Lower unit interchange chart (2024)

I have seen quite a number of posts asking for this so here goes:
.....(This chart for direct bolt on with no part changes)............

Horsepower--------------------------------------Years that interchange

40/48/50/55/60..... (small diameter housing)..................1976-1988
40/48/50.................................................................1989-1992
40/48/50.................................................................1993-2005
70/75............................(20 inch shaft)......................1978-late 1981
60/65/70/75.............................................................1982-1988
50/60/70..................................................................1989-2001
85-140.............(crossflow 13 spline prop shaft).............1978-1991
88-140.............(crossflow 13 spline prop shaft)..............1992-1998
120-140 Looper V-4... (15 spline prop shaft)...................1985-1991
75-115 60 degree........(bat wing unit 13 spline)...............1995-2006
150-235 & 2.6.................(crossflow V-6)......................1979-1991
185-225.........................(Looper V-6).........................1986-1991
185-225....................(Looper V-6 & Ficht)....................1991-2005
150-250.......................( Magnum Series).....................2002-2007
150-250........................(Lighting Series)......................1997-2001

I will add more as I get information !!!

Re: Lower unit interchange chart

great info, i added it to the TOP SECRET FILE.

Re: Lower unit interchange chart

didnt see the 1995-? V4 looper with 13 spline( yeah what I have !!)

small gear case... which makes it hard to find lots of prop choices....

the 15 spline large gear case has a ton of props available

( oops I see the "add more later" comment...sorry

thanks for the list , i just used it to verify a used parts motor purchase ill make

bob

Re: Lower unit interchange chart

Added yours Bob!!!!!

Re: Lower unit interchange chart

Pardon the lack of boat knowledge, but is this chart for every make of boat motor? The reason I ask is because I am currently searching for a used lower gear case for a 1989 50HP Johnson model #J50TLCEC and am having a hard time being able to tell what exactly will work on my boat. I found one that said it would fit any Johnson between the years of 1975-2006 but according to this chart that would not be the case. Correct? Thanks.

Re: Lower unit interchange chart

Evinrudes won't work on Johnson.......till you change the paint color.

Re: Lower unit interchange chart

Northwoods said:

Pardon the lack of boat knowledge, but is this chart for every make of boat motor? The reason I ask is because I am currently searching for a used lower gear case for a 1989 50HP Johnson model #J50TLCEC and am having a hard time being able to tell what exactly will work on my boat. I found one that said it would fit any Johnson between the years of 1975-2006 but according to this chart that would not be the case. Correct? Thanks.

Click to expand...

no way that all 50 hp outboard wether johnson or evinrude or both will have interchangable lower units from 1976 to 2006!!!!!!!!!!!!!!!!!!!

I know that 1989 was a year they changed lower units....follow the chart here.

bob

Re: Lower unit interchange chart

You need the 1989-92 year unit. Do yoiu need a complete unit or just the housing?

Re: Lower unit interchange chart

Complete lower unit

Here's the link that the ad went to that is supposed to help determine if the lower unit will work.

http://www.sterndrive.info/outboardmotor/help_identifying_lower_units.html

Here's the other info from the ad, maybe this would help

MEASURES

17 7/16" TALL

REAR HUB VIEW 4 1/16"

THE NUMBERS ON THE LOWER UNIT ARE;

187160

13CP

WATER PUMP # 391 049

Re: Lower unit interchange chart

Northwoods said:

Pardon the lack of boat knowledge, but is this chart for every make of boat motor? The reason I ask is because I am currently searching for a used lower gear case for a 1989 50HP Johnson model #J50TLCEC and am having a hard time being able to tell what exactly will work on my boat. I found one that said it would fit any Johnson between the years of 1975-2006 but according to this chart that would not be the case. Correct? Thanks.

Click to expand...

here are the choices for you the way i read that site..

http://www.sterndrive.info/outboardmotor/small_loop_charged_1975_1988.html

or this one

http://www.sterndrive.info/outboardmotor/small_loop_charged_1989_2005.html

but since you say you have a 1989 model the second link is for your motor...

I dont know what constitutes a large gear case for the 2 cylinder model outboards

maybe there were some commercial units...

good luck

bob

bob

Re: Lower unit interchange chart

Looking to see if these two will interchange, evinrude 25s from 1979 and 1984. Both NON-through hub exhaust.

http://www.boats.net/parts/search/BRP/EVINRUDE/1979/25904R 1979/GEARCASE - 25/parts.html

vs

http://www.boats.net/parts/search/BRP/EVINRUDE/1984/E25RCRD 1984/GEARCASE/parts.html

The prop shaft and many other part numbers match, but not the gears. The 1984 has bad gears, the 1979 has cracked case. Can I mix and match parts?

Thanks again.

