Logo
FULL SITE MENU

lower unit removal - Evinrude 4hp 1987

propeller

propeller

New member
Hello outboard people, can someone help me?

I am trying to re-animate my old Evinrude 4hp. It is a 1987, the model number is E4RDHCUD and it has "deluxe" written on the housing.

*****Skip to asterisks below for only the important part

This engine has sat for over decade untouched, but it pretty much started right up after replacing the starter recoil spring. I ran it for a few minutes and water (coolant) was coming out of the hole in back OK for a while-- a little weak, but OK. After running it, I disconnected the gas line and drained the garbage can of water, but then I realized that I wanted to burn off all of the fuel in the engine before storing it in my garage. So I ran it briefly without water which was probably not advisable, but I don't think it got that hot because I could rest my hand on the block with no problem.

Anyway....next time I run the engine in the water bucket--no stream or dribble out the back. I figure the impeller got destroyed while running the engine dry. So I have to get the lower unit off to access the water pump.

*****

I can't get the lower unit to separate at all from the upper part. I removed the three bolts holding it on (broke one) and I can only get the lower unit to slightly jiggle, but I can't get any space to open up to access the gear linkage connection.

Can anyone confirm exactly where the gear linkage connection is on this particular evinrude?

I am assuming that the linkage disconnect will appear if I can get the lower unit to separate by an inch or so--but I do not know this for certain. There does not appear to be any gear linkage disconnect in the upper engine housing part--or none that I can see at least. When I shift gears, there are no moving parts visible in the engine housing. The gear shift and linkage appear to be fully outside the housing.

Any assistance or advice would be greatly appreciated! Thanks

PS: I took several photos, but I'm having trouble with the "Manage Attachments" popup window on this forum. If I figure it out I will post the pictures
 
You should find a parts break down of that motor. To take the lower unit off all you do is remove the three bolts and pull the L/U off. You probably have a driveshaft stuck in the crankshaft. Try giving the L/U a couple of wacks with a rubber mallet once and see what happens.
 
Right, I just did a 1979 55 that was stuck. I have a plastic wedge to tap in and get presure, then gingerly smack the flywheel nut with an oak mallet. The motor is standing upright when I do this and I am careful to catch the lower unit as it breaks free. I think that model has an o-ring up at the splines. I use anti seize when assembling ......and plenty of it, along with a new o-ring. Clean out the crankshaft nicely first, of course. Pa just broke a bolt on an 18 hp Johnson today. A round and a half of threads were still showing, so I tacked on a 5/16" nut and let it cool, then heated lightly the exhaust housing with a propane torch......it came right out. Took all of ten minutes.
 
Thanks for these tips. I did already bang on it a bit with the rubber mallet--but I will try some more. I don't think I have any plastic wedges but maybe wood will work.

I have been searching for a parts breakdown of this model, but haven't had any luck yet.

Still unable to post photos--there must be a 24hr delay after registering for username?
 
Not sure about photos, I have trouble too, gotta ask my son Timmy (pictured). Hardwood will work, be patient. Check this other thread too. JB 80 is good and of course Liquid Wrench. Drill hole in a safe inconspicuous place close to powerhead there in the center (exhaust) housing. 1/4" will work too. You don't have to be fancy, you can JB Weld up the hole after also.......even high temp silicone. I do alot of these here in Minnesota. They rust too,but surely not as bad as salties.

http://www.marineengine.com/boat-forum/showthread.php?441470-Impeller
 
timguy, it's not frozen tight--there is some slight side-to-side play--it seems to be pivoting on either the driveshaft or the gear linkage. So I am thinking it's not corroded or rusted or anything.

I did look up a parts diagrams, but the resolution was too blurry to be of any help.

kimcrwbr1, thanks for that tip, I will use photobucket as a last resort, but I feel like I should be able to get this to work.

Also--are there any moderators listening? Am I missing something about the photo upload procedure? I read the rules and can't see anything about a delay for first time posters but could be wrong.

I go through the steps of uploading--it looks like it's working, and then no photo appears?
 
IMG_0281.JPG
 
upper part.JPG
Here is the relevant section for the upper part of the gear shift linkage.

lower part.jpg

And here is the lower part.

I can't tell if the gear shift rod releases in the mid section at Part 78

Or the lower section at Part 29.

Please let me know what you think.
 
