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904 flush and fill service question
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Author:  hideogumperjr [ Thu Nov 24, 2011 10:40 pm ]
Post subject:  904 flush and fill service question
I have a 93 dart with 125k shifts well but has some leaks and is going through some trans fluid.

I was reading in the Mopar website about the Torqueflite and it said if the tranny has over 50k dont even think about a flush and fill because chemical differences between saturated clutch plates and new fluid will cause a failure on the plates pretty quickly.

I also want to address the leaks but have not run them down yet figure mostly likely old rubber and work seals.

Any thoughts on flush and fill and performing a in-place seal replacement?

I see a "Torqueflite 904 External RESEAL Kit '60-63 With SLANT 6"
http://www.ebay.com/itm/370539322527?ss ... 1423.l2649

Thanks for your input,

John
Author:  SlantSixDan [ Thu Nov 24, 2011 10:54 pm ]
Post subject:  Re: 904 flush and fill service question
Don't know which "Mopar website" might have contained this wrong information about fluid incompatibility causing a quick failure, but…no. It's wrong.
Common leak points are the kickdown shaft seal (left front), the dipstick tube O-ring (right front), the shift and park cable O-rings (left side), the park housing to main housing gasket (center), the speedometer cable O-ring (left rear), and of course the pan gasket. Also inspect the shift and park cables themselves where they pass near the exhaust pipe; see here.

I wouldn't do any kind of a "flush"; it's a transmission and not a toilet. You can get a complete drainout of all the old fluid; the torque converter has a drain plug. Do the filter retrofit, too; see here.

The kit you see on eBay is offered by a reputable seller who is a well-regarded expert on these transmissions. I wouldn't have expected it to be quite so expensive, though.

While you have things open, do the band adjustments, too.
Author:  hideogumperjr [ Fri Nov 25, 2011 9:06 am ]
Post subject:  904 flush and fill service question
Danke!!
Author:  hideogumperjr [ Fri Nov 25, 2011 9:14 am ]
Post subject:  904 flush and fill service question
BTW here is the link regarding the flush and fill info.
Ehow not Mopar, yikes.

http://www.ehow.com/way_5883354_chrysle ... dures.html

Thanks again.
Author:  SlantSixDan [ Fri Nov 25, 2011 10:50 am ]
Post subject: 
The eHow piece appears to be someone's by-guess-and-by-gosh writeup of how they did what they did. There is no factual basis to the claim of fluid incompatibility, and it's difficult for me to put much of any faith in a writeup that says not all Torqueflites have a trans fluid cooler so some of them don't have fluid in/out fittings (wrong; all Torqueflites have fluid coolers, every last one) and that you should use "regular Dodge ATF" (whatever that's supposed to mean).

That's the problem with the internet, eh? Everyone with a keyboard is an instant expert, and in order to know which is the good advice and which is the bad advice…you have to be something of an expert! :evil:
Author:  supton [ Fri Nov 25, 2011 12:50 pm ]
Post subject: 
I remember before the internet, the "conventional wisdom" was to not do a fluid change (let alone a flush) after high miles was accrued. But, if the tranny started acting up, then by all means change the fluid. :roll: For some reason, it was believed that if you went past the OEM change interval, you'd somehow do more damage with a late fluid change than if you'd just left it alone. I don't ever recall hearing a reason for what could go wrong, though.

Yet these same people would likely have insisted that you were damaging an engine if you had 3,001 miles on the oil...

I don't think the ATF for this transmission has changed over the years (unlike engine oil, which has gotten markedly better). Just like the fluid for the rear end, or the grease for the front end. I'd think the factory recommendations for fluid changes / regreasing / other maintance would all be unchanged, despite all these years; and anything overdue for its maintance is all the more in need of it. I mean, if the application hasn't changed, and the fluid hasn't changed, then the original recommendations ought to still stand.
Author:  SlantSixDan [ Fri Nov 25, 2011 12:58 pm ]
Post subject: 
Hoah yeah, all the "common knowledge" that gets passed down from father to son and bench racer to bench racer.

ATF certainly has changed (and generally but not always improved) quite a bit over the years. See here and here.
Author:  supton [ Fri Nov 25, 2011 1:39 pm ]
Post subject: 
I stand corrected then--there are better ATF's for this application. That said, would running ATF+4 allow for "lifetime" fill on one of these older Torqueflites: or would the original __kmile fluid changes still be on order? Or something in between? I'm not sure how well sealed up (against ambient moisture and/or dust intrusion) this tranny is, nor what may accumulate in the oil, despite how good the newer fluids are.

My whole point for butting into this thread was to point out that Ma Mopar established these fluid change intervals for some particular reason. One becomes their own warrenty (or self-fulfilling prophecy) when they deviate from that. Like when when not changing the fluid on high milage automatics for fear of breakage... Makes me wonder how that old wife's tale came about in the first place. Probably from mistaking correlation to causation. [IOW, if the recommended interval was every 30k, yet most would make it 120k regardless--then a fluid change at 120k would likely coincide with some failure.]

