Water pumb base shims update on progress

[dozerII]

Help, I purchased a new water pump kit from I boats Sierra # 18-3314 replaces Merc # 46-73804A3. I removed my old pump and base and found no shimms under it. The new pump base is about a 32nd of an inch shorter on the bearing insert than the old one so will require shims. Where can I purchse them. I tied to find them on this site with no luck.

Glen

 

[Chris1956]

Re: Water pumb base shims

Re: Water pumb base shims

Blenn, Not all motors use shims under the waterpump base. What motor do you have? Is the LU original?

 

[dozerII]

Re: Water pumb base shims

Re: Water pumb base shims

The motor is a 1984 75hp 4 cyl Ser number begins with 655. I just purchased the boat and motor and don't have a lot of history on it. Because of this I decided to change the water pump. The bearing under the water pump is a tapered roller bearing and even with the old lower pump housing had play on the drive shaft. As I said there were no shims under the old base. I cleaned off the old gaskets and placed the old base back on top of the bearing with out a gasket and you can pull the drive shaft up about a 32nd of an inch and double that with the new base suppled by sierra. How do I know if this needs to be shimmed? There is no preload pin in the drive shaft, and I am not sure if it is an Alpha unit. I do know that tapererd roller bearing need a slight amount of preload though.

Thanks for replying
Glen

 

[dozerII]

Re: Water pumb base shims

Re: Water pumb base shims

Bump Can anyone help me with this please

 

[Dukedog]

Re: Water pumb base shims

Re: Water pumb base shims

No shims. Just two oil seals (in tha base), o-ring and gasket on tha bottom of tha base...

 

[dozerII]

Re: Water pumb base shims

Re: Water pumb base shims

Thanks for the responses. I put the old pump housing back in an tightened the nuts. There is up and down movement on the drive shaft.With the new pump housing in and tightened there is even more up and down travel. The outer bearing cone moves up and down in the leg quite easy. Is it possible there were no shims put in and the job done incorrectly last time? How does a person know if this leg is definatly one that does not require shims? I know from 27 years in automotives a taperered roller bearing with no preload, or at least movement will last no time at all.

 

[Laddies]

Re: Water pumb base shims

Re: Water pumb base shims

There are 2 ways to shim the w/pump base according to the mercury manual either by measuring the depth of the housing with the gasket in place and the bottom of the pump housing then subtracting the 2 plus .002 for gasket compression. The other way is to over stack shims on the top of the bearing then measure the gap under the pump housing with a feeler gauge then remove that amt of shims plus .002. Should be in your manual. I can not copy the process for you as I am already in hot water with JB. As you know as a mechanic all proper repair procedures come from an manual or school but with the number of talkers on this site you not allowed to give factual info. Just what come off the top of you head.

 

[dozerII]

Re: Water pumb base shims

Re: Water pumb base shims

Thanks for the reply Laddies. I do have the manual and understand the procedure for shimming, but was unsure because some said no shims, were required. I quess the real question was, there can be no up and down movement in the bearing cup at all correct?
Thanks Again
Glen

 

[Laddies]

Re: Water pumb base shims

Re: Water pumb base shims

The outer race should be held firmly in place

 

[Dukedog]

Re: Water pumb base shims

Re: Water pumb base shims

Thanks for straightin' me out Laddies. Guess I need ta read a little more 'stead of just lookin' at tha pictures :redface:

 

[dozerII]

Re: Water pumb base shims

Re: Water pumb base shims

The problem gets worse I need some advise. I recieved shim kits from I boats order today and used the procedure in the manual to calculate the shims needed 10 thou. I then slid the new housing and gasket down on rhe drive shaft and into the recess, held presure down on it and felt for free play up and down on the drive shaft. Not as much as before but still way to much in my opinion. I removed the pump base and the upper bearing cup and it looks to be worn very badly. The cup is bottoming out in the machine recess before it is preloading the bearing.
From these finding I am assuming there is a lot of time on this l/u and it is in it final stages of life. I don't have any history on this motor other than the previous owner said it worked great for the season he owned it. When I brought the boat and motor home I ran it in a barrel just to make sure it ran. It was very hard to start and smoked lots with a very rough idle. Went into forward and reverse smoothly . I asked the last owner about the rough idle and he said Merc are very cold blooded and he had a compression check done and said was good but gave me no numbers.
Is it worth looking for leg, do I put it together with the new water pump and unload it, rebuilding the leg myself looks like avery difficult procedure using may special tools.
What are your opinions?