If the gearoil is good with no water do not pull the gearbox without disconnecting the shift rod under the powerhead. the shift rod will get a burr on it from the spring and it will damage the o-ring under the bushing for the shift rod.
 
hmmm, conflicting opinions:confused:....what to do?

kimcrwbr1: Your advice is well-taken, but I cannot see of any place near the power head where there would be a disconnect of the gear shift rod--when I shift gears there is no movement of any parts under the hood that I can see. Do you know where I should be looking? I will try to take some close up photos. I don't know the condition of the gear oil, but I was under the impression that I can remove the lower unit without actually opening the gear box and draining the oil.

Boobie: hopefully, this is true--I don't see any kind of disconnect of the rod indicated on the parts diagram
 
You must pull the powerhead. If it comes off clean and the gasket is still good just brush a light coat of permatex aviation on it careful not to plug up the water circuit.
 
Look closely at the shift rod and see if you see any screws in it. To shift this gear case the rod ROTATES to get F_N_R. and just slips out of the power head when you pull it.
 
Last edited:
My bad I thought you had the small gearbox with forward and neutral only no need to pull the powerhead. Others here will know better it looks like the shift rod just pulls out of the pinion up top not sure how you line it back up putting it back together?
 
I just replaced the impeller on my Evinrude 5 1/2 horse. I bought the impeller from Discount Marine Parts. They were kind enough to provide detailed step by step instructions with the part. It included removing the power head and disconnecting the shift linkage. They also included all the gaskets and O rings for reassembling!
 
The 5.5 is a blast to work on. Love them, Got about 10 here. The 4.5 just pulls out, great engineering, like the Mercs. Only the little Mercs did not have good stainless steel driveshaft.
 
Can you explain a little more about "remove the powerhead"? The powerhead is the actual engine block section right? So does that mean you are separating the powerhead from the middle section?

Man, I hope I don't have to that much work for just a routine water pump rebuild.
 
The coupling is up top on the old motors, not the new ones. Yours just pulls out. It uses a rotation movement to shift gears rather than up and down. Your driveshaft is rusted into the crankshaft I would guess.
 
By way of update I have been:
1) beating it with a mallet;
2) hammering shims into the slight crevice;
3) moving it in and out of gear, and moving propeller.

Still no luck.

Incidentally, when the the transmission is in neutral and the engine is idling, the propeller wants to turn in reverse. What does this mean? I don't think it's supposed to happen.
 
Should mean that splines are off but since this shift shaft can only go together one way, then something is out of kilter topside. You gotta get that hole drilled and soak the splines with p-blaster,
 
Another hint. You can see that your water pump is connected to the tube by looking in through the exhaust opening, then turn the motor slowly clockwise until crank receives the driveshaft that last inch or so. The shift rod in-gauges slightly before the driveshaft. I like to do it in neutral. Have the motor upside down on the floor with a cushion underneath. Oops, why am I thinking about my wife now?
 
Thanks for checking in--

I am kind of stumped for the time being. I am hesitant to get rough with it and force i t.

Based on yours and everyone's advice--I am convinced that the shift rod should just pull out--without having to manually disengage it.

I have done a bunch of pulling, and prying, but I am afraid if I apply too much force the gears inside will get damaged.

I am pretty sure that it's the shift rod that is stuck rather than the drive shaft, base on how the lower unit pivots on the shift rod when moved around.

Also, when I pull down with a lot of force on the lower unit, I can see the shift rod (a small section of it is exposed by design) pull down with the lower unit.

So there is some give somewhere up near the powerhead.

I don't know--I am open to suggestions. Someone mentioned something about drilling holes and PB Blaster, but I'm a little nervous about that.
 
I am on the fence on this one, but you are right, the shift rod is likely rusted in. I use anti seize on all my assemblies, so its no one that I worked on. You will then direct spray with the motor upside down in the corner, or hanging up by a rope, or something. Let the spray run down the shift rod to the rusted coupling. Use plenty, don't rush it, add more each day. Otherwise an upper end dismantle would be an option. Never had one apart up inside the gearbox there. They are normally pretty trouble free.
 
If it comes to a power head disassembly--I might just give up.:eek:

But I might try your idea of anti seize on the shift rod and turning engine upside down. It's only 4hp so it's pretty light.

There is also a lubrication port on the power head section right about where the shifting handle/lever meets the vertical shift rod part. hmmm....
 
Back
Top