engine/trans id help

[achris]

Re: engine/trans id help

thanks I havnt pulled the drive yet I am going to go pick it up and pull it home next week. could the drive be locked just trying to get my ducks in a row. you said the possiblility of the drive being locked-up if this was the case would the prop behave as in i can put it in neutral and spin it i can put it in forward and it locks in place and the same with reverse.

thanks,
yonu

Looks like I have come in on this thread a little late. Let's see if I have this all right.

First off, identifying what you have. I think Bondo is right on the gimbal housing, it's definitely an early MC-1, '73 looks about right. The drive is either an 'R', 'MR', or Alpha One. You said you have the serial number from under the decal. Any chance of sharing? The other way to further narrow what you have it to split the drive (as you would for a water pump service) and see if you have a 'pre-load' pin in the top of the lower drive-shaft.

Engine. Ford. Looks like a 4 bbl carb, so if it's a 302, then it will be model 225. If it's a 351, then the model will be a 255. However, the 4 bbl 351 was never offered with the MC-1 drive. But that's not to say it hasn't been changed over the years. Those exhaust manifolds a certainly not standard. Anyway, measure the distance between the front intake manifold bolts, like BT suggested and post back.

Also as already pointed out, there is no clutch inside the engine flywheel housing. Just the flywheel and the coupler that the yoke from the front of the drive goes into. If you can turn the engine, then it locks up, you need to remove the drive. Once the drive is off, try turning your engine again.

Chris..........

Here's a video of how to remove the drive.

 

[yonu]

Re: engine/trans id help

soops i thought i had already posted pic of serial sorry

yonu

 

[thumpar]

Re: engine/trans id help

I guessed on a couple of the characters and came up with 0D421785 and it shows as R/MR ALPHA ONE STERNDRIVE

Is there a serial on the gimbal housing under the Mercruiser logo?

 

[yonu]

Re: engine/trans id help

sorry for the delay yeah I would say that is the right serial atleast that was what I came up with from the serial as well

quick question I am going to pull the outdrive this weekend to see if it is causing the issue and in the event it is I went ahead and started searching for a new/used sterndrive I found one local here it is a mc-1. I assume since I have the gimble housing for an MC-1 I can simply swap the alpha one back to an MC-1 correct.

 

[Bondo]

Re: engine/trans id help

sorry for the delay yeah I would say that is the right serial atleast that was what I came up with from the serial as well

quick question I am going to pull the outdrive this weekend to see if it is causing the issue and in the event it is I went ahead and started searching for a new/used sterndrive I found one local here it is a mc-1. I assume since I have the gimble housing for an MC-1 I can simply swap the alpha one back to an MC-1 correct.

Ayuh,.... No problem there,... Their direct swappin' sisters,...

 

[thumpar]

Re: engine/trans id help

Just make sure you get the same ratio drive.

 

[yonu]

Re: engine/trans id help

the ratio as in the lower unit or the upper unit and how do you tell?

Sorry,
yonu

 

[achris]

Re: engine/trans id help

Generally the ratio is controlled by the gears in the upper, but there are 2 different lower ratios too, but that would only apply if the overall ratio is 2 or 2.4... DonS created an excellent table showing tooth count and overall ratio... In the stickies...

http://forums.iboats.com/mercruiser...n-mc-1-thru-alpha-i-gen-ii-drives-586050.html

 

[yonu]

Re: engine/trans id help

ok real stupid question if I am swapping the whole sterndrive upper and lower would the ratio actually matter?

 

[thumpar]

Re: engine/trans id help

ok real stupid question if I am swapping the whole sterndrive upper and lower would the ratio actually matter?

Yes. It needs to be the correct ratio for your engine.

 

[84EdH]

Re: engine/trans id help

the drive ratio is a force multiplier, like gears in a standard shift automobile. if you have a big v8 engine, merc uses a 1.5 gear ratio, smaller engines need higher ratios for instance..1.98

this means the input shaft from the engine turns 1.5 times for every 1 turn of the propeller. for a less powerful engine, the input shaft (drive shaft of outdrive) turns 1.98 times for 1 turn of propeller.

 

[yonu]

Re: engine/trans id help

thanks yeah I knew about the multiplier thing just never gave it any thought heck never even thought much about it when I change the transmission in my car..

Ok according to the chart for my serial number alpha one I could have from a 1.32 upto a 1.98 since I don't have my drive handy to look at it in more detail how do I determin the ratio on the drive and how far with in that spectrum can i deviate.

Thanks,
Yonu

 

[thumpar]

Re: engine/trans id help

Well the 1.32 was used with the big blocks and the 1.89 is used with 4s. The chart is clear. An 888 uses a 1.50.

 

[yonu]

Re: engine/trans id help

Ok so 1.50 it is

 

[yonu]

Re: engine/trans id help

Well guys I want to say thank you asson as I pulled the outdrive the engine spun right over. just for good measure I placed a long probar in the ujoint and was unable to budge it to move I will be picking up a new/used drive in the morning. I am posting a couple pics of the inside of the gimble housing as I have a couple questions when I pulled the drive I saw the gimble bearing was shot so that gets changed however the ujoint bellow has no holes I can find but it is full of oil/water, sand and shell fragments wht should i check before installing the new drive. on the exhaust section of the housing there is a piece of rubber i assume this is the fragments of a shutter but I want a second opinion.

 

[alldodge]

Re: engine/trans id help

Yep looks like a piece of the exhaust flapper. Have to remove the exhaust elbows to replace, good idea anyway. Look down inside the y-pipe to see what else might be hung. I would recommend removing the gimbal housing and check the ring for play. You have gone this far just replace all the boots and be good to go.

 

[thumpar]

Re: engine/trans id help

I can see a piece of the shutters in there. I would just change the bellows if it was mine.

 

[yonu]

Re: engine/trans id help

ok by the boot i assume you mean the ones coming down from the exhaust risers? and which ring are you referring to?

thanks,
yonu

 

[yonu]

Re: engine/trans id help

I can see a piece of the shutters in there. I would just change the bellows if it was mine.

sorry your post came through while I was typing the last one. I had planned on changing the bellows just trying to figure where the oil/water and sand came from if there are no tears in the bellows

 

[alldodge]

Re: engine/trans id help

ok by the boot i assume you mean the ones coming down from the exhaust risers? and which ring are you referring to?

thanks,
yonu

The ring I mentioned is the gimbal ring. The pivot pin on top can get corroded and play can be felt. So while your in there just check it for wear.