P500 Pioneer 500 rear differential

[skinnyman]

I am looking into two issues my Pioneer 500 has. First is rear differential gear whine, the second is metallic looking rear diff fluid.

The 500 has had both issues since day one of my ownership with 26 miles on it.. I changed all the fluids same day I brought it home just like every "new to me" toy that I get. I found that the rear diff fluid had a metallic look to it. From forums I have read this is termed "Honda Gold" and to some is normal and don't worry about it. The front diff looked clear (clear meaning no metallic look) as well as the engine oil. I have been changing the rear diff every 50-75 miles since. Unit now has 600+ miles. Just drained it the other day and it looks the same as it has been.

It was mentioned to me the rear diff may need shimmed. I studied the service manual and decided to check what I can without removing the rear differential from the 500.

I checked the gear pattern first and to me it looks close compared to the service manual "pictures." I will attach pictures though not the best.

I then checked the backlash per the service manual procedure, three readings 120 degrees apart. Here they are..008,.008,.013. I did it once more,008,.010,.015 and again for fun,.009,.015,.008. Specs are .002-.007,service limit is .020. Measurements are in inches. I will attach pictures.

The "Gold" dust doesn't seem to be attracted to a magnet so I guess it is not steel. It looks like ,well, gold dust about the same amount each time I change it. I am including some pictures for keen eyes to see.

Has anyone been to this point? First pic is Honda gold.

 

[Admin]

 

[alloutdoors]

I will be interested in others chiming in, but my gut tells me just change the oil and enjoy the unit. I have owned multiple 500 units and the driveline is noisy, but it does get better with miles.

 

[NitroxDiver]

When I drain my rear diff on the p5 it often looks like it has glitter in it but it’s just air. It’s very hard to tell what you have in your oil from the picture but have you let the oil sit for some time after draining to see if it clears up?

 

[skinnyman]

I have seen the air bubbles you mention. There are not many and those are easy to see.. Clicking on the picture to enlarge it helps to see the metallic looking dust. I have let the fluid set overnight in the drain pan and the dust does settle some to the pan but most stays suspended in the fluid. In other words its still there. Thanks.

 

[Fischer]

I have seen the air bubbles you mention. There are not many and those are easy to see.. Clicking on the picture to enlarge it helps to see the metallic looking dust. I have let the fluid set overnight in the drain pan and the dust does settle some to the pan but most stays suspended in the fluid. In other words its still there. Thanks.

Did you buy it brand new? What's the rust color on your gears?

 

[skinnyman]

Bought it used, with 26 miles. I don't know about the rust color. Wouldn't it be great if that was it, rust ,LOL.
I thought about sending in an oil sample.

 

[NitroxDiver]

Bought it used, with 26 miles. I don't know about the rust color. Wouldn't it be great if that was it, rust ,LOL.
I thought about sending in an oil sample.

An oil sample may be good. If you take a sample I would recommend putting at least a couple hundred miles on the oil first. You mentioned that some of it stayed suspended in the oil after leaving it overnight. If it was metal particles I would expect all of it to settle. I also don’t know if the “differential “ has any bronze parts in it or not. It is just a spool with no actual differential so I assume it only has roller or ball bearings and they would typically not have any bronze. I think the rust color they are asking about may be the tooth contact paint.

 

[skinnyman]

From the diagrams in the service and parts manuals I agree with you about the bronze parts. There are shims to set back lash and pinion depth. There is a stop pin that is supposed to have clearance between it and the ring gear. I do not know what this stop pin is made of or if the clearance is correct. The input shaft and axle shafts seem to rotate smooth all though everything is still connected.
These particles are small, they fit in the grooves of my finger prints under 10X magnification. Thanks

 

[NitroxDiver]

From the diagrams in the service and parts manuals I agree with you about the bronze parts. There are shims to set back lash and pinion depth. There is a stop pin that is supposed to have clearance between it and the ring gear. I do not know what this stop pin is made of or if the clearance is correct. The input shaft and axle shafts seem to rotate smooth all though everything is still connected.
These particles are small, they fit in the grooves of my finger prints under 10X magnification. Thanks

That may be small enough to stay suspended in the oil. Not sure but I think I see real fine material in my rear diff oil too. The oil volume is very small in that diff compared to the front , I think that’s part of the issue with the oil looking so dirty.

