P500 Pioneer 500 rear differential

[skinnyman]

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

Boomersteve35, Thanks for your reply.

The exploded view of the P500 differential shows a stop pin and selectable shims for it. The service manual refers to it also with a specified clearance (.010-.020) between the stop pin and the ring gear.

This stop pin in my opinion is to keep the ring gear from deflecting away from the pinion under severe load. If the stop pin clearance was too tight this could be causing the ring gear to rub the stop pin. Should the stop pin be made of say brass or bronze that could be what I see in the oil. However over time I should see less of it it the oil.

What are your thoughts?

I just added some pictures from the service manual.

 

[Admin]

 

[ehart814]

At first I thought you were joking about changing the oil when you brought it home and then every couple miles and checking gear lash. I'm fussy, but not that fussy.

I ran my 500 over 4000 miles. The drivetrain whines. Top off the fluid. Give it a few miles (500-600 at least) and run the crap out of it. It will quiet slightly over time, but don't expect it to get silent. Also, run conventional fluids for break in (engine included). Don't even bother checking the diff fluid level unless you get a bad leak. Spend more time enjoying it. Sounds like you're definitely going to take good care of it - it will take care of you!

Mine started to use some engine oil around 2500 or so, if I remember right. I blame that on me switching to Amsoil too soon before the rings broke in enough. My advice is to run GN4 for at least a couple oil changes and run it hard to get a good piston ring seal.

The most important thing to be fussy about is the AIR FILTER! You will be amazed how quickly it will get dirty. Buy a spare or two so you can keep one clean and oiled when you need it!

 

[skinnyman]

ehart814, Yea guess I am fussy.

I am more curious as to why my P5 is this way .Because,,,,

My 2007 Honda Rancher 4x4 ,1995 Honda PC800 motorbike and the Mrs. 2003 Honda trx250 all are quiet and without the "Honda Gold" rear diff fluid. Hmmmm....

 

[ehart814]

ehart814, Yea guess I am fussy.

I am more curious as to why my P5 is this way .Because,,,,

My 2007 Honda Rancher 4x4 ,1995 Honda PC800 motorbike and the Mrs. 2003 Honda trx250 all are quiet and without the "Honda Gold" rear diff fluid. Hmmmm....

Oh gosh that PC800 might as well be electric when u compare the noise it makes to the P500! Haha. Cool bike for sure!

Idk I’ve had my share of Honda’s too and the 500 is just a noisy animal. Not much was in the NVH budget when they developed it. Even my 1000 has some whine from the rear diff. I actually noticed it tonight.

The 500 might be noisy but it makes up for it in reliability. Over 4K miles and I never replaced a bearing, tie rod end, ball joint... I did put a set of front brake pads on it tho!!


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[Bomersteve35]

Boomersteve35, Thanks for your reply.

The exploded view of the P500 differential shows a stop pin and selectable shims for it. The service manual refers to it also with a specified clearance (.010-.020) between the stop pin and the ring gear.

This stop pin in my opinion is to keep the ring gear from deflecting away from the pinion under severe load. If the stop pin clearance was too tight this could be causing the ring gear to rub the stop pin. Should the stop pin be made of say brass or bronze that could be what I see in the oil. However over time I should see less of it it the oil.

What are your thoughts?

I just added some pictures from the service manual.

View attachment 256879 View attachment 256880 View attachment 256881

Hey man just doing some reading on this stop pin thing looks lile honda has been using this style center diff for a while early 2000s I dont know it you can check the clearance on it without disassembly. I do remember you saying that the backlash wasn't exactly the same in all 4 spots. You may try to measure your ring gear movement side to side maybe the ring gear side bearing is bad. And that is letting the gear ride against the stop in all the time it would kind of explain why the patter on your gears was not centered. It was all the way out to the tip of the gear. Try to indicate the gear while pushing in and out on the axle shafts. Keep at it and have a nice evening

 

[Nathanp500]

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.

View attachment 256233 View attachment 256234 View attachment 256235 View attachment 256236 View attachment 256237 If itView attachment 256238

 

[906UP]

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

@Bomersteve35 answered your question and didn't even know it. The ring gears in the Honda diffs aren't ground, they are forged, shaved/skived and heat treated without any post heat treat machining other than the bearing journals. With this type of gear manufacturing the tolerances have to be much greater than with ground gears, which is why some are noisy and some aren't......as much anyway. I've had the front diffs out & disassembled on both my P5 & my T1Kx, I was a little disappointed with the finish but they are strong. Fill it with oil and run it, it will get quieter and smoother with age/use. These type of gears need to wear in.

 

[trigger]

@Bomersteve35 answered your question and didn't even know it. The ring gears in the Honda diffs aren't ground, they are forged, shaved/skived and heat treated without any post heat treat machining other than the bearing journals. With this type of gear manufacturing the tolerances have to be much greater than with ground gears, which is why some are noisy and some aren't......as much anyway. I've had the front diffs out & disassembled on both my P5 & my T1Kx, I was a little disappointed with the finish but they are strong. Fill it with oil and run it, it will get quieter and smoother with age/use. These type of gears need to wear in.

Thought about tagging you on this thread. Glad you stumbled onto it.

 

[ehart814]

@Bomersteve35 answered your question and didn't even know it. The ring gears in the Honda diffs aren't ground, they are forged, shaved/skived and heat treated without any post heat treat machining other than the bearing journals. With this type of gear manufacturing the tolerances have to be much greater than with ground gears, which is why some are noisy and some aren't......as much anyway. I've had the front diffs out & disassembled on both my P5 & my T1Kx, I was a little disappointed with the finish but they are strong. Fill it with oil and run it, it will get quieter and smoother with age/use. These type of gears need to wear in.

Funny.... I had the pleasure of working on a Polaris Ranger front diff that went bad. Looked at the ring gear and noticed that it was pressure cast. The teeth were not machined. So they pressure cast it and assemble it. The only shiny surfaces were the teeth where they engage the pinion teeth.

 

[skinnyman]

@Bomersteve35 answered your question and didn't even know it. The ring gears in the Honda diffs aren't ground, they are forged, shaved/skived and heat treated without any post heat treat machining other than the bearing journals. With this type of gear manufacturing the tolerances have to be much greater than with ground gears, which is why some are noisy and some aren't......as much anyway. I've had the front diffs out & disassembled on both my P5 & my T1Kx, I was a little disappointed with the finish but they are strong. Fill it with oil and run it, it will get quieter and smoother with age/use. These type of gears need to wear in.

906UP,
Thanks for your insight to the gear making process. I never owned a toy this close to new so the break in period is new to me.

 

[skinnyman]

Funny.... I had the pleasure of working on a Polaris Ranger front diff that went bad. Looked at the ring gear and noticed that it was pressure cast. The teeth were not machined. So they pressure cast it and assemble it. The only shiny surfaces were the teeth where they engage the pinion teeth.

ehart814, Thanks for your experience inside a differential..