Motor Mounts "Failed"

[DLCameron2]

Hello:

How do you tell if the Ace motor mounts have collapsed or failed, or if only an alignement is needed? I have 6V-92's on the Covington style 3 point (2 rear 1 front) mounts. I definitley have an alignment issue, but it may have been here for a while and gone "unnoticed". The mounts are not that expensive, but the engines may have to be lifted about 6" to get them out and replaced looks like a royal PITA. Also if yachtsman willie can run down a step by step alignment procedure that would be great.

Thanks for your input guys.

DC

 

[Brian Degulis]

The Ace mounts almost never fail. When they do the stud breaks and it's obvious. They do get stiffer over time and transmit more vibration but that will help to keep the engine aligned.

Brian

 

[Vincentc]

At Hatteras U - Jarrett Bay campus, it was recommended that you should occasionally go into you engine room and watch what happens when your engines are put in and out of gear. Seems to me that an engine mount would show itself.
Regards,
Vincent

 

[yachtsmanbill]

Hey DC... if you can wait until tomorrow afternoon I'll be happy to go through it with you. Its no problem, but for now weve got some stuff going on and a wake tomorrow (a memorial service for ppats brother) at 1 pm.
Its really pretty straight forward once you get started. The worst part is good leverage to loosen bolts etc... I recommend some stretching exercises to limber up first LOL !!! We'll be doing some in an hour.... (!) ws

 

[SKYCHENEY]

Don,
I just got your voicemail. I was in the North Channel and we didn't have any phone reception. I would like to tell you about how my shafts are centered in the tubes, but it is hard to tell as a PO replaced the OEM stuffing boxes with PSS dripless.

 

[mobilemn1]

Hey DC... if you can wait until tomorrow afternoon I'll be happy to go through it with you. Its no problem, but for now weve got some stuff going on and a wake tomorrow (a memorial service for ppats brother) at 1 pm.
Its really pretty straight forward once you get started. The worst part is good leverage to loosen bolts etc... I recommend some stretching exercises to limber up first LOL !!! We'll be doing some in an hour.... (!) ws

Ppat, sorry for your loss, you have my heartfelt condolences.

 

[ppat324]

Thank you, Daryl. The last 2 years have really been rough on me. 2 yrs ago, I lost my 32 y.o. son to a birth defect, last year I lost my husband and now, this year my brother. At least, with my brother I was able to prepare for it and say good-bye. With my son I got the call in the middle of the night and swore at the preacher who called for my daughter-in-law. With my husband, I came home from work and found him non responsive. 36 hours later, he was gone.
I thank God every day that I was able to meet Bill!!! without him i 'd of probably gone crazy. ppat

 

[Avenger]

Sorry about the run of bad luck ppat. I guess the stars aligned and sent Bill your way at the right time. Hopefully things are turning around for you.

 

[yachtsmanbill]

thanks, guys... I really think of Bill as my knight in shining armour. When I met Bill, I was soo low that I had to dig myself out of the earth just to meet him. Its been a whirlwind since I met him but I wouldnt change a moment. today, he went with me to the service and then to my family's house and was my support the whole time. ( I tend to stay away from my family as much as possible). he did really well with people he didnt know and didnt bug me to leave. Thank you Bill.... Ppat

 

[yachtsmanbill]

HE'S BAAAACK !!!!
I gotta admit one thing about life as of late... since Ive been Roamin', hatterasin' and Ppat'n, I NEVER GET BORED... EVER !!!!! And thats good!

Re: alignment. A few tools yer gonna need are a SUFFICIENT wrench, probably a slugging wrench for the coupling bolts (1-1/8"), a BFH (big friggin' hammer), a set of feeler gages, and a dial indicator.
Split the coupling faces enough to clean them with a small wire brush and make sure bubba didnt beat them together causing ANY burrs or dents. Turn the shaft a few full turns. It should just about roll by hand. If its much tighter than that, theres another issue down the line from there as in bent shaft or cutless bearing problems.
Set the dial indicator up on a solid mount and check the CLEAN shaft for run out. .000" is perfect, but I could live with .005" total runout. Figure the engines turning at 1500 with a 2:1 gear and the shaft is running at 750 rpm. Thats about 12 1/2 turns per second which aint that fast.
Next check the up and down play on the forward (in the tube) cutlass bearing. Owing to a 2 inch shaft, it may go U&D 1/8" or so. Any more and youll need to address the bearings...
IDEALLY the couplings should slide together on to the recievers. Thats the male and female fit on the faces. You should almost be able to squeeze them together by hand. They are just about size to size. If they dont, clean some more and also take a good straight edge across the faces. Bubba may have forced them together dishing the mating surfaces. A little bit you can file clean, but more needs machining.
At this point, they are "roughed" in. Check around the periphery with a feeler gage. 0-0-0-0 is great, but expect more like 0-.005-.010-.005 for your readings. This will indicate having to move the front end up or down, or side to side. As if thiis werent enough, they must still match RADIALLY. In other words if you looked at them super imposed on one another, they will lay EXACTLY on top of each other. This is JUST AS CRITICAL as the feeler readings!!!
Before they are tightened, the mounts need to be secured, and the readings should IDEALLY be 0-0-0-0. RADIALLY and AXIALLY. For tonight, I'll say, take some IBUPROFEN and then take some readings LOL. This will be an all day job. It takes time for this, plus EXTREME cleaning on the mounts/shims/bolts and probably making new shims as well. Youll be a master after this and the other side will be a breeze! Have at it!! ws

