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MARINER 4 STROKE 15 hp reverse gear problems

S

StevenDon

New member
IMG_20180214_105742.jpgIMG_20180214_105935.jpgIMG_20180214_110050.jpg
Engine serial no-OR323605
Model No: 7F15312ZK

Each time I engage reverse gear and put the boat under load, the gears make a knocking noise and do not engage. on the bank with the mufflers attached it does not happen. only in the water. I have checked it on a second engine to eliminate cable problems. could someone please point me in the right direction. Do i replace the reverse gear? is it worn? ( i could not find one picture to compare it against.) Or could it be the Cam rod or spring in there? Any help would be appreciated.
Thanks
Steve
 
Picture 3 shows forward gear.----Perhaps you need to adjust the shift rod to fully engage the reverse.
 
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When you pull the shift pin out of the propshaft does a ball bearing fall out? Push down fully on the shift shaft and look center of the forward gear is the flat part of the shift cam past center?
 
Time to look carefully at the shift coupling.-----On some one of the pieces is a left hand thread.-----On some both are a right hand thread.-----Up to you to look / understand how to get the lower shift rod to go down further !
 
If both are right hand the following may be the issue.----Folks tend to turn the upper nut too many turns to disconnect it.----Then on re-assembly they forget / do not know how important it is to get the correct set up.----Possibly you need to turn the UPPER / LONG nut down 2 or 3 turns before engaging the lower shift rod !
 
racerone said:
If both are right hand the following may be the issue.----Folks tend to turn the upper nut too many turns to disconnect it.----Then on re-assembly they forget / do not know how important it is to get the correct set up.----Possibly you need to turn the UPPER / LONG nut down 2 or 3 turns before engaging the lower shift rod !
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I have a second Engine the same type. The gears work fine on that engine. I tried this gear box on the same setup and get the same problem the reverse gear does not syay in when under load. So you think that my gears are fine? and this is only to do with fine adjustments?

Could it be the spring on the shift rod? Do the gears themselves look okay in the pictures?

Thanks
 
racerone said:
Hurry----Run to a shop.----They can likely set up the shift adjustment in say less than 10 minutes.
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The shift adjustment was fine for a long time. I have played with the adjustments. The same problem remains. you seem to be fixated on the shift adjustment!!

So in your opinion everything else is fine. the reverse gear and dog clutch?
 
kimcrwbr1 said:
When you pull the shift pin out of the propshaft does a ball bearing fall out? Push down fully on the shift shaft and look center of the forward gear is the flat part of the shift cam past center?
Click to expand...

The ball bearing is present.
the shift cam does go past center.

when assembled it all works fine. I can engage forwards and reverse gears easily. however once i apply throttle in the water the reverse gears starts slipping.
 
Does the shift lever travel the same distance from neutral to forward and reverse? Perhapse put the gearbox on with the propshaft out and see if the cam flats are center of the forward gear in each gear?
 
kimcrwbr1 said:
Does the shift lever travel the same distance from neutral to forward and reverse? Perhapse put the gearbox on with the propshaft out and see if the cam flats are center of the forward gear in each gear?
Click to expand...

cam-shaft-down.jpg

The distance is pretty much the same. here is the cam in reverse gear. it looks to be down far enough.
 
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