Swapping shift/drive shaft 40hp jrude lower units

[andrewddrennon]

First I`ll give you my situation. Bought a 1988 longshaft 40hp johnson jl40tccs......clutch dog and reverse gear are rounded.
I bought a used lower unit to put back on it but its a short shaft. So I want to change the short shaft unit to a long shaft unit with the shafts from my bad unit. Since I got the good short shaft lower unit for 75$, it will be alot less expensive to swap shafts than buying a clutch dog and reverse gear.

So I should be able to swap the drive shafts,pinions,shims,bearings straight up from gearcase to gearcase without re shimming. As I understand the actual gear case is not involved in shimming the pinion so nothing would change as long as I keep the origional bearing, shaft, pinion, and shims from each lower unit together. Sorry if this is hard to follow.

Anyone done this before? or have input?

 

[andrewddrennon]

Re: Swapping shift/drive shaft 40hp jrude lower units

Welll I went ahead and swapped everything thing. Tested it today and seems to work fine.

Only special tools you HAVE to have for what I did are, large snap ring pliers and the drive shaft spline socket. Also torque wrenches. And a maybe gearcase pressure tester.

Bearing carrier usually slides right out on these. ``freshwater''
Open end wrench plus duck tape is a great pinion nut holder.
Also If you have trouble breaking the pinion taper after the pinion nut is off you can put the drive shaft ``wrapped in a rag'' in a vice sideways and smack the top of the lower unit with a deadblow hammer.....be very careful.

Keep in mind I did this the least expensive way possible. All in all I have 187$ in a running 1988 40 horse johnson. Did some other stuff besides the shaft swap. Anyway I want anyone that reads this to realize that I strictly did this for cost effectiveness, so I dont expect it to last anywhere near as long as If I had rebuilt it. This was kind of an experiment involving the shimming procedure. I will post more if the backlash is so far off that i have a failure.

 

[boobie]

Re: Swapping shift/drive shaft 40hp jrude lower units

Good Luck. You may be allright as long as you kept the same parts together.