1983 Chrysler 45hp lower unit leak

[CApTaInGoOfy]

Hello everyone, noticed my lower leaking oil after being run on muffs. After turning the motor off I was going to pull the muffs off and noticed oil starting to seep out of the lower. Going to pull the lower tomorrow but wanted to get the input of the seasoned members of this site, as this site has helped me countless numbers of times in the past.

 

[Frank Acampora]

Before you drop the lower unit smell the oil. It may just be residual oil from running the engine. If it smells sharp and sorta like gasoline, then it is combustion byproducts and normal. If it smells like sulphur or rear end oil then it is lower unit oil and you need to find out where the leaking seal is.

 

[CApTaInGoOfy]

Before you drop the lower unit smell the oil. It may just be residual oil from running the engine. If it smells sharp and sorta like gasoline, then it is combustion byproducts and normal. If it smells like sulphur or rear end oil then it is lower unit oil and you need to find out where the leaking seal is.

Smelled like sulfur.....
Pulled the lower and found oil around the shift rod and the impeller housing.
Any tips on replacing the shift rod seal?
The seal below the impeller looks straight forward, remove and push new one in place as well as the prop seal. Been browsing thru the website to see what seal kit to purchase but why does the kit come with so many seals? Am i looking at the wrong kit? My model is 457H3P.

 

[Frank Acampora]

The same seals were used on almost all Chrysler 45 and 55 engines and even some early Force 50 HP engines. The shift rod seal can sometimes be salvaged by using a socket and piece of pipe to hammer it further into the casting. You want there to be some drag on the shift rod but no binding. If you want to replace it you must remove the shift rod. Then screw in an appropriately sized lag screw and pull the old one out. The new one is installed metal side up. The shift rod screws into a metal yoke and it is difficult to find the threaded hole. This is best done with the lower unit apart.

The drive shaft simply slips out of the lower unit so replacing that seal is relatively easy--pull the old one and tap in the new.

 

[wickware]

Is it odd that the Lower Unit would show to be leaking with oil coming up vs dripping down? Such as, @ the prop shaft seals and below the L/U to Leg Joint? Would a pressure test of the L/U and checking the L/U for water help in diagnosing? OR! Is it likely the Muffs are adding water pressure to the L/U and pushing L/U oil ?Up and Out??

With good L/U seals this has been a typical combustion residue on my 1970 35hp Chrysler. I have only had a prop shaft leak in the L/U since 1984.

 

[CApTaInGoOfy]

The same seals were used on almost all Chrysler 45 and 55 engines and even some early Force 50 HP engines. The shift rod seal can sometimes be salvaged by using a socket and piece of pipe to hammer it further into the casting. You want there to be some drag on the shift rod but no binding. If you want to replace it you must remove the shift rod. Then screw in an appropriately sized lag screw and pull the old one out. The new one is installed metal side up. The shift rod screws into a metal yoke and it is difficult to find the threaded hole. This is best done with the lower unit apart.

The drive shaft simply slips out of the lower unit so replacing that seal is relatively easy--pull the old one and tap in the new.

Will try "salvaging" it before separating the lower unit. Was able to purchase a seal kit, but it didn't come with a water pump body seal. Back to the marina. Thanks for the information!

 

[CApTaInGoOfy]

Is it odd that the Lower Unit would show to be leaking with oil coming up vs dripping down? Such as, @ the prop shaft seals and below the L/U to Leg Joint? Would a pressure test of the L/U and checking the L/U for water help in diagnosing? OR! Is it likely the Muffs are adding water pressure to the L/U and pushing L/U oil “Up and Out”?

With good L/U seals this has been a typical combustion residue on my 1970 35hp Chrysler. I have only had a prop shaft leak in the L/U since 1984.

Maybe the muffs are adding the pressure, did not think about that. When ran in a bucket, I did noticed the bucket water to have that oily residue/film. Have the lower unit down and in the process of replacing the driveshaft seal and the prop shaft seal. Prop shaft seal is stuck on... Any tips/ideas on how to get this thing off. Also for the water pump body seal, the rubber came out but there is a silver "race" that is still left in there... Do I remove this?

 

[wickware]

No Title

I am almost sure Frank suggested that I use 2 bolts and a plate ETC as a puller in the two threaded holes. It looked tighter than it actually was with the Allen bolts removed. I feel I used a small slide hammer to snatch ?Lightly or pull with two bolts equally using a simple matching plate?. Frank?s tip is in the search under wickware if you put in the key words.

Key words, ?prop shaft seal puller?, under wickware search should get you to the tip. Starting at the link below should be close to the tip.

http://forums.iboats.com/search?q=p...rchJSON={"keywords":"prop+shaft+seal+puller"}

 

[wickware]

No Title

4th pic that d/n show. Any suggestions why it w/n show with the others?

 

[CApTaInGoOfy]

I am almost sure Frank suggested that I use 2 bolts and a plate ETC as a puller in the two threaded holes. It looked tighter than it actually was with the Allen bolts removed. I feel I used a small slide hammer to snatch “Lightly or pull with two bolts equally using a simple matching plate”. Frank’s tip is in the search under wickware if you put in the key words.

Key words, “prop shaft seal puller”, under wickware search should get you to the tip. Starting at the link below should be close to the tip.

http://forums.iboats.com/search?q=p...rchJSON={"keywords":"prop+shaft+seal+puller"}

Was able to tap out the bearing cage. Used a heat gun to remove the bearing. Just heated the cage up and the bearing just fell out. Removing the seal on the other hand was a PIA. It finally gave with some ingenuity... Could not remember if the bearing was flush with the cage or not, figured out it was not flush after measuring with my calipers.
Was tapping the bearing cage back into the lower and couldn't figure out why it wasn't seating & I didn't want to smack it too much. Pulled it out & realized the bearing has a key. Have to line up the key & bearing! A couple smacks later & it was seated.

