Keeping Chrysler Caravan Transmision Reliable.....

[Kestas]

quote:

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Originally posted by trynew:
...The transmission outlet (nearest the wheel) runs to the bottom of the radiator, and the return line comes from the top of the radiator back to the transmission. Isn't this backwards? Since it is cooler on the bottom of the radiator, that is where you would want the return line to be, isn't it?

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Not necessarily. You don't want the transmission fluid to get too cold either. This arrangement allows for warming the transmission fluid when it's too cold. The key is to modulate the temperature, not reduce it.

That's also why - for those people inclined to add an auxiliary cooler - it's advised to add the aftermarket cooler to the fluid coming out of the transmission rather than for fluid going into the transmission.

 

[Kestas]

quote:

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Originally posted by rg144:
On the Chrysler forums people agree that the frequency of failures are no worse, if not better, than the industry.

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You and I must not read the same posts. When the A604 Ultradrive transmission came out, the warranty rate was 10%, an unheard of percentage for warranty returns in the industry. The Chrysler crowd has done nothing but lambaste the A604 Ultradrive transmission. Chrysler Corp. never really did much to improve the transmission's design.

Chrysler came within a hairsbreadth of being forced by the government to recall that transmission. I can only imagine the government backed off because it would have bankrupted the company (I've seen before where the government compromises with the auto industry), plus it wasn't really a safety issue. After that, Chrysler fixed a lot of transmissions for free under an extended goodwill policy (including my transmission with 80,000 miles).

 

[FazerZ]

*** LONG EXPLANATION ***

The A604 Ultradrive, or the 41TE, has gone through quite a few changes and has had some serious reliability related "growing pains"

All transmissions/transaxles (like a lot of automobiles) tend to go through this. When GM introduced their 4-speed automatics in the early 1980s, the first couple generations were a big mess and the number of reliability problems were large and widespread. The 440T4 (FWD 4speed auto) and the 700-R4 (medium duty RWD) come to mind. Only after about 4 years, did they work the bugs out.

Most of the problems with the A604 can be narrowed down to two main areas: Underdrive (UD) snap ring breakage causing Underdrive/Overdrive clutch failures AND weak/poor part manufacturing.

The UD snap ring trouble has been addressed three times in the last 10 years and this last generation seems to have the problem solved. The first generation snap ring was too thin and weak and would break causing transaxle failure. Naturally, the snap ring thickness was increased and the corresponding UD/OD plate was machined down and the housing modified to accept the new ring. This update happened in the mid 90s and allowed this complaint to happen LESS often. However, it was not eliminated. Towards the end of 90s (98 i think), the snap ring was increased in thickness AGAIN and the plate and housing modified AGAIN. This is the latest design and seems to have solved this major sore spot.

Poor quality parts (read CHEAP) and some readily apparent cost cutting tend to cause the remaining troubles.

Hub shafts too small causes breaks at welds/joints. Hub shaft enlarged and strengthened near middle of 1996.

Front planet carrier spines too soft causing stripping. Updated to hardened splines near the early 2000.

Hubs too soft causing excessive wear where the clutches ride the hubs. A substantial upgrade in hub construction and process was done around early 2004. The pieces now look like they will last and hold up for awhile.

The list goes on. DCX is constantly improving this transaxle and unfortunately its got a well earned bad reputation, HOWEVER this general design of transaxle is now what a large number of other manufacturers are now using. General design meaning adaptive controls and each clutch in the transmission/transaxle being controlled by a electronic solenoid.

DCX, or actually just Chrysler at the time, in 89 introduced a transaxle that was COMPLETELY different than anything on the market. The unit was the future of where later designs would probably end up. They just went a little too far with the cost cutting and not enough road testing.

No matter what the automatic transmission/transaxles, regular preventative maintenance is critical and can help avoid costly repairs.

Specific recommendations on your van: Auxiliary cooler is ALWAYS a good idea and on a lot of their vans now its factory equipped. Most modern transaxles run wayy too hot and need help in getting the heat out.

If there is no cooler present, get a transmission shop to add one or DIY if you plan to hold on to the van for an extended time/take long highway trips/heavy loads.

The recommended setup for the auxiliary cooler is in series with the main radiator and placed AFTER radiator. I've never seen a OE design that puts the cooler BEFORE the radiator. Overcooling is typically NEVER a issue. The torque convertor will generate plenty of heat, its just a matter of getting the fluid flow OUT at a decent rate. There have been bypass issues where the fluid has gelled because of low temperatures and FLOW was restricted causing lube related failures. Most models since the early 90s have a bypass built in the case.

