I have noticed that the rubber bushings between the fire wall and engine mount have developed radial cracks in the rubber. It's time to pull the engine and replace those bushings. Has anyone done this receintly? Do you have any advice or things to look our for? Should I consider replacing the Lord mounts at the same time?
I have noticed that when I start up there seems to be a lot of vibration through the airframe, but after warm up and in flight things are smooth as silk. Mag checks are normal, and I don't notice any sticking valves.
Patrick
Grand Praire TX
Across from Joe, down from chuck
Fire wall bushings
Moderators: GAHorn, Karl Towle, Bruce Fenstermacher
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GAHorn
- Posts: 21295
- Joined: Fri Apr 12, 2002 8:45 pm
You might have a collapsed lifter that's slow to pump up. Or it might be a leaking oil seal in the magneto allowing oil into the mag and dist-cap. (after startup it might sling the oil out towards the outer circumference and run smoother. I've had this happen to me. Requires removing the mags and replacing the oil-seal. Not a big deal...couple hours at most...you can do it on the bench.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
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wingnut
- Posts: 990
- Joined: Fri Dec 15, 2006 7:58 pm
0550155, rubber bushing
0550154-2, rubber pad
S1450-23N22-100, washer
S1450-23H16-095, washer
You'll need 4 each of the above parts for the firewall bushings. Replace the bolts and nuts too.
I have a set of 4 Lord mounts, H3006-1, new condition. had bought 2 sets for the last job accidentally. I'll sell all for $100
0550154-2, rubber pad
S1450-23N22-100, washer
S1450-23H16-095, washer
You'll need 4 each of the above parts for the firewall bushings. Replace the bolts and nuts too.
I have a set of 4 Lord mounts, H3006-1, new condition. had bought 2 sets for the last job accidentally. I'll sell all for $100
Del Lehmann
Mena, Arkansas
Mena, Arkansas
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4-Shipp
- Posts: 434
- Joined: Mon Apr 22, 2002 11:31 pm
I replaced the fire wall bushings last month. It took less than 2 hours and the only part I needed assistance on was having someone hold the wrench on the bolts on the outside while I tightened the nuts on the inside.
Other unsolicited advice:
Remove the front side cockpit panels and the rudder pedal covers. This will make it much easier to retrive the parts that you will drop.
Remove the brace from the front of the battery box to the engine mount (mine is a '53 B model - your's may be different)
I used a hydraulic engine hoist to raise/lower the engine just enough for there to be play in the bolts.
First, loosen the lower bolts to where there are 2-3 threads holding the nut on. Then raise the engine with the hoist (I just connected it to the lift lug on the top of the engine case) until the bottom mounts start to move off the fire wall. You will need about 3/4 of an inch clearance or so to get the new bushings in.
Replace the bottom bushings, bolts and nuts and tighten until they are snug.
Lower the engine until the engine mount rests against the firewall and snug the bottom bolts down.
Raise the engine to take the pressure off the top bolts. Loosen the top bolts until they too have 2-3 threads holding them. Lower the engine until there is the required clearance and change the tops.
Again raise the engine until the top mounts are snug against the firewall. Thighten everything back up, reconnect the battery box brace and you are done.
There is enough play between the flex in the engine mounts and the rubber bushings that alinging the mount and fire wall holes is a non isssue.
I was intimidated enough by this task to put it off for a while, but it was VERY easy. Good luck!
There are several other threads on this topic that you can search.
Bruce
Other unsolicited advice:
Remove the front side cockpit panels and the rudder pedal covers. This will make it much easier to retrive the parts that you will drop.
Remove the brace from the front of the battery box to the engine mount (mine is a '53 B model - your's may be different)
I used a hydraulic engine hoist to raise/lower the engine just enough for there to be play in the bolts.
First, loosen the lower bolts to where there are 2-3 threads holding the nut on. Then raise the engine with the hoist (I just connected it to the lift lug on the top of the engine case) until the bottom mounts start to move off the fire wall. You will need about 3/4 of an inch clearance or so to get the new bushings in.
Replace the bottom bushings, bolts and nuts and tighten until they are snug.
Lower the engine until the engine mount rests against the firewall and snug the bottom bolts down.
Raise the engine to take the pressure off the top bolts. Loosen the top bolts until they too have 2-3 threads holding them. Lower the engine until there is the required clearance and change the tops.
Again raise the engine until the top mounts are snug against the firewall. Thighten everything back up, reconnect the battery box brace and you are done.
There is enough play between the flex in the engine mounts and the rubber bushings that alinging the mount and fire wall holes is a non isssue.
I was intimidated enough by this task to put it off for a while, but it was VERY easy. Good luck!
There are several other threads on this topic that you can search.
Bruce
Bruce Shipp
former owners of N49CP, '53 C170B
former owners of N49CP, '53 C170B
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