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Got into a discussion about this on my DRZ 400. i started using them because i don't like waiting for shipping, and my local dealership is woefully understocked on everything.

my thoughts:

 "Ripping----- 09168-12002 washers from TT. Napa filter ps7931.

Ivan- the deal with the washers isn't about leaks, it's about not breaking the engine case. If you re-use a washer gasket or in your case use a nylon washer that will compress the threads pull in so far that it cracks the engine case.

Yes, except nylon is weaker than the metal the engine is made out of, and therefore it will crush and compress first.

http://en.m.wikipedi...ecific_strength
http://en.m.wikipedi...ensile_strength

The tensile strength of nylon is 45. Breaking strength of 78.

Even magnesium has a higher strength rating. So, by laws of physicsicon1.png, nylon will break, compress, wear, grind, and deform before iron,magnesium, steel, or aluminum. For a washer that is going to be constantly replaced, i think this is a good substitute.

The nylon washers comes off well wore out, crushed just like a crush washer, and needs to be changed. I used a rather thick one, and i've re used it on two oil changes, each time it comes off it is thinner. This'll be the last oil change it makes it through. It wont have enough nylon left to give anymore. This behavior of the nylon further proves that physics is right: the nylon is giving way before the metal, deforming into the shape between engine and bolt, and thus creating a seal. "

 

am I thinking along the right lines here? is there something I am unaware of that i am not seeing? i know many cars and heck, even my fathers lawn mower use nylon washers for oil drain plugs. the DRZ has already proven to be woefully under-engineered, and so I care less for an OEM solution. If anyone has any more info I would love to further discuss the benefits / ill effects of using a nylon washer rather than a crush washer.

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Ivan / all,

 

As long as you do not exceed the manufacturer's specified torque for the drain plug, you will not risk damaging the threads or the engine case.

 

You should be able to use copper, aluminum, nylon, neoprene (rubber), or composite washers. Some materials will seal better than others.

 

The only real concern is that you do not have a big leak that would risk running the engine without lubrication.

 

Torque is the measure of resistance to turning, and it is this value that you should follow when tightening not only the drain plug, but for all fasteners.

 

 

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Whoa dude you are looking way to deep into this.  Nylon washers work fine on drain plugs but they will split eventually.  This happens while tightening it so you will know right away.  If you want something fancy try a dowdy washer.  It's an o-ring bonded to the inside of a steel washer, rated for 10,000 psi.  The buna-n ones harden up over time but if you can find a Viton one you will be set for life.

 

Oh and don't torque your drain plug to spec.  35ftlbs is way too much keep it to 10-12 and you won't strip threads or break bolts.

Edited by 1987CR250R

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robb5, on 21 May 2014 - 6:52 PM, said:snapback.png

Ivan- the deal with the washers isn't about leaks, it's about not breakingicon1.png the engine case. If you re-use a washer gasket or in your case use a nylon washer that will compress the threads pull in so far that it cracks the engine case.

 

I'm sorry, Robb5 but your statement is incorrect.

 

You are assuming that Ivan is exceeding the specified torque for the drain plug.

 

Washers provide a BEARING SURFACE for the fastener - they distribute the load that fastener is exerting on the engine case, and they also keep the underside of the drain plug (flange) from galling the material of the engine case when the fastener is torqued.

 

You can test my statement - take a piece of plasti-gage and place it under a plastic washer, and torque the fastener to specification. Now do the same with a steel washer, and torque it to the same specification. The two pieces of plasti-gage will compress to the same thickness and indicate the same torque.

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The problem with plastic is it is affected by heat, can split which will reduce sealing pressure and not have the plasticity that copper will.

 

Different composites (plastics) have different melting points - most (that would be used for this application) will not begin to soften until you exceed 300 degrees F.

 

Yes, the engine case gets hot - but should not be anywhere near 300 degrees F. If it does, you have other problems!

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Copper washers should be available at any auto parts, industrial bolt/fastener store. Totally irrelevant whether it is for a Ford, Caterpillar or Honda. Too much thinking is just that.

