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Oil seeping from outdrive into engine bellhousing

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V-P MARC

New member
I finally tackled what I thought was a rear main crank seal changeout on my AQ125A. When we pulled the engine loose from the 270 outdrive housing we saw milky oil draining down the outdrive casting. It was seeping between the PDS and what appeared to be an oil seal. I was able to wobble the PDS in the seal. My question is there a bearing just beyond the seal that I saw. Also should the PDS be straight going through the seal or have a little wobble? I have a Clymer V-P shop manual that diagrams the AQ280 unit. It shows the seal and what appears to be a bearing through which the PDS runs. It appears to be just beyond the back u-joint. BTW the rear engine seal was not leaking. But the pilot bearing in the crankshaft for the PDS was in bad condition. All info will be greatly appreciated. Thanks, Marc.
 
If you have gearoil coming in through the PDS seal you will need to reseal the upper gearbox on the drive. First thing would be to pull the upper gearbox and replace the PDS bearing and seals it could be just water getting in the bellows and making its way up the PDS due to a bad bearing. Pull the upper gearbox and pay close attention to the shims under the lower verticle shaft bearing. If your dont get water out of the drive when you drain it your probably OK. Replace the U-joints and PDS bearing and seals. It is easier to do with the engine out and get a new bellows and put it back together. While the upper gearbox is off pull the water hose and inspect the fitting on the fork for corrosion. Now is the time to replace it and the water hose with the upper gearbox off.
 
I replaced the u-joint bellows several years ago. When I remove the upper gear housing all the u-joints come with it best I remember. So it slips off the back end of the PDS, correct? Will I be able to pull the PDS out at that time and remove the bearing and seal?
 
Yes you need to pull the PDS and forward seal out the drive side of the flywheel housing. First you pull the aft seal then the two large snap rings and the PDS and bearing should come right out. It is easier with the engine removed to tap on the PDS with a hammer handle. I put a speedi sleeve on my PDS for the front seal as it was all pitted up I just used a old damper pully to press the speedi sleeve on and used some thread locker to fill the pits as I pressed it on. Does you flywheel housing have the grease zert on top for packing the PDS bearing?
 
Picked up a new pilot bearing and PDS bearing and seals for the AQ125A/AQ270. These bearings are not sealed. The ones I removed were open caged as well. Would it be a good idea to pack some grease into them before installation?
 
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Well, I got a new problem. I decided to change the oil seal in front of the first U-joint. I removed two allen head bolts securing the clamping ring to the upper gear housing. Could not get the other two to budge even with heat, so I drilled out the heads. Know I cannot separate the clamping ring from the upper gear housing. What could be the problem?
 
According to my manual the u-joint assm and clamping ring with the drive gear on the end should all come out together. An allen bolt is then removed to take the drive gear off in order to pull the splined shaft to get to the oil seal. I made a couple of separators out of 3/8" stud and two nuts. Put them on the bottom ledge of the clamping ring and other ledge opposite. Rotated the nuts outwardly to not avail. I cannot see anything internally that would keep that assm from coming out. Back to the shop.
 
Alas! Success! Ended up drilling the two bolts that I drilled the heads off a total of about two inches. The corrosion on those two bolts had a vise lock on the clamping ring casting. Bopped it around a little, sprayed a little WD and separation was achieved.
 
Be sure and check the rolling torque on the bearing box while you have it apart. Pay close attention to the shims under the sealing washer. That is the 270 drive correct? Make sure the preload is correct using the string pull method I dont believe you have the crush sleeve bearing box.
 
Marc, I know that you have most of this work finished by now..... but I'll go ahead and post to this thread in hopes that it may help others!


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V-P MARC said:
I finally tackled what I thought was a rear main crank seal changeout on my AQ125A. When we pulled the engine loose from the 270 outdrive housing we saw milky oil draining down the outdrive casting. It was seeping between the PDS and what appeared to be an oil seal. I was able to wobble the PDS in the seal. My question is there a bearing just beyond the seal that I saw?
Yes.... most likely an industry standard 6206.
About $14 for a good quality bearing from a local bearing supplier!

Also should the PDS be straight going through the seal or have a little wobble?
No..... there should be no wobble. If you can detect a wobble, this bearing is WAY past replacement time!


I have a Clymer V-P shop manual that diagrams the AQ280 unit.
Toss that Clymer book in the recycle bin, and pick up an OEM.

It shows the seal and what appears to be a bearing through which the PDS runs. It appears to be just beyond the back u-joint.
That would be the forward-most U-joint (bearing cross).

BTW the rear engine seal was not leaking.
I would suggest that you replace it none-the-less.
You do not want to be pulling the engine a second time just to replace this part!!!!


But the pilot bearing in the crankshaft for the PDS was in bad condition.
Marc, the pilot bearing (an actual ball bearing) is a carry-over from when this engine was used in the automotive application.
It does NOT need to spin or turn in the Marine applicaiton.... it simply "centers" the PDS!
In other words..... it could just as easily be a bronze bushing!
Click to expand...

V-P MARC said:
I replaced the u-joint bellows several years ago. When I remove the upper gear housing all the u-joints come with it best I remember.
So it slips off the back end of the PDS, correct?
Yes, when removing the "Transmission", the "universal shaft" will come out with the transmission.
The "universal shaft" female yoke will slide off the PDS.

