I was just reading a few threads here about this dreaded "wave spring" failure issue which can result in catastrophic gear box damage.

Is there anything we can do to prevent it? Any maintenance? Should the spring be replaced at some point in its lifecycle? What is the root cause of such failures? Is it happening to all models?

And if anyone can explain exactly what the "wave spring" does it would be appreciated.

If you have a kw im under the impression your gearbox came with a revised wavespring, much better then the tj and earlier autos. Someone confirm?

I believe the spring can't be replaced without taking your gearbox apart, so there's no point in replacing it.

Regular fluid changes and a transmission cooler will help reduce the stress on your gearbox and improve its life.

Hit or miss with the wave spring. It breaks or it doesn't.

http://i28.photobucket.com/albums/c201/rc_maniac/trans2-08024temp.jpg

Breaky one on left, revised one on right. Probably breaks due to metal fatigue, nothing you can do to prevent it short of replacing it.


Someone else will have to tell you which models are affected, I have a TJ and TL, both 4 speed autos, and I'm interested in that as well.

KW/TW's were the only 3rd gen to get the revised washer so you should be right.
If the wave spring washer breaks, then the transmission has to come out and be stripped down to replace this item.
Best preventative measure would be to change fluid with the genuine Mitsubishi Diamond every 20,000kms, and as per Madmagna's suggestion, install a tranny cooler and external filter (as internal filter for these stay sealed for the life of the transmission and can only be replaced by again removing the transmission and stripping it down). I've had my wave washer replaced with the revised unit & I have just purchased the cooler and external transmission filter to install this weekend.

KW/TW's were the only 3rd gen to get the revised washer so you should be right.

Noooooo ! Recently I found my car to be a KL based on the manufacture date of June '04. I had believed it was a KW based on first registration date which was later in the year and I knew they were manuf KW's by then. My bad.
Is there no chance some KL's were fitted with the new springs?


Best preventative measure would be to change fluid with the genuine Mitsubishi Diamond every 20,000kms, and as per Madmagna's suggestion, install a tranny cooler and external filter (as internal filter for these stay sealed for the life of the transmission and can only be replaced by again removing the transmission and stripping it down).

Why is an additional cooler necessary? Doesn't the ATF cycle through the radiator somehow to cool it down? Are there known problems with the design?

The idea of an additional filter seems good, but if you're changing the fluid that frequently what's there to catch in a filter?
(apologies for any silly questions!)

If your car is a TL then it would most likely have the dreaded wave spring washer ( cost me $1000 to get mine replaced).

In line Transmission cooler helps to keep temperature at a more consistent level. It also has the benefit of increasing transmission life because of this.

The benefit of running an in line filter is it provides additional filtering of sludge, residues and metal particles which is part and parcel of transmission wear & tear. given that your transmission filter is inside the box, by running an external one and changing the filter at regular intervals will pretty much eliminate the necesity to change the internal one saving alot of money as well as assisting in trasmission life.

Why is an additional cooler necessary? Doesn't the ATF cycle through the radiator somehow to cool it down? Are there known problems with the design?
The in-radiator cooler is not adequate basically. The book service interval is 45000km. If you check the ATF at that point, it will more than likely look coffee coloured (if not black).

With an auxiliary cooler fitted in series with the radiator, you will get much better life out of the ATF - possibly even the book interval. I have mine changed at 25000km intervals even with an auxiliary cooler fitted, as dealing with a box replacement is $$$.


The idea of an additional filter seems good, but if you're changing the fluid that frequently what's there to catch in a filter?
(apologies for any silly questions!)

The first bits of spring... in effect, the external filter is your early warning sign (if you want it) as you can't deal with the internal filter.

I too always thought that from T/KL on all boxes FWD and AWD had the revised spring added. Plus with our AWD boxes coming from the EVO GTA, they would be strengthened from factory?

The changeover to the better wavespring was probably done as a "running change", ie not linked to the appearance of a new Australian model, as the box is (probably) made in one factory in Japan, and shipped all over the world to go into different models and even makes.Only an insider would be able to tell from factory records what gearbox serial number coincided with the new spring.

