A few questions from a newbee!!

Chris Hays

Petty Officer 3rd Class
Joined
Aug 14, 2007
Messages
87
First off i want to say what a wealth of information this site is, ive been looking for hours on here!! I am in the process, (albeit rather slow), of rebuilding a 1990 Glastron Sierra 175 with a Mercruiser 3.0l and Alpha 1 outdrive. I have replaced the floor and its now time to mount the gimbal housing and inner transom plate back up to the transom. I have ordered all new hardware to bolt it back up but have a couple of questions.

1/ Do i just mount the gimbal housing to the transom dry, or add some kind of sealer to the seal?? (It looks like the seal was glued to the housing but not the transom).

2/ How tight do all the bolts need to be between the gimbal and tran. plate?

3/ Is it easier to replace the gimbal bearing with the housing mounted to the boat or off wrestling it around the garage?? lol.:D

4/ Could i use my original output shaft as an engine alignment tool or do i need to fork out for the real jobby??

5/ I replaced the wooden beam, or lateral stringer??, where the front engine mount, mounts too. When mounting do i drill holes and use bolts and nuts or can i use lag bolts??

6/ When i get to mounting items like my battery tray and seats, what is the best practice for sealing the screw holes i will be 'reluctantly' putting in my brand new floor?

Sorry for all the questions but i am needing EXPERT advice and im sure ill find it here!!
Thanks
(Also, i am a heavy equipment specialist by trade so any questions on Diesel engines, electrics or hydraulics feel free to shoot me a message);)
 

Bondo

Moderator
Staff member
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Apr 17, 2002
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71,103
Re: A few questions from a newbee!!

Ayuh,...

1),.. As long as the surface of the transom is smooth,+ in good shape,....
I go Dry...

2),.. About 45/ 50ft.lbs. I believe...

3),.. On the boat is Much Easier...

4),.. No,... The input shaft will Not work...

5),.. Either will be Fine,.. It depends on what you have to work with...

6),.. Whatever trips your trigger,... 5200/ 4200, or about any polyvinylsulfide based caulking...
Personally,.. I would Not use Sillycone...
 

Chris Hays

Petty Officer 3rd Class
Joined
Aug 14, 2007
Messages
87
Re: A few questions from a newbee!!

Thanks Bond-O, i will implement your suggestions immediatly sir!!:)
 

waterone1@aol.com

Lieutenant Junior Grade
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Oct 10, 2004
Messages
1,235
Re: A few questions from a newbee!!

The only thing that I want to throw my two cents in on, would be your question about engine mounts. I prefer the idea of through-bolting as opposed to lag bolts. There is vibration and torque involved here, as well as the possibility of future work needing to be done. Even if you need to use an aluminum "L" bracket, I would suggest through- bolting.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: A few questions from a newbee!!

In the many years of working on 3.0L marine engines, I think I have only seen 1 that had thru bolts on the front mount, all the others have lag bolts. Usually there isn't enough room under the mount for thru bolts.


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Chris Hays

Petty Officer 3rd Class
Joined
Aug 14, 2007
Messages
87
Re: A few questions from a newbee!!

Thanks for all the input guys, now correct me if im wrong but mounting the engine front mount to the lateral stringer and getting it lined up perfect (lateraly), is very crucial?? or if the rear two mounts are connected first will this give me a central point? The reason being is that i have also replaced the stringer to which the front mount will bolt to so i have no existing holes to go by. I guess what im trying to say is i know there is up/down adjustment on the front mount for engine alignment but im guessing side to side is just wherever its bolted down at. Right??
 

Bondo

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Re: A few questions from a newbee!!

mounting the engine front mount to the lateral stringer and getting it lined up perfect (lateraly), is very crucial??

Ayuh,.... Very.....

What I do is to hang the motor on the rear mounts,+ suspended from a overhead lift, insert the alignment bar, to get it Close...

That gets the side to side fit,+ the up/ down is dialed in with the front mounts....
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: A few questions from a newbee!!

In the many years of working on 3.0L marine engines, I think I have only seen 1 that had thru bolts on the front mount, all the others have lag bolts.
I had lags in a 3.0 on my first boat and they pulled. Crappy builder and a novice operator (read "young throttle jockey") . . . but I ended up making a steel cross-member "cover" that sat over the lateral bed and through bolted to the stringers. Then I bolted the front motor mount "foot" to the new piece. Probably overkill, but come to think of it, they actually pulled twice, once from the wood and once after they epoxied the holes and reset the whole thing. FWIW that was a Stringer drive and all of the torque is transmited to those lags, so never mind . . . ;) :rolleyes:
 

Chris Hays

Petty Officer 3rd Class
Joined
Aug 14, 2007
Messages
87
Re: A few questions from a newbee!!

Does anyone know the OD dimensions of the alignment bar i would need to use to align my alpha one gimbal housing with my 3.0 engine. I could just turn some bar stock on the lathe down to the correct dimensions and save some $$$ in the process. I think as long as the end that fits into the splines is the same diameter as the base of each spline this should give me a correct, true fit. Also thanks for all the responses, i knew i came to the right place!!:)
 

waterone1@aol.com

Lieutenant Junior Grade
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Oct 10, 2004
Messages
1,235
Re: A few questions from a newbee!!

Well, for what it is worth, I have very little experience with 3.oL engines. When it comes to 5.0, 5.7, 7.4l the norm is to through bolt. Yes, it may be overkill for a 3.0L, but then again you are re-designing this as you go along. If you can, why not......if not...no big deal.
 

Chris Hays

Petty Officer 3rd Class
Joined
Aug 14, 2007
Messages
87
Re: A few questions from a newbee!!

Thanks for all the comments guys, really appreciate it!! As for the mounting of the front mount, i think i will go the through bolt route, as i can get to the underside of the stringer. With the lag bolts if the mount ever had to be removed, each time i re-screwed into the wood it would get weaker so bolts will be the way i go. (Will post some pics of boat in the 'rebuild/restore' thread, and also my trailer re-build in the trailer section), if your interested;)
 
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