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Discussion Starter · #1 ·
If I have to pull out the AX4S which seems to be working fine(with 100K on it), but leaking at the TC seal, what modifications would be recommended to prevent its demise? Shift Kit? Valve body mods?
 

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There is a recommendation in the service literature for several trannys I have worked on that involves enlarging the drain hole behind the seal to prevent fluid build-up and leaking from the pressure. Some rebuild kits also include a seal retainer, be sure to use it if supplied.
 

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I'm a strong believer in " If it ain't broke, don't fix it! "., especially when it comes to these transmissions. If the fluid was clean and red and it was working fine I would only drain it completely ( including the torque converter ) and replace the filter. Pay close attention to any debri in the pan or stuck to the magnet.

You could call a local transmission shop to see if they will let you take the dirty pan in for an opinion.

Good luck, Popeye
 

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The TC seal would have to be leaking really badly for me to pull the transmission to fix it. More than a quart a day bad considering you can get cheap Mercon V for about 2.99 a quart. But that is just me.
 

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Discussion Starter · #5 ·
I did the TCCA fluid change before it went on the road. Fluid was brown and didn't smell very good. Probably in there way too long. I dropped the pan last weekend to change the filter-found very little debris in the pan and on the magnet. 'New' fluid did not look new anymore, but smelled fine. Testing revealed that the leak starts when the fluid gets up to about 170 Deg F, and stops when it gets below 140 Deg F. I think I understand what is really happening now- the stator bearing expands with heat (and the fluid thins) such that too much fluid gets past it. The drain hole is too small to pass that much fluid, so the pressure behing the TC seal rises to the point that the seal cannnot contain it. Then it hemmorages ATF all over the driveway. When it cools, everything is fine again.
 

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You could try seal conditioner as an alternative to pulling the trans. Even if it doesn't stop the leak it may slow it down some.
 

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Don't use seal conditioners as a substitute for fixing the seal the right way.

QUOTE
Aftermarket products like transmission seal conditioner/stop leak can cause you thousands of dollars more in repair costs than you really needed to pay, if you had fixed the true problem first.

The manufacturers of these kinds of additives are often correct in what they advertise the products they sell will accomplish for you, but are extremely misleading in how they do it. For example, if you have an old clunker that keeps dumping fluid from an old dry or worn seal, pumping a bottle of stop leak in may temporarily solve the problem but the long term effects can be disastrous if you use it in a vehicle you plan to keep around for a while.

Here's what happens. The additive is absorbed into the o-rings and seals which then causes them to soften and expand. Good deal right? Expansion means a slighter tolerance between the seal and the components it was intended to seal right? Not always. What works for a short time actually becomes a bigger problem once the additive has had time to sufficiently penetrate the seal material. A high number of transmissions treated in this way will leak FAR MORE than they did before, after the seal has overly softened, in essence turning to jelly and falling apart. Another problem is that the seal swells so much that the moving part it was intended to protect will literally render it useless by ripping the softened seals to shreds due to the reduction of tolerance between the two parts. Imagine lightly placing your finger against a turning fan belt. No big deal right? There is light contact, some transmitted vibration and it really doesn't hurt your finger. Now try grasping the belt tightly in your hand or pressing your finger firmly against it. Different story isn't it? Now you see the difference in the reduction of tolerance between a seal and a moving part.

Even if the seal is retaining fluid between two non-moving parts,(Which is far less common)the additives in stop leaks and conditioners will eventually just eat the seal up by turning it to jelly until the seal has dissolved to the point where it can no longer withstand the heat and pressure contained in an automatic transmission. In either case what you end up with is a seal that used to work at 80% now works at 20% or less and you have a much more serious leak than you started with.

Another factor is the automatic clutch packs inside the transmission. Many of these additives will attack the friction material that is adhered to the steel discs that make up the clutch packs inside your planetary gear sets. Even using the wrong automatic fluid can ruin a clutch disc so imagine what a penetrating petroleum solvent can do. I've seen transmissions that have been treated with an additive end up completely without forward or reverse gears due to all of the friction material on the clutch packs being weakened to the point where they can no longer withstand the pressure and heat they must endure even during mild driving conditions. Some transmissions I've disassembled have been completely stripped of friction material and ended up clean and polished when they should look more similar to a sanding disc.(To use a commonly known comparison. In reality they don't look like a sanding disc but you get the gist of the comparison.)

In many cases the additive doesn't fix anything at all because the problem wasn't really the fault of a seal to start with. Often the true cause of your transmissions fluid loss is a worn driveshaft end, torque converter neck or worn case bushings in the front or rear of the transmission. In all cases it's much cheaper to have a qualified technician replace a faulty end bushing/seal or other damaged part in the beginning than to end up having the entire transmission overhauled because all your interior seals, o-rings and clutch discs (At least all of them that aren't made of plastic or metal)have turned to goo. What might cost you $100.00 to $300.00 now will certainly cost you hundreds, if not thousands more later. For most people their vehicle is the second biggest investment they will make in their lifetimes, don't take chances with it. Fix it right and it will thank you with relatively trouble free operation if you do.[/b]
 

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I think that's where my 98 is leaking from too. It's not that bad. I only have to put some fluid in every few weeks. I just get generic Mercon/Dextron stuff. Mechanics tell me it's exactly the same as Mercon V. Mercon and Dextron are supposedly so close you can't even tell the difference too.

But yeah, if I go on a lot of highway trips, it'll lose fluid faster, but whenever it starts to act funny (like shifting poorly around turns), I'll fill it back up.
 

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Would it be cheaper to just keep filling it up for 4 or 5 years or pull it out anda have someone fix it? You have a self flushing transmission :)
 

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Discussion Starter · #11 ·
If this thing leaked constantly, but slowly, I would consider leaving It. The problem is that it goes all at once. It's not cool to leave 3ft puddles of ATF as your calling card. It may not necessarily be cheaper to keep filling it, the actual broken parts are under $20. The problem is getting to them. I am starting to consider pulling the engine and leaving the transaxle in. I would also change plugs and water pump, and any other minor things which would be easy to access. Any thoughts?
 

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I'd strap an old skool refrigerator drain pan to the bottom of the trans where the leak was happening and catch the fluid, filter it and put it back in on the weekend.
 

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Discussion Starter · #14 ·
When I get around to fixing this properly, can I get a newer AX4N and install that? I believe the computer would need to change, but that doesn't sound too bad. If this is a real possibility I will start looking for a replacement now.
 

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I'd put on a better cooler. With the Gen 2 SHO cooler and radiator bypass the temp seldom got over 150F on the hottest days.
 

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Discussion Starter · #16 ·
I was intentionlly raising the temp by driving hard then holding the engine at 1500 in drive for about 20 seconds at a time while parked until I got it to leak. I will look into a trans temp meter in the future. I was able to cool the trans down below 140 in less than 10 minutes by turning on the AC so the fan carried air accross the cooler I installed. I have read that up to 200 deg F is reasonable for fluid temps. It's only above this point where significant loss of fluid and trans life occurr.
 

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200f isn't too bad as long as you are using synthetic fluid. Otherwise it is too high IMHO.

Still the cooler the better. You have to get below 120F before there are any negatives as to being too cold.
 

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Discussion Starter · #20 ·
OK once I get the leak squared away I'll switch to synthetic. How do I get the leak squared away?
 
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