U-Joint "Cross" parts for Alpha 1 Gen II - what part do I need

[MajBach]

Hi again. So getting back to my Mercruiser (2002 5.0L Alpha One Gen II). I've been procrastinating on changing the U-Joints for some time now. Over the last three seasons, there's been a developing clicking noise when turning all left/right. I went to order the parts today but damn...so many choices.
The first parts diagram I saw had the 'cross' (2 of them) as two separate parts numbers; one was for internal snap rings and one for external seen here:
http://www.boatparts.ca/mercruiser-alpha-1-gen-2/upper_gearcase_1998_up.html

iBoats is even more confusing:
http://ww2.iboats.com/Mercruiser-Al...5703141--session_id.960814166--view_id.272968

So, the questions I have are:
1. Are both crosses the same?
2. If so, does this mean I have an option on what kind to replace them with?
3. What are the advantages of one over the other (aside form the fact that one is like a fifth the price) and,
4. Do you need to change the yokes as well? I posted pics of my U-Joint when I first inspected them a couple of seasons ago and found no play or wear spots yet I was assured by the old salts here that my issue was in fact the U-Joints, So, if there is no sign of play or wear, then how do you know what pieces are in need of replacement?
Thanks a heap

 

[alldodge]

There are 2 types of joints used, ones with internal retaining clips and ones with outer retaining clips. Those with grease fittings and those without

Its easiest with serial number of the drive. Your first link does list them


https://forums.iboats.com/forum/engi...umber?t=238091

 

[harringtondav]

The iBoats diagram shows the correct U joints for your 1998 (0L100040 and up) drive. 758321T1 is an older version, and 865496A1 is for Bravo drives.

So 805536A 2 and 18-2097 are your U joints. The less expensive Sierra is identical to the OEM, and what I've used with no problems.

Both are 'permalube'. They come with a pipe plug to replace the grease fitting. The come with only a touch of grease, so I pull the caps, fill them with a good grease (Penzoil red synthetic) and push each cap back on until the grease bleeds back through the hole. Then you can either plug it, or install an included grease fitting.

 

[Stinnett21]

I have the same drive as MajBach, 2002 A1 G2 serial OM424120. How do you pull the pipe plugs? They look like a solid piece of metal with nothing to grab onto.

 

[Stinnett21]

harringtondav, can you elaborate on how to remove the plugs? I have my drive off and would like to explore this option before spring. Thanks for any responses.

 

[Chris1956]

When I replaced the U joints on my Alpha I Gen I, I took the old ones to the auto parts store and let them match 'em up. The races and bearings were a different size from OEM, but the outside of the u joint was identical to the OEM. The price was about 20% of OEM.

 

[MajBach]

You guys rock! Thanks
One unanswered question - if you don't mind: Do the yoke arms ever need replacing or is is it always just the cross?

 

[alldodge]

Rarely would the yoke need replacing. When it happens its either been damaged do to abuse or sealing surface is worn and speedy sleeve will not fit

 

[MajBach]

Rarely would the yoke need replacing. When it happens its either been damaged do to abuse or sealing surface is worn and speedy sleeve will not fit

Sorry to bug you again but I've been reading some of the links posted on this thread in an attempt to better familiarize myself and save future inquiries on topics asked about a billion times already.

So, for sh$ts and giggles I went to the mercruiser.com site and wholesale marine site and entered my drive number (0m407084).
The Merc electronic parts catalog shows three parts #s for the cross (805536A2 865493A01 865496A02) without really stating what the difference is. The wholesale marine parts cat displays 4 rows of styles for the Alpha One and I would assume that mine falls into the last category

Alpha One Gen II

OL949779 & Above

Following through with that is shows that the u-joint I require is Sierra 18-6406 U-Joint (the row above it shows the 18-2097 you mentioned.
Why is this so difficult for me to grasp? :facepalm:

 

[alldodge]

With your serial number you should have external clips which is last pic, do note the clips

805536A2 have internal clips Gen 2 GLM 28040, Mallory 9-72406, Sierra 18-2097



865493A01 have external clips replaced by 865496A02 (same part) or Sierra18-6406
Alpha I Gen II 0L949779 & UP - Bravo 0M111208 & UP

 

[MajBach]

With your serial number you should have external clips which is last pic, do note the clips

805536A2 have internal clips Gen 2 GLM 28040, Mallory 9-72406, Sierra 18-2097

Your patience is to be admired.
Why does that second one have so many c-clips?

BTW, I just dug up a pic I took when last I had the unit apart..go figure.


Nothing has ever made sense with this boat. I've run into the same problem with the engine serial number and serpentine belts etc. But, even if it was totally misrepresented and put together from parts from a scrap yard, it's really never given me any issues.

 

[alldodge]

Why does that second one have so many c-clips?

Don't know, just one I found to show the external clips.

Looks like you need internal clips, and your drive was probably replaced, or at least the upper section and/or drive shaft

 

[harringtondav]

harringtondav, can you elaborate on how to remove the plugs? I have my drive off and would like to explore this option before spring. Thanks for any responses.

If yours are Merc factory original, you can't remove the plug. But you can still add grease by pulling the caps, filling them one at a time and pressing them back on. You'll see the grease start to ooze back through the trunion cross drilled holes.

Both the Merc and Sierra replacements include a pipe plug. You can add your own grease fitting if you want. I recall the Sierra comes with both pipe plug and grease zerks.

 

[harringtondav]

When I replaced the U joints on my Alpha I Gen I, I took the old ones to the auto parts store and let them match 'em up. The races and bearings were a different size from OEM, but the outside of the u joint was identical to the OEM. The price was about 20% of OEM.

Spicer and others make unis that will fit the yokes, but their trunion/needle bearing is .6" diameter or less. The Merc and Sierra's are .7" dia. 36% more bearing area which is critical when you're trimmed full down in a hard power turn. That is why the Merc is called "Heavy Duty"

The Merc uni is around $83. The Sierra is $61, 35% less than OEM Merc

 

[Stinnett21]

Thanks harringtondav!