1988 Johnson 175 stiff to shift at engine

[Intoodeeep]

My 1988 Johnson 175 is stiff to shift at the engine. For those that have read some of my previous posts, this is the 1979 engine build. I have had a few issues and I know it is coming to a point where the lower unit will need to be rebuilt or replaced next year. Just a few goofy things it is doing. I have yet to have it out on the water yet. But it wasn't stiff to shift until after I had the engine running for an hour in the driveway to start the break in process on the motor and look for leaks and problems. I have pulled the lower unit and it shifts fine there. I do have to spin the prop to get it to engage but it does engage. The shift lever at the motor shifts clean and free as well when not hooked to the shift rod. It is only stiff when it is all connected. The shift rod is at proper height per OMC manual. Ideas?

I have been having issues with being able to engage forward and reverse from the control box. It is either one or the other. I can get it to engage now but it has to be past the detent for forward or reverse to engage. I just replaced the internal gears for the control box. But it slips out of position sometimes due to the shifter being stiff now. Which it wasnt before.

 

[metriccrescentwrench]

My 1988 Johnson 175 ...... this is the 1979 engine build......

OK, stupid question..... what does that mean? Is it an '88 175 or a '79 175?

 

[emdsapmgr]

The shift rod in the lower unit must be set to a set/exact height specification in order for the lower unit to shift correctly. The precise year of the engine/lower unit will make a huge difference in how the lower unit shifts. I looked up some factory service manual long shaft shift rod heights-none of them for your year units-but they do show the variance over the years, That variance could lead to your shifting problems-if you have mixed year parts on that engine: Standard long shaft rod heights: 1978: 21.6" +- .036", 1986 and 1990 22 1/16" +- 1/32".

 

[Intoodeeep]

Everything on the entire unit is a 1988 175, except the powerhead. The powerhead is a 1979 235. The carbs and intake manifold are from the 1988 175 as well.

 

[emdsapmgr]

So, what dimension did you set the shift rod at?

 

[Intoodeeep]

I set it at 22 and 1/16. Is it normal for it only to go into gear with the engine running. It will work forward and reverse, but only wants to go easily when running. Oh and that 22 and 1/16 is plus or minus a 32nd. Which one turn up or down still was within spec but made it stiff to shift.

 

[emdsapmgr]

The shift linkage will get sloppy if you do not have the correct plastic bushings on the shift lever shaft under the bottom carb. It mounts (slides thru) a long casting hole at the bottom of the intake manifold. The shift rod levers are the same part number between years. (324362) Various years use different (2) plastic bushings. 331839 is used on the 88 V6. 312708 is used on the 79 235 V6. They do not supercede to each other. If that lever has too much slop, due to incorrect plastic bushings it will be hard to shift properly. (It will be easier once it's running, but it will not shift properly/smoothly.) To me, that means the intake manifold hole for the shift rod shaft is not drilled to the same inner diameter, requiring different plastic bushings depending on year of the intake.

 

[metriccrescentwrench]

..... Is it normal for it only to go into gear with the engine running. It will work forward and reverse, but only wants to go easily when running.....

Yes, that's perfectly normal, reason being is that when the engine's not running you have a pretty good chance that the clutch dog isn't gonna' be properly aligned with a gear, to get around that you either need to rotate the prop by hand or else have the engine running.

 

[Intoodeeep]

The bushings are in place on both sides. not sure which part number they are but most likely for the 88. There is no slop there thow. It seems the slop is in the cable. It can pull the cable another 1/4 inch when it is shifted. I have ordered another cable just to compare and see if it makes a difference.