Hope some of this information helps give some specifics to the history of Chrysler's leap and how it keeps guys like myself on our toes. Nothing stays constant, except failure.

DH

 

[Kestas]

Fraser, glad to have your input and experience.

I met a transmission expert - such as yourself - who rebuilt the transmission on my 71 Cutlass. He too remarked at all the cheap parts used in modern transmissions. There's little robust about modern transmissions.

Some of your post reinforces some troubling thoughts I have on these transmissions, namely that any savings from increased fuel efficiency gained from these new transmission designs over the old 3-speed designs seems to be lost to the increased number of expensive repairs that these cars have seen. Decades ago, we never had to worry about replacing a transmission. They always seem to outlast the car.

What good is new technology that is supposed to save us money in fuel efficiency if it is so expensive to repair? It unconsionable to release a product that isn't yet thoroughly refined, then spend ten years of "field testing" at the consumer's expense to get it right. Technology just for technology's sake is a step backwards in automotive engineering and not what I call progress.

 

[Idrinkmotoroil]

I walked into a transmission repair shop today to talk shop on my Caravan's transmission and got some interesting info from the owner. He seemed like a decent guy, older gent who has a good reputation. I asked him about changing the transmission fluid in my van and he said it is a waste of time as long as the fluid is nice and read/clean. I was very shocked by that answer. He said he would gladly take my money to do it but it won't make things any better. He also said there are no more bands to adjust as it is all done electronically now.

Then he took me in the back of his shop. He said the number one failure of chrysler auto fwd transmissions is the pin around the differential breaking and penetrating the transmission case. He had a Chrysler Cirrus on the hoist with the exact problem and that is what happened to my friens van as well. He went on to say that Chrysler has addressed basically all of the interior design issues over the years and the transmission is actually very reliable now other than the potential ring breakage. The pin breakage usually happens when one wheel is stationary and the second wheel is spinning, such as in snowy conditions.

He said when you do a transmission fluid change you are only getting out about 4 quarts of fluid, where it holds in upwards of 12 quarts internally. I asked about the filter change and he said it only filters dirty fluid, if the fluid is nice and clean and red then there isn't any benefit in a fluid or filter change. He told me that him and his wife own three chrysler fwd auto vehicles including a caravan that has 200,000 kms on it and the transmission still runs perfectly.

In his opinion the solenoid pack can fail ,but that does not a issue, and then the pin failure is the only other thing that normally goes wrong with them. I also learned that a bad battery can damage a modern day electronic transmission, so keep the battery above 12 volts or replace it when it gets less.

Upon asking him what we can do about the pin breakage he did say that an aftermarket kit is available to reinforce the area which will keep the pin from penetrating the transmission case. He said that would cost $400. But my friend told me that Chrysler has addressed that issue with reinforcement of their own in newer fwd auto transmissions, so I dont know what to believe.

I still found it very intereting talking to the guy, he seemed like a very experienced and knowledgeable person. I think I will still change the fluid and filter though.

Joey

 

[DJStillman]

quote:

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Originally posted by Ken2:
Auto-Rx cleaning,
Magnefine or SPX Filtran in-line filter,
Schaeffer's new #204SAT ATF for +3 & +4 applications.
http://www.schaefferoil.com/datapdf/204SAT.pdf


Ken

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Has this fluid been approved by DCX??

 

[rg144]

quote:

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Originally posted by Kestas:

quote:

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Originally posted by rg144:
On the Chrysler forums people agree ....

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You and I must not read the same posts.

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FYI, here is the link Chrysler Trans forum - Edmunds Town Hall. The forum may be useful to Idrinkmotoroil.

Sorry, I should have mentioned the discussion is about minivan comparisons, not all vehicles - and how they exceed the reliability of the Honda Odyssey (and, yes, I've posted on that forum). And (big disclaimer follows), I am in no way defending the Overdrive transmission that Chrysler foisted on the unsuspecting public.

 

[FazerZ]

Regular service will help to keep Chrysler's 4spd on the road longer. It's best not to just leave the fluid in and hope for things work out. Transmission fluid temperatures seem not to be going down and unless you invest in some significant cooling to offset this, A simple, regular service is all that is needed.

More specifically regarding the differential carrier/spider gear rod causing massive case damage. This is a issue that started to appear in the later models, however most of these troubles are happening in high mileage units and in certain year ranges.

This happens in a variety of transaxles (certain model years of SATURN's TAAT and quite a few Mazdas) and can be attributed to material lack of hardness (manufacturer's deficiency) AND poor lubrication from lack of service or low fluid levels AND driver's error.

