upper motor mount removal 175 Johnson

[Timeking]

I have a 1982 Model J175TXCNB, with the powerhead and the lower unit already removed. I need to replace the upper motor mount (0387098) but the two bolts are frozen/rusted heads. There is no room to drill them or ez-out them out. I can sawzall them but will likely cause damage to the steering arm assembly (0392519 - see attached diagram). Is it possible to remove the steering arm assembly and the upper motor mount as one piece so I can properly get those screws out? How is the steering assembly held on? And how do you get the steering assembly off? Does it come loose at the bottom somehow and then lift out through the top?

 

[Joe Reeves]

Re: upper motor mount removal 175 Johnson

Assuming that the heads of the motor mount bolts still hold a wrench securely..... use a hand held propane torch heat the metal surrounding those large bolts. That should free them enough to back them out. I've yet to find one that wouldn't come loose in this manner.

The steering arm is attached by those two M/Mt bolts and by a large nut at its extreme bottom. To remove it without first removing the two top M/Mt bolts (which is not a good idea), remove the lower M/Mt side brackets, and then that large nut. You can then lift the engine (what's left of it) and the steering shaft straight up.

If you attempt this, I'd suggest that you remove the lower unit first to eliminate as much weight as possible.

 

[Dhadley]

Re: upper motor mount removal 175 Johnson

Just curious -- why do you need to replace the mount?

 

[Joe Reeves]

Re: upper motor mount removal 175 Johnson

Dhadley...... Good point, that didn't cross my mind. If a real shakey engine (sideways), that could be (and usually is) that the splines are worn at the bottom of the steering arm area.

 

[Dhadley]

Re: upper motor mount removal 175 Johnson

Or that nut is loose. Seen several guys replace the upper mount (sometimes twice) trying to get the sideways movement out only to find that nut was loose.

 

[Timeking]

Re: upper motor mount removal 175 Johnson

Yes, too much side to side play. I've had the head off and put 2 bolts down throught the motor mount, tapping them in, figuring that would stabilize the motor mount. But it didn't. I think you may have something there with the "Splines" idea. That is interesting theory. The spline is at the very end of the steering arm? So to get into there I need to take off the two lower side housings over the lower motor mount and then those 4 big bolts (that are seriously in there!! - I tried a regular ratchet and will need to step that effort up to a big breaker bar)..that attach the lower motor mount. Is that how I get into where the spline is?

 

[Timeking]

Re: upper motor mount removal 175 Johnson

Yes, too much side to side play. I've had the head off and put 2 bolts down throught the motor mount, tapping them in, figuring that would stabilize the motor mount. But it didn't. I think you may have something there with the "Splines" idea. That is interesting theory. The spline is at the very end of the steering arm? So to get into there I need to take off the two lower side housings over the lower motor mount and then those 4 big bolts (that are seriously in there!! - I tried a regular ratchet and will need to step that effort up to a big breaker bar)..that attach the lower motor mount. Is that how I get into where the spline is?

 

[Dhadley]

Re: upper motor mount removal 175 Johnson

Once the powerhead and lower unit is off you can take the bolts out of the upper & lower motor mounts. Then the mid section can be removed. Then you can get to the nut on the bottom of the steering shaft.

 

[Timeking]

Re: upper motor mount removal 175 Johnson

ok. thanks. I guess I have my weekend planned!!

 

[Joe Reeves]

Re: upper motor mount removal 175 Johnson

And if you actually drilled and tapped in two bolts directly thru the upper motor mount, (that's how it comes across to me), I strongly suggest that you replace that upper mount while you're at it.

 

[Timeking]

Re: upper motor mount removal 175 Johnson

I got it all apart and it was in fact the splined end of the steering arm shaft. It basically fell apart with the rotted out end of it stuck inside the lower mount which I will have to dig out. So much thanks again. At this particular point I'm going to make sure I have a complete list of what I am going to need to put it all back together, then make sure I can actually get all these parts, then order them all. Current estimate for this job in parts alone is running about $700, including the upper mount as you suggest.

 

[Timeking]

Re: upper motor mount removal 175 Johnson

In order to get the upper mount out, I had to destroy it. It was trashed anyway. Of course the forward screw that holds the upper mount (the one hardest to get at) broke off flush. If I can solve the remainder of the job below, I am taking that single bolt removal job to a machine shop.

So ... I had to remove the inner upper exhaust housing (pn 0323548) from the exhaust housing (pn 0392170) in attempt to get at backside of two screws that were rotted away. I got those out OK. Now I need to separate the plate assembly (pn 0327803) from the exhaust housing adapter (pn0327804) to get at 2 other bolts that broke off. But these 2 parts are stuck together tight. Any hints on how to get the plate assembly free from the adapter? All the bolts are either removed or have their heads drilled off flush. If I can get it apart, I can vice wrench them out ... and then I will be ready to put the whole thing back together. Yay! Sort of ....

 

[Timeking]

Re: upper motor mount removal 175 Johnson

oh yeah, should I try to pull the water tube out of its hole and replace that grommet while I am at it?

 

[Joe Reeves]

Re: upper motor mount removal 175 Johnson

The water tubes are atttached to the bottom of the adapter plate with fittings that are secured with two screws each. There is no way that they can simply be pulled out without creating further damage $$$$$$$!

 

[grid]

Re: upper motor mount removal 175 Johnson

I wish I worked somewhere we could get away with using propane. Each of us has his own acetylene/oxygen system; mine's smaller because of all the mobile service I do, but getting the system properly hot in a minute instead of a half-hour makes life tol'able.

 

[Joe Reeves]

Re: upper motor mount removal 175 Johnson

The acetylene/oxygen system is one you DO NOT want to use on or around aluminum which is the major metal used in the manufacture of outboard motors. The extremely high range of heat will melt aluminum rather quickly.

 

[Timeking]

Re: upper motor mount removal 175 Johnson

I cannot separate the plate assembly (pn 0327803) from the exhaust housing adapter (pn0327804) to get at 2 other bolts that broke off. The only thing holding the two pieces together is the corrosion. There were 8 bolts all that held this together. Only two of those came out, the remaining six have had what was left of their heads drilled off. Any suggestion on how to separate these two pieces?