Removing 93 Johnson 250 V8 Lower Unit

[skidog519]

I am trying to remove the lower unit on my 1993 Johnson 250 hp V8 so I can replace the impeller. There were two side bolts on each side that I removed and a large center bolt. It appears something is still holding it together.
I put the gear selector in forward gear, this was recommended to me if it was rotating hub. I tapped it with a hammer and a piece of wood but it did not budge.

I am not totally sure if it is rotating or counter roatating but I also tried reverse for a counter rotating hub and it did not drop down either.

I read some of the forums on other engines and they say to release the gear selector rod under the carb. I used to have a Mercury 150hp and once the bolts were removed the unit dropped down. That doesn?t seem to be the case with this one.

Any suggestions would be appreciated.

 

[MarkV_Deep6]

Re: Removing 93 Johnson 250 V8 Lower Unit

Have you disconnected the shift shaft and removed the bolt under the trim tab?

 

[rndn]

Re: Removing 93 Johnson 250 V8 Lower Unit

Welcome to the forum and check the post above. It sounds like you did not do as suggested.

 

[skidog519]

Re: Removing 93 Johnson 250 V8 Lower Unit

No I have not disconnected the shift shaft and the bolt under the trim tab. Where are these two items? Thanks

 

[ezeke]

Re: Removing 93 Johnson 250 V8 Lower Unit

First remove the lower cowl/cover. It is split so it is easy to get out of the way. Just remove the clips inside and take the screws out from the starboard side.

Then you can easily disconnect the shift rod. The disconnect is just under the carburetors/intake manifold. You will see the end of the shift rod rising up from the midsection.

Then remove the seven bolts from the gearcase and the unit will drop. It will be a lot easier to do with a helper. This diagram is a little different, but the bolts are in the same positions and the count is the same.

Mark the position of the trim tab (106) before you move it so that you can put it back aligned as it was. Try not to rotate the shift rod.

 

[skidog519]

Re: Removing 93 Johnson 250 V8 Lower Unit

Thanks you for the diagram and explination ezeke! I just got the boat last summer which is boat #2 and I dont have a manual for it yet which I neeed to get. Where you are showing bolt #6 & #7 I think one of them holds the zincs in place and really doesnt go to the housing but Ill take them all out, thanks again everyone

 

[ezeke]

Re: Removing 93 Johnson 250 V8 Lower Unit

On most models you have to remove the trim tab (bolt 5) to get to the bolt (bolt 6) that is hidden above it. There is a bolt (bolt 7) in front of the anode bolt which you also have to remove.

The one in between 6 and 7 on your gearcase holds the anode but is not one of seven you have to remove.

 

[MarkV_Deep6]

Re: Removing 93 Johnson 250 V8 Lower Unit

Ezeke's diagram is very good and he went to the trouble of circling the bolts to remove.... Bolt # 70, under the trim tab is what your after, along with the shift shaft disconnect. His recommendation or removing the lower cowl will make the work so much easier, but on the V8, if your careful, you can disconnect it with the cowl still attached.

That lower unit is quite heavy....be careful, have the engine tilted to take some of the weight. Let us know how your doin.

 

[ezeke]

Re: Removing 93 Johnson 250 V8 Lower Unit

Thanks, but it is bolt # 72 that is hidden under the trim tab. 70 is the large one forward of the anode bolt (#53).

Getting the shift rod loose is simple enough with the lower cover on, even on the V4 looper. It is getting the shift rod back in place and reattached that is made considerably easier by having the cowl out of the way.

 

[MarkV_Deep6]

Re: Removing 93 Johnson 250 V8 Lower Unit

Sure looks like 70 to me. Sorry if I missed it, but 72 appears to be the bolt that attaches the anode. That one does not hold the lower unit on the V8.

Just looked at the diagram again....that's confusing. Just take of the trim tab and you will see the bolt. It's a bit off center and a little hard to reach.

 

[skidog519]

Re: Removing 93 Johnson 250 V8 Lower Unit

Thanks for all the replies; it has been a few weeks since I was able to try the suggestions. Although I don?t have it off yet, I was able to locate all of the bolts and I have removed the cowl, thanks Ezeke for the advice on doing that. There is one bolt that sits way back in there and there is not way to get a socket on it so I guess I need to try a socket with a swivel; I think it is bolt #70. This lower unit is much more difficult than my old Merc 150 was to take off.

I am hoping once I get it off I will have easy access to the housing the impeller sits in. I don?t have a temp gauge on the helm so I think it is a good idea to replace the impeller every couple of years is that good maintenance practice?

Again thanks for all the help and suggestions, I hope to drop it tomorrow,

Skidog519