golfnut311

I need some technical help here. My car started making a god awful screeching sound at 25 MPH or higher. It would drive OK, but the noise was just horrible. The interesting thing was that all six gears seemed to be OK it just made that noise. When I pushed in the clutch and coasted, the noise went away. I assumed it was the transmission since the noise didn

xviper

Here goes:
The engine connects to the tranny via the clutch, thus, you can disconnect the power to the tranny buy disengaging the clutch.
The tranny is connected to the prop shaft (drive shaft) but can be disconnected if you put it in neutral. So, if you have the clutch to the floor and the tranny in neutral, the tranny can be completely isolated from everything else in the drivetrain. If in gear, the tranny will always be connected to the drive shaft.
The drive shaft is connected to the differential. The differential is connected to the half shafts. The half shafts are connected to the wheels/tires.
So, from the drive shaft to the wheels, is a constant and solid connection that cannot be disconnected unless something breaks.
When you have everything connected and you are accelerating forward, the engine drives through the clutch, that drives the tranny, that drives the driveshaft, that drives the diff, that drives the wheels.
When you are decelerating, the wheels drive the diff, that drive the driveshaft, that drives the tranny (if in gear), that applies force back to the engine (if clutch is engaged).

ps. I am curious however .....................................
You have an '01. In the whole time that you have had this car, have you ever had the diff fluid changed? If so, with what?
If not, then this might be an indication and a confirmation of my theory that the diff fluid is critical to the function of the diff and should be changed early in the car's life (within the first couple thousand miles and then annually thereafter if driven normal mileage).
If it has been changed, perhaps the wrong fluid was put in?

golfnut311

xviper - thanks for the quick reply. First, I think I understand what you wrote, but based on that, how can the differential be going bad (causing noise) only on acceleration? Even with clutch to the floor, the differential is still moving, correct? The noise immediately goes away as soon as the clutch is pushed to the floor.

Second, my book is in the car (at the honda dealer), but the diff. fluid was changed at approx. 15K miles. I put in Mobil 1 Synthetic Gear Lubricant (SAE 75W-90) as specified by folks on this site. No problems with it.

I just changed it again at 30K about two weeks ago. This time I put in Honda VTM-4 Differentail Fluid as my local auto parts store did not have any of the Mobil in stock, and I wanted to do the 30K maintenance. (note, I just found a bottle of the Mobil 1 in my garage - ARRGH - I thought I was out of it.) I did the Tranny, Diff, Oil, Filter, etc. etc at the same time.

After I heard the noise, my first thought was that one of the bolts was not tightened and came loose and I lost fluid. Inspection showed everything still tight. Even so, I removed the filler bolts for both the tranny and the diff. and fluid was right where it should be, so that seemed to be OK. That's when I decided to take it to the dealer.

Thanks again for your help. The posts you put up on this site are always extremely helpful and to the point.

xviper

[QUOTE]Originally posted by golfnut311
xviper - thanks for the quick reply.

golfnut311

xviper - THANKS!!! Incubus' post is exactly what mine was like. Since I went into the Honda parts department and asked for Diff. Fluid and that's what they gave me, I guess I have a beef with them. Thanks again for all the help and the explanations.

golfnut311

hey xviper, one last question, what does the GL mean when they say you need GL5 or GL6 oil in the diff? I want to sound half way compentent when I go into the dealership to complain they gave me the wrong stuff. The worst part is that the stuff they gave me has nothing to indicate the GL strength(?). Thanks again.

xviper

First, as far as I know, there does not exist a GL-6. It is a designation (by API - American Petroleum Institute) to describe a specific kind of application and service rating. "GL" stands for Gear Lubricant.
Have a look here:
http://www.stle.org/public_forum/subject.c...&ForumID=21#478
And here (near bottom of the page under "Automotive gear oils":
http://www.wearcheck.ca/literature/techdoc/WZA008.htm
Anything without a "GL" rating CANNOT withstand the extreme pressures and load as found inside our differentials.

ps. Here is more ammunition for you:

This is a memo that was issued to all Honda Canada dealers. Honda deemed that they had no appropriate fluid for the S2000 diff and wanted to make sure dealers did NOT put in something that was already in stock. They specifically indicated that the recommended diff fluid for the S2000 was NOT used in the diffs of CRV's and Pilots. One can easily deduce that the converse is true as it is obvious that the two fluids are NOT the same.

golfnut311

Man, you are really something!! Thanks a ton for all of this. I just got off the phone with the assistant Service Manager. He didn't know that the VTM-4 should not be used in the S2000 and wanted to know how I found out that it wrecks the differential if it is used!! Since they sold me the fluid as good for the s2000, I think they may push Honda of America to honor the warranty to fix it or they may be paying themselves to fix it. Should be interesting to see how this pans out.

Again, my sincerest THANKS to you for the great information. I'm distraught that my S has her rear end in a sling but elated that I probably won't be paying to have her fixed. Wonder what they will put in her when they do fix her. Guess I'll have to really press them to make sure they put in the correct oil.

xviper

I wish you the best in this endeavour. Let us all know how it turns out.

Road Rage

Is it any wonder we get the heebee-jeebies every time we hand oiver the keys to someone else, dealer or corner gas station?

The amount of misinformation on a dealer's own line of cars is amazing. VTM-4 for the diff. I would almost be willing to testify as an expert witness if your case went to litigation, just to be able to explain to the judge./jury what GL-5 means, what 90w means, what Honda's specs for fluids mean, and how stupid the dealer was.

If asked if I thought the VTM-4 might have been the proximate cause of the diff failure, I would say it was never a question of "if", merely of "when".

Good luck to you.