Help identifying gearcase

[swimmin' for shore]

I buy and sell used outboard parts. I know a lot of the stuff. Still identifying some of it. In any case, I brought in a case today that I t hought was for a Merc V6 (later models without preload pin). I thought that right up until I checked the ratio, which is 2.25 to 1, rather than the V6 cases of 2 or 1.87 or 1.75. So, I started exploring a little further. I assume it's a 4 cylinder now. 8 splines on the driveshaft, and the driveshaft is 18-3/8" from the waterpump up. There are 15 splines on the propshaft. Anyone give me an idea of what this came from?

 

[Faztbullet]

Re: Help identifying gearcase

If it has the bolt in carrier it off a big bore inline. Thr 4 cylinder(100/115/125 use a 2.07:1 ratio and the 3 cylinder 70/75/80/90 use a 2.3:1 ratio. You will need tocheck to see if it has a 3 or 6 jaw clutch....

 

[swimmin' for shore]

Re: Help identifying gearcase

It has the same housing as the V6 engines. My understanding has been that the different lower units that used the 3 or 6 jaw clutch were up in the mid-90s. I'm more apt to think this is in the late 80s or early 90s. I still think it's to a 4 cyl. Just haven't been able to be positive. Unfortunately, I don't have another motor from that era to take a lower unit off of and compare. Stuck a little.

 

[Dukedog]

Re: Help identifying gearcase

Will it bolt up tp a V6 downhousing (any year)? Merc/Mariner did offer some "different" high altitude gear sets in different years for different V6 motors...........Most were in tha 2.30 something range.

 

[swimmin' for shore]

Re: Help identifying gearcase

It would technically bolt up, I think. It wouldn't work, though, because the driveshaft is 1-1/2" or so shorter than the V6 gearcase. It's definitely not for a V6. I'm just not sure whether it's for an inline 6 or inline 4. Case is the same as the V6, like I said, but driveshaft is shorter and gear ratio is different. I just can't seem to find much online about it.

 

[Faztbullet]

Re: Help identifying gearcase

How about a picture? What is the case diameter?

 

[Dukedog]

Re: Help identifying gearcase

20" inline 6 driveshaft is 'bout 3/4" shorter than tha V6, front stud won't line up either. Real close but no cigar. Best I can remember. All other studs/bolts line up ok. 2.0,2.4,2.5 V6 gearcase is tha only type that will "bolt up" ta tha V6 downhousing. Picture like Fb says................