problem after diff drain/fill; funnel part fell in diff?

[mojoe]

Did a drain and refill on front and rear differential today on our 2016 Subaru Outback. First attempt at this for me, and everything went great until . . . I used a small funnel and plastict tube to refill the front differential. I had used it before to refill the CVT, worked great. The tube has a small black plastic tip on the end. This time, when I finished the refill and removed the tube, the black plastic tip didn't come with it. I stuck my finger into the fill hole and felt nothing. I shined a flashlight in the hole but couldn't see much. Poked carefully with a skinny screwdriver in with no results. Put the fill plug back in and drove the car for about 10 miles, ran great.

So, am I good to go, or am I in trouble?

 

[BobsArmory]

Well the gears will mash it up pretty good. Was it hard or soft plastic? I'd pull the cover and get it out.

 

[HemiBenny]

Well, since you’ve driven it, it’s mashed to pieces. Pull the drain plug and see what comes out.

 

[el Nuke]

Did a drain and refill on front and rear differential today on our 2016 Subaru Outback. First attempt at this for me, and everything went great until . . . I used a small funnel and plastict tube to refill the front differential. I had used it before to refill the CVT, worked great. The tube has a small black plastic tip on the end. This time, when I finished the refill and removed the tube, the black plastic tip didn't come with it. I stuck my finger into the fill hole and felt nothing. I shined a flashlight in the hole but couldn't see much. Poked carefully with a skinny screwdriver in with no results. Put the fill plug back in and drove the car for about 10 miles, ran great.

So, am I good to go, or am I in trouble?

If there were some sort of pump and filter that it could interfere with, I’d be more worried, but since it’s inside a differential, I would probably let it ride and move onto the next thing on my list.

 

[el Nuke]

I’m reminded of the infamous yellow plug thing with early 2000 Ford pickup transmissions. Evidently all these certain type of Ford transmissions they used in those Ford half tons had a little yellow plug installed on some internal opening on the valve body that protects it from getting foreign matter inside it during the build/install at the factory. And that plug is not removed once the transmission is built and installed into truck, so the transmission will go through its life with this little spinning-top shaped plug just rolling around in the fluid inside the pan. That’s a good way to know if a transmission fluid and filter on that transmission is the first that’s been done - the presence of the plug inside the pan when you drop it down to change the filter means it is likely the first time the pan has been dropped.

So if thousands of those Ford transmissions can operate for millions miles with that plug rolling around in the fluid, surely your differential can handle a small plastic piece doing the same inside its guts.

 

[HemiBenny]

@el Nuke is right, it’s not gonna blow your diff up if it’s a “small” piece of plastic.

Still, I wouldn’t have a problem dumping it and replacing it instead of having it floating around in my new fluid. Most of the mashed, chewed up plastic will probably come out with the fluid. I would think mashed up plastic would stay suspended in that fluid for a while before settling to the bottom. What’s the capacity on that front diff? ~1.5 quarts? No great loss.

 

[mojoe]

This is the funnel. They show the "tip" as a connector, to join two pieces of tubing; I was using it to get into smaller openings.

https://www.amazon.com/Franks-Funne...refix=funnel+king+transmission,aps,109&sr=8-7

 

[Japanese]

You just added extra lubrication in the diff. (jk)
Drain the oil, run it through a strainer or а cheesecloth. Pour it back, drain it a couple more times and run it through the cheesecloth/strainer. That should get the plastic debris out.

 

[Elkins45]

If it were mine I would drain it and refill. I would be very surprised if a little piece of plastic harmed hardened steel, but I wouldn’t continue to give it the chance.

 

[HemiBenny]

This is the funnel. They show the "tip" as a connector, to join two pieces of tubing; I was using it to get into smaller openings.

https://www.amazon.com/Franks-Funnels-Transmission-Funnel-Tubing/dp/B0D1K84XBF/ref=sr_1_7?crid=FBQHHSJB8FOL&dib=eyJ2IjoiMSJ9.MGMM00KriUe3fmBoSdyO1rrpl1lLYsVLcp-G4u1EaMI8k8F_yAo6Wr7EvLJRYQ3ULBvrNb6bajINyTKxEVzbmkhNdXzK6s7wVLHXU95G_ftK3riP-HNSUdVxB0abLTeF_FqhDKVG2XiHCLXlp6Ynlz4c4392SC1kUXGoudpfzT2V7rydItCOMIYjuRZFfTtEIP1j28ikWfkEchd24-Fzo5l3kowncZfUfNKgt73qUQN-KiPvopBlE1etYlhVoEW3Ys9Ealdtj3bnkXGMIef2I4EPtu9W0vJ7QE36A2X_JsY.VZCKBps3ITh4dhKkZ46OiQLsJuOcAd5u4Nby-fvgewM&dib_tag=se&keywords=funnel+king+transmission&qid=1763855656&sprefix=funnel+king+transmission,aps,109&sr=8-7

That’s a bigger piece of plastic than I was imagining.

Just drain and refill, or do as @Japanese suggested. (Get the foreign material suspended before draining by taking a drive around the block.)

It’ll be fine.

 

[dnewton3]

It's not the gears that are at risk. It's the seals ... If a small piece of plastic gets under the seal lip, or embedded into it, that could cause a significant leak.
I'd do some drain/fill cycles to make sure the remnants and bits are flushed out.

 

[Japanese]

So, am I good to go, or am I in trouble?

Forgot to mention to leave the drain open (with a pan underneath it) when you pour it in the 2nd and 3rd time, so the oil goes in and right out and it will be able to wash out some piece from inside the diff.

 

[mojoe]

I think I will just drain and refill. As HemiBenny points out above, capacity is only a hair over one quart. I've got it on the shelf, so no reason to take a chance. Besides, it won't take half as long as it did today, which was my first time. I learned a few short cuts, the hard way!

Thanks for all replies and suggestions!

 

[Chris142]

I’m reminded of the infamous yellow plug thing with early 2000 Ford pickup transmissions. Evidently all these certain type of Ford transmissions they used in those Ford half tons had a little yellow plug installed on some internal opening on the valve body that protects it from getting foreign matter inside it during the build/install at the factory. And that plug is not removed once the transmission is built and installed into truck, so the transmission will go through its life with this little spinning-top shaped plug just rolling around in the fluid inside the pan. That’s a good way to know if a transmission fluid and filter on that transmission is the first that’s been done - the presence of the plug inside the pan when you drop it down to change the filter means it is likely the first time the pan has been dropped.

So if thousands of those Ford transmissions can operate for millions miles with that plug rolling around in the fluid, surely your differential can handle a small plastic piece doing the same inside its guts.

Big difference between that plug in the pan where it can't go anywhere vs a ring and pinion spinning around

 

[D60]

It'll just extrude if it gets mashed.

A couple decades ago I did the same thing with a TTB front diff and the conical caps that go on gear oil bottles.

Many years later I had it apart and it had just wedged itself behind a ring gear bolt.

 

[mojoe]

Okay, I did another drain and fill, then strained what I drained through cheesecloth. Bits of what I assume to be the black plastic tip are evident (see attached); ground up really fine after about 20 miles.