merc 5.7L coupler number

[bolo789]

hello to everyone, <br /><br />iam going to chjange my 1989 mercruiser 5.7L ENGINE COUPLER, can any one help me with the right part # for this coupler,<br /><br />also if when i get the coupler shoul i get the outdrive yoke to go with it ??<br /><br /><br />thanks for any info guys

 

[Bt Doctur]

Re: merc 5.7L coupler number

If theres any doubt, pull the motor and then match it,check the input shaft for any damage to the splines first. yoke is usually replaced if it shows a groove from the seal.and/or is leaking oil.

 

[Don S]

Re: merc 5.7L coupler number

It depends on your serial number if Alpha drive,<br />and if you have a Bravo drive it's even a different one.<br />Regarding the shaft. IF you are talking about the splined shaft, if the raised splines on the shaft are the same width and height the complete length of the shaft, it's fine. If they are narrower or shorter or twisted, it needs replaced.

 

[bolo789]

Re: merc 5.7L coupler number

thanks don and dt doctur, i dont have the serial number right now, but the year is 1989 merc 5.7 L 260, with a newer the newer alphaone drive with a 1.47 geay ratio.<br /><br />the yoke iam talking is the tounge that attatch to the drive shaft that goes in the coupler. maybe it is call by a diffrent name lol, thanks guys, reason for changing the coupler is at the end of the season i was getting a bad virbration and i hearg a screching sound coming from the bacp of the coupler , i was catching so much blues and stripers that i fogot to poke my nose for rubber smell, the next week as i was going out the rpm start climbing but the boat speed was not, after run for a while i i got some speed and went fishing. then the day i was pulling the boat out, i was at idle, and the heat guage was going all the way up antil i rev up the engine and the temp fall right back down, that could be the empeller, i know that, but i dont want to launch the boat then found out my coupler is shot.<br /><br />so i will change it now. i think the alinement guy did a bad job on the alinement last season, because it was busting his chaps to get it right, <br /><br />any way thanks guys

 

[Don S]

Re: merc 5.7L coupler number

IF you look at the coupler, you will probably find all kinds of metal shavings around the back of it.<br />The splines are gone, that was the screaching noise (Probably) the reason for the overheat is the shaft in the drive has to be turning to turn the pump in the drive. Since the coupler is spun out, the shaft won't turn therefore the water pump doen't work.<br />If you spun the couple out like that, get a new yoke (Splined shaft) for the upper that goes into the coupler.

 

[bolo789]

Re: merc 5.7L coupler number

thanks don, very well said, i know the guy who did the coupler did a very bad job because i was there, he could not get it right then all of a sudden when i turn my back he said it is ok but the tool he was useing was still going in kinda tight. well he will not do it f sure again.<br /><br /><br />again thanks guys i will post when i lifted the engine.

 

[bolo789]

Re: merc 5.7L coupler number

up date hey guys i took of my coupler and it is shot.<br /><br />so now the drive i was useing last season, will now be my spear, i got a new drive so my ??? is do i just change the coupler only been now i has a new drive with new yoke , i will not need the yoke that came with the new coupler,<br /><br />thanks for you all respond

 

[Don S]

Re: merc 5.7L coupler number

If the new drive has a NEW yoke, no reason to change it. But if you should need to use the old drive for some reason, be sure to put the new yoke on it before installing it on the boat.<br />And make sure you have the alignment dead on before you install your new drive, or you will be installing a new coupler AGAIN, very soon.

 

[bolo789]

Re: merc 5.7L coupler number

thanks muck again don, man you realy know your stuff, god bless you.