used/ new ower unit will not shift well into reverse

[ottawamerc]

I have a 1981 228 hp apha 1 R model lower unit. My original unit tossed a forward gear so costs dictated that I buy a used similar lower end. I rebuilt the lower end with the best parts from both units. Now before I match the lower unit to the upper gear case I can shift forward-neutral-reverse with a positive lock in both. Once matched to upper unit and attached to the boat it would not shift to reverse. I check all shift cables and adjustments and they seem ok. I finnally added a little shim material to the shaft in the upper gearcase that mates to the lower unit. I now have a marginal reverse but I can rotate the prop against the clutch? I'm starting to think that I might have to shim the reverse gear to get a proper lock, although there was no shims present when I disassembled the unit.<br /><br />Any suggestion would help!!!

 

[FreeBeeTony]

Re: used/ new ower unit will not shift well into reverse

Sounds more like a cable adjustment to me....<br />Try this web page for instructions on adjusting the cables.<br />I rebuilt my lower unit against the advice of some on here.....I used the shims that were installed previously as you did. I don't think the shims have anything to do with the shifting though.....I would recheck the cable adjustment.

 

[ottawamerc]

Re: used/ new ower unit will not shift well into reverse

Thanks for the quick response. I have checked the cable adjustment and it seems ok, but I will read the web page you sent me to see if it has new ideas.<br /><br />Thanks again

 

[Don S]

Re: used/ new ower unit will not shift well into reverse

DO NOT put any shims between the upper and lower gear case or you will never get it to hold oil. To tell you the truth, if you have been swapping gears around, you MUST keep the pinion and forward gear as a matched set, they are machined that way. Putting different sets together will cost you gears real quick. The reverse gear can change but not the forward gear.<br />All the shims and shimming done on the drive is to get the proper gear contact pattern and preload on the bearings, and has nothing to do with shifting. So the only thing I can say there is GOOD LUCK.<br />Now, on to your problem, when you put the drive in forward, the clutch dog will hold in only one direction, if you turn the prop by hand in the other direction it will ratchet. Same in forward and reverse. One direction it will hold the other it will ratchet.<br />Do you have a Mercruiser service manual?

 

[ottawamerc]

Re: used/ new ower unit will not shift well into reverse

Yes I do have the manual.

 

[Don S]

Re: used/ new ower unit will not shift well into reverse

8 months to answer a question???? <br />You gotta slow down and quit rushing into things

 

[ottawamerc]

Re: used/ new ower unit will not shift well into reverse

Took a while to charge the batteries !

 

[Bondo]

Re: used/ new ower unit will not shift well into reverse

Originally posted by Don S:<br /> 8 months to answer a question???? <br />You gotta slow down and quit rushing into things

<br />

I finnally added a little shim material to the shaft in the upper gearcase that mates to the lower unit.

What kind of shape is the Shift-Shaft Bushing in ?????

 

[ottawamerc]

Re: used/ new ower unit will not shift well into reverse

Well there's a little play, whats considered normal?<br />Also I was wondering about filing alittle off of the shift lever on top of that shaft(the one that connects to the shift cable). Could that give me more throw on the linkage?

 

[Bondo]

Re: used/ new ower unit will not shift well into reverse

There's about 1/8th" of fore,+ aft Play in a Merc. propshaft..............<br /><br />The Shift Shaft should have No Play........<br /><br />How about the Bellcrank shaft,..??? You didn't Bend it did you ..???<br /><br />Grinding Parts is Not the Answer...........

 

[ottawamerc]

Re: used/ new ower unit will not shift well into reverse

Ah no I didn't bend it but I did increase the length of the bore as recommened by the Merc dealer here, so I should replace the bushings? how come it worked on my old drive?<br /><br />Scott

 

[a.d.mobile]

Re: used/ new ower unit will not shift well into reverse

hi I have 2 questions<br />1. did you mess with the shift spool, this is the pice that goes thru fwd gear and the dog pin goes thru.looks like a 1 inch pully.<br />2. did you just replace the shift cable? if so was it a aft installed cable. meaning the cable screwed into the pivot from the outside.<br /><br />bob