Engine Shock Mount Replacement
 

Does anyone have any experience changing front engine rubber mounts? My question is: can I get away with not disconnecting everything (oil lines, throttle cables, etc.) by only lifting the engine high enough to remove and replace the rubber mount pads? I heard the bolts will not line-up very well unless the weight of the engine is supported, so are there any trade secrects on replacing the rubber mounts?

I had the front mounts replaced at last years annual. It was going to be an easy annual and the A&P could have been looking for extras, not a problem as they were probably the original 1973 mounts. His labor estimate was 4 hrs. and that is what was billed. I did ask how it would go and he said something like - they raise the engine and "slip them in" so I guess you are on the right track. Im sure your a better mechanic than I am but I could have probably found a way to make a mess of the job - was happy to pay the $200 labor. Just an observation I posted on the CPA site last year thinking I would get some response - like how cheap can you be?? and that is that when he handed me the old mounts I could see that there was no damage and that only the one in compression was affected, the other 1/2 was like original -- so -- why not just buy 2 sets and only use the new ones on the compression side?? Good luck with your work.

Yes you can. The only things that I totally disconnected were the mufflers from the "Y" pipes (normal aspirated).

Thanks for the info. I didn't think about the muffler. Also, what position should the throttles be in? Full forward or full aft? Or leave it in the middle so it can move in either direction?

I had plenty of slack in the throttle, misture and prop cables.. I raised the engine just enough to change out the lower donuts.

So, how did you keep weight on the nose wheel? Did you put wooden supports on the tail boom?

Yes, used a pole bolted to the tail tie down with a cushion to keep from maring the paint on the lower boom in the area around the tie down.

Sounds like an easier way to keep the tail down than what the book says to do (build a wooden support). What kind of pole did you use? How did you keep the pole from sliding around on the ground?

Not the best photo but this is a boom cradle with adjustable height
Has a wide plate on the bottom to support the pipe that has another pipe inside to adjust height with series of holes and pin
The saddle for the boom is on a swivel and is just a piece of heavy iron strap (like 1/4 x 3) bent in the shape of the boom and has a piece of rubber glued to the inside
These belong to Jerry DeSantis and I have some better pictures somewhere but it's really pretty straight forward design
Oh, there is one for each side :-)

I'm looking for help with engine shock mount part numbers, for a 67' model. My parts manual shows shock mount kit# J-9613-31, but only for the front engine front mounts, and the rear engine aft mounts. The front engine aft mounts, and the rear engine forward mounts are not listed. So are all four engine mounts the same? They certainly don't look like it. I'd appreciate any help with engine shock mount part numbers...especially the front engine aft mounts and rear engine forward mounts.

I have a 1967 337B and the shock mounts are all the same type. I find the Barry mounts are significantly less expensive than the Lords. I have not noticed a difference in the service life.

You can find the part numbers in this table from Sky Geek.

http://www.skygeek.com/cessna-barry.html

Wow, thanks for the cheaper option...especially if it's the same quality. One final question, are these mounts sold individually or in pairs of two or four, for the $150ish?

Sorry, its each, so times four per engine.

Lord mount was having some kind of clearance sale. Might check with them too.
I used the Barry mounts on my rear couple months ago and they worked great too.

So, I ordered the Barry mounts instead...saved a little bit of cash. However, for an FAA PMA approved part I have to wonder. First, one set was missing the "spacer" that comes with the mounts. Half the mounts were labelled top/bottom, the other half did not...but it did at least have the part number on them...still it would seem there would be standarization in their manufacturing process. Next time, I'm buying Lords.

I put the new mounts in the front engine today. Right now three of the four mounts line up with the bolts. The two rear mounts and right front are aligned, but the left front mount is not aligned. Has anyone ever had this problem? I haven't tightened the rear mounts yet, but if I do will this make the front mount line up better? Any suggestions?

It can be a little tricky but you just have to lift the engine a little and jockey it slightly to get everything to line up. You may need to take out one of the other bolts to get the other started. Do you have two people? Take a small drift punch to line up the hole closer works too.

Finally got the new mounts on the front engine. After trying several different ways to lower the engine back into the mounts, there was only one way that it worked. Get the front mounts/bolts aligned first...it required the muscle of 3 guys to wiggle the engine into place. Then the aft mounts line up nicely after tightening the front mounts up...and stepping on the engine accessory section to compress the engine mounts. But finally, all bolts and mounts are back in place. Next! The rear engine mounts.

Here's a pic of a new mount on the rear engine.