AU2 auto issues

Beer Baron · 26-12-2010, 11:54 PM

Hey Hey,

My I6 AU2 auto sedan is starting to vibrate.

It does it at 90kph in 4th with the torque converter locked. Its a vibration like the rears wheels are out of balance but it pulsates. Cant feel it through the steering just every where else.

It doesn't do it in 3rd with the torque converter locked just 4th. That rules out wheels and diff. So im thinking gearbox is starting to show its age ?

30,000km ago i flushed all the fluid and fitted an oil cooler so the fluid is still reasonably good.

Opinions ?

frd906 · 27-12-2010, 10:52 AM

Could be the tail shaft is out of balance, or the uni joints are shot, also the bush in the back of the gear box could be stuffed,

There was a thread on this some where with the same problem

Fordsgofaster · 27-12-2010, 12:01 PM

I'd near put money on a rear uni, Checking to see if there's play won't tell you the story either.

I think its lost lube in one of the caps, usually felt during mild acceleration & higher cruise speeds. Solidified grease & sometime rust take up all the spare space in the effected cap so checking for play won't show it up.

Beer Baron · 27-12-2010, 03:15 PM

Quote:

Originally Posted by Fordsgofaster

I'd near put money on a rear uni, Checking to see if there's play won't tell you the story either.

I think its lost lube in one of the caps, usually felt during mild acceleration & higher cruise speeds. Solidified grease & sometime rust take up all the spare space in the effected cap so checking for play won't show it up.

Even if its in 3rd changing the pedal position i cant get to happen, only in 4th when the torque converter is locked ?

mik · 27-12-2010, 03:21 PM

my series 2 xr6 the tailshaft uni`s were getting a bit of play in them at about 130000 k`s, i did mine early last year iirc, definately worth checking if they have`nt been done.

Beer Baron · 27-12-2010, 03:41 PM

Will have to wait till Wednesday so i can put it on a hoist.

blackers10 · 28-12-2010, 11:50 AM

joshes car had some bad vibrations and was using a tonne of fluid, turned out to be the bearing/bush in the back of the gearbox

otherwise if its the box i still have my built gearbox here waiting for sombody to buy..
yours for only $750
shift kitted, extra clutch packs and all that fun stuff

Fordsgofaster · 30-12-2010, 11:18 AM

Quote:

Originally Posted by Beer Baron

Even if its in 3rd changing the pedal position i cant get to happen, only in 4th when the torque converter is locked ?

It could well be something more serious, but that still sounds like a uni. 3rd gear generates more torque & will force the uni past its tight spot. 4th gear converter locked the engine has less mechanical advantage over the drive line + its rpms are pulled down so the actual force its exerting on the tail shaft is less, this is when a crook uni will start vibrating.

No real way to check them either, even on a hoist, they will look & feel fine. Only real way is to pull them apart & of course for the cost of them you then just turf em & fit new ones.

Beer Baron · 30-12-2010, 08:49 PM

The vibration went away but its back again.

au adam · 30-12-2010, 10:07 PM

Ok try this out.One of my utes was doing this.Turns out the thermo fan had stuffed itself,this resulted in the trans fluid getting hot and the same thing you have decribed happening.It was the low speed fan,not the AC one.
If you have some body that has access to computer testing equipment id have that looked at.

Beer Baron · 30-12-2010, 10:49 PM

Fans work fine, They **** themselves about a month ago and have brand new ones fitted and working fine.

I'm thinking the tail shaft like people have suggested or the box is packing it in.

au adam · 31-12-2010, 05:51 PM

Quote:

Originally Posted by Beer Baron

Fans work fine, They **** themselves about a month ago and have brand new ones fitted and working fine.

I'm thinking the tail shaft like people have suggested or the box is packing it in.

Well that eliminates that,we replaced the auto thinking it was stuffed ans later on found out it was the fan.After we replaced the fan it was OK for a while but it started again.Turned out the thermostat needed replacing too.
Honestly i would look in this area too.Take note if it is doing it when it either hot or cold.Mine was really bad after getting off the freeway and then driving on local streets.

Beer Baron · 31-12-2010, 06:01 PM

Does it cold, hot all the time.

Beer Baron · 04-01-2011, 03:19 PM

Went to my mechanic friend today and put it on the hoist. My torque converter is stuffed.

blueoval · 04-01-2011, 03:43 PM

Get the stock converter stretched out a few hundred rpms while its out. Its a cheaper form of a stall converter.

Beer Baron · 04-01-2011, 04:59 PM

Quote:

Originally Posted by blueoval

Get the stock converter stretched out a few hundred rpms while its out. Its a cheaper form of a stall converter.

I'm just going to convert it to manual and sell the auto on as parts or something. FTG can do me a kit for about $1150 to my door.

blueoval · 04-01-2011, 06:02 PM

Thats not bad at all. Make sure you post up the pics when you get it done.

sd1800 · 11-01-2011, 12:54 AM

How did he confirm it was the converter? I had the exact same symptoms as you, was told it was my converter, spent $900 on a semi-recoed box to find out it was my oxygen sensors.

I had identical pulsating symptoms @ converter lockup and it was my oxygen sensors leaning out the mixture. I discovered this by watching my trip computer and whenever I would get the Pulsating vibrations my instant l/100km would drop considerably, and then rise again when the vibrations went away. If I disconnected the battery and reset the ECU the problem would seem to fix itself for a couple of hundred K until the ECU relearnt it's previous bad readings.

Drive the car with your Oxygen sensor disconnected just to double check this isn't the problem.

Mr Hardware · 11-01-2011, 12:56 PM

sd1800, i can see your concern, but a busted o2 sensor on an I6 doesn't display the same behaviour as one on a V8.

Dave_Obsession · 11-01-2011, 03:10 PM

Quote:

Originally Posted by blueoval

Get the stock converter stretched out a few hundred rpms while its out. Its a cheaper form of a stall converter.

Can you do this?? How much would it cost? Or is it worth getting a hi-stall, even a mild one (2400rpm etc)?

How do they actually do it? I'm not very mechanically minded, only when it comes to detailing!!!

blueoval · 11-01-2011, 03:22 PM

Quote:

Originally Posted by dave93761

Can you do this?? How much would it cost? Or is it worth getting a hi-stall, even a mild one (2400rpm etc)?

How do they actually do it? I'm not very mechanically minded, only when it comes to detailing!!!

If you get someone that knows what they are doing, it can be done for a few hundred bucks plus the R/R of the gearbox. To buy a TCI, JMM or Dominator style converter you would be about $450 plus R/R gearbox. All in all its only a few hundred bucks difference.

To modify a stock stall, they open up the guts and flatten out the fins in the converter I believe. Meaning the engine has to rev a bit harder to get the converter to move hence the stall converter effect. At least I think thats they way its done.

I have heard there are still benefits of getting a small stall fitted to even a mildly modified engine. The 2400rpm stall Im getting is second hand from a member I know of so I will be saving more cash, but for the extra 400rpm over stock it will help my off the line take offs and launches no end. Should also limit the amount of bog I get down low off the lights too. This then equals a bit more

than before. haha

Have a look at what you may be up for for an off the shelf item.

TCI
http://www.compperformancegroupstore...ry_Code=SNSCNV

JMM
http://www.jimmockmotorsport.com/html/whats_new.php

Dominator
http://www.dominatorconverter.com.au/streaker.html