 

[Fischer]

Bought it used, with 26 miles. I don't know about the rust color. Wouldn't it be great if that was it, rust ,LOL.
I thought about sending in an oil sample.

The thing that's weird from the pictiures is part of the gear looks rust colored the next part of the gear looks clean. Might just be the pictures ,however it looks that way. With 26 miles on the machiene strange, let us know what you find out.

 

[The Green Goat]

Call me crazy, but I don't think that's rust. To me, it looks like gear marking compound, most likely for assessing backlash and gear mesh.

I think the 'gold dust' you're seeing that isn't magnetic, is chips of this flaking off. I personally wouldn't worry about it.

https://i.ebayimg.com/images/g/7aEAAOSw~bFWJpop/s-l500.jpg

 

[Fischer]

Call me crazy, but I don't think that's rust. To me, it looks like gear marking compound, most likely for assessing backlash and gear mesh.

I think the 'gold dust' you're seeing that isn't magnetic, is chips of this flaking off. I personally wouldn't worry about it.

https://i.ebayimg.com/images/g/7aEAAOSw~bFWJpop/s-l500.jpg

No doubt about your observation, however, my 500 has never been like that, I wonder how many 500 owners have seen this on their machines?

 

[Fischer]

No doubt about your observation, however, my 500 has never been like that, I wonder how many 500 owners have seen this on their machines?

No doubt about your observation, however, my 500 has never been like that, I wonder how many 500 owners have seen this on their machines?

If it was me, and I had that I would wonder why? I tell anyone this, if I have issues with one brand, I will try my luck with another, until it's right and not make excuses for a brand that I think I may be loyal to.

 

[skinnyman]

The yellow on the gears I put on. It is for checking the gear pattern. The service manual says to use prussian blue but I had gear marking compound. It will mix in with the oil.
I checked the gear pattern in two spots 180 degrees apart. My pictures are of one spot but both sides, coast and drive side of the ring gear teeth.

 

[Keebler]

The picture of the gear and fill opening looks to me like water in the oil that has been beat into a foam. I use to have a car that would have a foam about that color in the oil filler cap during really wet cool spring seasons. My thought is that you might have two things going on, the stuff on the gear from moister and the suspended partials in oil from bushing material.

 

[trigger]

Neither of these two issues is really an issue. They all have gear whine, it's a low geared machine and it gets better over time. Not an excuse, just a fact. These also have square cut gears and even at 600 miles are still meshing. I change my diff fluids every other year, more for water intrusion or condensation concerns than metal shavings.
My suggestion is to stop wasting time looking for problems and more time trying to break it. You won't.

 

[Bomersteve35]

I have set up a few race ford nine inch rear ends. Your backlash is ok as parts heat up they move. Steel doesn't expand like the aluminum. Case does and .009 is good as it will usually tighten up with heat. The patterns look ok also both centered on the gear face. I wish the one pattern wasn't all the way to the outside of the tooth but it may just be the way honda ground the gears. Gold in the oil would be one of two things a brass wear part or maybe an oil additive for break in.
At the first oil change I plan on doing everything to get the break in oils out and switching to higher quality synthetic. If I saw your patterns and lash I wouldn't be worried

 

[J80]

Bought it used, with 26 miles. I don't know about the rust color. Wouldn't it be great if that was it, rust ,LOL.
I thought about sending in an oil sample.

It looks like someone made a mistake and squirted some mustard on ya gears thinking it was a hotdog when I changed my gear oil out it didn’t have that mustard color on the gears

 

[J80]

Never mind I seen your post of you putting the mustard on them

 

[Timmy]

Never mind I seen your post of you putting the mustard on them

Take my advice. My 2016 P500 has over 4,000 miles on it. It runs better everyday. You can’t kill a Honda. LOL