"Mitsubishi F4A51 Automatic Transmission Hazard Problem" happens in the States as well.

http://www.thepetitionsite.com/1/mitsubishi-f4a51-automatic-transmission-hazard-problem/#13485763287612&action=fb_connect&fb_id=0

This one is worth aread for the technical info:

http://www.transmissiondigest.com/tech/TD200508/200508ShiftPointers/200508ShiftPointers.htm

http://www.club3g.com/forum/2423133-post23.html

Evidently not!! Mine's a 2003 KJ AWD same INVECS II as evo GTA also. Original washer was a wave spring type. Which was promply replaced with upgraded unit upon discovering bits of the wave spring washer last tranny service :(

Ahh ok, well, since I had the cooler put on and tranny flushed every 15-20,000km, I haven't had any issues with mine yet.
That reminds me, I need mine flushed after my cross country trip.

The first bits of spring... in effect, the external filter is your early warning sign (if you want it) as you can't deal with the internal filter.
Be too late by then wouldn't it? Bits of spring been through the transmission already.

TL owner here, and I have had the Wave Spring damaged and a revised one put in.

Now I could be wrong, so don't flame me here, but I don't think regular Gearbox oil changes and/or Trans cooler will stop the wave spring failing.

Its a piece of spring steel, which seems to have been manufactured wrong, hence why a revised one doesn't fail...

Again, I could be wrong, so don't shoot me down....

Ahh ok, well, since I had the cooler put on and tranny flushed every 15-20,000km, I haven't had any issues with mine yet.

Wow, that's fairly frequent. I'm wondering what's causing the spring to break. Obviously it's not sufficient to meet some load conditions, but they do work ok for thousands of k's, so whats happening? I wonder if temperature plays a role? Or is it dirty ATF?
Has anyone had one break with an external cooler fitted?
Also, has anyone had one break even with fairly frequent ATF replacement?

I posted a poll here (http://www.aussiemagna.com/forums/showthread.php?t=97495&p=1531200#post1531200)

Wow, that's fairly frequent. I'm wondering what's causing the spring to break. Obviously it's not sufficient to meet some load conditions, but they do work ok for thousands of k's, so whats happening? I wonder if temperature plays a role? Or is it dirty ATF?
Has anyone had one break with an external cooler fitted?
Also, has anyone had one break even with fairly frequent ATF replacement?

Only because half the time my car sits in one spot for weeks to months at a time, which it will be doing again soon.

i had my box rebuilt last year, all new internals, new seals the lot and a revised wave spring :)

well i need not worry because i have converted to Manual. but i have a friend who just bought a AWD magna, is there any reccommended option for a filter/cooler setup on the cheap?

well i need not worry because i have converted to Manual. but i have a friend who just bought a AWD magna, is there any reccommended option for a filter/cooler setup on the cheap?

2nd gen cooler from wreckers & Magnefine filter from ebay.

Noooooo ! Recently I found my car to be a KL based on the manufacture date of June '04. I had believed it was a KW based on first registration date which was later in the year and I knew they were manuf KW's by then. My bad.
Is there no chance some KL's were fitted with the new springs?

One certain way of telling the difference between a KL and a KW is that the KW has the extended front and rear bumpers with side reflectors. Also, if yours is a KW then it will be the GTVi AWD like mine and not an Ei AWD.

One certain way of telling the difference between a KL and a KW is that the KW has the extended front and rear bumpers with side reflectors. Also, if yours is a KW then it will be the GTVi AWD like mine and not an Ei AWD.

Thanks vlad, I've learned about that now, no its definetly a KL. I just made an assumption about it based on my limited understanding at the time of when they made the W series, and got it wrong. Lol, basically it went "they made the KW in '04, this is an '04, therefore it must be a KW". Brilliant.
Apart from the bumpers and mirrors and possibly wave spring, we're there any other differences?

Sounds like they reverted to similar bumper style as my KH at the end there, probably reflects some desperation. Trying to recover the glory days of the early 2000 years perhaps. Actually I like the big bumpers, but a bit of a pain when parking.

I notice they changed the bonnet on the KL too, has additional lines on either side following the body line. I don't like them, prefer the smooth uninterrupted sweep of the bonnet on the KH.

The VIN number incorporates the model designation in the 4th and 5th characters.

manual conversion?