Can someone explain tranny and differential interactions, etc
 

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

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?

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.

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

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.

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.

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:
https://cimg3.ibsrv.net/gimg/www.s2k...1bd993846f.png
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.

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.

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

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.

RoadRage - Thanks for the comments. I should hear from the dealer sometime today as to the status of who is going to pay for this. I certainly hope that they have enough sense to either pay it themselves or get HOA to pay under warranty. I won't do it as they sold me the Diff. fluid when I asked for it for the S2000. I'm not sure, however, that the Asst. Service Manger believed me when I told him the VTM was the cause of the failure. So, I might have some "splainin' to do.

xviper, RoadRage - The dealer got back to me and they will pay for the Differential (a replacement, not just a rebuild), they will pay for the clutch TSB and they will pay for the convertible cover strap replacement TSB. No hassle on my part at all. They called and said it would all be covered.

Thanks again for your help and support. You guys are really great. If your ever in my neck of the woods, let me know and I'll buy ya a beer or two.

Amen brother! I simply will not take my car to anyone anymore unless some work requires special tools I don't have and can't get. I'm looking at picking up a hydraulic press when I get back from OTC so I can do my own bearings and bushings. For the $150 it costs for a shop press I can avoid subjecting my car to incompetent wrench monkeys. I can strip bolts as well as anyone. I don't need to pay $75 to have someone else do it for me.

Here is my inventory of disasters:

1. Scratched valve cover
2. Cracked alternator housing
3. Broken ABS cable
4. Engine mount nuts removed and not replaced (why I don't know)
5. Leaking transmission input seal
6. Clutch reassembled incorrectly, release bearing not lubed
7. Prop shaft bolt stripped, another one bent

All this from TSB054 and a CV joint replacement. About 30 days of time in the shop fixing THEIR mistakes. 3.5 f**ckups per service. nice.

:LOL:

are they sure they filled the differential? The VTM-4 doesnt come in quarts but rather gallons, so they would have to know that they need to fill the differential, not just put in however much.

As I've indicated, you don't fill a diff or tranny casing by precise volume. You keep putting it in till it falls out the fill hole. No decent mechanic would just put in xxx cc.

Well if they arent competent enough to know its know the right fluid they might just put in however much they think is ok. Look at the techs who have botched tightening the drain bolts/oil filters, on top of many other simple jobs.

Holy hell....Why did I just find this?? When I purchased my car in May, I took it to Honda to get my tranny and differential fluid changed. When I was there, they could not find the correct differential fluid and said it was special order or something. But, ended up finding some and used it. :rolleyes: I never saw it and the part # was not on my invoice. I have a very uncomfortable feeling that I have VTM-4 in my rear end.

My car has 60k on it.
The woman I bought it from got it serviced there, so either she never had the differential fluid changed, she has always used VTM-4, or Honda had the right fluid in stock.

Question??
Would the differential survive this long without changing the fluid or with using VTM-4?? (considering the car has never been auto-x or hard driven)

I've only put about 2k on it with the newly changed fluid. I will be changing this fluid ASAP just in case.
I just can't bear the thought of my differential going out of something stupid like this.
Please comment. :brokehrt:

Don't panic. Just don't take your car to a dealer you don't trust to do the right thing (I'm still looking for one of those which 100 miles). You can get everything you need from an auto parts store and you get off your but and do it yourself. It takes 10 minutes to drain an fill the tranny and diff.

Tranny oil is just motor oil, 10W30. You can pay more but you get the same thing mainly. Diff oil is called light gear oil and you get it from pep boys or auto zone or what ever. The trick to diff oil is trying to understand which you need from the several kinds, none specicially marked as TLSD. Read the bottle and find the weight, GL5 rating and the part where it says designed for LSD use. I got Mobil 1 last time I think. Get a fluid transfer pump which will be right on the same rack. Make sure the screw top on the pump will screw onto the bottlle, it makes it much easier.

Take you 3/8" drive ratchet and plug the square end to the fill bolt (the one with 4 sides). loosen it but dont remove it. Take you catch can, put it under the drain plug and with your 17mm wrench loosen and remove the bolt. Remove the fill bold by handle completely now. If you have another pan go to step 2
follow the same proceedure. Loosen fill, remove drain, remove fill wait till it drains.

Go back the the tranny. Install and torque to spec the drain bolt, attach the pump to you bottle of smelly goo and insert the tube in the fill hole. Dump until you see yourself pumping it out the hole you atr putting it in. It's gone, Secure the filler cap.

Now go back to the diff and repeat.

Presto magico you are none in less that half the time it would take the dealer to even get you on a lift.

If you buy your Mobil 1 in boxes of 6 like me the question about what it;s for has just been answered.

there's a TSB on replacing the convertible straps? anyone have a link...first I've heard about this

Damn, my post made no sense at all :thinker: I've got to stop posting just before bed :o

I'll check on that TSB...

:D
Ok, first of all I do trust these guys to do my work they are very reputable and I have never had a problem there before. Everyone can make a mistake and I wasn't sure if one was made (a very costly mistake at that)

With that said, I went by Honda this morning and spoke to a couple people in parts and in service. Although, I never really found out exactly what type of fluid they put in my differential. They appear to have known the difference in the differential fluids.
They said they put Hypoid 80w90 in it. (is this correct fluid)

I'm still planning to put some Mobil 1 in there as soon as I can find some.

the question is, what is the dealership going to use to put in the diff this time around? You may just want to get the Mobil 1 yourself and hand it to them.

