2003 VY SS Auto transmission issue

**PedroWilsoni** · 03-27-2011, 01:25 AM

Have an issue with clunking on 2003 VY SS auto at low speeds, bought recently. Advice really appreciated.

Recon auto trans fitted 3 weeks ago - with heavy duty extended-spline drum and heavy-duty clutch brake and 4/5 wet clutch kit, high-pressure switch in trans. New torque converter, tested fine.

Has a clunk when stopping quickly over 40 kmh and double-clunk when reversing. Will also clunk in and out of first gear when following 20kph granny in motorised shopping trolley (aka Huyundai Excel).

Mechanic says "Nature of the Beast", but I can't believe a clunk could be in a car that retailed for $50K

Any ideas what the clunk during first/idle or reverse/idle is? Any auto mechanics out there??

**bigrondownhiller** · 03-27-2011, 03:26 PM

Have you checked the universal joints and transmission mount?

**PedroWilsoni** · 03-29-2011, 12:37 AM

The transmission firm also replaced the tail shaft coupling which they said was shredded. I kind of presumed they would have noticed an issue with the mountings and mentioned it too. What do you reckon BigRon?

I will take your advice and get the rear universal (and the transmission mounts) looked at. Previous owner drove it pretty hard it seems. Wrecked the previous transmission so maybe universal is rooted too.

**mick08** · 03-29-2011, 01:13 AM

is fluid level right? Tricked up autos can be finicky on fluid levels, some say to check it wif the parkbrake on and in Drive, or check it within 25sec of switching off the IGN. Also the type of fluid can give probs if its wrong. Clunking more in reverse definetly sounds like an eng/trans mount, quick check is the select drive with ya foot firmly on the brake and give it a rev, have the bonnet up and a mate watching the engine, do the same in reverse and youl soon see if a mount is cactus, did this on an AU Falcon once and the fuckin engine nearly jumped out the bay!

**Cutlass** · 03-29-2011, 03:11 AM

Is this a 4L60e transmission?? Maybe they forgot the case saver anti-clunk spring or replaced it with a solid upgraded case saver. The solid one clunks more but also does a better job of distributing the load on the case lugs.

**PedroWilsoni** · 04-08-2011, 04:15 AM

Hi Cutlass,
It is a standard 4L60e box, apparently that's what came with the 5.7 auto - same trans as all the other variant 6cyl VYs. Has only done 800kms since the heavy-duty recon trans was fitted. Is a reputable mob that did the job, ATA out near Rosebery in Sydney. He swears there is nothing wrong with the recon unit and it is possible it also has an upgraded case saver. Everything else was upgraded as I posted originally.

The auto trans guy says I should look at the throttle position sensor. He reckons it might be sending incorrect info through the computer to the trans and it is shifting down gear thinking the engine is at lower revs than it really is - the higher pressures resulting in the random clunks. Does that sound feasible? Can a TPS be tested or do they wear out? A replacement is $188 from Holden.

With more driving, more detail - the clunk/thump only happens intermittently in three different situations - when you come to a stop and it drops down out of gear; if you tap and release the throttle in reverse - i.e. reversing into a parking spot slightly uphill; and in heavy traffic if you accelerate slowly to about 90% of the range in 1st gear (or 2nd) and then take your foot off the gas, it might drop up to next gear with a little thump. No issue at all with 3rd to 4th gear.

I guess when I think about it the car sometimes seems reluctant to shift up gears under power, even in normal shift mode (as opposed to Power Shift mode button), which could possibly allude to the same problem - TPS is telling the transmission that the engine is running at lower revs than it actually is...

I have heard a faulty TPS can cause all sorts of weird problems.

Any advice greatly appreciated!

**Cutlass** · 04-08-2011, 06:42 PM

Sure sounds like they left out the anti-clunk spring (aka case saver spring)

**PedroWilsoni** · 04-13-2011, 03:22 AM

Thanks for all your advice. It does have the case saver spring.

I went back to the auto trans shop today. The boys at ATA beefed the box up as I said, but I wasn't aware they did it with Billet HD components, heavy duty valve springs, and that they upped the transmission psi from 40 to 60lb. The trade off is the occasional thump under the console when it drops into idle, and the weird double-thump sh*t sometimes in reverse - which sounds like it is also coming from the rear of the vehicle. They offered to downgrade the auto transmission to standard psi and springs - which will eliminate the thump - but they reckon the standard transmission will get trashed pretty fast with the 5.7L, like the last one did with previous owner.

The auto mechanic assures me the thump won't hurt anything, and said that the way they rebuilt the 4L60e transmission it will suck up absolutely everything the 5.7L modded motor can throw at it. (currently pumping out a measly 251kw)

I have almost decided it might be better to live with the thump, rather than get my lead foot amputated. A friend suggested turning the radio up louder.

I will still get the rear universal looked at. Will get the diff eyeballed as well.

Any opinions, anyone?