Shift Cam and Follower Wear - 1963 100hp

[bh357]

Does anyone know how much wear is permissible to the shift cam and follower on a 1963 Merc 1000, before shifting performance will be affected? Specifically, my problem is slipping in reverse. Forward engages fine. I received the new cam and follower today, and the old parts look worn compared to the new. Tomorrow I should be able to provide some measurements.<br /><br />Thanks.

 

[bh357]

Re: Shift Cam and Follower Wear - 1963 100hp

As promised, I measured the parts this morning. The old parts appear to be about 1mm shorter than the new. This was measured with both shift cams on one shaft, with the followers held in position in the grooves. The difference in overall lengths was measured.

 

[Laddies]

Re: Shift Cam and Follower Wear - 1963 100hp

One of the problems with those older in line engines was, if shifted in to reverse when tyhe engine was not running or the prop is no turning theyn would twist the upper shift shaft, which are hard to find and very expencive, if that is the problem in some cases it can be corrected wilh a small washer ahead of the shift pin and against the cross pin to get a little more reverse

 

[bh357]

Re: Shift Cam and Follower Wear - 1963 100hp

Thanks Laddies.<br /><br />My shift shaft appears straight and not twisted. Every time I shifted without the motor running, I made sure I was turning the prop by hand at least.<br />Do you think that the 1mm difference would be enough to be causing my slipping. I do have a bit of wear on the clutch dogs, which was shown in a previous post. I was unable to locate anyone here that can re-machine the clutch dogs.

 

[Laddies]

Re: Shift Cam and Follower Wear - 1963 100hp

It don't take much wear to cause them to jump gear, we take ours to a local machine shop and they recut the surfaces for us

 

[bh357]

Re: Shift Cam and Follower Wear - 1963 100hp

expencive, if that is the problem in some cases it can be corrected wilh a small washer ahead of the shift pin and against the cross pin to get a little more reverse

Laddies, is there much risk of messing up forward by shimming the shift pin as you mentioned (about a 1mm shim)? I put the l/u back together with the new cam and follower, and can still make reverse slip by hand, although it takes a good bit more effort to do so than before.<br />Any advice for finding a machinist who will re-cut the clutch and gears? I've called a number of machine shops in the area, and nobody can help me.

 

[Laddies]

Re: Shift Cam and Follower Wear - 1963 100hp

bh, we have never had problems with a shim washer just make sure that the engine don't jump gear. I am 30 mile south of the bridge and don't know what part of the state your in let me know about where you are and I can ck around for you--Bob

 

[bh357]

Re: Shift Cam and Follower Wear - 1963 100hp

Thanks for all your help Laddies. I am located in SE Michigan (Lapeer county), and work in Warren. Lots of machine shops near Warren, but I struck out on all that I've called.<br />How big of a shim washer do you usually use? I have a brand new cam and follower. I don't want to over-shim to the point of losing engagement of forward.

 

[Laddies]

Re: Shift Cam and Follower Wear - 1963 100hp

Usally a 1/32 no more than 1/16 will do. The only dealer that I know down that far is Vick Brinkman at grass lake over by Jackson, he's a good guy and might know some one that can do the work in your area Call Brinkman Props and ask for him, tell him you were talking to the ----- from up north and we were bragging on him--Bob

 

[bh357]

Re: Shift Cam and Follower Wear - 1963 100hp

Laddies, I put in what appears to be a 3/64" shim. I'm guessing to the actual thickness (it appears slightly larger than 1/32", measured with a ruler). In forward, I can still notice a bit of fore/aft play in the propshaft, but not as much as before I shimmed it. I'm guessing that this means that forward is still fully engaging. In reverse, I can no longer manually force the prop to slip. This is even with putting all my strength behind the prop, with the drive shaft clamped so as not to move.<br /><br />This weekend I plan to try her out on the water again.<br /><br />In the off season, I still plan on having the dogs reground, and hopefully do away with the shim.

 

[Laddies]

Re: Shift Cam and Follower Wear - 1963 100hp

Good Luck