GM fix for the Saturn was to change the rod material and machining. I have never seen any sure fix for Mazdas, other than guys welding the differential rod in place.

In the DCX transaxles, the rod damages the transaxle case because the spider or carrier side gears seize to the pinion pin causing it to twist breaking the roll pin and allowing it to walk/fly/launch out. There have been a number of fixes, aftermarket and factory. The factory fix consists of a pair of brackets that cover the hole that the pinion rod sits in, PREVENTING the pin from working out and damaging the case. However, this does not prevent the pin from seizing. In NEW factory units, the roll pin that holds the rod in place was eliminated and now the rod floats and the brackets hold in place.

From what i tell, if the unit has poor lubrication (read poor service and/or leaks), your chances for this scenario increases. So, the easy solution is to keep the fluid changed on a regular basis and keep the fluid level at the correct level. Get those leaks fixed if present!

Some last suggestions are about wheel spin and tire sizes. When stuck in snow, ice, mud, wheel spin can cause this area to fail as well. One wheel spinning while the other is stationary is bad news for those spider gears and pin. Be smart when you get stuck, get help. You would be surprised how much work appears after a snow or ice storm related to differential failure.

Always use the same brand and size on the front wheels, differences in wheel size will again overwork this area and contribute to differential failure. Mix tire brands all you want on the rear axle (excludes AWD vans), it will not affect the tranaxles.

AGAIN, regular service on your vehicles' transmission/transaxles WILL improve reliability and reduce repairs.

DH

 

[Idrinkmotoroil]

thanks, great info, much appreciated.

One thing though, not spinning the tires up here in our climate is tough as heck during the winter months. It happens a fair bit, not just when you are stuck. Can't imagine manufacturers building vehicles where their owners are having to be conscious of not spinning the wheels in winter driving.

 

[Ken2]

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Has this fluid been approved by DCX??

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DCX has not approved any other source for +4 than their own. In the case of a non-approved "recommended for" +4, you're relying on the warranty from the oil maker. I trust Schaeffer in this regard.

quote:

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One thing though, not spinning the tires up here in our climate is tough as heck during the winter months. It happens a fair bit, not just when you are stuck.

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Four real winter tires, not just all-season tires, might be a real bargain is they save a transmission, as well as having safer traction.


Ken

 

[Gary Allan]

FazerZ

That's a great testimony to ulitmate incompetence in engineering. You can't make it sound any better than it is. They made junk ...and I'm sure they still make junk. They've over sophisticated the simplicity of the automatic for what? .359 mpg on the EPA urban cycle? The minivan itself save the motoring fleet billions of gallons over the old family truckster.

I won't buy an automatic if I can avoid it. It does not matter what the level of reliability or frequency of incidence is on a given contemporary automatic. The smallest of part failures still results in $2000 worth of repairs. It's not like a MAP sensor going bad.

From your disertation there ...it looks like it took 20+ years to figure out that they were total jerks in engineering their transmissions for the prescribed service duty. During that time ...the engineers that shoved this lame mockery of engineering on the public have probably either been promoted or retired ...and a new echelon of brave new young bucks are building equally as sophisticated (overly so) devices for their own glorification.

When autos were up to the task for the lifetime of the car ..the whole car was junk before the trans let go. The TH350, 400, the C4, C4S, C6, the TF-727, 904 were lifetime transmissions with more torque and hp being applied to them than 99% of the contemporary automatic. True abuse was the only thing that typically killed them. The past 25-30 years has seen that they've made the engine last 200,000 miles without major service ..while making the automatic a crap shoot. While the cost of maintenance and repair on engines has gone down (replaced with infinitely more reliable managment systems in manufacturing costs) autos have proven (aside from perhaps timing belts) to send a perfectly good vehicle to the junk yard due to the costs of a rebuild.

Lame is lame no matter how many reasons or excuses you can think of. I see no reason to have any more faith in a contemporary automatic than I have over the last 20 years. If the improvement is so radical in reliability, the manufacturers should offer a simple 100k warranty on the auto ..or 5 year unlimited mileage. They don't ..they're still a crap shoot.

I'll pay ten to one on trans failures over engine failures to anyone (failure requiring rebuild for remedy. Rebuild being qualified as a $$ equivalent to 75% of a complete overhaul or more). I would even extend this wager to engines that are marginally maintained ..and transmissions that are flawlessly (even overly) maintained. Maintenance does fix items that are design flaws.