Re: Lower unit interchange chart

if you use this site, and click on the little magnifing glass, next to the part#. you will get interchangable parts. http://shop2.evinrude.com/ext/index.aspx?s1=bf6ad09c53cead335fcfd8a6471c0f7f

Re: Lower unit interchange chart

tashasdaddy said:

if you use this site, and click on the little magnifing glass, next to the part#. you will get interchangable parts. http://shop2.evinrude.com/ext/index.aspx?s1=bf6ad09c53cead335fcfd8a6471c0f7f

Click to expand...

didnt seem to work...

I remember fishing around and when i clicked a part a screen popped up with all the motors made that used that part....but this link you give, that doesnt happen....

at least for me.

bob

Re: Lower unit interchange chart

Bob J. That would be a most useful site. Maybe someone out there has it.

Re: Lower unit interchange chart

James R said:

Bob J. That would be a most useful site. Maybe someone out there has it.

Click to expand...

Yep..Boats.net has it. When you select a part it also lists the other engines that use the part.

http://www.boats.net/parts/search/BRP/EVINRUDE/parts.html

Re: Lower unit interchange chart

Faztbullet said:

I have seen quite a number of posts asking for this so here goes:
.....(This chart for direct bolt on with no part changes)............

Horsepower--------------------------------------Years that interchange

40/48/50/55/60..... (small diameter housing)..................1976-1988
40/48/50.................................................................1989-1992
40/48/50.................................................................1993-2005
70/75............................(20 inch shaft)......................1978-late 1981
60/65/70/75.............................................................1982-1988
50/60/70..................................................................1989-2001
85-140.............(crossflow 13 spline prop shaft).............1978-1991
88-140.............(crossflow 13 spline prop shaft)..............1992-1998
120-140 Looper V-4... (15 spline prop shaft)...................1985-1991
75-115 60 degree........(bat wing unit 13 spline)...............1995-2006
150-235 & 2.6.................(crossflow V-6)......................1979-1991
185-225.........................(Looper V-6).........................1986-1991
185-225....................(Looper V-6 & Ficht)....................1991-2005
150-250.......................( Magnum Series).....................2002-2007
150-250........................(Lighting Series)......................1997-2001

I will add more as I get information !!!

Click to expand...

I am currently looking for a lower unit to fit a 1982 60hp 14spline 20" shaft. After looking at your chart it looks like i have several year options. my question is how do i know if its a small diamiter housing or not?

Re: Lower unit interchange chart

I have small metal shavings in my lower unit oil. its not creamy though. I guess I am looking for a lower unit aswell (tear) But I am not looking to pay out the ***. I build import car motors all day But when it comes to an outboard I can make out what I am looking at but it is all diffrent.

I have a 1983 or 82 johnson 140 v4 seahorse. The lower case gears must have screwed up. I cannot get the lower unit drain plug out. So I put some vaccum line on my gear oil and shoved it down in the lower part of the gear case and was letting it over flow out (not correct but kinda works) and I seen metal shaveings and what not.

So I cant understand what lower unit to buy. I read something like 85hp-140hp? are interchangeable. But what is all this about drive shaft length and shifter length.

If someone could tell me the years or hp or size lowerunit i wold be veary greatful. I hope someone can help me understand all this.

Re: Lower unit interchange chart

civichatchboi said:

. ....... So I put some vaccum line on my gear oil and shoved it down in the lower part of the gear case and was letting it over flow out (not correct but kinda works)...............

.

Click to expand...

well this part of your post has me totally baffled.....

not that it is important, but you might want to re phrase that..

any way this line on the chart is what you need to remember...

85-140.............(crossflow 13 spline prop shaft).............1978-1991

so that seems like:

85 hp
88 hp
90 hp
100 hp
110 hp
112 hp
115hp
120hp
130hp
140 hp

if it is one of those CROSSFLOW hps and it has 13 splines on the prop shaft and it is in between 1978 and 1991

you should be ok

good luck

bob

Re: Lower unit interchange chart

Thanks bob.

I slowly weved it down into the lower case.

Ok thank you for helping me. I know this site probley has the same quistions over and over like most sites. At least this one they dont bash you as hard.

hey is this true as well if you KNOW your motor is all OMC-OEM.

"IF the motor has two 2-barrel carbs made of aluminum positioned one above the other, it is a cross-flow from the late 70's.
If there are 4 individual plastic carbs, you have a "looper" from the mid 80's on up"

I have been digging trying to find this out. Is this true? I pulled a plug and looked at the piston just to be sure and what you say is accrate. And I do have 4 carbs. So is that guy right to? seems alot easyer to pop the cover off the motor and look at the carbs then pulling a spark plug.

Let me know if you think that is right aswell.

thanks iboats

Re: Lower unit interchange chart

If it has two 2 barrel carbs on a V4, it's a crossflow from the 1960's through the 1990's.

There were no 140 crossflows after 1984; that's when the V4 loopers come in.

The early V4 Loopers had 15 spline propshafts on the extra long gearcases but had 13 spline propshafts on the others. That's clearly shown in the parts catalogs which have different diagrams and parts lists for the different drives.