Hypoid 80w90 is fine to use in the s2000's diff

I'm going to change the fluid myself this time, now that I see how easy it is.(they charged $30 in labor.)

Great!! I'm still going to change mine b/c I'm not 100% sure that's what they used.

make sure it says GL-5 on the bottle somewhere

Just to add...I've used Mobil1 75W90 synthetic gear oil with great success in my car. countless clutch dumps and tons of drifting, plus a weekend at the track. Fluid came out like new, I was pretty shocked.

It's also available all over the place :)

I'm searching for some....I've been by 3/10 local auto parts places with no luck.

Billman-

Where can you get 16" Ce28n from? Offsets?

it should be right next to the transmission fluid. every autozone i've ever been to carries it

Japan.

Ordered in June, should be here around Feb 15th. 8.5 month wait, already paid in full :banghead:

Offsets are near stock, .5 wider per wheel.

Autozone had Mobil gear oil...but, it wasn't 75w90. :(

If you ever want to sell let me know first!! :LOL: What's the weight on these?

Was the car still under the 36k warrenty when Honda serviced it and replaced the diff? I just bought an S2000 and it sounds that it is having the same problems as you discribed 100% but the car has 63k already. Please HELP!!! Thanks All

Bump

If it's having the same problem (extreme noise as speed goes up, goes away when clutch is pushed in) then take it to the dealer and have them look at it. Did you change your fluid recently? Did you get some from the dealer? Did the dealer change the fluid?

The diff oil was changed at 48k by honda by the original owner. I then changed it out a second time because did not know the maint history of the car with mobile 1 75w90. What options do I have? If the diff fluid was changed to the dealership, will i still be able to collect on the warrenty?

I know this thread is old, but many are probably still reading it for the first time, and I'm sure the mistake still happens from time to time. Here's some helpful hints.
GL4 or GL5 is a hypoid oil/lube. both should be adequate, but use GL-5. Here's the helpful stuff - If you want to know if what comes out is hypoid or not, smell it. GL/hypoid oils stink, and stink even more after being used. They have a very distinct smell and if you aren't sure, open your bottle of new stuff and smell-compare with what came out of your diff. They should both smell like crap. :D

I'll be trying this now. :thumbup:

I have a question about the Mobil 1 stuff, i have always used 607 Almasol SAE 90 on my diff, i did notice that some how the quart has gone up considerably ($18) can i go to Mobil 1 without any problems?
Whats a better fluid, Mobil one or Almalsol, based on your experiences?

Thanks i need to do a fluid change really soon.

btw, how many quarts does the tranny need?
thanks again :thumbup:

I have a "whirring" sound that increases with acceleration, however, it does NOT go away when I press the clutch in while decelerating. I bought the car 3000 miles ago, and it had just been serviced at a Honda dealer with the 105k service which includes all fluids. I will be changing the tranny and diff fluid this week, just for piece of mind.

My question is, does my "whirring" sound seem like a symptom of a bad diff (because dealer put wrong fluid in)? My original though was that is it a wheel bearing gone bad. I am planning on having th dealer replace both rear wheel bearings and hubs. I'd hate to have that done, only to find out that my actual problem is the diff.

Thanks for any input.

If the sound is linked to vehicle speed and remains the same regardless of engine speed and clutch position, then I would conclude that the problem is probably after the transmission, though the output side of the transmission is still being driven by vehicle motion.

If the fluid change doesn't resolve the issue and you have the wheel bearings changed, be sure that the axle nuts are torqued correctly afterwards. https://www.s2ki.com/s2000/topic/929...e-nut-tsb-diy/

Well, I changed the diff fluid today - no change in sound. So I'm now hoping that it's the wheel bearing(s). I am planning on having those replaced at the dealer with OEM parts here in a few weeks. Hope that solves it, otherwise, a new diff is in order.

Does the sound occur at low speeds? Can you jack the car and try to listen to where the sound is coming from?

It does, but is hardly audible at speeds below 30mph. I doubt I'd be able to run it up with the wheels off the ground safely.

It sounds a lot like a noisy throw out bearing, but I know for a fact that isn't it. It is coming from the rear of the car and is directly proportional to vehicle speed. It is completely independent of gear selection or clutch position. That leads me to believe that is is either a wheel bearing, the diff, or possibly something on the output side of the tranny.

I thought about taking it to the dealer, but I don't know that I trust their diagnosis, and sure don't want to pay them to fix something that isn't broken.


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Did you find an answer to this issue? I ask because I'm experiencing something similar. Having never driven an S2000 before I don't know what "normal" noises it makes, but I'm pretty sure this is not normal. Same thing - loud mechanical whirring coming from the rear end at speeds above 30mph, independent of speed above that. Clutching in does *not* get rid of the noise. The dealership I purchased the car from did a fluid change prior to me taking delivery as part of their standard procedures for rehabbing used cars, but did not specify the fluids that were changed (I didn't ask what was used). So far I've only driven about 50 miles, and the sound has been present since the first mile.

Calling the dealership tomorrow to figure out what diff fluid they used, hopefully they have a record of that. If its not the diff fluid (eg. if they used the correct fluids specified in this thread), what else might I be looking at? For reference, the car has 2650 original miles on it, so I'm hoping its not other mechanical failure.