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I series mercruiser lower gearcase

N

Nor'east

Guest
"I had problems last season wi

"I had problems last season with shifting into forward, I thought that the shift cable was bad in the lower unit,took the drive off, turns out that the cable had been recently been replaced with all the seals and pump. Now I am thinking that the lower gears are stripped.The drive has a hard time shifting into gears in the driveway and I have spent hours with the mechanic trying to adjust the lower cable. I have drained the lower gear oil and there appears tobe no metal flakes in oil and the oil has no water to speak of(color is light greenish)and has sat in a clear glass jar for a day and no water. What I am trying to find out is weather or not the drive should be replaced, and if there is anyother way to tell if the gears are really bad or if it is just the cable adjustment? I know this is a question that could go many ways but I and the mechanic are at a loss..Tahnks so much for any help!!"
 
"I may have more questions tha

"I may have more questions than answers.. Year and model of drive, just to get indication of potential wear. It should only take a few minutes to adjust the lower shift cable, not hours. You said it was hard to shift into gear -- is it actually going solidly into gear or just physically difficult to make the shift?

When cable disconnected at the front bolt at black connector mount beside the engine--
a. Will the unit go into gears when the cable connector is pushed and pulled to front (reverse) and rearmost (forward) positions?
b. Does it move fairly easily using this cable connector?
c. If it does not move easily is the cable path smooth and not kinked?
d. Does the upper shift cable move smoothly when the throttle arm is moved back and forth?

When the cable is reconnected does the shifting become much more stiff, or is it next to impossible to get to move into gear position?"
 
The lower shift cable may have

The lower shift cable may have been crushed or bent or otherwise damaged during installation. This makes them useless and the only cure is to replace it.

Rod
 
"Although you say the cable ha

"Although you say the cable has been recently replaced I am still leaning towards the cable.

When you say you had trouble getting into forward, describe what you mean by trouble.
Cheers
Peter C"
 
"When shifting into forward or

"When shifting into forward or reverse the shift is smooth at the control and with the cable disconnected it is also smooth, at the prop the gears spin and sound as if the teeth are just missing and then every once and a while they catch and it goes into gear with the cable connected. When trying to go into forward I get that grinding sound and I don't want to push it to much and wipe out whats left of the gear.This is a first series outdrive mercruiser 1973 to a Ford 302 V-8. I really appreciate the help guys!!!I hope I am not on a gooose chase with you and have to replace the gear box....."
 
"After 35 years of use the dog

"After 35 years of use the dog clutch corners that do the engaging may be getting too rounded to engage fully anymore.

You will probably need to have the lower gear housing torn apart to investigate. The forward & reverse gears have the dog clutch teeth that mate with the sliding gear selector machined into them. If the teeth are worn, these gears as well as the drive pinion gear are all replaced as a set. This will cost several hundred dollars to have done, unless you do it yourself.

Doing it yourself will require several special tools, and the new gears have to be properly shimmed which is a trial and error process.
You may be better off buying a new lower gear unit from SEI for about 800 bucks. As a bonus, you get a nice shiny new paint job to boot!

Rod"
 
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