I have a silicone gel oozing out of the inner spacer, for the UL and LR Lord mounts on my IO360. My A&P-IA is telling me that they have to be replaced, as they are leaking and therefore unairworthy. These particular mount sets are nearly $500 each, and are barely three months old. Do I really have to change them?
Search strings: Leaking mounts; gooey substance; leaking spacer; bad mount cushions; leaking mount cushions.
The gel spacers are used in the UL and LR positions of the most current part number for the Lord mounts, for the IO360 in both the the Super and Sierra. The earlier Super mounts used a solid spacer in all four positions. The Barry replacements also provide only the solid spacer; Barry does not produce the gel spacer. For the Super, you have the option of using the four solid mounts instead, if you can get them, as the cushion supersedure is not mandatory. For the Sierra, your are technically stuck with using the two solid and two gel mounts, if you go strictly by the parts list. On the other hand, as long as you use the proper multi-layer cushion set (as also comes with the solid spacer for the LL and UR), the solid-spacer mounts will work fine in the Sierra. The gel has no in-flight function. Its purpose was ergonomic; to reduce the apparent shaking felt in the cabin when the engine was started or shut down. Even the solid mount spacers have a rubber jacket, to protect the engine mount frame against impact damage.
These gel spacers are one of Lord’s worst ideas. It simply is not possible for the thin rubber jacket to contain this gel for the long term, when it is being hit by the edge of the mount cushion any time the engine shakes hard (during start-up and shut-down). As a result, the gel begins leaking out within a couple of months of installation; especially in the lower right mount.
Lord stonewalled me for years on this issue, with the occasional gesture of occasionally sending me two free gel spacers, when I sent receipts that demonstrated the extremely short life span. To our good fortune, we have now received an actual Email from Lord. It essentially states that gel leakage DOES NOT RENDER THE MOUNT CUSHION UN-AIRWORTHY! So you can now print this and show it to your mechanic when warranted. I have pasted it it at the bottom of this note.
In addition to the leaking gel issue, there are two other important factors involving these same mounts.
1. They have a ‘built-in sag’. If you look at a brand new set, they will appear to be sagging down in the direction of the load. Make sure that your cushions have other visible deterioration in addition to apparent sagging, before paying for new ones.
2. Because they have a designed-in orientation requirement, these cushions have holes that must be aligned with roll pins in the cushion pad of the engine mount frame. It can be tricky to get these holes on the pins, and to keep them there while the bolt is tightened down. But it must be properly done! You may find damaged or missing pins from previous bad work, whether by an owner or an inexperienced mechanic. Make sure the pins are there, and get properly used. It can be a big help if you mark the position of the pins and holes with a grease pencil or similar.
———- Forwarded message ———-
From: Bernie Chan
Date: Fri, Aug 7, 2009 at 10:57 AM
Subject: RE: Contact Us Form
Cc: “Snyder, Paul J (Grandview)”
Thank you for visiting our website and inquiry.
The P/N of the gel spacer is J-12891-1 and I don’t believe we sell them individually. However, you can try our global distributors like Aviall, AAR, API etc. Their contacts are on our website.
Please note the leaking of the fluid (gel) doesn’t hurt anything – it’s just a silicone fluid. The job of this fluid in the spacer is to reduce motion at start-up and shut-down. So, if you are OK with the way it’s currently operating, then there’s no problem leaving them in there. The mount will still work well during normal flight.
Please note that these dampers can be damaged during installation.
Hope above help. Let me know if you have further questions.