Lower unit adaptation?

[JasonB]

I have a '76 85hp V4 that is likely in need ofa lower unit. This is one of the hydro-shift units. These units seem to be hard to find used. Is there any way to adapt a newer mechanical shift unit to it? Seems like '78 and newer units are dime/dozen.

 

[ledgefinder]

Re: Lower unit adaptation?

I would advise you to keep looking for a hydro-shift. They usually aren't too hard to find, may just be going through a random dry spell where you're at. You can use 1973-76 V4s, and most of the 1977s (I think all but the 135/140).<br /><br />I think the newer (1979+) will bolt up, and the driveshaft splines are OK, but you'll have to swap over the linkage in the powerhead as well. <br /><br />DHadley answered this question within the last couple months, try using the search feature here.

 

[JasonB]

Re: Lower unit adaptation?

Thanks, I'll try the search again. Must have missed it the first gop through.<br /><br />The glaring issue with teh '79+ is the water pump. My hydro has two outlets where as the newer ones have one outlet. The shift shaft is also a bit different. The hydros seem to be like gold when I run across one. Just brainstorming for a solution where I would have something easier to deal with.

 

[JasonB]

Re: Lower unit adaptation?

Found that post and thought I would paste part of DHadley's response here in cane anyone finds this post while researching this in the future. Looks like I will continue my search for a HM case... Not sure I even want to consider rebuilding this one. It leaks like a sieve and is missing the skeg...<br /><br /><br />Quote from DHadley:<br /><br />"Any 20" V4 gearcase will interchange from 73 to 76. The 77 85 and 115 20" models will have the same bolt pattern and will work. The 77 140 has the larger case and wider bolt pattern as do the 25" 85's and 115's.<br /><br />The linkage can be interchanged but the bolt spacing on the lower unit case is the determining factor."

 

[Dhadley]

Re: Lower unit adaptation?

Oops! Jason nailed it!

 

[xikxak]

Re: Lower unit adaptation?

jasonb, I have a hydromechanical shift for v4.I was going to try to convert to my mechanical shift. too many problems.it just need another shift rod. if intrested.xikxak@yahoo.com

 

[xikxak]

Re: Lower unit adaptation?

I dont know what you mean by 2 outlets on water pump.Mine has one as far as I can see. it bolts up perfectly to 1978 140 v4, except for shift linkage.I think they only made this unit till 1877.

 

[JasonB]

Re: Lower unit adaptation?

dave, the waterpump on my '76 feeds two tubes running to the powerhead (one for each bank?). It might just be a housing difference though, but I have been unable to find a replacement housing for mine that has a stripped screw. <br /><br />I think you can guess at the years by the skeg as well. The '73-'77 has a vertical trailing edge while the later models that do not fit have a swept skeg I believe.

 

[xikxak]

Re: Lower unit adaptation?

Mine has a swept skag,and one tube running to powerhead. also shift rod has fixed cam on bottom and adjustible lollipop top. this is the unit referred to in dhadleys old post.