15 replies to this topic

[Jimbo]

Okay, so it sounds like my transmission is about to say "seeya" and parachute off and start a new life in a town where no-one recognises it.

So this time, it's not my power steering having a cry, it's genuinely the transmission....

And, I also have a theory in how it might tie into the shitty off boost stuttering.

First things first. The noise. I don't know SFA about AT's but it's making a rather disturbing audible rattly/whirring noise when the car is stationary, which has progressively gotten worse . I can hear it perfectly when pulled up along side another car or a wall.

The noise, however, is ONLY present when the AT is in a drive gear and the car is stationary (example, waiting at lights in a driven gear [1,2,3,D] with handbrake/brake on). Also makes the noise in R.

Put it into N or P and it pretty much stops or the noise becomes barely audible.

Once I drive off, it silences instantly. Operation of the gearbox is perfect. Goes into all gears fine, doesn't flare and changes gears on cue. Oil levels in the box are fine and were replaced early this year.


Now, here's my theory. Front diff. This is something I have never gotten to so far and is probably still (barely) swimming in the oil that was squeezed in on the factory line 17 years ago. The oil reeks but the levels are still okay in the diff.

My theory is that the oil has pretty much had it and the diff is stuttering (?) off boost with low load, hence the behavior which corrects itself when boost is applied (more torque on the front diff).

This is just a theory. 

Only other thing I can think of is maybe one or a few of the outer flex plate bolts (x4 connecting to the TC) have come loose. Though, by now, I would have thought it'd have sheared off and gone postal, if that was the case.



 

[Barbbachello]

The correct application of a 5 speed should fix it. Nah but srs ive got no idea 

[Jimbo]

If I had the cash do it, man, I tells ya.

[RX25SE]

Could be a cracked flex plate, around the crank bolts.
Or possibly a rooted convertor bushing in the front of the trans.
I doubt it's the front different as all its components are stationary when stopped in drive (or any time the vehicle is stationary)








Id go 6sp if doing a conversion, but I believe rarer cars should be left standard.


Shhhhhhh don't tell Mark.

[El_Freddo]

When was the last time the filter was replaced?

 

This could have a dramatic effect on noises/performance...

 

But like others, my AT knowledge is limited.

 

Cheers

Bennie

[Jimbo]

As far as I'm aware, still the original trans filter! Only just discovered it's location not that long ago!

It's on the to-do-list.

Jase, lel, I will be keeping it to standard specs. There's still some life left in it yet!

In regards to the bushing, are you talking about the whack-in rubber ring seal at the front of the box where the shaft comes out of the box? If so, I replaced that while I had the engine out earlier in the year.

[RX25SE]

As far as I'm aware, still the original trans filter! Only just discovered it's location not that long ago!

It's on the to-do-list.

Jase, lel, I will be keeping it to standard specs. There's still some life left in it yet!

In regards to the bushing, are you talking about the whack-in rubber ring seal at the front of the box where the shaft comes out of the box? If so, I replaced that while I had the engine out earlier in the year.

 

Trans filter will reduce flow to the cooler if its getting blocked, this will eventually cause overheating of the trans.

 

The 'whack in rubber ring' is the converter seal, the bushing sits behind that and supports the rear of the converter. Similar setup where the tailshaft slips into the extension housing.

 

If it's either of these, then its box out.

[Barbbachello]

Set fire to it

[El_Freddo]

Set fire to it

Because it can't/doesn't/won't do skids?

Cheers

Bennie

[Barbbachello]

Because it can't/doesn't/won't do skids?

Cheers

Bennie

Nah just easier than dealing with autos lol

[Jimbo]

For some bizarre reason, after I had done the spark plugs on Saturday the AT has stopped making the sound of death.

The only think I can possibly put it down to is the fact I jacked up the engine respective to the bank I was doing at the time. I think perhaps the transmission was allowing some sort of sound resonance or vibration to become abnormally loud. Perhaps something was slightly out of alignment and lifting/angling the engine has caused it to stop.

I'll continue to monitor it closely but just seemed odd that it suddenly stopped after I had done the plugs. Win!
 

[Beckers]

Nah, it's Jimbo's magic touch.

Good outcome, hope it stays that way m8.

[duncanm]

is it a forked engine or transmission mount, maybe ?

 

Rattling gone could well be that you've shifted something away from banging on a subframe or chassis somewhere.

[El_Freddo]

Rock/road debris dislodged? I'd imagine you'd need it to be a large rock/piece...

Glad it's sorted and I too hope it stays that way

Cheers

Bennie

[Jimbo]

I must have done something, it's still not making a peep! It was less of a rattling sound as such, but more of a dull muffled rattling with a louder whir.

No idea what I did!

I think I might be up for new engine mounts anyway. Really need to get it up on a hoist and have a geezer.

[motoboy76]

Top stuff Jimbo....