Commodore VX Auto Trans Failure - How To diagnose?

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Commodore VX Auto Trans Failure - How To diagnose?

Postby JohnDee68 » Tue May 15, 2018 12:02 pm

Hi All,

I have a Commodore 3.8 Auto VX 2002 Wagon Acclaim (standard factory config)

While driving, I heard a sort of "plastic like pop" noise, then the drive to back wheels stopped.
There had been a similar noise to tappets out of adjustment (older style cars) for some time prior (few thousand kms before. which seemed to be louder in bell housing area. I had been trying to work out why and where it was, thinking it was trans or something in the area.)

Anyway, I have taken out the trans and torque converter.

How do I check if the torque converter and or trans drives are faulting?

the car is now on its third motor, but original trans and torque converter and has around 470,000 km on the clock. I have had it since 42,000km.

Any advice of what should or shouldn't turn on the torque converter (on bench) and the trans drive splines (on bench) would help greatly for me to diagnose.

Kind regards
John.

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Re: Commodore VX Auto Trans Failure - How To diagnose?

Postby Holden202T » Tue May 15, 2018 12:35 pm

if the torque converter was still connected to the flex plate then I dare say the issue is somewhere in the gearbox, but I'm not too sure theres too much you can do without pulling it apart ....

definitely rip the oil pan off and see if theres any chunks of metal in there ..... take the converter off, see if the splines on the end of the input shaft are ok, does the input shaft turn normally etc ....

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Re: Commodore VX Auto Trans Failure - How To diagnose?

Postby JohnDee68 » Tue May 15, 2018 12:57 pm

Thanks Holden202T,
The torque converter seems to be OK, from visual. But how can I tell if it is ? YouTube say different ways to check it, but none seem to give a basic concept. Like is it meant to have resistance both ways when you turn the big spline etc?

I understand that the oil needs to be pumped from the trans through the center spline of the trans to the torque. So If there isn't any oil in the Torque Converter for example (i need to check on that). Could that be then there is either a trans pump failure or blockage to the torque converter?

There wasn't any signs of anything abnormal in the trans when I removed the pan. Though this is my first experience with a auto trans. I am just learning (the hard way of course.) how a auto trans actually works (the basics).

i did do some basic tests while it was still in the car. though as there was no check engine light on and there was noises in the area of the bell housing ( like steel ball in a tin can). and the mileage it has done. i believed it to be mechanically somewhere in the trans?

thanks,

John.

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Re: Commodore VX Auto Trans Failure - How To diagnose?

Postby vlad01 » Tue May 15, 2018 1:41 pm

I'm not 100% sure if it will cause complete loss of drive but I know the pressed steel reaction shell has a pissy pressed tin splined section on the back of it and they can and do completely sheer off in the 4L60E. My mate rebuilt his in the VY as it was on its last legs (done nearly 500k at that point, started playing up at 200k) and he showed me all the bad areas in these trans that are weak and that one one his was 99% sheers off and hanging by a thread, the whole design of the box was actually pretty poor it terms of robustness and long life. He replaced all the weak areas and installed a full stage 2 and the large servos plus many other mods.

Basically shake it over a bin and start again. They are a really good box once you do them up, but stock they are woeful at best, even worse is the old 4L60. All mine failed at or before 200k. 4 or 5 boxes of them died on me. Only box I didn't have die was the 4L60E out of my VR as it only had 100k on it so I sold the box right away and converted to T5. Also my other VP is still auto but havn't even started it in 4 years and its got 73k on it so obviously still good. Plans are a T5 for that anyway.


I would suggest to get another lower k one and rebuild it as it won't be worth fixing that and you want to make sure you rebuild a 2nd hand one as the chances of getting one that will not fail on you is pretty slim. Had 0 success in that regard with replacing 4L60E in other people's cars I know, all failed with in a year of replacing.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.

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Re: Commodore VX Auto Trans Failure - How To diagnose?

Postby JohnDee68 » Wed May 16, 2018 12:22 am

Hi Vlad01,

I re looked at the gearbox today. as the Converter seemed to be OK, according to little info I could find on YouTube to test it.

The gearbox spline is unable to rotate ( seized solid). There are two or three bits of broken metal pieces which can be seen down the side of the spline inside the bearing area. pic attached.

I am planning to dismantle the gearbox in a couple of days to see IF it is a cheap and possible easy repair for now. To get me home (700km) where I can look to begin rebuild of a spare old one there.

Anyway, thanks guys for your advice and I will hope to get back here with what I find. hopefully it'll be good news.

thanks again,

John.
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Re: Commodore VX Auto Trans Failure - How To diagnose?

Postby pman92 » Wed May 16, 2018 7:09 am

The larger outter spline in your photo is meant to be solid, it splines to the stator in the converter and doesnt turn. The smaller center shaft spline is meant to turn, thats your input shaft, which splines to the turbine in the converter. The impeller in the converter is connected to the housing of the converter itself and turns at engine speed. You will notice the end of the converter where it goes into the trans there is 2 big notches, they line up and drive the pump (the pump drive is down behind that seal where your photo is pointing. If you see broken metal down there its very likely pump failure. Pump is unbolted and removed from front of trans I believe. Take care to ensure converter is in all the way correctly prior to installation in the vehicle (if pump drive isn't lined up, you will break the pump from converter pushing on it if you try to do up bellhousing bolts)

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Re: Commodore VX Auto Trans Failure - How To diagnose?

Postby Holden202T » Fri May 18, 2018 1:12 pm

yeah its too hard to tell in that photo, but it certainly sounds like the pump has failed.

so it just so happens I have a picture of what the pump should look like from when I rebuilt my T700 ..... so the black part in the centre is the pump drive that should lock into the two slots in the converter hub, then your larger splined section will be inside this.

P1120445.jpg

so if you cant see a black thing with two tabs, then its probably fairly certain the pump has packed it in.

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Re: Commodore VX Auto Trans Failure - How To diagnose?

Postby JohnDee68 » Sun May 20, 2018 8:29 am

Hi Guys,
thanks so much for all your advice and help.

Yes, on dismantling of the trans. (a good learning experience.)

The oil pump had shattered completely. I hope, it is just from age, not from anything sinister lurking further down the track.

Thanks again, help and advice appreciated.
Regards
John.

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IMG20180517133036[1].jpg

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Re: Commodore VX Auto Trans Failure - How To diagnose?

Postby delcowizzid » Sun May 20, 2018 8:54 am

It's very easy to smash the pump fitting the box with the torque converter already on the engine like people try to do .make sure you fit the converter in the gearbox and keep turning it till it clicks all the way in before refitting to the engine
If Its Got Gas Or Ass Count Me In.if it cant be fixed with a hammer you have an electrical problem

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Re: Commodore VX Auto Trans Failure - How To diagnose?

Postby JohnDee68 » Tue May 22, 2018 11:41 am

Hi, thanks for your picture of the gearbox oil pump. It helps.

Can anyone tell me, does the oring go on last or does the metal spacer go on last?

Regards

John.

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