Merc 150 slips, bangs, bucks when shifting

[dogfish]

My 150 Merc has been showing an increasing problem. At low RPM shifting into forward or reverse (previously only in reverse) it seems to slip as I shift into gears slowly and noisily and then tends to bang and buck. At high throttle no problem. Seems as if there is play in the system as well as slack in shifting. Motor kicks repeatedly with a thump until I up the throttle. Not sure if the shifting and bucking problems are related or two separate fixes? <br /><br />I read another post to this board that makes me think I might be able to fix this by doing some adjusting at the motor to take out slack when it shifts into gear. Getting ready to take out the wrenches and the manual.<br /><br />Any info on similar experiences and how they were fixed or advice would be appreciated. Thanks.

 

[twofing]

Re: Merc 150 slips, bangs, bucks when shifting

did any one ever have an anwer for you .i have the same problem with my 135

 

[ZmOz]

Re: Merc 150 slips, bangs, bucks when shifting

Could be that either the shift cable needs to be adjusted or the cam in the control box is worn out. I had to replace the cam in my control box and it is obviously a part that wears out easily...cost about $26 for the part.

 

[twofing]

Re: Merc 150 slips, bangs, bucks when shifting

thanks.... is that cam shaft hard to replace?

 

[greasemonkeyozi]

Re: Merc 150 slips, bangs, bucks when shifting

a slight short grinding noise when shifting into reverse is normal in some cases. If its really giving you a problem, your cable could be the problem. Have you attempted adjusted it yet?

 

[twofing]

Re: Merc 150 slips, bangs, bucks when shifting

no but will tomarrow......<br />even if it is fine going foward?

 

[twofing]

Re: Merc 150 slips, bangs, bucks when shifting

Hi, My 135Merc makes a clunking noise when i put it in reverse..... <br />Could there be an adustment in the linkage or is my lower unit on the way out.?...<br />no noises in forward...<knock wood><br /><br />any help would be apriciated.... thank you

 

[twofing]

Re: Merc 150 slips, bangs, bucks when shifting

*******

 

[Gilbert A.]

Re: Merc 150 slips, bangs, bucks when shifting

Twofling: When my mechanic had done everything in the control box and had adjusted the cables--both going to the box and at the motor--as much as possible and found that he could only find the reverse gear by sacrificing a solid engagement in forward, he decided we would have to order a new shift shaft (the vertical one going down into the gear box). It appears to me that here Mariner/Mercury is much less trouble-free than OMC, since I had the latter before and never ran into this kind of problem.<br />Gil

 

[mellowyellow]

Re: Merc 150 slips, bangs, bucks when shifting

remove shift cable and try to shift manually.<br />if it shifts good, problem with cable.<br />if same problem, poss. worn clutch dog.<br />good luck,<br />M.Y.

 

[twofing]

Re: Merc 150 slips, bangs, bucks when shifting

*******

 

[Nordic Merc]

Re: Merc 150 slips, bangs, bucks when shifting

I have a similar problem on my 115 merc. It makes a chattering noise in reverse with an increase of throttle (sounds like the reverse gear is slipping over the pinion). I was told it probably is the clutch dog. I dont think it's too expensive to repair but you need some special tools. Good luck.