[ February 13, 2005, 11:07 AM: Message edited by: Gary Allan ]

 

[Kestas]

Good post, Gary.

 

[kenw]

"Maintenance does fix items that are design flaws."

as one having spent 30 years fixing bad designs, I would differ here. (as I reread your post I suspect a typo left the word "not" out)

regardless:

Maintenance cannot fix design flaws. It may avoid some of the consequences. It may and often does mask design failures; in fact maintenance is usually the scapegoat for design defects. Personally, the co-scapegoat is "manufacturing defect".

A good design cannot be built wrong in a normal production environment.

A good design comprehends potential maintenance and manufacturing tolerances/variables and is designed to accomodate much of the variance that these imprecise operations entail. Including the human element.

We call it DFMA, DFR, DFS (Design for Manuf and Assy, - Reliability and - Service.)

the Japanese call it Poka-yoke (goof-proofing).

 

[Kestas]

It's no wonder the American auto industry is going to get hit hard by the $7000 cars built by the Chinese and other Third World countries. I'll bet they don't have 4-spd automatics. Look out for these cars in a few years. This kind of competition will put a stop to the nonsense we've been seeing with all this hollow engineering built into today's cars.

 

[kenw]

quote:

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Originally posted by Kestas:
It's no wonder the American auto industry is going to get hit hard by the $7000 cars built by the Chinese and other Third World countries. I'll bet they don't have 4-spd automatics. Look out for these cars in a few years. This kind of competition will put a stop to the nonsense we've been seeing with all this hollow engineering built into today's cars.

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you can bet the 7k cars don't have heated leather buttwarmers, indash navigation systems for the brain-impaired, runflat tires and pressure monitors for those who can't afford a $1 tire gage....etc....

 

[brianl703]

Tire pressure monitors are mandated by the FedGov, so unless there's some kind of "special exemption" for Chinese imports, they will have them.

 

[Islandvic]

quote:

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What good is new technology that is supposed to save us money in fuel efficiency if it is so expensive to repair? It unconsionable to release a product that isn't yet thoroughly refined, then spend ten years of "field testing" at the consumer's expense to get it right. Technology just for technology's sake is a step backwards in automotive engineering and not what I call progress.

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The accountants control what the engineers can build.

Automakers build vehicles for the interest and profit of shareholder's, not the interest of the consumer.

 

[bulwnkl]

quote:

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Originally posted by Gary Allan:
FazerZ

That's a great testimony to ulitmate incompetence in engineering. You can't make it sound any better than it is. They made junk ...and I'm sure they still make junk. They've over sophisticated the simplicity of the automatic for what?...

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Unfortunately, it's not just the automatics that do this. In fact, the things one sees on BBs like this indicate that the grenading diff scenario happens FAR more frequently on D-C manuals than automatics. The NVT350 in the Neon (and I don't remember what else) would appear to come apart more than they hold together some days. As an aside, the factory retrofit "fixes" for the problem don't seem to be terribly effective, and it happens to people using D-C fluid, Amsoil, RedLine, Pennzoil... you get the idea.

I'd like a lifetime automatic transmission so long as I don't get it by having the rest of the car only last 100,000 miles. Simple good engineering would be my preference.

 

[keith]

quote:

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Originally posted by Islandvic:
The accountants control what the engineers can build.

Automakers build vehicles for the interest and profit of shareholder's, not the interest of the consumer.

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The ONLY reason for operating a business is to make a profit. The way to do that is to satisfy the customers needs. It might sound good, in a "bash big corporations" kind of way, to say that they only care about shareholders. But no legitimate corporation will survive that way.

(governments can survive and thrive with mediocre product, but they have the power to force you to pay them)

 

[Islandvic]

quote:

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It might sound good, in a "bash big corporations" kind of way, to say that they only care about shareholders.

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I'm not bashing big corps. I have a BBA and MBA, so I don't bash big business and many legitimate corporations function this way.

Look at Ford's case.

Ford knew of the problems in the Pinto's and Firestone tires.

Documents recovered in investigations show correspondance between Ford accountants, engineers, and the Board of Directors etc etc analyzing the cost of recall vs. the cost of lawyers and settlements.

Settlements and lawyers was determined to cost less than recalling Pintos and Firestone tires.

Not all corporations put their shareholder interests first, but some do.

Someone who graduated from my High School a few years ago died in an Explorer/Firestone related accident and Ford awarded the family a large settlement.

The settlement can not bring him back or is enough "payment" for what happened.

What the settlement did do is help save Ford $$$.