Rear Differential Trashed?

[magicball81]

Well yesterday I was driving down the highway (70-75 mph) and heard what sounded like the exhaust, although louder than usual, when I was on the throttle. Just around the corner from home it started making this atrocious growling noise from the rear of the car. I placed it in neutral and it seemed to subside. I placed it back into gear and it started to growl again. I pulled over to the side and it turned into a clunking noise at what seemed to be every rotation of the tire. Needless to say I had it towed to the dealership.

Diagnosis: Rear Differential Assembly :cry:

Unfortunately, sounds like it is going to have to be done. I think I may have purchased a used vehicle that was beat on being that I bought a MY00 used in July '06 w/ ~52K and I have had to put in a clutch (ouch) and now this. I only have put an additional 6K since then all city and highway and no track or drag time or hard launches.

Additionally, I had just had it in for the 60K service done from the same dealer and they did not identify anything during the service whether from the fluid, test drive, inspection, etc. I would have thought there would have been some sort of indication prior to this happening, but I guess the service is not that intrusive.

Anyway I guess I am posting this in the event anyone else starts to hear a noise coming from the rear of the car to go get it check in hopes of preventing something more major. And I guess I am inquiring if anyone else has had this same problem.

Thanks for your time.

[XLevel]

Comptech reinforced dif time! Might as well do gears while you are in there, and driveshaft spacers if you are lowered.

[Rocketman]

Man that SUCKS! How many miles since the inspection? Did they change the diff oil? Maybe they forgot to fill it....or replace the fill plug....:duh:

[magicball81]

Well I thought about doing additional things while they were in there, but I am buying the complete rear assembly. I highly doubt they are going to crack it open considering they won't crack it open to rebuild it instead of replacement.

I called one of the local (independent) Honda shops about rebuilding it and they shied away from the opportunity and basically pointed me in the salvage direction which I am not going to bother with at this point.

The service was done 3/27 so it was three weeks to the day and I'll estimate 200 miles since it was one tank of gas.

Other than that I am at a loss as to the suddenness of it happening post inspection. Unless there is a core charge, which I doubt, I may have a used diff for sale.

[repiv]

They know for a fact that it's the rear diff? Your description of the things you did when the noise happened it somewhat vague, so it's hard to do a better diagnosis online. For example, when you put it in neutral, you say it subsided. Does this mean the noise level dropped or disappeared? When you put it back into gear, does that mean you connected the drivetrain with the engine and it was under power? Or did the noise come back from just putting it into gear but not engaging the clutch?
At that last service, did they change the rear diff fluid? Maybe they put the wrong stuff in.

[magicball81]

Viper thanks for your reply and expertise. Let me try to explain it better. They "diagnosed" and I use that lightly to the rear diff. I would suspect that interprets to "short of pulling it all apart, that's what we found". They called me at the end of the day today so I am going to call them in the morning and see if I can get more details on how they diagnosed the issue.

For your first question. I engaged the clutch the noise level dropped. I placed it in neutral and disengaged and it was at the same level.

I then engaged the clutch placed it into gear again and the noise came back at a higher level. When I disengaged it got louder based on the RPM. Finally, the higher the RPM the louder the noise was. I had the top up and under power it was loud enough you could not have much of a conversation if someone was beside you.

Please forgive me if the details are vague, once this happened I tried to pull over soon so that I did not cause any further damage.

As for the service, yes they did replace the rear diff fluid. I am not sure which oil they used I will call tomorrow and get further details on that as well. On my receipt is is generically marked Qty (2) Part Number: G-Oil Description: Gear Oil

The only thing prior to this which I noticed about four weeks ago was highway vibration at about the same speed which was intermittent and whether I was under power or not. The front tires are about due for replacement and have inconsistent wear so I credited it to that instead of potentially something else. This may have been my ignorance.

Once again thanks for your help and insight.

[repiv]

I'll address your latest comments and explain my rationale for asking some of the things I did.

I engaged the clutch the noise level dropped. I placed it in neutral and disengaged and it was at the same level.

I then engaged the clutch placed it into gear again and the noise came back at a higher level. When I disengaged it got louder based on the RPM.OK, this is a bit confusing. "Engaging" the clutch is liftng the pedal up and taking your foot off it. "Disengaging" is pushing it to the floor. Usually, such damage makes more noise under power. This means that when the clutch is up and the tranny is in a gear. When you put it into neutral and disengaged the clutch (pedal to the floor), you have essentially disconnected the engine from the tranny and the tranny from the driveshaft. When under power, the engine drives the pinion gear, which drives the ring gear. When power is disconnected (like when clutch is down or tranny in neutral), the rear wheels drive the ring gear, which then drives the pinion gear. In this latter case, noise should be reduced, but still there. You can easily eliminate the tranny as part of the problem. So, can you confirm which is the case? Other tests can be done to see if it's the CV joints.

Finally, the higher the RPM the louder the noise was.This is pretty typical of bearing or gear damage.

As for the service, yes they did replace the rear diff fluid. I am not sure which oil they used I will call tomorrow and get further details on that as well. On my receipt is is generically marked Qty (2) Part Number: G-Oil Description: Gear OilBe VERY subtle when you persue this. In other words, act dumb. Find out if they put in VTM-4 fluid (dual pump oil). This is gear oil they use in the diffs of CRVs and Pilots. If they did use this, they OWE YOU A BRAND NEW REAR DIFF FOR FREE! The use of this fluid can result in severe and irreversible damage to an S2000 rear diff. In some cases, damage can occur in a matter of days, but can take some weeks. Honda has documented cases where a dealer has put in this fluid and the dealer has had to pay for a new diff. This may be the case with you. You need to find out.

