DP-SM prop shaft seal and setting rolling torque?

[ChrisCraftFan]

So looking at the manual we need to set the rolling torque when putting the prop shaft carrier back in. How are you all doing that. I don't want to take the entire thing apart but I says that failing to set it back to what it was will change the gear lash and tooth contact pattern. neither of which sounds good to me? anyone know how to deal with that?

 

[dypcdiver]

You need a sensitive inch / pounds torque wrench and it is done on the input shaft, with the prop shaft pointing upwards best of luck.

 

[ChrisCraftFan]

I do have the torque wrench. so do you check what it is before you start and then just put it back?

 

[dypcdiver]

The manual is a bit fuzzy regarding the torque for the unit with seals fitted as it is all set up without the seals. Your choice!

 

[Lubak572]

When I changed the seals & o-rings on mine, I just put the housing back in and tightened it down. Probably not the correct way, but I had a VP mechanic tell me thats what he does.

 

[GeorgeDes]

Make sure you use a beam type torque wrench for this. A click type really won’t give the correct reading. An inch-lb beam type wrench can be bought at most bicycle stores or sports stores. As I recall the rolling torque value is in the DP-SM repair manual along with the gear paste patterns.

 

[GeorgeDes]

You should not need to concern yourself with the gear mesh patterns as long as you don’t mess with any of the shims.

 

[BRICH1260]

Can someone please explain "rolling torgue" and how it is measured. I have used many torque wrenches to install bolts, but cant figure out how "rolling torque" is utilized. Thanks.

 

[ChrisCraftFan]

Here is how i understand it. The Spanner nut retaining ring is tightened and you rotate the drive shaft. The retainer nut can change the lash and contact pattern of the gears Don't think it has anything to do with the shims at this point.
.

 

[GeorgeDes]

To determine the rolling torque you really need a beam type torque wrench. A click type will not work. What you do is put an appropriate size socket on the wrench and while turning the wrench in a smooth and even rotary motion note what the reading is on the beam. You may have a higher break away reading but what you want is the reading while the shaft is actually turning. Easiest way I can explain it.

 

[FormulaGust]

So I just went replaced the seals in the lower unit of my DP-SM but I was unable to split the upper and lower units apart. Would it be possible to set the rolling torque using the prop shaft? Has anyone else replaced the seals without splitting the cases?

 

[dypcdiver]

Simple answer to that is NO. Because you will be involving the seals and extra bearings and there are no torque settings for that.
If I was you I would split the units, when I split mine I found a lot of debris from the risers in there. Do you have the manual showing where all the bolts are between the upper & lower? Mine split with a gentle tap using a hide hammer after 20 seasons in salt water.

 

[blamtro]

You need a dial torque wrench:

 

[Lubak572]

I split the cases on mine when I replaced all the lower seals on mine. I could not isolate the problem first, which is the proper way. I had a little water in one drive. I have a mity vac hand pump that does pressure/vacuum. It will build pressure and vacuum when I block tube with my hand on both. But when I tried using the drain fill adapter I put the fluid in, my guage won't come off zero for either on the empty drive. I don't get it. I tried using both the bottom drain hole and the middle fill check hole. So I just changed all the lower seals. But I had to crank on that retaining ring using that special VP tool to get the bearing housing all the way in. There was a spec in other than the rolling torque one.

 

[Lubak572]

There wasn't a spec in the manual on how to do, other than the rolling torque one. The manual wasn't very clear on resealing drives IMO.

 

[FormulaGust]

I have removed all of the bolts (2) and nuts (4) that the manual specifies and nothing. I have used a little bit of heat and some penetrating oil and still nothing. I even used some wood and a hammer to try and split it.

 

[dypcdiver]

Sounds strange to me, I have just looked at mine and if you have the anode off, the area under that could take a piece of timber and then you could use something large and heavy to hit it with and not do much damage. Your choice.

 

[Lou C]

Don’t hit or pry anything. I came up with a way to do this by using some bolts in the lower drive mount holes and a piece of threaded rod in the trim ram rod holes. Then use 3 scissor jacks to push off the upper unit. One on each side under the trim rod holes and one in front under the bolts in the lower front mounts. This is for an OMC Cobra but the same strategy will work for an SX or Merc drive...

 

[Lou C]

Here's a pic...see the bolts and the rod through the trim ram rod hole...using the scissor jacks will separate the units with no damage....

 

[dypcdiver]

Nice one Lou C.