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400 upper reseal

smoky

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"Gentlemen, new to forum,new t

"Gentlemen, new to forum,new to boating. its snowing in Alberta right now so its a good time for me to post. I picked up a 17ft,'81 Tempest,3 ltr GM motor with an OMC 400 leg at a farm estate auction; the boat had sat for 4 years unused while the family settled the affairs. Its in decent condition for its age with only a few minor repairs needed, the biggest being a leaking output seal on the upper. I have purchased the oem manuel from Searay and have completed the tilt drive conversion to grease to this point. I have seen in other posts the mention of removing the leg without disconecting the shift cable in order to do the ball gears. Would this removal also allow one to then seperate the upper drive in order to access the lower seal or will the cable interfer? Also I see numerous cautions as to not damage the cable during removal, exactly what type of damage and where would the damage occur if it were to happen."
 
"[url=""]http://www.crowleymar

"http://www.crowleymarine.com/brp_parts/7087.cfm

Here is a good website for diagrams, you may have a hydro-mechanical drive.

And yes you can drop the lower without removing the cable.

Tilt the drive 10 degrees or so up and remove the 4 screws on the top of the drive, this will allow the lower unit with the exhaust to drop have a small table ,cooler or chair ready on the port side.Lay the drive on the table and remove the cotter pin holding the shift cable, to the lower.

Place on bench and follow the manual on how to replace seals in the lower.Word of caution shims are like gold, do not bend or mess one up.

To get to the ball gears, i rebuilt my lower, and and when the lower was off i pulled the water pump rebuilt that and then you will have access to the pinion gear nut. But that won't give you access to the drive shaft thru the intermediate.

You may be able to pull the upper ball gear and shaft if you tilt the drive all the way up, i lower the bow of the boat all the way down so the rear of the boat is way high. Will give you better access.

If you can't get the upper shaft clear, remove the rubber bumpers mark them so you can reinstall exactly the way you removed them, and remove the four bolts that hold the trunion caps, and remove the caps.. And lift the upper drive off, and place that on the table.

Please be very careful of the cable do not pull on it, moving the upper port 6 inch's will give you access to the drive shaft with the other ball gear.

Remove the screws that hold the water deflector and bearing holder, and pull the shaft out of the intermediate.

Now is a good time to inspect the splines of the shaft. Grease real real good the splines when reinstalling the shaft, After installing new ball gear.

Ball gear kits are available on e-bay $119.00.

When apart would be a good time to rebuild with new seals the upper as well.

To get everything back together reinstall the upper, on the trunion holders, line the truinion metal bushing with the openings facing the rear and reinstall the trunion caps.

Place the lower on the table and hook back up the shift cable and install the lower to the upper and , grease the trunion zerks. There is a zerk in a hole in the front of the drive half way up grease that its the exhaust, swivel.

Good luck !"
 
"Thankyou Chiefalen, Its the

"Thankyou Chiefalen, Its the upper that I need to reseal, the lower had been rebuilt by the prior owner. I am looking to do the ball gears as well so the trunion removal is what Im considering; what Im afraid of is damaging the cable becuase Im not clear of the range of movement possible before damage would occur. Im assuming when you say 6 inches port thats the limit of travel allowed; anything beyond that damages the cable? Also are we talking kinking it internally or pulling it free from a mounting? Also sorry for the delay in replying, the snow made for a bunch of sick cattle."
 
"[url=""]http://www.crowleymar

"http://www.crowleymarine.com/product_support/omc.cfm

Great site for diagrams and how too's.

You will notice they call for you to pull the lower cable, if you do that you do risk messing the cable up, and i still think you may have a hydro-mechanical drive.

Now my method bye the way i have used many times leaves the cable alone. I do not pull on the cable like a tug of war. i gently move it with the lower.

So i will go thru it again YOU ARE FREE TO USE ANY METHOD YOU DESIRE.

Remove the four top screws, the whole lower and exhaust will drop. Place on a table port of the drive. Do not pull on the cable be gentle.

see how the cable disconnects from the lower,you can disconnect it or not, what you want to do is lower the trailer bow all the way down and the drive tilted about 10 degrees up before you start you can acess the 4 bolts for the water pump, pull them. You can then rebuild the water pump, and pull the rubber bumpers and the trunion caps that you have marked becuase they must be replaced in the exact same location not switched or placed backwards, THE EXACT SAME LOCATION!

Now with the trunion caps removed you can turn the upper on the same table the lower is and pull the upper ball gear, and the ball gear that is attached to the drive sahft that comes out the intermediate.

I have done this many times before, read my previous post. the link will help also.

If you wish me to talk you thru it i will, call me anytime post here in the open forum, and i will give you my email and will email you my phone number."
 
"To reseal an upper, I remove

"To reseal an upper, I remove the drive so I can put the upper gearbox on my nice sturdy work bench.
The 2 most common leak points on the upper:
1. Steering shaft seal
2. o-ring around exh hsg cover because drive is not shimmed properly.

trying to replace the steering shaft seal with the upper on the boat would be kinda tricky for me, but to each their own method.

and #2 doesn't require resealing the upper at all. Just 1 o ring on the exh cover, and proper shims.

Pressure and vacuum test the best first step before tearing into anything."
 
"Hy Stat, since the boat sat f

"Hy Stat, since the boat sat for 4 years unused I knew seals could be an issue. the only leak is from the upper with the oil exiting through the small holes lower down the leg. once I saw the leak I put in some 140 gear and that runs out also. Im assuming the pinion seals are shot just by the volume of oil coming out and by the fact the oil leaks by gravity till its all gone indicating a leak low on the drive. Im also hoping Chiefs method allows the upper gearbox to be removed to a bench; its the cable that Im reluctant to touch. Ill start in on it once seeding is done,if I get in over my head Ill take Chief up on his generous offer. Thanks to you both ."
 
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