 

[DLCameron2]

Yachtsmanbill and PPat:

Sorry for your loss. Willie, thanks for the input. Luckily the ACE mounts are easy to adjust. I will attempt the runout test etc., once I see what happens when I loosen the coupler bolts. I am gonna use an impact gun to loosen them, hopefully that will make it a little easier. Do you know what the torque spec. is for tightening the coupler bolts?

If I can get the alignment within .005" I would be very happy. I get the feeling it is far from that now, but we will see. Thanks again!

DC

 

[ppat324]

Thanks for the condolences... its been a ruff couple of weeks; not to mention we put the "fun" in disfunctional around here...
You may get those bolts loose if you have a good impact wrench. A $29 harbor freight unit probably wont work. Mine took a slugging wrench and a
4 lb hammer and a lotta cussing. A few I had to heat with a propane torch as well.
The bolts are 3/4" grade 8 sae with oil quenched nuts
( 1-1/8 on both sides ). After they are wire wheeled clean and never siezed, I would guess about 125 lbs ( no torque table here...) would put you in the ball park.
After this part, its also seriously time to look at the stuffing box hoses and all the stuff down there at the business end. Keep us in tune to what you find ok? ws

 

[krush]

Hey bill, did ya bust out the "graph" when you did yours? Us modern boys use that new laser stuff---it tells ya what shim to stick under which foot. Checks for soft foot too. Pretty neat shit (and $$$ too Hahaha). I needa learn how to use the graph, old guy I worked with said he was fast with it.

 

[ppat324]

Well Krush old boy, I learned to do coupling alignment when a LASER was something out of a Flash Gordon movie. Give me a set of dial indicators and I'll align a 5000 hp BFP in two moves... hopefully yer battery dont crap out in the middle of that 3 day job!
Seriously, FWIW, any boat is nothing more than a case of softfoot. The laser did make an easier job out of aligning turbine diaphragms. We used to do it with a piano wire and a grounding sounder. Of course wire sag over 100 feet was an issue. My how times have changed! ws

 

[DLCameron2]

UPDATE:
Yesterday I uncoupled the starboard coupler. Had to go buy some "big Boy" wrenches as the bolts are 15/16" and the ACE mounts are 11/2" nuts. Any way; I took off the marine gear oil filter for more room to work and visibility. The coupler came apart fairly easily, hand tools only, no hammer. The coupler was initially "tight together" at the top and about .050" clearance at the bottom. I adjusted the front mount down until the faces of the coupler were "aligned" I ended up using a .020" feeler guage. I tried to do the runout test per Bill's instructions but could not get a repeatable reading on the dial guage. In the end the front of the engine was lowered close to .125" to attain the alignment I have now. I am waiting for a 15/16" crow's foot wrench so I can confirm the torque on the bolts, then I will go for a test ride. I have owned this boat 6 years and the PO did a lot of work on the shafts etc. prior to my original sea trial. I think what needs to happen is a full out check of the running gear on land then a re-check afloat. Probably be spring 2010 before that happens. The ACE mounts make it possible to do a good job rather "expediently", I am really glad I did not have to work with shims. Thanks for all of the input.

DC

 

[yachtsmanbill]

Good for you!!! Sounds like you did a pretty good job. The only points I would add are, did the register slip together by hand? And how did tou check the radial alignment?
Assuming both couplings are the same diameter (within pretty close dimensions) and after the parallels are set, you can use a decent straight edge at 12,3,6, and 9 oclock to see how close you are. Close, as in having your nose in there with a flashlight trying to see <.010" air gap. I hope the last connotation makes swnse.

 

[yachtsmanbill]

JFTHOI (just for the heck of it) I would guess with 15/16 bolt heads, the trannies arent Allisons. That would make the bolts 5/8. Mine are 1-1/8 . ws

 

[SKYCHENEY]

I've been in Don's engine rooms. Those are Allison M20's coupled to 6v92TA's.

 

[Trojan]

5/8 sae grade 8 bolts require 230ftp of torque. Chances are they are grade 5 sae and require 154ftp of torque. You need to check the markings on the head.

BILL

 

[yachtsmanbill]

At first I thougt DC was refering to a 15/16 bolt dia. (!) I know the wrench size on mine is 1-1/8 and am guessing its a 3/4 bolt. Definitely mine had 6 hash marks and are SAE. I found it wierd that the Allisons would have 2 different sizes... are the shafts 2" with the big couplings etc etc...? ws