the steering horn at the end of the pivot is a short term fix. the real problem is the clearance between the shaft and the tube it runs in. I think the best fix would be to ream out the tube and plate the shaft to make it bigger and grind it down till it fits tightly into the tube.

[N201MKTurbo]

I finally bought a LASER steering horn for that plane. I think I paid $600 for it. ~1995.

[PT20J]

The steering horn looks to me like a part that any good machine shop could easily rebuild.

[Fly Boomer]

6 minutes ago, PT20J said:

The steering horn looks to me like a part that any good machine shop could easily rebuild.

Under what circumstances would the horn need to be heat treated following rebuild?

[PT20J]

52 minutes ago, Fly Boomer said:

Under what circumstances would the horn need to be heat treated following rebuild?

I don't see anywhere where Mooney calls out heat treating for the horn. The gear legs are called out as being heat treated. 

[Shadrach]

2 hours ago, Fly Boomer said:

Under what circumstances would the horn need to be heat treated following rebuild?

Even if it is heat treated, unless the steel structure is compromised, there is no need to do anything but replace hardware. Pressing in a new bushing should not require compromising the existing metallurgy.

[Shadrach]

7 hours ago, Ragsf15e said:

Wait, isn’t “sloppiness” from a different issue than the 8” ride?  The slopiness issue is pretty easily resolved with new bolts bushings or heim joints depending on what’s causing it (my IA needed to replace a small joint).  The 8” ride is from misalignment (vertically) of the nosewheel causing it not to seek neutral steering on its own.  Do either require the steering horn rebuild?

It is different. 8 second ride is a caster angle issue. Positive caster angle is more stable in a straight line and self centering. Negative caster angle makes for faster turn in but is less stable. The Mooney is spec’d for positive caster angle but only just. If it’s out of adjustment enough to go negative, the 8 second ride becomes a possibility. If the steering linkage is worn, the 8 second ride is going to be that much worse. I get a noticeable shimmy at taxi speed if the nose tire is 5psi low. I theorize that even the slight change in geometry caused by a low nose tire shifts caster angle aft and causes the shimmy.

[Ragsf15e]

27 minutes ago, Shadrach said:

It is different. 8 second ride is a caster angle issue. Positive caster angle is more stable in a straight line and elf centering. Negative caster angle makes for faster turn in bits less stable. The Mooney is spec’d for positive caster angle but only just. If it’s out of adjustment enough to go negative, the 8 second ride becomes a possibility. If your steering linkage is worn, the 8 second ride is going to be that much worse. I get a noticeable shimmy at taxi speed if the nose tire is 5psi low. I theorize that even the slight change in geometry caused by a low nose tire shifts caster angle aft and causes the shimmy.

Yeah that’s what I was thinking. I’ve had the slop/dead spot before and my IA replaced a heim joint that was wearing.  Never had the shimmy though.  I guess I would have thought a low tire would move the tire center aft (based on nose truss geometry) and that would make it more stable, but I’ll have to think about that some more.

[Shadrach]

7 minutes ago, Ragsf15e said:

Yeah that’s what I was thinking. I’ve had the slop/dead spot before and my IA replaced a heim joint that was wearing.  Never had the shimmy though.  I guess I would have thought a low tire would move the tire center aft (based on nose truss geometry) and that would make it more stable, but I’ll have to think about that some more.

Since adding polished wheel covers, I eyeball the tires rather than put a gauge on them. Prior to the wheel covers, I away gauged the tires during preflight. 

[Brian2034]

Okay,

Have everything out and apart!!

Mains, nose gear, steering horn.

Thought I might turn a new bushing for the steering horn but I  called Lasar first.

The brass bushing is $80

The Nas bolt from the SB is $4.00

My steering horn has Torrington bearings where the Nas bolt goes and they look good.

And I need additional shims, I don't recall their price but a couple bucks each.

Also I might need a reamer to straighten the hole up for the brass bush.

The rest of the landing gear is in surprisingly good shape just needs to be blasted and painted.

And of course new shock disc's.

These look like original era disc's

Also my gear doesn't have the Mooney SB M20-202 , I probably should get the spacer in case after the updates the gear requires it 

 

 era disc's