Side note: in that SAE paper you linked to (here) I like how the goal was to find a "lifetime" fluid fill for the FWD transmission--without ever defining what "lifetime" is. The old-school 120-150kmiles? [Figure 8 seems to indicate maybe 120k under severe taxi service.] As much as one is well-advised to stick to OEM fluid change intervals (unless if it can be documented that they are in error--or that newer fluids undermine that), I have to wonder if "lifetime" fluids ought to be changed every 100k (or other "recommended" interval).
Author:  Jeb [ Fri Nov 25, 2011 4:33 pm ]
Post subject: 
I still think it's a good idea to service the transmission at the designated 30,000 mile interval. Mainly because of the reverse band adjustment and the filter change. Plus it's going to take you a couple of years to put 30,000 miles on the car. My dad never serviced the transmission in my truck, so when I started driving it back in 04 I decided to service the trans. It had 80,000 miles on it since a rebuild and the amount of crap in that pan was amazing. It was horrible, I had to wash all the muck out just to find the little donut magnet.

A lot of new cars now have "sealed" transmissions. When I took a former employers Tundra to the dealer to have it serviced at 60,000 miles I told the service guy that it was shifting funny and needed the fluid/filter changed (fluid had already turned dark, smelled really bad). His reply was that the Tundra had a sealed transmission like the Phords. They would flush it but the filter was in there for life.

IMO 30,000 miles is a lot cheaper than a rebuild or breaking the reverse band. At least Chrysler put a REAL filter in their transmission, instead of the "screen door" that GM stuck in my TH350.
Author:  SlantSixDan [ Fri Nov 25, 2011 7:41 pm ]
Post subject: 
At least as far back as '70, the specified normal service interval for trans fluid was…life of the car. Severe-service recommendation varied from 30k to 50k miles. I don't agree with life-of-car transmission fluid philosophy, but there's "life of car" and then there's "life of car". "Life of the car" means about 10 years, 15 max, for the vast majority of any given make, model, and year of automobile. Trans fluid does degrade with thermal cycling and usage; modern fluids are more durable than older fluids, but it's still wise to replace it every decade or every time the transmission is opened up for major service.
Quote:
Makes me wonder how that old wife's tale came about in the first place. Probably from mistaking correlation to causation.
Yup! Figure: most people don't think about or mess with the transmission until it starts making problems. Then either they do a "Hail Mary" (badly overdue trans fluid and filter change), which doesn't magically fix the trans, which soon thereafter finishes breaking.
Author:  hideogumperjr [ Fri Nov 25, 2011 10:07 pm ]
Post subject:  904 flush and fill service question
Wow thanks for the fin info in this thread, quite illuminating.
Soundsl like a seal replacement and band adjustment are in order here. I doubt that much has been done to this car but I will check the service records for it for my own edification. I got it from a one owner with records included.
BTW I was checking it out tonight and found that the tranny pan had a round depression on it and the external filter but didnt find the drain plug, is it on the back side of it?
Cheers.
John
Author:  Fopar [ Fri Nov 25, 2011 10:56 pm ]
Post subject: 
There is no drain plug :( you loosen the pan bolts and place a large drain pan under the transmission. Then remove all but a few of the bolts you may have to gentle pry to get pan loose on one side so the fluid can flow out. It is quite messy, after you get the pan off have a drain plug installed. :wink:

Richard
Author:  exoJjL [ Fri Nov 25, 2011 11:29 pm ]
Post subject: 
Quote:
and that you should use "regular Dodge ATF" (whatever that's supposed to mean).
I seem to recall reading this somewhere; likely the Dodge operators manual that came with the car? So since you own a Dodge you need to buy "dodge ATF." You know, a merketing thing to get you to buy their brand of ATF that they filled the tranny up with at the factory.
Author:  Jeb [ Sat Nov 26, 2011 12:47 am ]
Post subject: 
Quote:
BTW I was checking it out tonight and found that the tranny pan had a round depression on it


That's where the donut magnet is located. The "dimple" helps keep it in place.
Author:  hideogumperjr [ Sat Nov 26, 2011 9:22 pm ]
Post subject:  904 flush and fill service question
So in reading the "filter retrofit" thread I noticed a couple of things that give me pause.
First it says to change my 63 pan to a later pan because "The reason why you need to change the pan is that when they changed to the in-pan Dacron filter for '64, they put a circular depression in the pan to provide sufficient clearance between the pan and the Dacron filter, which is thicker than the '63 and earlier pickup screen. This is why my '62 has "dropout" problems when cold (Dacron filter w/'62 pan); I really need to fix it 'cause it's not good to starve the pump for fluid like that."

Question is my tranny has the circular depression and its a 63.

The second questions the statement further along "Pans thru '63 had drain plugs, so it sounds like you already have a '64 or later pan. The new current-production pan is certainly nicer, but you would likely have no trouble using your present pan with the in-pan filter."

And I dont see a drain plug, is it possible I have a later tranny in my car? Or am I just missing something obvious?

BTW Thanks for all the help and expertise available and so freely offerred, I really appreciate it and I am sure there are plenty of folks that feel the same way!
John
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