[GeekyDragon]

Quick addition, if you did find that they put the wrong diff fluid in, continue acting dumb and have them PUT IT IN WRITING before confronting them. Otherwise you might find that stories change once you ask them to pay for the diff...

If this is the case, a good method would be to have them fax you a note with the exact service they did (including part numbers for the fluid). Just tell them you need it for your insurance or soemthing.

Good Luck.
--GD

[magicball81]

I was definitely looking at it backwards sorry. I was thinking of the pedal motion and not the internals of the clutch.


I engaged the clutch the noise level dropped. I placed it in neutral and disengaged and it was at the same level.

I then engaged the clutch placed it into gear again and the noise came back at a higher level. When I disengaged it got louder based on the RPM.

Should actually be:

I DISENGAGED the clutch the noise level dropped. I placed it in neutral and ENGAGED and it was at the same level.

I then DISENGAGED the clutch placed it into gear again and the noise came back at a higher level. When I ENGAGED it got louder based on the RPM.

Hopefully it makes better sense now.

I plan on heading over there tomorrow morning to talk with the service rep. in person. Since they have to order the assembly I would assume they have not torn it apart yet. I suppose I should just ask what does the "G-Oil" mean on the work order seems dumb enough.

In the event they tell me the right thing is there a way I can determine the difference between the two oils? Say for instance I ask them to drain it to look for metal etc is there a color difference, consistency, etc?

Thanks.

[magicball81]

GD,

Thanks for the heads up. I have the W.O. sitting right in front of me and oddly the diff oil is the only item on the list that does not have a Honda P/N. I will be sure to try and get something in writing outlining the P/N used for the change.

Thanks.

[Rocketman]

You might want to check the whole W/O. I just had a 30k inspection done, with diff oil change. They specifically asked me if I wanted it done, and I said yes. On my W/O, the diff oil change is listed as a separate item, and the P/N for the oil is MT 08798-901. On the first part of the W/O is the parts list for the 30k inspection. This includes "Gear Oil", with no part number, just as your does. If you do not see a "Rear Diff Fluid" entry on your W/O, it probably wasn't done.

Good luck!

[repiv]

In the event they tell me the right thing is there a way I can determine the difference between the two oils? Say for instance I ask them to drain it to look for metal etc is there a color difference, consistency, etc?

Thanks.

I've never seen the VTM fluid or even better, smelled it. The fluid we're supposed to have in our diffs is a GL-5 fluid. This fluid just reeks of sulfer (like a bad fart or mashed hard boiled egg). Know that Honda (car division) does NOT have an in-house rear diff fluid for our cars. They must get it from outside. The recommended fluid is hypoid gear oil from their motorcycle division. Their marine division also carries a fluid that is suitable for our diffs.

[magicball81]

Rocket,

I looked at my W.O. again and I do not see 08798-901, but I do have 08798-9031 which is the Manual Transmission fluid. When I talked with the Service Rep. today I asked whether or not the diff. fluid was changed @ 60K and she said yes. They did not ask whether or not I wanted that done as part of the service. I am assuming since it is part of the recommended service they just do it by default.

Viper,

Thanks for the info. I will be sure to get my nose close if I am able to get them to drain all or some of it.

Thanks again for the help and good wishes.

[magicball81]

Ok so just a quick update. I went over to the dealership today to talk to my "service advisor".

First, I questioned how they did the diagnosis. Simply put test drive, put it on the lift spin the wheels listen to it etc. I asked if he'd drained the fluid to look for metal and the likes and he did not. Seems rudimentary, but she stated they have their best tech on it (I hope that's not what they tell everyone) so I'll wait to see.

Second, I questioned whether or not the rear diff. fluid is replaced as part of the 60K and she said yes and showed me the list of items performed for the service. I questioned what type of fluid is used and she told me the Honda recommended fluid (rather nondescript).

I tried to play as dumb as possible, so I kind of let these things go and not push them as to not draw suspicion to my questions.

I put everything in perspective and figured it's going to have to be done one way or the other so let them continue. I requested the old diff. assembly so at the very least I can try and sell it to recoup so of the cost. Since the Tech has not drained the fluid as well I requested to inspect the old fluid prior to disposal so I can inspect it.

Like I said I figured this is the best way to be able to look at the fluid and see if it the correct type without accusing them of using an improper fluid so we'll see what happens. It is supposed to be arriving Tuesday so I'll keep the thread updated as things develop.

Thanks again.

[negcamber]

Magic...I just lost my diff this past weekend too. One thing you might consider is to get a rebuilt diff from Hardtop Guy with 4.56 gears. The gears are a great performance mod and the total cost will be a lot less than if the dealer replaces it with a new one from Honda (unless of course you can get them to admit using the wrong diff oil).

[magicball81]

negcamber,

Sorry about your loss! You are right though it is definitely cheaper than the OEM setup. My car is currently NA and I think I am going to keep it that way. However, I will most likely have it done and send the old diff. to Hardtop Guy to be rebuilt and have it installed sometime next year since I see a 50/50 road highway combo. Well either that or just sell the core to someone looking for one. Thanks for the advice.

[magicball81]

Sorry for my late follow-up things have been a little crazy and I've been enjoying the FLA sun. I got my car back about ten days ago and I've been driving it daily. The growl is definitely gone and the car it acting like its old self. Actually, it feels just as it did prior to the day the diff. went. They emptied the fluid and gave it to me along with the old diff. Definitely has an odd smell so I think they used the right fluid on the service (unfortunately). Regardless I have the old diff. in storage and will be sending it out sometime to have it rebuilt with different gearing and hopefully reinforcement. Thanks for your help xviper. Hopefully this thread will help someone else along the way.