Universal alt bracket\not rehash :-)

weinie · Mar 13, 2015

You could've done the whole upgrade job in the time you have taken to argue against doing it! hehehhe

woodster · Mar 14, 2015

some pics of your set up would be nice to see......

Richard19068 · Mar 14, 2015

Skipper said:
So it was yoooo! :-D

Thanks Richard. You may not know it but you likely will have a huge amount of useful info.

Was there anything different about the setup ie upgraded alternator, etc? Was the belt tension correct? Was there corrosion? How many hours on the engine?
Did you replace the case?
Sorry a lot of question marks.

It was / is a stock setup. I believe the belt tension was correct. No corrosion on the aluminum timing case (although the iron block does have some amount of rust). The boat was 20 years old when I bought it 10 years ago and didn't have an hour meter. I've put 1,000+ hours on it in the last 10 years (too much motoring but we still want to get to the island and home when there is no wind).

The crack is just below the ear on the case where the bracket attaches. Laterally along the inside radius. I hope you can understand what I mean. My ability to describe it other than that is lacking. I couldn't see it without a mirror because you can't get your head down there very well (especially when the engine is running

) . I wouldn't have noticed it except I had a nagging oil weep that I finally traced to that crack. It's just a hairline and I sanded off the area, roughed it up, cleaned it with alcohol and or acetone and put JB weld on it and it hasn't leaked for the last 100 hours or so since I did the replacement. The new replacement alternator mounting setup takes the pressure completely off of that ear so I think it's going to be okay.

Let me know if I can add anything else.

dparilla · Mar 14, 2015

FWIW, when I installed the new bracket on my M25 it actually was a shorter belt. It moved the top pin out a bit, but caused the center of the pulley to actually be 1/4 inch to starboard.
As for your coolant pump failure...recently I have seen two M18s whose alternators were slightly out of alignment causing torsion on the belt. They were slipping so the owners cranked up the tension on the belt causing the coolant pump to be pulled off center. In one case, the bracket had no washers or bushing remaining and was skewed off axis (impending failure) and this was forcing the belt off travel. The second was caused by a mis-sized pulley on the alternator that was too big and again damaged the belt, causing the owner to pump up the tension and flat out destroyed the coolant pump.

dparilla · Mar 14, 2015

Both were original brackets, by the way.

Richard19068 · Mar 14, 2015

Skipper said:
The first pic is the setup. Typical original Universal config of the time. The coolant pump just failed last weekend (leak and belt bits below pump) so will have the motor apart this weekend, and want to do other cooling sys tasks ie new hoses clean out HE, and looking at alt bracket.

2nd pic is the issue with new alt bracket. That measure tape is touching the port wall. I believe the new bracket will cause the alt to move about 3/4 inch farther to port.

Wow, that is close. I know mine did move a little but I can't remember for certain now which way it went. I think though that it went closer to the engine - further from the compartment wall. But that would be a b**** if you did the work and then it didn't fit. Maybe Weinie remembers. He and I did it within a week or so of each other.

weinie · Mar 14, 2015

I don't remember, but if there's no access panel or way to reach the studs on the heat exchanger, it's going to be impossible to install without cutting away some wood.

jibes138 · Mar 14, 2015

Skipper said:
There's an access panel to the quarter berth. In the alt pic it's visible just above the alt. I would have to cut away the permanent wall just below the panel if the new setup doesn't fit.

All you need is a shorter belt. It looks like you have a lot of room to swing the alternator closer to the motor? Do the upgrade, get a shorter belt and you should be fine. I see you have the same bolt into the face of the exhaust manifold, that's the one that sheared on my motor.

dparilla · Mar 14, 2015

I converted to a serpentine belt system. It is a full inch shorter in diameter than the v belt.

Stu Jackson · Mar 14, 2015

Why?

Skipper, PLEASE go back to my Reply #9.

I clearly said: THIS IS NOT AIMED AT YOU.

I have no idea why you took off on me.

I believe it is unwarranted and quite frankly, well let's just leave it at that, shall we?

I think Dan nailed it when he said:

dparilla said:
The frustration is not with your question. But directed at the myriad owners on this site and others that have not completed several essential repairs (this and the harness immediately come to mind.) I have recently run into an owner who upon my survey telling him to replace the bracket, he balked. His mitigation to his insurance company was to install a beefier adjusting arm, they accepted it, and less than a month later, he called me to find out about a new bracket as well as well as replace his oil filter threaded nipple, and coolant pump sheave and timing cover. All damage done when the alternator let go. I am glad you are taking the proper steps methodically, but hope you can understand the exasperation that sometimes occurs with the umpteenth re-addressal of the issue. Hopefully your question will help others focus on fixing the right items on their engines.

