I have a lower unit that is heavily pitted and the seals need replacing. After pricing seals I found a "guaranteed" lower unit and opted to do a whole unit exchange rather than a repair. After comparing the two lower units there is a noticable difference in the O-Ring groove that slides into the power head, mine has about an 1/8 groove, the replacement has a 1/4 groove.
When I checked the length I discovered the replacement is about 1/2 longer than the original and will bottom out on the taper when inserted into the power head about 1/8 from being up.
My question concerns the shimming of the lower units and the possibility of swapping the shafts between units. From what I read in the manual the gears on the prop shaft are shimmed outside the unit and then inserted into the housing. The drive shaft has a nut on the bottom that holds it in place and it appears that once removed, the shaft and pinion gear will pull out from the top.
Does anyone know if these shafts are interchangeable between year models and HP as I don't know really what the replacement unit came off of, it was supposed to fit my unit and does other than the shaft length. Also, If I do the swap keeping the same pinion gear and reinstalling it with whatever shims I find on the drive shaft, will this work? The best I can tell from the manual the shims are on the prop shaft. I have already pulled the carrier bearing housing on each unit and I am down to removing the two lock rings. Also, is there a special tool required to remove the nut, the manual refers to a specific tool but was wandering if anything else might work.
I hestitate to tear into the gears portion of the lower unit without asking the above questions as to whether the shimming would be affected by swapping just the shaft or would I be better off just installing a seal kit on the old lower unit and stick with my pitted housing.
Thanks in advance for your time and thoughts. If anyone needs a shaft with a 1/4 groove for the upper O-ring I have at least a shaft if not a whole lower unit available. I am not sure what it fits as I know it don't fit a 1990 88 SPL.
When I checked the length I discovered the replacement is about 1/2 longer than the original and will bottom out on the taper when inserted into the power head about 1/8 from being up.
My question concerns the shimming of the lower units and the possibility of swapping the shafts between units. From what I read in the manual the gears on the prop shaft are shimmed outside the unit and then inserted into the housing. The drive shaft has a nut on the bottom that holds it in place and it appears that once removed, the shaft and pinion gear will pull out from the top.
Does anyone know if these shafts are interchangeable between year models and HP as I don't know really what the replacement unit came off of, it was supposed to fit my unit and does other than the shaft length. Also, If I do the swap keeping the same pinion gear and reinstalling it with whatever shims I find on the drive shaft, will this work? The best I can tell from the manual the shims are on the prop shaft. I have already pulled the carrier bearing housing on each unit and I am down to removing the two lock rings. Also, is there a special tool required to remove the nut, the manual refers to a specific tool but was wandering if anything else might work.
I hestitate to tear into the gears portion of the lower unit without asking the above questions as to whether the shimming would be affected by swapping just the shaft or would I be better off just installing a seal kit on the old lower unit and stick with my pitted housing.
Thanks in advance for your time and thoughts. If anyone needs a shaft with a 1/4 groove for the upper O-ring I have at least a shaft if not a whole lower unit available. I am not sure what it fits as I know it don't fit a 1990 88 SPL.