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What the person warning about cracking cases might be trying to say is that he thinks that an excessively crushed nylon washer will allow the drain bolt to run too deep into the threads to the point where they wedge into the bottom of the threaded portion of the hole, then causing a crack.  This may or may not be possible on the DRZ, but it sounds a little far fetched.

 

Nylon washers are a poor choice because they aren't stable with respect to compression under normal circumstances that can exist on motorcycle engines.  Copper, aluminum, or the aforementioned Dowdy types will hold the prescribed torque reliably.  At issue in this is the simple question of whether or not the drain bolt will stay in place, or vibrate out when the going gets tough.  As far as replacing them all the time, why?  I know "the book" says you should, but if they're in good shape, and they don't leak, why bother?  I probably reuse copper washers on my own stuff 10-12 times before replacing them.  No problems.

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What the person warning about cracking cases might be trying to say is that he thinks that an excessively crushed nylon washer will allow the drain bolt to run too deep into the threads to the point where they wedge into the bottom of the threaded portion of the hole, then causing a crack.  This may or may not be possible on the DRZ, but it sounds a little far fetched.

 

It's a known "issue" on the DRZ when using the stock crush washer, which is cone-shaped (and not flat like your typical crush washer).  What happens is either the owner reuses the crush washer too many times and/or over-tightens it.  The crush washer wedges into the chamfer at the entrance of the threaded bore and acts like a wedge… With enough torque… crack, there goes your sump drain.

 

crankcase-drz400-crack.jpg

 

^ damage

 

0515001345.jpg

 

^ stock DRZ crush washer

 

Me, I always use a new flat copper or aluminum crush washer (their cheap) and I tighten them by hand till I feel a little give (washer crushing) and stop… same method whether its a car engine sump, diff, trans, etc…

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A lot of hydraulic fittings use o-ring boss fittings.  In o-ring boss the hole is counterbored and an o-ring sits in the male part of the thread.  You could probably replace the conical washer with an o-ring and no longer have this problem.  In fact, the o-ring in an o-ring boss fitting looks just like that washer after taking a compression set.

Edited by 1987CR250R

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Seems like this would be an easy question to answer by threading the plug in by hand with no washer and seeing if it bottoms on the flange. :excuseme: After that, material shouldnt matter as long as it seals and holds tight. Nylon does squish and split easier, which IMO is only a reason to have spares.

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I recently got a pack of Pro-Bolt nylon washers to try on a oil drain bolt for my YZ450F, since the left oil drain washer surface has been somewhat damaged from a repair. I had an outer piece of my Time Sert repair threads break off in that oil drain, leaving the washer surface not completely smooth. The inner part of the washer surface on the crank case has a very small jagged section, or raised "ridge" on it, enough that it will leave a small indentation on any washer I use on that drain bolt. It has a slow oil leak because of this. I can ride the bike, but I stick a peice of foam under the drain bolt to see how much oil is seeping out and constantly check it.

The nylon washers didn't stop the oil leak, even tried using 2 of them. Also tried an o-ring and that might have helped a little, but didnt stop the leak. I even looked into ways to smooth out the washer surface on the crank case, but it seems like it would be too difficult and risky. I am trying to figure out what to try next, and it would be nice if I can fix this without having to use a gasket maker on the washer every oil change. I'm wondering how a dowdy washer might work, and doing research I came across this thread and saw the DRZ crush washer and other aluminum crush washers. I'm wondering if this could be the answer....do you guys think it's worth trying? Is the DRZ washer the right size for the YZ's M8 drain bolt? If not the DRZ washer, what other aluminum crush washers are out there that might work? I'm thinking it might help to have a bit of a softer washer so it will form an even better seal.

I was getting ready to lean the bike over again so I can pull out the drain bolt and finally try a gasket maker. I have Threebond 1211, which should be one of the best for this application right? I know it works great from everywhere else I've used it, but have never used a gasket maker on an oil drain. I also have this AGS oil drain thread sealant which I haven't tried yet. I heard to be very careful using anything on oil drain threads as it could get into the oil. Pictures:

20180704_131042.jpg.120293bf8bb0bb57da1cb7d3858d8e49.jpg

20180704_131057.thumb.jpg.1b0c918185e4cb624bcecdb4394de9b6.jpg

The oil drain with the outer portion of Time Sert threads broken off, can't really see the little jagged area on the aluminum but you can see how there is less surface area for the washer to seal:

5b3eaede3b2a2_20171020_195057(2).thumb.jpg.30342bef46560b1a751dde87bc7b7f9e.jpg

Please let me know what I should try or what might work the best to stop this oil leak.

