DP-SM won't shift in to FWD or Rev.

[Lubak572]

Got both drives off and on stands. 1 didn't have reverse last year thought it was new cable I installed that was misaligned. When shifting by hands feels correct but doesn't link up input and output shafts at all. I hit something in water and bent prop when I lost all gears. Trying to isolate problem- shifter fork or cone clutch? Any ideas?

Also how important is vacuum test? I see a lot of guys just pressure test. My other drive passed both pressure tests but leaked slowly on vacuum tests. I did per VP service manual. At 5 inches of vacuum lost an inch in about 10 minutes and at 15 inches lost an inch in 2 minutes. I did not do the heavy oil part to isolate.

 

[Lubak572]

 

[dubs283]

Likely broke the coupler between the upper/lower units when you struck something with the prop. Coupler is designed to fail. Have to split the drive to inspect/replace

You need to check the prop shaft runout as well. Volvo has a pretty tight tolerance, like .003" or something ridiculous like that.

A sound sealed drive will always fail a vacuum test, the yoke seal is a vacuum break seal for when the drive cools down after use

 

[Lubak572]

How hard is the coupler replacement job? I have split the drive before and changed water pipe and seals. Wondering if I can tackle myself.

So your saying not to worry to much about a slight vacuum leak?

 

[dubs283]

If you've split the drive before you've seen the coupler. Its between the upper/lower driveshafts

I'm saying you should worry if you don't fail a vacuum test.

 

[Lubak572]

If you've split the drive before you've seen the coupler. Its between the upper/lower driveshafts

I'm saying you should worry if you don't fail a vacuum test.

Is this what you are referring to?

 

[dubs283]

Yes