We keep repeating it for those unlucky skippers who haven't gotten the message yet after 25 blinkin' years.

And, yes, I understand you have a different motor, with different physical constraints.

I enjoyed your pictures, which reflected what you so clearly described. You write very well. You also did a nice job on the coolant pump & source. See how much fun it is to share good stuff?

Attacks are really unnecessary.

I can't make you do something you don't wanna do. Just as much as we all can't make those skippers with M25s do what they NEED to do.

I hope whatever choices you make will help you avoid a broken (and unavailable) timing case.

Good luck.

Stu Jackson · Mar 14, 2015

Skipper said:
Ok. Thank you sir.

Skipper, one other thought after looking at your pictures again. IF, I say IF, those two pieces to the left UNDER the adjusting bracket are castings, ITWMB I'd replace those right away.

Again, good luck, and thanks. for your comment.

woodster · Mar 14, 2015

Skipper said:
The first pic is the setup. Typical original Universal config of the time. The coolant pump just failed last weekend (leak and belt bits below pump) so will have the motor apart this weekend, and want to do other cooling sys tasks ie new hoses clean out HE, and looking at alt bracket.

2nd pic is the issue with new alt bracket. That measure tape is touching the port wall. I believe the new bracket will cause the alt to move about 3/4 inch farther to port.

thank you

Maine Sail · Mar 15, 2015

Skipper said:
We know the old alt brackets on M25's are prone to failure. However, I cannot find any specific info re where on the bracket they failed.

I've seen pics that Main posted that show the timing case failing(attached), but not the bracket. So I'm wondering how the timing case failed in that picture without the bracket failing. Was it loosely adjusted etc. Or maybe I just can't see the bracket failure in the picture.

So where does the bracket fail? Is it the adjusting arm? The lower bracket itself? The bolts? The equipment to which it's mounted? (-IE the timing case ear)

Please no warnings about should the bracket be changed, it's your boat\choice, all that. Aware that they have failed in the past. Just curious how they fail. Mine is the M-18 which I can't find a single documented failure, only one chap who had a crack. Also, I've discovered that the new bracket requires slightly more space to port, and my engine room is spaced such that I would have to modify it :-0 to enable the new bracket upgrade installation. So am looking at options IE: a custom solid steel adjusting bracket, quality bolts, etc if in fact they are the failure points. I just don't know the failure point.

Yes I have seen a failed bracket, and fixed it, on a Universal M-18. On that one the bracket failed NOT the adjustment arm. When it failed it also apparently created a hairline crack in the timing gear case, but it did not leak, so we left it alone. The timing gear case hole was also ovaled out.

I also had a customer with an M-18 which had a blue timing gear case installed before he bought the boat.. I did not do this upgrade but the timing gear cover had been replaced and the alt bracket had been upgraded. This points to another M-18 bracket or gear case failure. Both engines had stock alternators.

The only adjustment arm I have seen fail is the one from Stu's photo. Not a single one of the 10 or failures I have done have had the arm fail but a couple were bent as a result of the failure. In my failures it is usually the cast aluminum bracket that fails but I have seen the timing gear case fail first too.

The failure modes are two fold.

#1 Sometimes the timing gear housing fails and the bracket is fine/intact.

#2 Usually the bracket fails. The factory bracket is / was cast aluminum and the adjustment arm is steel.

Just because stuff is not on google does not mean the issues don't exist. I have done at least 10 of these for actual failures and perhaps another 10-12 more for preventative replacement. I think I have pictures from just two or three of those job. I also have a number of these engines that have blue timing gear covers and I'm not the one who did the repair.......

The old cast aluminum alternator bracket is a weak point and can fail regardless of whether it is on an M-18 or M-25. The timing gear cases on both engines are also weak points with almost identical dimensions. I have seen these engines run 25+ years with no issue, then out of the blue it fails.....

FWIW I have adjustment arms with similar dimensions driving 180 amp alternators. I believe the failure of the arm in Stu's photo was secondary to the aluminum bracket failing...

The big problem now is these timing gear cases are getting very, very, very scarce, the M-25's are non-existent, so any failure could mean an entire new engine or buying a used engine to salvage parts...

Universal alt bracket\not rehash :-)

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