Shims under engine mounts – all different heights!

[Alex]

Hi everyone,

Im in the process of a 4-5 month maintenance to do list on my Lurhs (6BTAs and ZF 220A gears). One of the items on that never ending list is to replace the engine mounts (rusted studs/nuts and rubber doesn’t look too healthy).

All of the mounts (Barry) have been shimmed differently on all 4 corners of each engine. From 1/2″ aluminum stack to 1 1/2″ under the actual isolator mount.

The setup is like this: (top to bottom)
1. Isolator/engine mount
2. Aluminum shim stacks (all different)
3. Aluminum angle stock thru bolted to the stringers
4. Stringer

Should I remove and rebolt the aluminum angles to the stringers to better match the heights I need and remove all the shims spacers; essentially getting my adjustment only from the mount studs?

Thank you.

Topic

[Alex]

Hi Rob. Not sure how to report that my latest topic was flagged as spam for some unknown reason.

Its post #121722 related to relocating the thruhulls for better access.

How do I proceed with trying to get the post active for discussion?

Thanks!

[Alex]

Thank you Rob,
After two weeks of fighting it, I have come to the conclusion that engines need to come out anyways. For other reasons that I will discuss in a separate thread to keep topics on course.

At that time I could raise the stringer brackets to better match the heights while the space is available.

[Rob Schepis]

If done right the shims should be no issue and not worth the trouble of moving the stringer brackets unless there is an issue with the structural integrity of the brackets as they are currently mounted or the shimming is extreme? The shims could help with giving clearance to slide the isolators out from under the engine/gear brackets. Worry more about keeping them all in-plane with proper pre-load and greased/servicable.

Vibration Isolator & Engine Mount Views

[Author]

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