Mercury 175 wont shift

[gohawks688]

Ok guys, i have a 1999 mercury 175 2 stroke ( will get serial number when i go back out to the garage). I went to do a shake down run today and it would not shift out of neutral.
Here is what i have done so far.

Disconnected shift cable and verified that the cables move freely. The problem does not seem to be in the cables/control box.

Dropped the lower unit and tried to shift the engine by hand and with the cables (Engine off). It will still not shift. This seems to isolate the problem to the linkage on the engine itself.

any ideas? Boat has shifted like butter until pulling out of storage this season. I am stumped.

 

[racerone]

??----Was it still your lower unit on the motor ?-----Was it in " secure storage "-----Nothing could have happened during normal storage to loose forward and reverse.

 

[gohawks688]

It was in my garage. Used last for black mouth in January. Shifted fine at that time

 

[gohawks688]

If the lower is disconnected from the engine and the shift cables are disconnected, what else is left to bind?
Could it be corrosion at the upper shift shaft?

 

[Faztbullet]

Check the gear oil...

 

[racerone]

See if the lower unit shifts with it laying on the work bench.

 

[gohawks688]

I will check the lower out.
But haven't I narrowed it down to the engine half of the linkage since its still frozen with the lower disconnected.
Does any one have experience with the upper shift shaft binding? Is it true I have to pull the power head to get to it?

 

[gohawks688]

I will check the lower out.
But haven't I narrowed it down to the engine half of the linkage since its still frozen with the lower disconnected.
Does any one have experience with the upper shift shaft binding? Is it true I have to pull the power head to get to it?

 

[gohawks688]

well I picked up a used engine hoist and ordered the eye bolt for lifting the power head. Hopefully the bolts aren't rusted into the midsection and I am able to separate them fairly easily. Not sure what I will do once I gain access to that area. Heat and penetration oil until the shaft loosens up I guess.

 

[jimmbo]

Before yanking the Powerhead, can you get a long Straw to shoot some penetrating oil at the Shift shaft bearing, but first check that rest the Linkage isn't seized up

 

[Chris1956]

Those upper shiftshafts have a single bushing in the midsection. I never saw one corrode, however, I suppose they could rust in the swivel pin, but I never saw that either....

Drop the gearcase first. Now disconnect the shift cable at the motor. Now tap on the upper shift shaft, from the bottom. it should move up a bit, allowing you to grease the bushing.

 

[gohawks688]

Those upper shiftshafts have a single bushing in the midsection. I never saw one corrode, however, I suppose they could rust in the swivel pin, but I never saw that either....

Drop the gearcase first. Now disconnect the shift cable at the motor. Now tap on the upper shift shaft, from the bottom. it should move up a bit, allowing you to grease the bushing.

I am assuming no zerc fitting to grease this area?
Lower is dropped and shift cable already disconnected. I will give this a shot and see if it loosens up.
I have been spraying with PB blaster and ATF to see if I can loosen it up but it hasn't budged yet. I am afraid to really beat on things for fear of bending the shift shaft.
Can you describe the location of the bushing? I am having a hard time finding a good diagram or pictures. Is it at the top of the midsection where the shift linkage connects or down inside the midsection? What is the "Swivel pin"

 

[gohawks688]

Before yanking the Powerhead, can you get a long Straw to shoot some penetrating oil at the Shift shaft bearing, but first check that rest the Linkage isn't seized up

I've been shooting PB blaster and ATF into this area but it hasn't budged yet. I can get it to move slightly by tapping with a hammer. I am afraid of bending the shaft however, it seems to be unobtanium.

 

[Chris1956]

Take a look at the crowleymarine site. They have the exploded parts pictures for your motor.

The shift rod bushing is likely a piece of plastic wrapped around the shift rod top casting bushing surface, just below the lower carb. Actually in the parts list, you may not even have a bushing.

The Swivel pin is the steel steering arm and attached hollow shaft that connected thru the swivel assembly to the lower yoke. The upper shift rod runs thru it. Actually your swivel pin may be stainless, as the changed from steel to SS in the 90s.

 

[gohawks688]

Mercury Marine V-175 HP Throttle Lever & Shift Shaft Parts

Mercury Marine v-175 hp throttle lever and shift shaft parts. Buy a genuine Mercury Quicksilver or aftermarket part.

www.marineengine.com

here is the parts diagram for my motor. Based on that DWG i am thinking the only binding could be between pc 46 (shift arm?) and the midsection, or between 46 and 43 (link rod), or 43 and 32 (bracket slide).

I can easily disconnect everything besides the shift arm and the midsection to try and isolate that bushing.

Would it be wise to try to use force to rotate the shift arm in the midsection to work out the corrosion or do I run the risk of damaging/bending the shift arm/shaft?
Should i pull the power head for access instead?

 

[gohawks688]

Those upper shiftshafts have a single bushing in the midsection. I never saw one corrode, however, I suppose they could rust in the swivel pin, but I never saw that either....

Drop the gearcase first. Now disconnect the shift cable at the motor. Now tap on the upper shift shaft, from the bottom. it should move up a bit, allowing you to grease

Tapping up from the bottom plus soaking with ATF for a week i was able to free the shift shaft!

 

[jimmbo]

Good. Keep applying ATF or other lube keep moving it to flush out any contaminates

 

[Chris1956]

Put some good marine grease on the bushing, after it is cleaned out. Hopefully you do not have the pull the shift rod out, as that usually requires you to pull the powerhead.