The water pump body drive shaft seal on the other hand, not sure how to remove that. My water pump body is still in good condition as it was replaced last summer, but the seal in it got ripped, when I was removing it from the driveshaft...Must of snagged it on something.

 

[CApTaInGoOfy]

This is the seal that I am talking about...

 

[wickware]

No Title

I am not seeing a W/P seal in my personal Pic but I am seeing one in the Clymer Manual. My 35hp pumps good water.

We?ll have to get into you adding a Tell Tale to easily see a solid stream out the side vs spry out the exhaust (if you d/n have one).

 

[oldboat1]

that tell tale -- might have just routed that tube down inside the cowling to a grommet in the pan.

 

[CApTaInGoOfy]

I am not seeing a W/P seal in my personal Pic but I am seeing one in the Clymer Manual. My 35hp pumps good water.

We’ll have to get into you adding a Tell Tale to easily see a solid stream out the side vs spry out the exhaust (if you d/n have one).

Is this a modification of some sort? My motor does not have that on the side...

 

[wickware]

No Title

It is an add-on to allow you to see the solid cooling water flowing out the side vs water coming out the back with exhaust.

Removing the pipe threaded plug on the head and adding a 90 degree hose fitting. Will allow you to run a ?? line down and out the base vs the cover. Out the cover as "was" shown looked ideal but it required aligning the line each time the cover is removed. I forgot ?Once?, LOL! Out the side of the base shows while driving, as well. Plus, the solid stream w/o exhaust is a Plus.

Selecting ?Photos? at the end of #4 shows the pic with the fitting (I?m Learning). Plus, I have included the Pic again. Adding the line is easy and helpful on the water to monitor your flow if the plug ?is not seized from salt water or etc?.

 

[CApTaInGoOfy]

It is an add-on to allow you to see the solid cooling water flowing out the side vs water coming out the back with exhaust.

Removing the pipe threaded plug on the head and adding a 90 degree hose fitting. Will allow you to run a ?” line down and out the base vs the cover. Out the cover as "was" shown looked ideal but it required aligning the line each time the cover is removed. I forgot “Once”, LOL! Out the side of the base shows while driving, as well. Plus, the solid stream w/o exhaust is a Plus.

Selecting “Photos” at the end of #4 shows the pic with the fitting (I’m Learning). Plus, I have included the Pic again. Adding the line is easy and helpful on the water to monitor your flow if the plug “is not seized from salt water or etc”.

Will definitely look into doing this, as it is difficult, at least for my novice eyes to determine if I am getting a steady stream b/c of the exhaust.

 

[CApTaInGoOfy]

No Title

Will this seal have an adverse effect on the impeller function? I am imagining water being pushed past this seal. Also is there some sort of gasket that is needed on top of the lower unit. My lower unit had red RTV on it when I pulled it.

 

[oldboat1]

CAp -- don't believe your motor uses an O ring up at the top of the driveshaft, but can check a parts diagram. That red RTV sealant has no place, though, and should be removed -- also up at the motor if you can peek and reach up there to get the stuff out. I wouldn't remove the powerhead just to get at it, but driveshaft splines should be clear (no grease either). It looks like the PO was a believer in sealants (stuff around the impeller housing and wear plate looks like better gasket sealant, anyway.) Black Permatex gasket maker/sealant is good, if using anything -- not sure your manual would call for anything. Can get a replacement shaft seal for the top of the housing, but would leave it in place if it's intact. There shouldn't be any sealant there either.

wickware -- would be curious to hear what your surface head temp is after installing that tell tale (more curious to hear what the running temp is both with it, and with the hose pinched off). Diversion of cooling water may be negligible, but have never seen before and after temps with DIY installations -- good chance to get an infrared temp gun too (good purchase if concerned about running temps).

 

[Frank Acampora]

That water pump drive shaft seal is redundant. The impeller rides against the top of the water pump casting and very little water will get past it to the seal. There is no O ring seal at the top of the drive shaft. If you intend using the engine a lot, the crankshaft, being hardened steel, can rust in the splines cold welding the drive shaft in place--even though it is stainless. Thus: You will want to lightly grease or use anti-seize on the drive shaft splines.--Again, A LIGHT COAT. Too much will pre-load the drive shaft, driving it too far into the lower unit.

 

[CApTaInGoOfy]

CAp -- don't believe your motor uses an O ring up at the top of the driveshaft, but can check a parts diagram. That red RTV sealant has no place, though, and should be removed -- also up at the motor if you can peek and reach up there to get the stuff out. I wouldn't remove the powerhead just to get at it, but driveshaft splines should be clear (no grease either). It looks like the PO was a believer in sealants (stuff around the impeller housing and wear plate looks like better gasket sealant, anyway.) Black Permatex gasket maker/sealant is good, if using anything -- not sure your manual would call for anything. Can get a replacement shaft seal for the top of the housing, but would leave it in place if it's intact. There shouldn't be any sealant there either.

wickware -- would be curious to hear what your surface head temp is after installing that tell tale (more curious to hear what the running temp is both with it, and with the hose pinched off). Diversion of cooling water may be negligible, but have never seen before and after temps with DIY installations -- good chance to get an infrared temp gun too (good purchase if concerned about running temps).

Read the 15 page sticky about telltale installation, when I get a chance will try it.