Volvo Penta outdrive is stuck on studs

[cobalt220]

1998 Cobalt 220 purchased used, two years ago.
Drive Unit DP-SM 1.95(M22)

I am trying to remove my vertical drive unit for maintenance of the u-joints, and replacement of the bellows.

I have followed the removal instructions in the volvo penta manual. The six nuts have been removed, the shift linkage disconnected, and the pivot rod has been removed from the vertical drive.

The drive seems to be fused to the transom bracket and will not break free. I have used penetrating oil and tapped the housing with a hammer.

It will not break loose.

The drive is supported by the eye bolt screwed into the dip stick hole.

Any advise on how to break it loose??

 

[Bondo]

Re: Volvo Penta outdrive is stuck on studs

Ayuh,... Hook the trim rams back up,+ see if they'll push it off...
The shaft is probably rusted Solid in the gimbel bearing...

 

[cobalt220]

Re: Volvo Penta outdrive is stuck on studs

I am not able to use the trim rams at this time, as the boat itself is still under shrink wrap. I wanted to keep the wrap on as long as I could. We have had some pretty serious rain events here in the last weeks, so I wanted to keep it snugged up until I am ready to break it out for launch.

I am not seeing any movement of the vertical drive. It is fused to the transom housing. The area where the vertical drive meets the six studs, shows no signs of moving - it is as if it is one piece of metal.

I thought of heating it, but wanted to save that as an absolute last resort, as I was hoping for some ideas that might solve my issue from my post.

 

[bruceb58]

Re: Volvo Penta outdrive is stuck on studs

You don't understand what causes these to stick. Its the driveshaft that is getting stuck. That joint that you are talking about is not your problem and no heating of it is going to help you.

 

[cobalt220]

Re: Volvo Penta outdrive is stuck on studs

Ok - so I have a frozen drive shaft.... ummm now what?

I don't want to think about what has to be done to gain access to it to release it.

Could someone explain what the process entails?

 

[Don S]

Re: Volvo Penta outdrive is stuck on studs

BIG Heat from an Oxy/Act. torch on the housing around the 6 studs. The drive has probably never been off, and they get corroded around the stud if not removed, cleaned, and greased every year or two. Look around the studs, is there a gap or is it filled with white corrsion?
There is not set way of doing things like this. however, there are preventive maintenance schedules that prevents these type problems.

 

[Lou C]

Re: Volvo Penta outdrive is stuck on studs

You might want to find a good Volvo shop to get it off for you because you might do more harm than good trying to get it off yourself...and then once it's off...follow the maintenance manual and remove it at the end of each season and do all the maintenance and you'll never have that problem again...

 

[cobalt220]

Re: Volvo Penta outdrive is stuck on studs

Don S.

I would agree with your advice. I presume that the outdrive has never been off the boat. There is white corrosion built up around the studs.

I was hesitant to agree with the frozen drive shaft theory, as there is no movement between the housing and the mounting flange. I would think the lash in the u-joints would provide for some movement, indicating the flange and outdrive housing is the problem, and not the drive shaft.

I had hoped there was a trick other than heat, that would have broken it free.

Thanks for the replies.

 

[Don S]

Re: Volvo Penta outdrive is stuck on studs

I would think the lash in the u-joints would provide for some movement,

There is no lash, (at least there shouldn't be) in the ujoints.

 

[cobalt220]

Re: Volvo Penta outdrive is stuck on studs

I was able to remove the pivot housing. The driveshaft slid right out, no water, no rust, absolutely clean. The U joints look clean as well.

The vertical drive is still bonded to the pivot housing. Heat application from a torch has not provided a release either.

I am contemplating carefully cutting the pivot housing away from vertical drive with a pneumatic disc cutter. It will obviously trash the housing, which is nearly $700 to replace, but I don't seem to have too many other options at this point.

The bellows were in good shape, as was the coolant hose. I could cheat and simply re-install the pivot housing and leave it bonded together, until the day comes when the bellows and or coolant hose need to be replaced, but I would rather get it straightened out now and not put off the inevitable.

 

[Don S]

Re: Volvo Penta outdrive is stuck on studs

Before you cut the bellhousing off, try this.
With a long brass drift, try to drive the studs and bellhousing off the drive. Hit each stud in a criss-cross pattern to drive the bellhousing off.

 

[dakine]

Re: Volvo Penta outdrive is stuck on studs

Here is what I would try.
Shock is required to bust loose the corrosion products that are locking the studs.
I would use a big air hammer in criss cross pattern on the studs with a brass drift or buffer plate to prevent peening.
The rapid blows of an air hammer often get results when the slower hits from a sledge do not.

 

[cobalt220]

Re: Volvo Penta outdrive is stuck on studs

Thanks to both Don S. and dakine, and PB Blast penetrating fluid.

I soaked the unit for 24 hours in PB Blast, which claims to penetrate just about anything. I then employed the suggestions from Dakine and Don and used a brass drift to impact the studs. After two hours of patient manipulation, the single piece is now two!

It was a great relief to get them apart. Thank you for the help.

 

[dakine]

Re: Volvo Penta outdrive is stuck on studs

Sometimes, not very often, brute force and ugliness is the answer