The International Cessna^® 170 Association

So, I think it's time to replace the engine bushings "Lord" mounts. My question is, what do I have to remove to replace the bushings? I'm hopeful I can hoist the engine and replace them without disconnecting everything. Any pointers would be great!!

Thanks!!

This is not an easy task. The engine and bushings fit just so. You will be cussing. I've removed and reinstalled 2 engines but I've slept a night or two since so I can't give you any pointers other than this. I'd think you will probably want to remove the exhaust doing this.

BTW, why do you think it might be time to change these. Do you have evidence your engine is dropping such as unequal prop spinner to cowl gap? Many bushing look like hell in a very short time but looks doesn't necessarily equate to them being bad.

Bruce Fenstermacher wrote:This is not an easy task. The engine and bushings fit just so. You will be cussing. I've removed and reinstalled 2 engines but I've slept a night or two since so I can't give you any pointers other than this. I'd think you will probably want to remove the exhaust doing this.

BTW, why do you think it might be time to change these. Do you have evidence your engine is dropping such as unequal prop spinner to cowl gap? Many bushing look like hell in a very short time but looks doesn't necessarily equate to them being bad.

They're pretty cracked and certainly sagging. I'll try to get some pictures and see what the condenses thinks.

Just to be certain of your question, the firewall mounts or the isolator mounts of the engine legs ?

Engine mounts not firewall

Bummer, what’s not to disconnect, disassemble.
These are replacement items at engine overhaul or removal. If you look at the sample you’ll see the isolator is encased in a metal jacket and has a metal core. The ring lip of the metal jacket keeps it from moving in the engine mount leg, the metal core is trapped in the engine mount, so relative movement is the deflection of the rubber.
If you can see actual damage to the mount by actual metal to metal contact, then I guess you need to find an engine hoist but I wouldn’t jump into this unless I was forced.

Just some info on the mount isolators. Overall length is about 2.125, the metal case is 1.6, the ends although not equal should position the isolator in the middle of the mount gap. The bottom extends .300 from the case, the top extends from the gear leg the same amount ( the rubber portion is .230 + lip .065 ).The engine mount capturing the isolator is 1.5 wide.
So basically plus or minus the occasional .005 here and there, the gaps should be equal between the isolator and the engine mount ears. Hard to imagine any sagging here unless the rubber completely dis-bonds from its metal jacket which is a bit out there.

This mount is about 30 years old, doesn’t look bad and the rubber has no flex to it. That might be a more likely reason to change these at engine overhaul, just to get something more supple to make the super smooth Continental seem smoother, if that’s possible.

Can I add to this post the question of where is the best place to procure these isolators?

Thanks