Will I be able to pull the PDS out at that time and remove the bearing and seal?
AFT-most seal first.
Then remove both larger snap rings.
With any luck and no corrosion, the PDS and the bearing should come out!
Click to expand...

V-P MARC said:
Yes. And I realize now I have not been greasing it like I should.
When you grease the PDS bearing in the future, do so with the engine running at idle! Dynamic -vs- Static!
Click to expand...

V-P MARC said:
Picked up a new pilot bearing and PDS bearing and seals for the AQ125A/AQ270. These bearings are not sealed. The ones I removed were open caged as well. Would it be a good idea to pack some grease into them before installation?
As mentioned....... the crankshaft pilot bearing could just as easily be a bronze bushing. None-the-less, go ahead and apply grease to it.
As for the PDS bearing...... yes! Always Pre-Fill the grease cavity just prior to installing the AFT-most seal!
Click to expand...

V-P MARC said:
Well, I got a new problem. I decided to change the oil seal in front of the first U-joint.
I think that you are refering to the transmission's main drive gear oil seal.... correct?
If so, this is AFT of the universal shaft!

I removed two allen head bolts securing the clamping ring to the upper gear housing. Could not get the other two to budge even with heat, so I drilled out the heads. Now I cannot separate the clamping ring from the upper gear housing. What could be the problem?
OH BOY!..... this can get a bit complicated.
Heat is to be applied to the thread insert areas of the main gear case as to expand and help break/soften corrosion.
Just AFT of each cap screw head is a delicate shoulder.
This shoulder provides a water seal.
If you drill out the cap screw heads, you can easily damage these delicate shoulders, rendering the clamping collar useless!
Best method is a Good Machinist, a Milling Machine and straight flute cutter.

OK.... corrosion within and around the cap screw bolt shanks is preventing clamping collar removal.
If you end up with a damaged clamping collar, please note that when installing a NEW collar, you MUST re-calibrate shim values for both sides of the BB shoulder.
Click to expand...

V-P MARC said:
Alas! Success! Ended up drilling the two bolts that I drilled the heads off a total of about two inches. The corrosion on those two bolts had a vise lock on the clamping ring casting. Bopped it around a little, sprayed a little WD and separation was achieved.
Yep...... been there/done that many times over the years!
Examine the delicate shoulders very closely before re-assembly!!!
Click to expand...

kimcrwbr1 said:
Be sure and check the rolling torque on the bearing box while you have it apart. Pay close attention to the shims under the sealing washer. That is the 270 drive correct? Make sure the preload is correct using the string pull method I dont believe you have the crush sleeve bearing box.
Yes..... I fully agree!

Exhaust all efforts at polishing the seal surface washer before replacing it. Make Dang Sure that you polish the surface in a complete radial fashion!
You can easily remove up to .006" with no ill effects!
None of these seal surface washers are machined identically.... meaning that if you replace this part, NEW rolling torque values and shim values MUST be done!
Click to expand...

kimcrwbr1 said:
http://www.ebay.com/itm/Volvo-Washe...ash=item2cbed135b9:g:9gYAAOSw-3FZDnly&vxp=mtr
The shims under this washer control bearing preload because your PDS was probably flopping around you want to confirm the pinion bearings have the proper preload
I guess that I'm not following this one.

The seal surface washer contains the shims that control the Pre-A transmission Bearing Box Pre-Load for the main drive gear. (not sure what "pinion" is)
These shims are just AFT within this washer!

and be suree and replace all the O-rings when you put it back together.
Yes..... this is a must!
Click to expand...


And by the way.....

What some call a bell housing is actually Flywheel Cover in the Marine world.
The AQ series upper unit is actually a transmission.
The horizontal transmission gear is the "main drive" gear...... (not a pinion)
The two other gears are "driven" gears.
And lastly.... when we speak in terms of Port, Starboard, FORE and AFT..... we will all be on the same page!


I know..... I know..... I'm a bit anal re; this!


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Yes it is a 270. New u-joint spiders and two more seals on the way. Good thing I finally got going on this. A catastrophic failure in that driveline was probably not far off. I did go ahead and replace the rear crank seal and gasket. BTW the u-joint closest to the upper gear housing had broken and missing needle bearings. Thanks guys for all your expertise and info. Marc.
 
I have pinion stuck in my head because the bearing box is exactly like the pinion on the rear axle of my truck except it uses the crush sleeve for bearing preload. You should be OK but do the pull string test once you torque the yoke to spec. I just used a spring type fish scale the 270 calls for 1.1-2.2 lbs on the string to spin the bearing box on my sp-a mt.
 
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My u-joint spiders are Detroit 2266909. What is a replacement for that? I ordered Spicer 5-789X 7260 series which they said replaces 5-106X. I don't think they will work.
 
The dimension between the outer edges of the snap rings of the 5-1306X and the 5-789 is supposed to be 2.125 according to Spicer literature. The 5-789s that I have measure 2.165. Is that why they were on ebay?
 
Well, I guess that's a false alarm on the u-joints. They are installing just fine. Wasn't sure if the snap rings would seat but they did.
 
Well, I guess that's a false alarm on the u-joints. They are installing just fine. Wasn't sure if the snap rings would seat but they did.
 
If the bearing cross trunion caps are clipped at the inside, you'll want the Spicer 5-1306X........ or equivalent!


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