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Bump   ....any thoughts on my drain plug washer issue?

I know this is a simple thing to fix. I'm thinking I should get a pack of flat aluminum drain plug washers that say they're softer than copper:

https://www.denniskirk.com/bolt-motorcycle-hardware/aluminum-m8-drain-plug-washers-dpwm8-15-10.p141227.prd/141227.sku?utm_source=google&utm_medium=cse&gclid=Cj0KCQjwyYHaBRDvARIsAHkAXcs-Cv4RLSaYlq4Zpvrf5fPXueNlRPlv1bvjfLs6B-HolIWTHRvyl8YaAq5kEALw_wcB&ad=244288898358

and most likely use some high temp silicon (threebond 1211?) on one or both sides of the washer. Otherwise some kind of "cone" drain plug washer like for the DRZ. What would be the best option with the drain plug washer surface on my bike being a little messed up?

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Bump   ....any thoughts on my drain plug washer issue?
I know this is a simple thing to fix. I'm thinking I should get a pack of flat aluminum drain plug washers that say they're softer than copper:
https://www.denniskirk.com/bolt-motorcycle-hardware/aluminum-m8-drain-plug-washers-dpwm8-15-10.p141227.prd/141227.sku?utm_source=google&utm_medium=cse&gclid=Cj0KCQjwyYHaBRDvARIsAHkAXcs-Cv4RLSaYlq4Zpvrf5fPXueNlRPlv1bvjfLs6B-HolIWTHRvyl8YaAq5kEALw_wcB&ad=244288898358
and most likely use some high temp silicon (threebond 1211?) on one or both sides of the washer. Otherwise some kind of "cone" drain plug washer like for the DRZ. What would be the best option with the drain plug washer surface on my bike being a little messed up?
The DRZ washers are 12 and 10mm.

You need to get a flat honing stone and flatten the surface so it will seal. It's a rather simple fix.

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On 7/10/2018 at 4:09 PM, ohiodrz400sm said:

The DRZ washers are 12 and 10mm.

You need to get a flat honing stone and flatten the surface so it will seal. It's a rather simple fix.

Thanks. How big/small of a honing stone, so it will fit in the space between the left engine case and the frame rail? Where can I find/order one?

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You are going to have a very hard time stoning the opening square to the threads. If it is not square, it to still going to leak.I'd source a oring washer.

My Kubota tractor uses them. I bet the oil drain on my BX25D is the same size. Suzuki does too but they are very small (just 6.mm). Dorman sells them as well (any auto parts store).

164850seal%20washer%202.jpg

 

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We have small stones at work that would be perfect. They are about an 1" wide by 2.5. - 3". You would probably have to pull the motor or at least rotate it up to be able to hold it flat against the surface. All you need to do is knock down that ridge that is holding the washer up.

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On 7/13/2018 at 8:06 AM, William1 said:

You are going to have a very hard time stoning the opening square to the threads. If it is not square, it to still going to leak.I'd source a oring washer.

My Kubota tractor uses them. I bet the oil drain on my BX25D is the same size. Suzuki does too but they are very small (just 6.mm). Dorman sells them as well (any auto parts store).

164850seal%20washer%202.jpg

 

Thanks for the recommendation, it saved me a lot of time. Got a M8 o-ring washer from Napa and at first it leaked a few drops of oil while the bike was running, but now it doesn't leak more than a drop if anything. I assume these should be replaced every oil change

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On 7/13/2018 at 10:06 AM, William1 said:

You are going to have a very hard time stoning the opening square to the threads. If it is not square, it to still going to leak.I'd source a oring washer.

My Kubota tractor uses them. I bet the oil drain on my BX25D is the same size. Suzuki does too but they are very small (just 6.mm). Dorman sells them as well (any auto parts store).

164850seal%20washer%202.jpg

 

:thumbsup::thumbsup: Never knew those existed.

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