broken lower drive shaft removal

ab1

Petty Officer 2nd Class
Joined
Mar 2, 2010
Messages
111
So I blew my lower unit and started taking it apart to see what happened. I removed the prop bearing housing, and the drive shaft came out just by pulling...well most of it anyway. Seems the lower drive shaft broke right at the pinion bearing. I can get a wrench on the pinion nut but of course the broken shaft just spins and it's too far down to get a hold of it. Any tricks to breaking this nut loose? Should I stuff a rag in the gears and just keep turning? I think this is the only damage so it's a much cheaper fix than a new lu, I just can't get it out....any help or old-school tricks will be very much appreciated!! :)
 

mikesea

Lieutenant Commander
Joined
Oct 1, 2006
Messages
1,830
Re: broken lower drive shaft removal

take the pump off,then the bearing carrier under it,you can then grab it with a vise grip,but,better is a good pipe wrench,you may have to angle it a bit to get the bite
 

ab1

Petty Officer 2nd Class
Joined
Mar 2, 2010
Messages
111
Re: broken lower drive shaft removal

It's the lower drive shaft...broken off a good 6" down past the water pump housing so a pipe wrench could never get to it. All that is left is the broken shaft, pinion bearings, pinion gear, and pinion nut. I can get to the nut from the prop housing, but the shaft just spins because I can't get anything down there to stop it from turning. I'm hesitant to jam the gears becuase everything else is in good shape and I don't want to damage.

93 150 - GLETR
 

Cofe

Lieutenant Commander
Joined
Apr 23, 2009
Messages
1,883
Re: broken lower drive shaft removal

I have ran into a similar situation before but not on a lower unit.
So I was wondering if you can get a socket on it, and bump it with a air impact wrench?
 

ab1

Petty Officer 2nd Class
Joined
Mar 2, 2010
Messages
111
Re: broken lower drive shaft removal

The clutch dog (?) is in the way so I can't get a socket on it. I am using the thinnest 7/8" open end wrench I have just to get some bite.

Is there any way to get the clutch out. If so the pinion gear would probably just fall out and I could pull it out the prop housing. The remaining shaft is very short...prob 1.5"
 

Cofe

Lieutenant Commander
Joined
Apr 23, 2009
Messages
1,883
Re: broken lower drive shaft removal

Since the shaft is destroyed, you may be able to drill and tap a hole in the shaft and thread in a bolt. If the nut is right hand thread, then thread for a right handed bolt.

If this is the right picture of your lower unit, the clutch dog is held in with a pin.
 

Attachments

  • Lower.jpg
    Lower.jpg
    124.1 KB · Views: 3

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,931
Re: broken lower drive shaft removal

It aint to big a deal to do this, just take a shop towel folded over 3 times on itself and jam the gears,take a long drift rod and whack the nut loose. Now the problem is getting the pinion gear to loosen itself form the splines, sometimes a long prybar on top of clutch dog will pop it loose.
 

bankerjohn

Chief Petty Officer
Joined
Mar 21, 2008
Messages
444
Re: broken lower drive shaft removal

It's the lower drive shaft...broken off a good 6" down past the water pump housing so a pipe wrench could never get to it. All that is left is the broken shaft, pinion bearings, pinion gear, and pinion nut. I can get to the nut from the prop housing, but the shaft just spins because I can't get anything down there to stop it from turning. I'm hesitant to jam the gears becuase everything else is in good shape and I don't want to damage.

93 150 - GLETR

Seems like just putting the engine in forward or reverse would prevent the pinion gear (and the lower drive shaft) from turning, allowing you to remove the nut!

What am I missing?
 

ab1

Petty Officer 2nd Class
Joined
Mar 2, 2010
Messages
111
Re: broken lower drive shaft removal

Seems like just putting the engine in forward or reverse would prevent the pinion gear (and the lower drive shaft) from turning, allowing you to remove the nut!

What am I missing?

The shaft is broken far enough down that it now has some back and forth play, so it won't stay engaged with the forward gear enough to turn it...tried that. Also tried turning the prop shaft with another wrench on the pinion nut but I was starting to dig into the prop shaft with the pipe wrench.

Looks like I'll jam it up with rags and then try tapping a bolt into it if necessary. It's just so far down there I don't know if I can drill and tap it. Hopefully the rags stop it up enough to bang it loose.

Any other good ideas are much appreciated. Thanks for the help so far!
 

ab1

Petty Officer 2nd Class
Joined
Mar 2, 2010
Messages
111
Re: broken lower drive shaft removal

It aint to big a deal to do this, just take a shop towel folded over 3 times on itself and jam the gears,take a long drift rod and whack the nut loose. Now the problem is getting the pinion gear to loosen itself form the splines, sometimes a long prybar on top of clutch dog will pop it loose.

What's a drift rod? I've never heard that term before and I've been around once or twice. Just a long wrench?
 

mikesea

Lieutenant Commander
Joined
Oct 1, 2006
Messages
1,830
Re: broken lower drive shaft removal

Didnt realize ,OK,fastbullit ,I think ,is saying get a long punch,chistle ETC and use torque to turn the nut off,whack it hard with a hammer to get it to turn ,if you cant manage to use a wrench and stop it from turning,get a good bite on a corner of the nut and whack the drift rod or = and SHOCK it loose,nice 4 lb hammer,or ,if you have an air chisle,make a long punch out of the old piece of driveshaft,which you can also make the drift rod into
 

ab1

Petty Officer 2nd Class
Joined
Mar 2, 2010
Messages
111
Re: broken lower drive shaft removal

Well, I'm still struggling with the broken shaft but I suspect I just need to replace the entire unit. After further teardown, I can see some scarring in the verticle shaft near the top where the thrust washers were, and some scarring down where the drive shaft broke including a decent scratch. They don't look too deep, but are definitely noticeable. I just don't want to put it back together to fail again or risk missing something else that is broke I can't identify.

Would you even both with this, or just replace it? Does scarring affect the verticly shaft? If replace, can anyone help me understand what lu's are compatible with a 93 Johnson 150 20" shaft? I posted on the interchange thread but can't seem to find this hp/year range.
 

mikesea

Lieutenant Commander
Joined
Oct 1, 2006
Messages
1,830
Re: broken lower drive shaft removal

I dont think the scarring you mention will have an effect(DONT THINK)but havent seen it.You have bearings and races that they ride in,so no moving parts actually ride on alum.However,not knowing what your parts list will entail,you might do yourself a favor and locate a good used one.the 20" may be difficult.Most v-6 engines were on larger boats.But that dont mean they arent out there.Im pretty confident most 1980's and the 90's crossflow and looper engines interchange.If you do locate one,be sure to do a more precise investigation.
I just read the chart fastbullit posted,I dont quite understand it ,because,I know you can interchange crossflow and loopers,at least some years.You have to change the shiftshaft in many cases,maybe thats the reason the chart dont show them as inter changable
150-235 & 2.6.................(crossflow V-6)......................1979-1991
185-225.........................(Looper V-6).........................1986-1991
185-225....................(Looper V-6 & Ficht)....................1991-2005
What I get out of it is,1979 to 2005 can interchange,my reasoning is,I have a 1985 crossflow on my 1996 looper right now.Works fine.I did reuse the shiftshaft.Mine is 25inch,but the shafts are all that change that.
 
Top