1979 Chrysler 75hp lower unit

[Dhicksaw]

I got my 1979 Chrysler 75hp running thanks to the replys to my other post but now I have what looks to be gear oil comeing out of the exhaust port in front of the prop. Is this possible? I was also wondering if anyone had the torque specs and prosidure on resealing the lower unit. Thank you

 

[jerryjerry05]

Re: 1979 Chrysler 75hp lower unit

Usually the stuff dripping down is unburned gas/oil.
You need to make sure it's not gear oil.
Drain the oil.Make sure you remove the right screws.
There is a screw on the side you do NOT remove.
It's the linkage anchor post.Will cause lots of problems.

Is the oil clean?Color?
Once it's drained,pressure test it and see if it leaks??
Too much pressure will blow out the seals.
Pictures?Serial#s Model#??

 

[Dhicksaw]

Re: 1979 Chrysler 75hp lower unit

It was a brownish color foam on top of water but I pulled the drain plug on lower unit today and water come out first so it's leaking some where. Model 757H9E
Serial 6566
Thank you

 

[Dhicksaw]

Re: 1979 Chrysler 75hp lower unit

I pulled lower unit down and put some air to it. The only spot I'm loosing air is threw the water pickup slots in lower unit.

 

[Dhicksaw]

Re: 1979 Chrysler 75hp lower unit

I'm not sure if the seal I need it going to be in a lower unit seal kit or a water pump kit? Does anyone know?

 

[Frank Acampora]

Re: 1979 Chrysler 75hp lower unit



If air comes out the water intake slots: The rear O ring on the prop shaft spool is leaking. You need to pull off the prop, remove the anode, and unbolt the four bolts behind the anode. Then, using two lengths of all thread, pull out the spool. Now you can remove and replace the O ring. You have the option of buying one from a Mercury dealer or trying to fing one at atGraingers or McMaster Carr.

Although the first photo shows the complete prop shaft/ reverse gear/ bearing carrier/spool, you will not need to remove anything except the spool.

Check the casing to be certain there is no corrosion damage or scoring to leak past the new O ring. If that is the case, you may need to replace the casting too.

 

[Dhicksaw]

Re: 1979 Chrysler 75hp lower unit

Thank you for the info. Does anyone know the torque specs for the bolts I need to remove?

 

[Dhicksaw]

Re: 1979 Chrysler 75hp lower unit

pulled my prop,anode, and in the back of the anode ther is bearing race. i dont see a spool. i also have a 2 piece lower unit. thank you

 

[Dhicksaw]

Re: 1979 Chrysler 75hp lower unit

I think I found the problem. When I seperated the bottom half from the top half of the lower unit I found a flattened out oring and it looks like the gear oil and water was mixing in a little front hole that goes no where thanks for all your help