Volvo Penta 4.3GL - are rear engine mounts adjustable?

[pgwin]

In attempt to align the 4.3L with the gimbal bearing, I'v'e adusted the front mounts for elevation - 7 exact turns of both front engine mounts and that takes care of the vertical alignment.

Now the horizontal alignment of the coupler bore to the gimbal bearing is off a tad, can I push the front of the engine to the right or left- do the mounts allow this at all - or if not can the rear mount be moved right or left

Can any one shed light on how the rear engine mount works or pivots - it is impossible to see it with only the drive removed and engine covers removed.

Any thoughts on how to push front of engine to the right or the left. Any pics of a rear engine mount - google could not find it.
thx,

Paul

 

[Dave-R]

Paul :Generally they are always right on. That is unless someone has removed something. Seems like there is a square washer that the bell housing sits on and is bolted down. This is to make sure the engine at least in the back is exactly where it should be. Make sure you partially insert your alignment tool and tap it up, and down, and side to side to move the gimbal around first. Some have suggested loosening the front mounts of the engine and raise and lower the front of the engine with a hoist until the alignment bar slides in. There should be no horizontal alignment. Rotate the engine 90 deg and try again. Dave-R

 

[pgwin]

Dave - thanks for the explanation on the rear engine mount - sounds like it is a positive indexing of the engine to the transom housing rather than an adjustable.

My boat has never had anything done to it, - so on the good side - i don't need to wonder if the PO had moved things around or monkeyed with the rear mount, (and on the bad side - the engine alignment neglect is why were having this conversation!). I think it is highly probable to assume the rear mount is as it should be.

I rotated the engine 180 and the horizontal imbalance in position transferred to the other side (so it is minor coupler spline alignment to the crankshaft itself causing this (it was only about 0.020 inch off to begin with -but i like to get as perfect as possible. I'd say it is net zero off center horizontally - solved.

I will have to replace the coupler as the standard alignment shaft will not insert with the tool O.D. of 1.011" (actual measured), i had to turn a 1" piece of steel down to 0.990" to be able to insert it - which is because the internal splines have grown (taller smaller I.D. due to wear). I'm hoping the drive slides back in - now that it is aligned and to replace the coupler next year when i have time to do it.

I'm going to replace the gimbal bearing as it is not perfectly smooth - as felt when rotating the alignment tool inserted in it - i attribute this wear to the misalignment of the engine putting a larger horizontal load on the bearing.

Now to go find a bearing puller or make one from all-thread

 

[Dave-R]

My eyes aren't as good as they used to be, but the splines look okay to me. Were you having vibration problems, or doing regular maintenance ? After you install your new bearing, check the alignment again. It may get better. I use either a 3 jaw puller, or a harbor freight rear axle bearing puller to remove the bearing. I also have a heavy round solid oak post I use to set the gimbal bearing. You can download a manual which will help you a lot. Good luck. Dave-R.

 

[pgwin]

originally when i bought it, it made a backlash type of noise after the engine warmed up good. Sounded like it was coming from the gimbal area (hard to detect) but not the engine. Engine ran fairly smooth. The noise was really only heard at idle and not in gear - maybe some time i thought i could hear it faintly when moving.

also the PO only did the maintenance at the 50 hr mark by the dealer and never pulled the drive in 10 yrs. He thought since only 125 hrs and stored inside in sunny California it wasn't needed. But i found the front mounts needed 8 turns to get the alignment fairly exact - so either mounts compressed (doesn't look like it) or it was set wrong from factory - possible but then how would they install the drive - so mayby the rubber in the mount has "shrunk".

The coupler splines have deformed and each spline grown about 0.010". I had to turn down a 1" shaft in 0.002" increments until 0.990" when i could just get it to slide in the coupler - and this is completely free of any alignment - no other parts touching the 1" shaft. So the coupler splines have deformed.

I think i'll try an axel puller.

Here's the full write up pulling the drive - inspecting: http://forums.iboats.com/forum/engi...line-bearing-u-joint-inspection-advice-needed

thx,

Paul