1992 Evinrude 25hp front lower unit bolt frozen

marvinjansen

Petty Officer 1st Class
Joined
Jan 10, 2010
Messages
278
I am trying to remove the lower unit on my 1992 Evinrude 25hp outboard, a VE25elens model. I have the for side bolts removed and the shift nut off. The problem is the front stud seems to be frozen in the upper housing and won't let the lower unit come down. I have tried heat, beating on the stud with a brass punch, beating on the front of the lower unit with a rubber mallet, and it has come down maybe 1/16"or so. I think maybe there is electrolysis between the SS stud and aluminum, Wonder if I can use a vice grip and twist the stud out of the bottom unit? Any suggestions?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,044
Once you get the stud turning it should help.-------How much heat did you use.---------Yes over a period of time the white powder ( aluminum oxide ) will jam it very tight.----------The other possible issue is the driveshaft / crankshaft splines jammed with rust.
 

marvinjansen

Petty Officer 1st Class
Joined
Jan 10, 2010
Messages
278
No Title

Used propane torch and got it warm, not glowing red hot. Seems to flex at back but not at front. Has come down a little more now, maybe 1/8" now after more pounding with rubber mallet. If I start twisting on stud I will need to replace it for sure, but it may be the only way. Also wonder how tight or frozen the stud is in the lower unit? Will let sit a little longer with PB Blaster soaking in. Should I get it really hot, like with acetylene?
 

Attachments

  • photo216408.JPG
    photo216408.JPG
    19.4 KB · Views: 0

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,044
There may be a short tube there for alignment that is jammed.----Acetele is very hot and is not needed.----Use a bit more heat from propane.----Water thrown on it should sizzle when it is hot enuff.
 

marvinjansen

Petty Officer 1st Class
Joined
Jan 10, 2010
Messages
278
Moved a little bit more, maybe 1/4" now. But is frustrating. If it is the shaft that is rusted, is there anything else I can do to get it to come down?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,044
If it has moved a 1/4" then likely the crankshaft splines are free.----Carefully try with a prybar or plastic wedges.----Is the wee black plastic sleeve off the upper shift rod ??
 

marvinjansen

Petty Officer 1st Class
Joined
Jan 10, 2010
Messages
278
No Title

I have loosened the nut on the lower shift rod from the upper shift rod. It looks like it should go up and through the upper. I am not sure what to do here?
 

Attachments

  • photo216414.JPG
    photo216414.JPG
    24 KB · Views: 0

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,044
The nut will not go up and through there.---If there is paint on the upper rod it has to be scraped off.----Then move the upper nut up.---You will now see a wee black plastic keeper.----That keeper is split and needs to come off.
 
Last edited:

marvinjansen

Petty Officer 1st Class
Joined
Jan 10, 2010
Messages
278
No Title

here is a pic of how far it has dropped and the shifter rod where I disconnected it. Have pried with large screwdriver and used hear and PB Blaster and used a rubber mallet on the front of the lower unit where it is thick. Will leave alone for a while and maybe it will fall on its own, would be nice.
 

Attachments

  • photo216415.JPG
    photo216415.JPG
    15.3 KB · Views: 0
  • photo216416.JPG
    photo216416.JPG
    10.9 KB · Views: 0

marvinjansen

Petty Officer 1st Class
Joined
Jan 10, 2010
Messages
278
other outboards I have owned and changed the impeller had a shift rod that I took loose after I lowered the foot (Evinrude 15hp) and my Yamaha 4hp has an access hole to loosen the rod. Does this one, 1992 25hp Evinrude EV25Elens, have more than one place to disconnect the shift rod from the upper? I think I see a black plastic sleeve but it is in the lower shaft that goes into the foot.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,044
I believe I said that there is a split black keeper on the upper shift rod --!!!!!!!!!!!!!!!!
 

marvinjansen

Petty Officer 1st Class
Joined
Jan 10, 2010
Messages
278
OK, I am trying to move that brass nut up the shaft to remove the keeper. I cleaned the rod above the nut and put a 7/16" box end wrench under the nut head and tapped with a hammer. Not seeing movement, do I need to just tap harder or is there a special tool to move it up or what? I do appreciate the help from those who have gone through this themselves and appreciate your patience.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,044
Post # 8 gives clear instructions.--It does not mention any special tools.---The paint is the problem !!
 

marvinjansen

Petty Officer 1st Class
Joined
Jan 10, 2010
Messages
278
Impeller replaced and water circulating. Thanks for the help. What helped was a walk on the beach to relax. Then a little heat on that brass nut on the shift linkage and using a dull chisel and hammer to tap the nut up the shifter shaft enough to remove that plastic cone shaped clip. Then used a heavier mallet to strike the lower unit on the captivation plate in front where it is thick and down came the lower unit. Removed old impeller that was worn but all there. Put in new impeller with little key in properly. Assembled and tested. Thanks for the help.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
You got lucky. The next guy may not be so lucky when he knocks a big chunk out of the anti-cavitation plate.
 
Top