Manual for showing how to replace rear engine mount bushings

[sitkamick]

I just noticed that my rear engine mount bushings on my 1985 Mercruiser 260 are needing to be replaced. Is there a good service manual that I may download so that I can see the procedure done? I have a Clymer manual that came with the boat but it lacks more than I could print here. I have the kit with the bolts ect, but no clear instruction on how to remove the old bushings. Looks like they need to be pressed out from the top down.
Sure would like to find a service manual that would help me with this problem.
The Seloc manual doesn't seem to have much either.

 

[alldodge]

Re: Manual for showing how to replace rear engine mount bushings

Your not going to find much in the Merc manuals either. You have to remove the engine to get to the area. It's a hard surface against another hard surface and only some washers which allow for slight movement. What happened that required your bushings the need to be replacing?

 

[sitkamick]

Re: Manual for showing how to replace rear engine mount bushings

Sorry to hear that. For some reason, I thought that the Mercruiser Manuals would be much better than the aftermarket ones. Thanks for the information.
I have my engine out for repainting and noticed that the rubber was starting to delaminate and thought as the engine is already out it would be best to do so. It is probably the original from 1985, so I am happy to find it out now rather than later after it has completely disintegrated.
I am still curious though, which number manual covers my engine anyway. Possibly #3?

 

[alldodge]

Re: Manual for showing how to replace rear engine mount bushings

Your manual would be number 9
Boatinfo - Mercruiser Service Manual nr. 9 - 1985-1988 - GM V8 Engines

I'm wondering if the terminology we are using is leading us in different directions. Bushings on the rear mount are fairly soild, which parts are rubber and coming apart?

 

[81 Checkmate]

Re: Manual for showing how to replace rear engine mount bushings

No manual here...Alldodge will have to get that for you.

But when i replaced mine i had to remove the flywheel cover off the engine and press out the old bushings and press in the new ones. We have one of the old ratchet presses at work and i used that to get them out...then i used a u joint C clamp press and socket to press them back in at home .They are a tight fit.

Good luck!

 

[achris]

Re: Manual for showing how to replace rear engine mount bushings

As much as the genuine manuals are so much better than any of the after-market ones, they are written for certified Techs, who are already qualified mechanics. There are very few 'step-by-step' instructions on anything. As they are written for techs, they assume a certain level of knowledge, which sometimes is beyond the average DIYer.... That said.... That's why we are here, to try and fill that gap between your knowledge and the service-manual.

As 81 Checkmate has already said, they press out from above and the new ones in from below. I wouldn't try doing it with the flywheel housing still on the engine, take it off. Just remember to include any spacers that may be with the new bushings. If you miss those out, you'll never get it to align properly...

HTH

Chris.......
BTW, as your engine is close to a boundary between 2 manuals (#3 and #9), best supply your engine serial number to determine the correct one...

 

[sitkamick]

Re: Manual for showing how to replace rear engine mount bushings

Engine serial number is not an option. A couple of years ago, the previous owner put a rebuilt engine in and I have not been able to find a serial number anywhere. This seems to be the hold up for me at this time.

AllDodge: The bushings that I am talking about are mounted in the Flywheel Housing.

 

[achris]

Re: Manual for showing how to replace rear engine mount bushings

Engine serial number is not an option. A couple of years ago, the previous owner put a rebuilt engine in and I have not been able to find a serial number anywhere. This seems to be the hold up for me at this time....

Maybe a drive or transom housing serial number can point us in the right direction... Got either (or both) of those?

 

[sitkamick]

Re: Manual for showing how to replace rear engine mount bushings

Serial number on upper outdrive unit is 6935745 and number on lower unit is A 420671 F. It's an Alpha 1 Gen one outdrive I believe. I do know that the engine is a 350 Chevy w/4 barrel carb.
The paper work that came with the boat dated the engine as 6-13-06 on the rebuilt engine sheet but no serial number to be found.

 

[Bondo]

Re: Manual for showing how to replace rear engine mount bushings

Ayuh,.... I wish Bt Doc would see this,...

He's got pictures of a tool he built outa pieces of pipe, 'n threaded rod, a few washers, 'n maybe a socket for pushin' those out, 'n in,...

 

[achris]

Re: Manual for showing how to replace rear engine mount bushings

Serial number on upper outdrive unit is 6935745 and number on lower unit is A 420671 F. It's an Alpha 1 Gen one outdrive I believe. I do know that the engine is a 350 Chevy w/4 barrel carb.
The paper work that came with the boat dated the engine as 6-13-06 on the rebuilt engine sheet but no serial number to be found.

Nope, it's an 'MR'... But it is 1985, so manual #9 is the right one, for the original engine. For the drive, manual #6....

Chris.......

 

[sitkamick]

Re: Manual for showing how to replace rear engine mount bushings

Thanks Chris. On my way with just what Bondo mentioned. Got all thread, socket, to push the old ones out and a large socket to recieve the bushings on the other side. When I get it done, I will let the folks know how it worked. My arbor press (2 ton) didn't give me enough room to use it so the all thread will have to do the work. Plenty of corrosion so I don't think that they are going to come out easy. Anyway, I will keep you posted.

 

[81 Checkmate]

Re: Manual for showing how to replace rear engine mount bushings

Yea....Guys like Bondo,Chris and others sure do make it easier on the novice DiYer.

Side note...Just from my experience, the new bushing that i bought were aluminum....So be carefull not to bogger them up while pressing the new ones in.

 

[sitkamick]

Re: Manual for showing how to replace rear engine mount bushings

Got by bushings out! Using a 1-1/8" 1/2" drive socket on the top and a 1-11/16" 1' drive socket on the bottom, 1/2" all-thread heavy washer and much torque to push the old bushings out. I applied a little heat to the aluminum housing to help it grow and release the corroded bushings. After removing the old bushings, I used a wire wheel on a air die grinder and cleaned the bores out real good. Then a light coat of grease and they pressed back in very nicely. Incidently, the new bushings are nicer to work with. A few less parts to deal with and they are a little "beefier" than the old ones. The outside of the bushings are steel instead of aluminum.

Thanks to all that helped me with my project, it went better than expected even though it took a lot of torque to get the bushings moving, they finally came out. My 1/2" drive impact wrench wouldn't budge them a bit so a ratchet with pipe gave me the extra "omph" that it needed.

Thanks again to all.

 

[81 Checkmate]

Re: Manual for showing how to replace rear engine mount bushings

Thats great...i love happy endings!