Knocking noise from Auto box

[Nafeman]

Hi there.

I was aware of a slight knocking noise when turning and accelerating when I bought my '89 Aerodeck (EX2.0i Auto) a couple months ago. I put it down to a simple CV joint, so it didn't worry me at the time (Just allowed me to knock them down on the price a bit). However, I've been driving it a bit more recently and the noise has developed a fair bit and isn't really sounding like a CV joint failing anymore... It's too "clean" a knocking. It only sounds when I turn and accelerate, close to and on full-lock in both directions. It sounds kind of like a ratchet. As soon as I straighten up it disappears, whether I'm still accelerating or not. I definitely don't think it's the CV anymore.

So I popped it into see my mechanic yesterday and he's worried it's inside the gearbox :(

So, my questions to you guys are...

The ALBs on the front wheels... There's no sensors on the CV joints, so is ALB engaged inside the Auto box? Could this be why my ALB light is on? (Again, I had just put the light down to a failing sensor). If so, what could be causing this? I wasn't sure if it was something related to the ALB teeth making it sound "ratchet" like. The auto box doesn't appear to be struggling and there's no noticeable vibration.

Could it be to do with the differential inside the box, hence why it only appears when I turn and accelerate?

Is this a common problem? If so, is it rectifiable?

Any help would be really appreciated.

Cheers, Nathan

[A18A]

It really does sound like a CV joint problem to me. the only other similar sound I know of is from putting the gearbox in park while driving over about 5 kph

the ALB sensors are supposed to be mounted on the hubs, and there's rings on the outter cv joints that the sensors get their readings from

[Nafeman]

There's definitely no wires or anything suggesting the ALB sensors are on or anywhere near the hubs or the outer CV joints. That's why both me and my mechanic suspected the ALB sensors on the front end are in the gearbox.

He suspects the differential, which I can see why. But I'm hoping (just hoping) it's just ALB related.

[Nafs Asdf]

The sensors are at the hubs. If I remember correctly they're attached to the fork, and have a round-ish cover on them. Maybe yours have been removed. Does your ALB warning light work like it should ie. comes on when you turn on the ignition and goes out when you start the car?

And it really does sound like a CV joint problem, mine did exactly what you describe when they were bad. Finding a replacement joint with the ALB gear ring might be tricky tho. There was a company selling them on ebay in the UK, but unless they were shitting me I bought the last one they had.

Edit: you should download these: Shop Manuals (http://www.pauldesign.ru/honda/shopmanual.html)

[Nafeman]

Cheers for both your inputs guys... You've given me a bit of hope at least :lol:

I'll have another look for the sensors tonight if I get chance. Can't recall the ALB light coming on and then going out once the engine's started, but that's one of those things I get used to I guess. It is definitely off once the engine's started though, and comes on after a few revolutions of the wheels, suggesting it's working, but still...

I'm going to book the car in at garage either way, as if it's simply the CV joint then I haven't got time to replace that anyway. I was just hoping to be able to give Mr Mechanic some more info as he's quite sure it's not the CV joint.

EDIT: Cheers for the manuals. With regards to the error codes... What is the "control unit" that the codes flash up on?

[Nafs Asdf]

Cheers for both your inputs guys... You've given me a bit of hope at least :lol:

I'll have another look for the sensors tonight if I get chance. Can't recall the ALB light coming on and then going out once the engine's started, but that's one of those things I get used to I guess. It is definitely off once the engine's started though, and comes on after a few revolutions of the wheels, suggesting it's working, but still...

I'm going to book the car in at garage either way, as if it's simply the CV joint then I haven't got time to replace that anyway. I was just hoping to be able to give Mr Mechanic some more info as he's quite sure it's not the CV joint.

Actually, the light coming on while driving means you have a problem with the ALB system. The ALB control unit is located behind the cassette tape holder in the center console. There's an LED-light on the control unit that will blink an error code, remove the plug on the side of the center column (can be on either side, depending on the model) and you'll see it. The LED will start blinking when you turn on the ignition.

If what you're saying about the sensors is true, then they have likely been removed and will cause the ALB system to not function. You should be getting the error code for the sensors in that case.

Download the shop manuals from the link I posted, the info on ALBs is in the 88 supplement (the ALB system changed in 88, so the info in the earlier shop manuals might not be correct). You'll everything on troubleshooting the system there.

[Nafs Asdf]

btw, I think you put this under the wrong topic ;)

[Nafeman]

Opps bum, so I did :lol: I was looking for the right topic then got distracted and started looking for H22a transplants :lol:

Sorry, I meant the light coming on is working properly as I obviously have an ALB problem :)
So there's a bung/plug on the side of the centre console level with the stereo where the LED is hiding?

[Nafs Asdf]

The control unit is bolted to the floor, so look for it at about where your feet are.

[Nafeman]

Ok, cheers bud :)

[Dr_Snooz]

Are your CV boots torn?

[Nafeman]

Are your CV boots torn?
I had a brief look last night. The CV boots look to be in great knick. I was going to jack the front end up and try popping it into drive and turning (and maybe holding a wheel at a time) to see if I can locate where the sound is coming from exactly. Ran out of time though.

On a slightly better note... I have managed to locate the ALB sensors :lol: They're not exactly noticeable when the car's on the ground and looking from the front. Looking from behind it's a bit more obvious... They're in the regular spot :lol:

[Nafs Asdf]

Did you get a chance to look at the error codes? If the warning light comes on, you obviously have an issue with the ALBs, but I don't think that the clicking sound is related to it. My money is still on the CV joints. Can you tell which side the sound is coming from?

[Nafeman]

No I didn't get a chance. Though I printed off the fault codes so I'll take them off tonight as well hopefully.

No, can't tell what side it's coming from yet.

[Dr_Snooz]

If your boots aren't torn, then it's unlikely that it's CV joints. What does your AT fluid look like? How does the trans perform when making this noise? How does it perform the rest of the time? A ratchet type sound could just be something simple like a cable rubbing the tire. Does the car run well generally? Was it well cared for or kind of beat up? My feeling is that if the car has been well cared for, then look for simple things. If it was driven hard by crackheads, then look for the more obscure. Remember that the trans is filled with fluid, so a "clean" "ratchet" noise coming from there would be more like a muffled ratchet submerged in oil. It's possible that one of your drive axles is not seated properly or the splines are damaged.

[Nafeman]

Cheers for the reply bud. Yeah the car seems to have been well cared for. They wanted to make sure it went to a good home to make sure it had the same amount of love. They didn't know anything about cars, so whenever there was something wrong with it they took it to the garage. I cannot fault the performance and power. As I said, there's no vibration or anything... Purely just a noise... though a worrying noise unfortunately :lol:

It definitely sounds like a dry, clean, "non-muffled" sound, so yeah, it kind of suggests it's not submerged whatever it is. And no you mention it, it kind of does sound as if it could simply be something rubbing on the tyre, though it sounds quite solid (not plastic like a splash guard) and it doesn't really sound much more when I pick up speed whilst still turning.

Also, I tried knocking it into neutral whilst still rolling around a corner and it stopped, suggesting it's related to being in drive. Though I'm going to give that another go as I only tried it once as I rolled up in the car park and I came to a halt pretty quick.

Still need to jack the front end up and have a proper look.

[Dr_Snooz]

Can you post a video of the noise?

[Nafeman]

Actually, I'm not sure :lol: I'll have a go this weekend. I should be putting my regular A to B car back together this weekend, so I'll be able to park the Aerodeck up and properly have a look.