REFLECTOR: Lord Mounts

steve korney s_korney at hotmail.com
Tue Sep 9 11:29:22 CDT 2008


Engine Mount (Lord) Frequently 
Asked Questions
How do I take care of my engine 
mounts
Where a component maintenance manual is available for a system, its 
requirements take precedence.

 
General Comments
 
Bonded sandwich assemblies are natural rubber or specially blended  
synthetic compounds bonded to two plates. The normal installation

requires four assemblies, each consisting of two sandwich mountings and one 
spacer. Satisfactory performance requires that the spacer be

designed to the correct length to precompress each mounting to guarantee proper 
positioning of the mountings. When properly installed, these

mountings provide excellent isolation of engine vibration, resulting in 
smoother, quieter flight. Always order replacement mounting by the mounting 
assembly number to insure the correct spacer.

 
Visual Inspection of Installed Mountings
At each annual inspection and at FAA required inspections of the  
aircraft's engines, all mounting assemblies should be visually inspected

in their installed state while supporting the engine's weight. The correct 
visual inspection procedure is as follows: 

Inspect all bonded sandwich mountings for metal-to-rubber bond 
	separations, flex cracks, rubber deterioration due to exposure to fluids, 
	and mechanical damage such as cuts in the rubber surface. 
	Visually inspect all bonded steel parts for cracks and excessive nicks, 
	scratches, or gouges. 
	Inspect all nut locking wires for looseness and tighten as necessary. 
	When applicable, measure all drift indicators in each mounting assembly 
	for excessive deflection. 
	Whenever any of the conditions detailed above in steps (a), (b), and (d) 
	are found, remove the mounting assembly from the engine, disassemble, 
	inspect, and repair it as described in the maintenance manual. 
	

	

	

 
 
CAUTION
Whenever the aircraft engines are cleaned during a  normal 
inspection, cover each mounting assembly to protect it from

contamination by cleaning fluids or solvents. This also applies to engine 
lubricants. Should any such materials accidentally get on a

mounting assembly, wipe it off thoroughly as soon as possible with a clean rag.

 
Disassembly
To remove mounting assemblies from the engine/aircraft, it is  necessary 
to remove the engine weight from the mountings by the use of a

chain hoist or equivalent, and disconnect the nuts and bolts which hold the 
mountings in place. In general, removal of one mounting at a time

can be accomplished, if necessary, without removing the engine weight from the 
mountings.

 
Cleaning and Inspection

Wipe oil and dirt from bonded mountings, but do not dip in cleaning 
	solvents. 
	Steel bolts and spacers should be inspected for cracks or damaged 
	threads. Examine spacers for crushing of ends caused by excessive tightening 
	torque on bolt. Replace if either condition is apparent. 
	Examine bonded rubber mounting for oil swelling, bond or rubber 
	separation, and shear or compression set. Bond separation, oil swelling, or 
	flex cracks in the surface of the rubber is cause for rejection. The affects 
	of shear and compression set are determined by measuring the dimensions 
	shown in Figure 1. Reject parts which have an eccentricity greater than 
	dimension "A" or an overall thickness less than dimension "B" as shown in 
	Table 1. 

 Figure 1.

	

 


 
 Table 1.
	
	
		
			Mounting Series Number
			Eccentricity Max. "A" inch.
			Thickness Min. "B" inch.
		
		
			
			J1552
			
			0.05
			
			0.29
		
		
			
			J2245
			
			0.06
			
			0.45
		
		
			
			J3049
			
			0.07
			
			0.71
		
		
			
			J6113
			
			0.05
			
			0.39
		
		
			
			J7401
			
			0.06
			
			0.75
		
		
			
			J7530
			
			0.06
			
			0.75
		
		
			
			J7649
			
			0.06
			
			0.75
		
		
			
			J7763
			
			0.08
			
			1.02
		
		
			
			J8381
			
			0.06
			
			0.75
		
		
			
			J9555
			
			0.06
			
			0.75
		
		
			
			J9612
			
			0.08
			
			1.22
		
		
			
			J10533
			
			0.10
			
			0.80
		
		
			
			J10776
			
			0.10
			
			1.01
		
		
			
			J12165
			
			0.20
			
			1.00
		
		
			
			J12397
			
			0.20
			
			0.86
		
		
			
			J12454
			
			0.20
			
			1.30
		
		
			
			J12799
			
			0.20
			
			1.28
		
		
			
			J13051
			
			0.23
			
			1.40
		
		
			
			J15199
			
			0.40
			
			1.60
		
		
			
			J7763-34(BTR-II)
			
			0.14
			
			1.02
		
		
			
			J9612-30(BTR-II)
			
			0.14
			
			1.20
		
		
			
			J9612-32(BTR-II)
			
			0.12
			
			1.20
		
		
	
	 

Best... Steve

From: gstull at tampabay.rr.com
To: reflector at tvbf.org
Date: Tue, 9 Sep 2008 11:22:16 -0400
Subject: Re: REFLECTOR: Lord Mounts












I work as an A&P. All production aircraft that 
I've seen, including heavy jets, use metal self locking nuts. I've never 
seen anything else used. Castle nuts and cotter pins may be used somewhere for 
engine mounts, but I've never seen it

  ----- Original Message ----- 
  From: 
  Terry Miles 
  To: 'Velocity Aircraft Owners and Builders 
  list' 
  Sent: Tuesday, September 09, 2008 8:09 
  AM
  Subject: Re: REFLECTOR: Lord Mounts
  

  
  Dave, 
  Steve,
   
  In another note, 
  Steve Korney said I should have castle nuts and cotter pins on the engine 
  mounts.  I think I would have used what came in the Velo engine kit, and 
  I have metal locking nuts on these bolts.  I am checking with the factory 
  on that today.
   
  My question is about 
  torque setting now.  Would it be 38 ft lbs with the metal lock nuts or 
  with castle nuts?  Would the different hardware change the torque 
  value?  Thank you both for this input.  I want to learn, and I 
  appreciate your help to me.
   
  Terry
   
  
  
  
  
  From: 
  reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On Behalf Of 
  davedent at comcast.net
Sent: Tuesday, September 09, 2008 1:26 
  AM
To: Velocity Aircraft 
  Owners and Builders list
Subject: Re: REFLECTOR: Lord 
  Mounts
   
  
  When it comes to engine mounts I have always torque 
  the 7/16" bolts to 38ft lbs and have had very good success with them.  It 
  looks like your mount bolt is not torque correctly.  But may be just 
  fine.  Just torque them to 38lbs and they should be OK. Make sure you 
  bolts are not bottomed out.  Like being to long.  Also that the 
  spacer is also installed. 
  
   
  
  Remember also that most rubber products get harder 
  with age.  In the environment that our engines run in I wouldn't keep 
  them more then eight years.  Even less it they start cracking.  
  
  
   
  
  Believe me there is a difference between 
  manufactures of mounts as well.  You get what you pay for. 
  
  
   
  
  Also keep solvents and oils away from them and keep 
  them clean.  The harder they get the less effective they are and so being 
  more damage is done to the rest of the plane. Don't take rubber mounts 
  lightly. They do a lot more then just hold the engine in place.  
  
  
  Dave
  
  

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