upper / lower alpha drive

tystick

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1990 merc 4.3 L with Alpha 1 drive <br /><br />Questions so far..<br /><br />1. Upper & lower do not want to separate so easy. Do not want to force but where do i pry or bang? this is 1st time at this....<br />double checked and all 4 nuts loose or removed and allen screw removed also.<br /><br />2. Removed the drive shaft assembly - plenty drive oil in bellows as i suspected - bad yoke seal. <br />Question is the carrier assembly for oil seal is loose on shaft and has movement...before disassembly - is this indicate other issue or just that seal is shot?<br /> Also can oil in bellows remain?<br /><br /> I can see a clip inside bellows like a c-clip that seems to be loose - is this right?<br /><br />Thx in advance - Robert
 

Bt Doctur

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Re: upper / lower alpha drive

there are 5 nuts, 1 allen under trim tab, 1 allen holding the trim tab.tab needs to be removed firstto get to the other allen.
 

tystick

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Re: upper / lower alpha drive

yes 5 nuts and both allen screws are removed yet it does not budge - i want to whack it but know that probably is not a good move - any tricks?
 

Don S

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Re: upper / lower alpha drive

I think I gave this to you once before, but if not, here it is again. It's a link to the Merc service manual.<br />Section 3A shows how to take it apart, but there is also an alignment pin on the back that sometimes hangs. I usually use a putty knife blade between the sections on the back to pop the pin loose. On the front, corrosion builds up around the studs. You can pry between the side bolts and the housing (DO NOT PRY AGAINST THE CAVITATION PLATE) with care to free it from the corrosion. You just have to be VERY carefull how and where you pry on it. "Look before you leap" works.<br /><br /> http://www.boatfix.com/merc/Servmanl/6/6covr3.pdf
 

tystick

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Re: upper / lower alpha drive

Thx Don <br /><br />Is that what they call a dowel pin?<br /> #8 in section 3B.<br /><br />I appreciate the patience :)
 

Don S

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Re: upper / lower alpha drive

If you are talking about the drawing on page 3B-8, yes, that is the dowl pin I was refering to.
 

tystick

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Re: upper / lower alpha drive

After reviewing gimbal bearing replacement and comparing the mercstuff site to the merc manual...<br /><br />Why does the merc manual recommend installing gimbal bearing with notches inward while the mercstuff site says you should put notches outward for future ease in service?<br /><br />Also the merc manual says to always replace bearing and carrier assembly - not just bearing. The mercstuff site seems to sell bearing only.
 

Bt Doctur

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Re: upper / lower alpha drive

From my older Merc manual it says you can just replace the bearing IF it has not spun in the outer race,just tip it till it can be removed thru the slots.The best option is still to replace it as a unit for peace of mind with the slots outward just in case you need to do a quick change someplace.
 

tystick

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Re: upper / lower alpha drive

what is the issue with the slots? What are they for?<br />Is there any inherent advantage to slots facing inward? Otherwise why do it as it seems harder to replace bearing later.
 

bigbrownbuku

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Sep 17, 2004
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Re: upper / lower alpha drive

the outer will seize in the t-plate sometimes thats why its a serviceable item. the outer comes with the bearing, change it out everytime. later service manuals changed from slots out to in to prevent this from ocurring. after all it is "preventative maintenance"
 

tystick

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Re: upper / lower alpha drive

To discourage anyone from changing out only bearing, notches should face forward?<br />Therefore the Mercstuff web site is not accurate or not up to date?<br />I guess that having the option is confusing as there are not many parts that have different recommended installation methods. <br /> Ironically, the printed manual is more up to date than a web site!
 

tystick

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Re: upper / lower alpha drive

Does the roller bearing retaining ring that is after the retainer stay loose until the yoke assembly is reinstalled into drive shaft housing?
 

Bt Doctur

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Re: upper / lower alpha drive

if your referring to the one with the large slots, yes. it what threads into the case and expands the "O" ring for sealing.
 
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