 

[Laddies]

Re: Water pumb base shims

Re: Water pumb base shims

Just a couple thoughts, in some cases the bearing will become a slip fit on the shaft instead of a pressed fit when that happens the bearing race is held firmly but the shaft will slide up and down in the inner cone and it fells like the bearing is moving. So you have 2 choices tear the unit down, that will take a spanner for the carrier nut and look things over or if you have 3 hands you can pull up on the drive shaft, hold preload on fwd gear and check for gear lash, then shift into rev and check the lash. I am presuming that your manual has the procedure in it. If you tear it down keep track of the shim placement and you should not have to re shim the housing.

 

[dozerII]

Re: Water pump base shims update on progress

Re: Water pump base shims update on progress

Thanks for the reply Laddies. The bearing cone is still tight on the shaft, Does it sound plausable the bearings and gears have enough wear they have moved down in the LU enough to loose there preload?
It finally warmed up enough here to go out and do a compression test on the power head. The compression was as follows from top cyl down 140,130,140,140. I have included a couple photos of the plugs maybe someone can shed some light on them. Number 2 has some porcelain corroision around the electrode. I have never sean this before, what could cause this? Note in the second photo number two plug is the second from the left.

Thanks Glen

 

[rodbolt]

Re: Water pumb base shims update on progress

2nd pic 2nd plug from the left has been burning water with the fuel.
you may wish to take a look at the ex divider plate before going further.

 

[dozerII]

Re: Water pumb base shims update on progress

Thanks, everyone for the help. I will pull the exhaust divider next days off and take a look.
Glen

 

[CharlieB]

Re: Water pumb base shims update on progress

I must not have made my morning coffee strong enough as I am still a bit confused as to the bearing play you have.

Can you please post another picture of the shaft/bearing, something isn't clear.

If the bearing was worn, gear lash should be reduced, if the gears are worn then lash should be increased.

I gotta go fix my 2nd pot of coffee and wake up!

 

[CharlieB]

Re: Water pumb base shims update on progress

My confusion is that this bearing is used to set the pinion height and thus, gear lash, the bearing cone/cup direction is absolutely critical.

Merc parts diagrams show shims in the housing UNDER the cup.

Is there any possibility that a prior owner has installed this incorrectly?

That picture you can take and post could be worth a LOT.

 

[dozerII]

Re: Water pumb base shims update on progress

Hello Everyone Thanks for the info I will Post a Pic ture as soon a I can. Work gets in the way of thing you enjoy to do. Can anyone tell me where to get an exhaust diverter plate and gaskets. They are not listed from what I can see in the IBoats parts catalog.

Thanks again Glen

 

[CharlieB]

Re: Water pumb base shims update on progress

Check this page for any part #'s for your motor then search iboats, ebay, etc

Your exhaust gaskets are items 19 and 21

http://www.mercruiserparts.com/Show...20&bdesc=END+CAPS,+MANIFOLD+AND+EXHAUST+COVER

 

[dozerII]

Re: Water pumb base shims update on progress

Thanks CharlieB I tried to take a phot of the actual set up and it is to tight to show detail, so I did a moch up on the table with the parts to show how it is put together. As you can see in the photo the bearing cone is pressed on the drive shaft and the cone slides down on top of it and into the machined surfase of the the LU. Then the water pump base goes in on top of the cup. Where I shimmed was between the cup and the base to stop the cup from moving up and down in the LU housing. Also thanks for the lead on the exhaust diverter parts.


Glen