salt water corrosion, lower unit dt75

[stylesabu]

i bought a complete suzuki dt75 for parts. I cant get prop shaft housing out.I have done this before on my good motor. any ideas on how to break the corrosion. i made a slide hammer adapter to pull it out,doesn't help. I check my other motor, I'm not missing any steps,no snap ring or thing else, its just siezed. I have tried pb buster, wd 40. it just won't seperate.

 

[Marion Moore]

Re: salt water corrosion, lower unit dt75

For my DT115/140 lower units I had a guy weld M10 bolts to standard threaded rod to make rods that would interface with my puller. I put a lot of pressure on the prop housing while I heated it then quickly cooled it with water. I repeated this many times. I then used PB blaster to let it soak. With pressure applied I used a large drift to "twist" the prop housing back and forth while the puller pulled. It took a while every time but I have seperated 3 of them. A couple were very corroded.

 

[stylesabu]

Re: salt water corrosion, lower unit dt75

what did you heat it with? and i assume since you had bolts welded to collor that you had to replace it? thanks for the reply

 

[Marion Moore]

Re: salt water corrosion, lower unit dt75

The bolts were to make a puller for the prop housing. If you have a service manual and look at the actual tool that suzuki calls for you will see that it is fairly easy to make. My guess is your biggest problem is you don't have a puller to exert the necessary force needed to move the prop housing. I don't have your engine but I assume it is very close to my DT140 or most other prop housings.

The second part, I heated the prop housing and exterior of the LU with a standard LP gas torch. I have used MAPP gas too. You can melt the aluminum housing but I don't think a LP touch will get that hot unless you parked the flame on a spot and held it there for a long time. Remember to cool it quickly with water before you try to do any tapping or moving. You want the metal to shrink back to the original size. Besides, you are only heating it to make it swell and move that stuck joint but you are talking micorscopic movement.

I assume you are talking about removing part # 27 http://store.brownspoint.com/DT75/fig026-758897.asp .

 

[stylesabu]

Re: salt water corrosion, lower unit dt75

that is the part. I have oxy acytelene torches. i have factory manual. and I have a snap-on 5pound slide hammer. I haven't tried coling it down yet will try that next. I wiil also check manual to see what puller looks like. thanks

 

[99yam40]

Re: salt water corrosion, lower unit dt75

I have used a very large flat washer or flat plate with a hole bored in it that the prop shaft would pass through without binding but would ride against the lower unit housing, drilled holes into it for bolts to screw into the threaded holes or ubolts to go around the webs in the prop shaft bearing housing. By tightening the nuts or long bolts with nuts evenly around the unit allowed me to pull against the lower unit housing itself and put more pressure on everything and get the carrier to start to move and then use a regular puller. I have done this on Suzuki and Johnsons. Some heat helps.

 

[stylesabu]

Re: salt water corrosion, lower unit dt75

got it apart, couldn't save prop housing tho. thanks

 

[Marion Moore]

Re: salt water corrosion, lower unit dt75

I hate that it broke but at least you got it apart and maybe you won't need that part in the future.