legendre

Howdy folks,

We're again experiencing a squeak / squeal from the rear end of the 1998 CR-V. It seems to manifest when it's being driven on slippery roads, and (due to slippage) the rear wheels are running at different speeds & torque loads.

It's a groaning, squeaking noise, like a.. slipping friction clutch.. that's dry, or something.

The wife had it looked at once, and was told there was a service bulletin about it, something to do with improper lube levels or types in the rear drive. Thing is, that rear drive unit doesn't seem to leak anything, ever.. so I'm not sure why it keeps reappearing.

Thoughts? How do i fix this, so it doesn't return?

ETA: I know virtually +nothing+ about the AWD system in this vehicle. What exactly is going on in the rear drive, is it like a standard LSD - with additional, automatic electrical / mechanical control?

ap1jnky

Fluids in the rear are low my crv did the same thing when i made a real tight left hand turn one time scared the **** outta me low rumble noise... drain it top it off with honda dual pump fluid ll. I used royal purple loves it so far and no problems.

Sticker Bomb

The fluid in the rear end still needs to be changed regularly just like any other fluid, just like you would your tranny, coolant. Change the fluid to start with and see if that helps with it.

legendre

This isn't a low rumble, it's a squeaking-groaning noise at about 400-600Hz.

And to clarify, it only manifests when the rear wheels are being +driven+ at different speeds - as in, when accelerating on slippery surfaces and one / both rear wheels are slipping at various rates, trading power back & forth.

Help me out here.. first off, what's "Honda dual pump fluid II"? And which Royal Purple product are you referring to? Are you using both at once, or what?

Do you use a friction modifier? If so, how much of which?

legendre

Final drive lubes certainly do need regular inspection for level and condition. But I've never changed them on any regular basis - except in motorcycles.

How often do +you+ fully change out your rear axle lube, and what do you replace it with?

And since I'm asking questions as usual, is the front final drive part of the transmission, or does it have its own lubrication that needs separate servicing? In this case, the transmission is a 5-speed manual.

Sticker Bomb

Rear diff fluid does needs to be change just like any other vehicle, they are nothing like a motorcycle.

You should be changing it every 60,000 miles (100,000 kms) same with the transmission fluid.

The transmission fluid should be 5w30 oil, But I have always ran ATF fluid in mine. For the rear end, go to the dealer and pick some up. Since they are always upgrading the fluids, I have no clue what they use now since I have not worked for them for about 2 years.

stangrcr1

Dealer still uses and sells Dual Pump Fluid II. Just got 2 quarts last week and changed mine. The change out takes 1.1 quarts if you get all the old stuff out. Get new crush washers for the drain/fill plugs while you are at the dealer.

RevIllusions

There is a bulletin to make sure the fluid is good and clean, even suggesting that the dual pump II mentioned above to be use as it is backwads compatible. Recalling from memory, the bulletin basically says if the fluid is at the correct level and is clean, and still makes noise...then replace the rear end. I have the same issue and have not done so yet.

legendre

Thanks for the input - but does anyone actually know what's causing the noise?

For instance, is it a limited-slip rear end, and the noise is the sound of the clutch(es) breaking away when the torque limit is reached?

Or is it something much uglier, like a bearing squealing?

legendre

I kind-of misspoke. In fact, I do change gear lubes in cars at least that often.. and in a cycle like a BMW or Guzzi, more like every 10,000 - or at least once per year.

Shaft-drive cycle rear ends are just like an automotive rear end; ring & pinion, minus the differential gear.

5W30 or ATF in a 5-speed manual? I need to look that up..

stangrcr1

The rear axle is an open diff.

Change the fluid and drive it for a bit. If the noise stops, great. If not, time to get under there and see what is making the noise.

legendre

Err.. how can it be a plain, open diff on an AWD vehicle? Here's what the factory service manual has to say (sorry, it's long..).




So is the dual-pump / hydraulic clutch mechanism only responsible for coupling / decoupling the entire rear drive unit - or does it also have some manner of control over how much torque is applied to each of the rear wheels?

ETA: Heh, wow, yeah.. it's just that cheesy. Not so much as an LSD back there, just an open diff after the clutch. So is it the clutch that's making the noise?? Slipping and squalling when power is being shifted to the rear drive?

It is a wet clutch, right? Looks like it, being all multi-plate and whatnot.

vrc123

You might want to do a search on burnishing the clutch pack before changing the fluid. Basically, you drive in reverse at full turn lock with the steering wheel. You do it for something like three or four circles one direction and then the same in the other direction. I wish I had read about that before I did the fluid change out.

Sticker Bomb

Yes ATF in a standard tranny. It works better because it keeps the tranny cooler and it helps keep everything cleaner inside because of the detergents it has. I Also find it shifts smoother using it, and I know a lot of race drivers that use ATF is their standard trannys, That's why I use it for.