lower unit make a grinding noise when i put it in reverse

[donhicks1]

I have a 2003 40 hp 4 stroke engine. When I cranke it in neatral it makes a little very little grinding noise as if its not quite in gear I move it a little past neutal it stops. I went fishing today put it in reverse, gave it some gas
heard a good grinding noise but it moved very slowly Is
there a way top ajust it or is the gears bad in the lower unit
Thanks
Don

 

[tashasdaddy]

Re: lower unit make a grinding noise when i put it in reverse

you probably need to adjust your remote shift cable at the engine end. also when shifting, do it quickly, and meaning fully. do not try to ease it into gear. easing it into gear, wears the teeth on the shifting gears. this is common when the engine is set up and not taken on a shake down by the mech.

 

[donhicks1]

Re: lower unit make a grinding noise when i put it in reverse

you probably need to adjust your remote shift cable at the engine end. also when shifting, do it quickly, and meaning fully. do not try to ease it into gear. easing it into gear, wears the teeth on the shifting gears. this is common when the engine is set up and not taken on a shake down by the mech.

I adjusted remote cable it adjusted all the way out. I took
the remote cables off. put in foward gear tried to turn propeller it locks in gear put in reverse it turns a little
as its not all the way in gear. it clicks when it turns
any surgestion

 

[Silvertip]

Re: lower unit make a grinding noise when i put it in reverse

The prop will ratchet in one direction and lock in the other when in gear. That's normal. If the shift cable is adjusted all the way to one end or the other it's not adjusted properly. With the cable disconnected, put the shift lever (the one on the engine) in neutral. Then make sure the throttle/shift lever on the control box is in neutral. Bring the end of the shift cable up to the lever but don't connect it. Adjust the trunion (the threaded barrel) until the cable end and the attachment point on the lever are exactly aligned. Do not push or pull anything. When perfectly aligned, attach the cable.

 

[Texasmark]

Re: lower unit make a grinding noise when i put it in reverse

If I could add a tad to Silvertip's reply.

F gear ratchets in one direction (so that the prop will/can freewheel upon deceleration). R locks in place.

When I adjust shift linkage, I put one hand on the engines shift lever (remote cable removed) and the other on the prop. I slowly move the lever back and forth finding the center of the movement of the prop and lever in the N position. Then do as he said.

Also, idle on most engines of today is around 675 rpm (that I know of). If too fast, it makes shifting into R difficult also. But with what you said, you have a linkage adjustment problem.

Mark

 

[donhicks1]

Re: lower unit make a grinding noise when i put it in reverse

okay lets go back I unhooked both cables from engine.
I put it in neutral turn freely. put in foward locks in gear.
put in reverse acts as if its stripped out. not locking in
gear. I put it in gear manualy. that way it should go right
directly in gear. it going in reverse but it sounds as it
striped out do you think its the dog clutch or reverse gear . need help

 

[donhicks1]

Re: lower unit make a grinding noise when i put it in reverse

I pulled tlhe propeller and shaft. dog clutch looked good
and the foward and rear gear looked good. no metal
flakes found in lower unit oil. I am confused. I used my old cable do you think the cables sre not the right ones
needs help

 

[Texasmark]

Re: lower unit make a grinding noise when i put it in reverse

Guessing now. The shift rod could be in the wrong tooth. Being in the wrong tooth means just what you mentioned. The shift is way too far for one gear and short for the other. Sounds like what you have.

With the prop shaft out, look up into where the front end of it sticks and you will see the shifting cam. It has 3 "lands" on it for the three gears (FNR). Looking at it through the hole in F gear, move the shift selector through it's positions and see if the lands come and go symmetircally, or if one (F) is there longer than the other (R).

If you see that, then I'd say you need to split the case and move the shift spline one tooth in the direction causing more R.

Make sense?

Now, the question. On a 2003 engine, has the lower unit been off the engine before? If the answer is yes, you have your solution. Whomever put it back together didn't get the shift cam centered.

Mark

 

[donhicks1]

Re: lower unit make a grinding noise when i put it in reverse

I dont know if it have. I noticed when I put it in neutral it
acts as if its still a little in forward its not turning freely. when i move it a llitle past neutral it spins freely. I believe
its has to do with what you said theshift shaft is not lined up, can you give me some instruction on how to

thanks
Don

 

[Texasmark]

Re: lower unit make a grinding noise when i put it in reverse

You just answered your question with that last thread, second sentence.

Remove the lower unit as if you were redoing the water pump. Put it in a vise with adequate cushioning to support it.

With a pair of vise-grip pliers, rotate the shift shaft all the way in one direction....remember, any time you go to reverse, the prop must be spun (by hand) to get the cog in the clutch dog (shifter) lined up with the slots in R gear.

Mark your starting point and rotate the shaft the opposite direction, slowly rotating the prop for the reason given until it has traversed it's full range. Mark that point.

Turn the shaft back half the distance and you should be in the center of N. The prop should turn freely.

Go to the shift lever under the cowl and do the same thing. Move it all the way forward, all the way aft, and come back to the center of those measurements. That should put the shift linkage in the center of N.

Reassemble the lower unit and you should be there. You may have to slightly bump the shifter to get the splines to line up but that shouldn't hurt that much.

If it doesn't line up you might try both directions and use the one that fits closest to where you centered things.

Mark

 

[donhicks1]

Re: lower unit make a grinding noise when i put it in reverse

I got that so far so good. I got one more question, When
droping lower unit do i unhook the shift rod from top of
engine. does the shift rod come down with the lower unit
or will it stay up when lowing unit

 

[Texasmark]

Re: lower unit make a grinding noise when i put it in reverse

I am not intimately familiar with your engine but the rod needs to stay with the lower unit as it is stuck in a shifting cam (down there) that moves the clutch dog which is the gear that we are talking about.

Some have a clamp under the carbs (2 stroke) that holds the rod up as you mentioned. Others, like my midranges, have the shift spline sectioned a few inches above where the lower unit separates and they just push together (male-female connections).

If it looks like you have a clamp on it you have a clamp and the purpose is to hold it in place. Naturally it needs to come off.

Mark

 

[donhicks1]

Re: lower unit make a grinding noise when i put it in reverse

Okay I got it was a pin under motor. I think that the 2003
model is diferent. I pull lower unit no problem, The shift rod goes up and down.I did not pull the water pump
because I got lost. I think the lining up is a little diferent. If
there is some simplier ways of lining up cam gear please
let me know I think I might have to take it to the shop I just hate to give a shop money for 3 or 4 hours at 65.00
a hour. you help is highly appreciated, down at the bottom of the shift shaft there is a rubber boot on it I have a manual but its no good is there a guide or somehing I can go through the steps
Thanks
Don