Lower unit cross reference

Gulf Boater · Mar 26, 2012

Hello all I just picked up my first boat 1994 Bayliner Capri 1700ls it needs a new lower unit can anyone
Tell me what year units will fit my motor it's a force 120 do I have a long shaft or stub just ordered manual
Online but a local guy has one from a 1990 85hp and says it will fit an L shaft, is that what I have ?
This is all new to me so please give me any info you may have.
Thanks in advance.

bentle · Mar 26, 2012

Re: Lower unit cross reference

1990 is where the 90 hp force begins. 1989 is the last year for the 85 hp force motors . Both will work but the 1989 85 hp has a different gear ratio. 1990 90 hp gear ratio is the same as your 120 hp gear ratio. Keep your drive shaft from your lower and pump housing just in case you may need them for parts.
Your motor should have the short shaft.

Gulf Boater · Mar 26, 2012

Re: Lower unit cross reference

Thanks for that I just checked it is a 90 HP so I should have no issues ?

bentle · Mar 26, 2012

Re: Lower unit cross reference

Good to go . If you have any other issues then post it and someone will help.

tater76 · Mar 27, 2012

Re: Lower unit cross reference

Carefull!!! there was a transition between 94-95 to the Merc style lower unit. If your manufacture date is mid to late 94, its possible you have the merc lower. Before you order/buy one, remove the existing lower unit, and count the splines on the shaft. If there are thirteen splines then it is a newer Merc style, and older units won't work because most have 15 splines on the driveshaft. I learned the hard way after rebuilding a 94 1/2 120 with a used crank from eBay. Got it all back together only to find that the crank from a 92 had 15 splines and my lower had 13! $300 later I put the correct crank in.

Gulf Boater · Mar 27, 2012

Re: Lower unit cross reference

Are you talking about where the upper drive shaft fits into the coupler ? My lower unit has been completely taken apart was like that when I got it. The drive shaft seems to be in 2 pcs the lower part has 13 splines as does the coupler it sits into. Does that mean I have the newer unit ? Do you know what options I have. Where can I find my mfg date ? Sorry for all the ? But was going to pick it up today.

OK Just got email from owner and he says that the shaft has 13 splines ? However it is a 1990 so that contridicts what was said by tater76 as in his case the newer motors had the 13 spline ? Getting confused now and someone else wants to pick it up from him not sure if I should chance it or not

bentle · Mar 27, 2012

Re: Lower unit cross reference

If yours is 13 splined and the other is also 13 splined then you are in good shape. What I was told is the 120 hp force didn't change to 13the splines until 1995. However it sounds like you are good to go. If you have your old drive shaft and coupler then you may need them to make 1the 90 lower fit your 120 force. And if the other doesn't have these two parts then you will need them.

tater76 · Mar 28, 2012

Re: Lower unit cross reference

I was talking about the end of the driveshaft that fits into the crankshaft (the long shaft). If you have a two peice, you will likely be fine as long as the end of the driveshaft has the same amount of splines as the crank like bentle said. The two peice shafts have one end being 13 and the other 15 (all that I have seen anyway). You just need to verify with the owner, that he is looking at the right end. The crankshafts changed to 13 spline in 95 ish, eliminating the two peice shaft.

Gulf Boater · Mar 29, 2012

Re: Lower unit cross reference

Thanks for the help. The one I had my eye already sold but at least I can use this info to help find a replacement.

What is the average cost of a rebuild for lower unit ?

bentle · Mar 29, 2012

Re: Lower unit cross reference

Man thats crappy. Sorry to hear that.
The rebuild can cost 1200 to over 2000 for parts.
If the lower is bad because of broken gear or bearing and such then you will want to replace everything in the lower gearcase.
If it were me and money permitting?
Then I would replace with a rebuilt lower than comes with a warranty.
These lowers can be a bugger to rebuild.

bentle · Mar 30, 2012

Re: Lower unit cross reference

I do know that a 1989 force lower will work with a 13 splined drive shaft up through 1994
Make sure that whatever lower you purchase will work for a 13 splined drive shaft coupler and drive shaft.
Also make sure if it has the splined end shift coupler or rod coming out of the lower and or the one that fits with a pin style shift coupler. You will need the one with pin style coupler for your 1994 F-outboard or at least this is what it should have.

Gulf Boater · Mar 31, 2012

Re: Lower unit cross reference

Thanks for your help on this Bentle. When I got the boat it came with an estimate to fix the lower there was roughly $400 in parts they had listed and total wanted $700 with labor. Luckily the part #s were on the estimate (seal kit,main bearing,impeller kit,and cover assembly) I was able to source these parts my self for $165 all new. I believe the problem was the main bearing seizing cause I cannot turn by hand when I do get it to turn its very crunchy sounding. All my gears all appear perfect they actuall look like new. The motor itself is very clean and never seen Saltwater so other than that main bearing I don't see anything else that needs replacing I'm thinking of going to a shop to see how much they will put it together for

bentle · Mar 31, 2012

Re: Lower unit cross reference

Well its worth a look and see. Let us all know what you find out.
Good luck.

Lower unit cross reference

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