lwr unit interchangeable 28/25 86-84?

[mattUSAF]

Hi, first time poster here. I have a 84 Johnson 25hp that has a cracked skeg. The crack runs into a bolt hole and theres some grinding where the bearing in front of the forward gear is so its not repairable. I found a lower unit/gearcase for cheap on ebay that looks exactly like mine but its an 86 28hp. Size, shape, bolt pattern and drainage holes all look the same. Will it work?

 

[iammonroe0701]

Lookup shopevinrude and compare part numbers for both gear cases. From what I see by the part numbers it won't.

 

[mattUSAF]

Im wondering if something internal changed and caused the part# of the whole unit to change because I noticed that a few years look like they have the exact same lower unit casing. "Gearcase & Brg. assy" means the whole lower unit with everything in it right? I'm thinking about paying the 100 for this used one just to try it because its looking like no site sells just the skeg. I would hate do buy a whole lower unit over a broken skeg

 

[iammonroe0701]

It could be just different gear ratio or something. Drive shaft also could be different going into case. It's worth a try if you can get it to work.

 

[Campster]

I believe the 86 28 will fit just fine..your original part for a complete gearcase assembly is 394636, replaced by 395855, replaced by 396843, replaced by 398156, replaced by 432811. The original gearcase assembly on the 86 28hp was part 398156, replaced by 432811. So in other words, both use the same replacement parts. As I don't have your exact model #, I just spot checked a sample model in years you stated for hp you stated. You would need to check exact model # to be 100% sure there wasn't any variation in the specific models, that is unlikely, so it should work fine.

 

[mattUSAF]

Awesome. Where do you see superseded part#'s? My model # is j25rcrd but i was thinking the part with the # plate was replaced because I thought rcrd was for the rope start only and el__ was for electric start. Mine has electric start and rope. Either way, it looks like all the models for that year have the same part number. I appreciate the help, guys.

 

[iammonroe0701]

If you look at shop evinrude they show 2 different part numbers for the gearcase assembly. I think I read somewhere on here that johnson/evinrude motors that were ending in "8", like 28,88 hp were oddballs.

 

[Campster]

Matt...you can search by model# on marineengine dot com and see gearcase parts explosion and corresponding part # info. Just plug in your model number into proper area on site. Sometimes the 8s are oddballs, but appears they share same gearcase replacement part # across the two models you mentioned.

 

[mattUSAF]

Ah, I see it. Yep, looks like they both start with that 432811. Im gonna go ahead and order it. Thanks

 

[Campster]

Suggest servicing water pump before you install. Good luck with the new gearcase.