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Pulling Duro Props - oil change

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I'm pulling duro props to get to the drain plug so i can change the lower unit oil.  ( let me just say are they kidding !!! )  Does anyone have a trick or tip to help me. I've purchased the nessary O rings and tools.  When i tried to get to off but they seam to be on there to stay.

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Lets start with the basics and work thru this. First of all it`s "Duo" Props, as in two. Second you will need a special set of wrenches, commonly sold in a set to get the prop nuts off, they are different sizes. Do you have that special wrench? If not check on ebay. Have you been able to get the nuts off?

If you have been able to remove the first prop nut, smaller one, but the prop will not come off, it may be seized to the shaft. You will gingerly have to pull, tap, persuade it off the prop shaft without damaging it.

Give us a little more detail as to exactly where you are in the process and we`ll work you through it.

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Thanks for the correction.  

 

I was able to pick up the special wrench, O rings and proper lube from the local Volvo dealer.  No the issue starts with I can't get the first nut off.  

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1 hour ago, Thumb520 said:

Thanks for the correction.  

 

I was able to pick up the special wrench, O rings and proper lube from the local Volvo dealer.  No the issue starts with I can't get the first nut off.  

Ok. Have you put the drive in gear to prevent the propeller from turning with your torque? Does the handled (smaller) wrench fit tightly over the first nut? If so, you may have to slip a small hollow bar over the handle to get a little more leverage. I'm not sure what size the nut is, but should be a common size mm, you can use a traditional socket and breaker bar on it if needed. You might squirt some break free on the threads and see if that helps.

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Gingerly will not help.

dont waste your time....you need a puller.

they tend to lock up if they are not pulled and greased.

I do mine quarterly.

 

 

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When we. A group of boaters get a tough nut?  WE jam the prop with a lifting strap around the blade at the 12 o clock position. the strap is chained on to a truck trailer hitch ball.

Bring over the air operated IMPACT driver. 1 second later the nut is off.............. Drive is in neutral. Check  the impact driver IS SPINNING in the OFF direction....FIRST  !!!

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You need a pump you fill from the bottom,Walmart sells the lube pump screws right into a quart jug.   The first time I did it the oil was very very black the previous owner relied on his marine for work.   Well since the props did not come off with out a puller I don think they ever did it, so I then ran new oil and flushed that out, now I do it every year at the end of the season.

 

 

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jds  brings up a common problem with those buried drain plugs.  Screw doing them by a new  fast food hamburger flipper.  Now working at a marina. Or even a more experienced marine mechanic trying to make as much money as fast as possible.  Burying them is a SURE WAY to cause damage to the lower drive parts in my opinion.  It is a factory designed way to increase dealer & marina profits. ......Those seized on props ?   Also totally designed in by the company. In my opinion.  Our club  members with Mercs have never had those problems.

Even the DIY guys who DO NOT grease the shafts. For whatever reason.   The props come right off. Worst case is a clamshell gear puller with a little force applied. Still a piece of cake job.

Only REALLY TIGHT PROPS ??  Are on the thru the bottom of the hull racing inboard engines. They use a Marine Taper end of the drive shaft. The guys bring over a STRONG person to tighten the daylights out of the double nuts forcing the prop tighter onto the tapered shaft with a keyway.  Totally unneeded.

Almost always a Clamshell Gear Puller job. We have had to remove the prop & shaft together. Then ship it to a BIG hydraulic press place to get them apart.

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Product Details volvo prop wrench tool

Product Detailsthis may require an adaptor to match threads

Product Details30 mm socket

Product Details 1/2 drive torque

Product Details block of wood

use the 30mm socket w/ a larger wrench (1/2) or bigger to break the rear nut first.  i use a block of wood while drive is in neutral - wedge the wood between the props and housing - don't use the prop tool as the shaft will bend, use that tool for hand threading or taking off after the nut is broken loose.  then remove the rear prop, use the prop tool to remove the front prop nut, remove the front prop and clean the prop shaft and re-grease.  reverse the order  (torque the rear prop to 50 ft.lbs or 70 N-m whichever your torque wrench has shown on it.  the lube oil screw or hex nut can be removed.  I would suggest purchasing a few extra of these just to have - (8mm allen wrench)  - Tip - remove this drain/fill first as there is still a vacuum on the drive and you will not make as much of a mess.  once the screw is out, have a drain pan under the drive and remove the dipstick on top, and the vent screw on the side of the drive, you will need to take the cover off.  do all this while the drive is up first, then when screws are removed lower the drive for draining.  

insert the fill tube - i have an adapter for mine to match the threads.  screw it in and hand pump in the new drive fluid until it comes out the "vent" hole - not the dipstick - screw the vent back in and the dipstick first, then raise the drive and remove quickly the drain fill hose and screw in the plug.  grease the shaft and put the props back on.

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no pins, just use a heavy duty socket and wrench to break the rear nut loose and not the flimsy prop tool wrench.

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You will not be able to use the 30mm socket on the front (larger) nut as it is a different size but also primarily because it must fit over the inner shaft and will not be deep enough. You might measure and look for a large open box wrench for that or a large crescent wrench.

The main thing to learn after you have changed the oil is to annually lube the prop shafts and threads so that next time everything comes off much easier. Maybe even with the prop tool.

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i able to pull the props off.  The tips made all the difference.  Now I'm facing the impossible screw ( who does this, put a hex nut or bolt !!) Any tips to get this loose.  I'm now soaking with liquid wrench, and I hit i with an impact screw driver. 

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If it is NOT LEAKING oil at all ?  Leave it alone.  I usually drill & tap a NEW hole with a EXPERIENCED MECHANIC beside me to pick the lowest part of the CHAMBER.  He WILL know the best place to drill into. Allowing space to drill & tap easily.

Use  A NEW drill bit to make the hole. Have the tap ready to use. A oil drip pan is NEEDED under the drill hole spot.

DO NOT remove any of the oil in the gear case. The goal is to drill the hole. Quickly tap in the threads. REMOVE THE TAP. We used a BOTTOM TAP.   Run the correct screw in & out of the hole.......

The now OPEN THREADED hole will cause the nearby tiny chips to flow out. If the oil stream looks too slow or odd shaped ?  Have a very small diameter drill bit ready to wiggle the chip free to flow out.   This fix does work.  If you are not happy?  put the NEW factory screw into the hole & refill.  Remove the drain screw again.  Done.  I / we have done this enough times since I was about 25 to know it does work.

Or have the prop shaft removed & drill & tap.  Your call.

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3 hours ago, Thumb520 said:

i able to pull the props off.  The tips made all the difference.  Now I'm facing the impossible screw ( who does this, put a hex nut or bolt !!) Any tips to get this loose.  I'm now soaking with liquid wrench, and I hit i with an impact screw driver. 

 

Glad to hear that you got the props off. Volvo used three types of screws there, slot, nut and hex, you. Have a hex head?

I would suggest utilizing the hammer driven impact unit and adapting it somehow to fit the size screw fastener that you have. Mine is slotted and I have to use an impact driver to loosen mine. Hang in there, just try not to damage what you have. The impact along with a proper fitted socket should get it. Keep us posted.

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