Question on engine mount replacement

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no1fishhead
Posts: 28
Joined: Jul 18th, '06, 06:07
Location: Annapolis, MD

Question on engine mount replacement

Post by no1fishhead »

I need to replace mey engine mounts on my 31 Bertram powered with cummins 6B5.9s. Any advice on how to jack up the engines to remove/replace them???
Thanks,
Rob
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In Memory of Vicroy
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Joined: Jun 29th, '06, 09:19
Location: Baton Rouge, LA

Post by In Memory of Vicroy »

I've seen it done with a floor jack shimmed up against the hull with some 2X12's.

UV
no1fishhead
Posts: 28
Joined: Jul 18th, '06, 06:07
Location: Annapolis, MD

Post by no1fishhead »

Do you mean a bottle jack? Where do I place the jack on the engine to press it up? Is there a good place which will carry the load?
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In Memory of Vicroy
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Joined: Jun 29th, '06, 09:19
Location: Baton Rouge, LA

Post by In Memory of Vicroy »

The Cummins manual has a section (page A-123) on replacing the front and rear engine mounts. For the front mount, it says jack up using thefront of the oil pan to push on, and be sure to put a piece of wood at least 8" long and an inch and a half thick transversely against the oil pan. Says to spread the load over as much of the oil pan as you can and also use planks to spread the load as much as possible on the hull. Picture shows a hyd bottle jack. Remove the fronts, install new ones, then the rears. Says to remove the mounts by taking the cap screws (3 per side) loose from the block after taking the cap screws off that hold the mount to the engine bed and slide out. Thus you don't have to jack the engine up but a little. Snug up the cap screws and remove the jack, then torque cap screws that hold mount to block to 45 ft. lbs.

On the rear mounts, disconnect the prop coupling and jack under the flywheel housing, again using a block of wood on top of the jack.

I'm staying home for a while watching nervously as about 15 grosbeaks with a huge crane are cutting down two huge water oaks in my neighbor's yard that hang over our house. You can send me a fax # and I can fax you the pages out of the Cummins manual when I get to the office after while if you'd like.

UV
no1fishhead
Posts: 28
Joined: Jul 18th, '06, 06:07
Location: Annapolis, MD

Post by no1fishhead »

Very good UV, I have the manual and thank you very much...I would never have thought of looking it up in the cummins book. I think I cracked a shaft coming in from fishing (caught White Marlin, tunas) Sunday heading back to my slip in OC, MD. Developed a very bad vibration and there is nothing fouling the props. My bet is that I craked a shaft. This shaft is very old and has some corrosion so I'm having the "Vitamin Sea" put on the hard and planning on replacing the shaft, mounts and both shaft logs....lots of work to do in 3 days. Thanks again, Rob
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TailhookTom
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Joined: Jul 3rd, '06, 14:12

Alternative

Post by TailhookTom »

I don't know if this helps, but when I changed the mounts on my Volvo diesels, my genius friend showed me how to use the motor mounts as jacks to change the mounts -- we undid the jam nuts, unscrewed the main nut until it was barely attached, and then turnd the bottom nut to lift the engine until it was against the main nut. Once there, we slide a timber under the engine and then undid the top nut on the mount and slide it out and put the new mount in.

Once done, repeat three more times.

Tom
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