Transmission Questions

Transmissions and Rear Ends

  1. JLN5thAve

    JLN5thAve Well-Known Member

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    Ok - backstory - 1988 Chrysler Fifth - The Pearl

    Transmission went out in 2005 after a road trip from Albuquerque to Little Rock, to Tulsa and back to Albuquerque.. Happened leaving a Walmart, and it slipped and lurched its way to a stop about 5 miles down the road. It drove up on the tow truck the next morning however, and they said it was cause the transmission was cold - ANYWHOOO

    I have been working on my car again, and in my attempts to move her - (I had checked the transmission - however the car would not run long enough to warm up, so therefore I did not have an accurate reading... I know.. OOPS) She moved fine, and then started lagging on shifting from P to R and P to 1... I checked the transmission again since it warmed up a lot more by that time, and the fluid was not on the dipstick anymore. SOOO -

    After sitting ten years, did my transmission fluid evaporate?? Or possibly seep out? If so, would I be safe to refill it, and have it run fine?? I cannot afford a transmission, and do NOT want to screw this one up.. It has roughly 20,000 or less miles on it.
     
  2. BudW

    BudW Moderator Staff Member

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    Transmission fluid does not evaporate, nor does it just vanish. It must be leaking somewhere.

    Most transmission fluid leaks are minor – but four areas, the fluid is under pressure and cause significant leaks in those areas.
    - The front pump seal
    - The front pump to case gasket/O-ring
    - Transmission cooler lines (about 5-10 PSI normally and 70+ PSI when lock-up clutch is engaged). This does include the brass fittings between lines and case
    - cracked case

    Another leak/fluid loss area is the transmission cooler, inside of radiator, leak. If leaking, it can push ATF into the cooling system (when lock-up clutch is engaged) or coolant into ATF (mainly when hot and car is turned off). In this case, you can open the radiator cap (don’t do this hot) and if you have a milky substance in coolant – then transmission cooler (aka: the radiator) has a problem.
    This problem is not as common with Chrysler as it is with other car lines – but does occur from time to time.
    If your coolant is green and clean, then this is not an issue.


    If the coolant is good, the next thing to do is to get transmission fluid to proper level. The “Fill” and “Full” lines are 1 pint difference (not 1 quart like for engines). Overfilling an automatic transmission causes more problems than an underfilled transmission has.

    The fluid needs to be warm and fluid checked in Neutral – after it has been ran through the different gear selections once (and only once with the shifter). I would perform the gear selection after fluid level reaches the dipstick, first.

    Having a long funnel is easier, in my opinion, like this one:
    funnel A.JPG

    After fluid is between the lines, I would (if possible) wash the engine compartment and under car in transmission area well, then place clean scrap cardboard under engine and transmission to assist with locating leaks.
    This might be best done without car soaking wet.

    Finding a leak under a freshly cleaned car makes the job easier – in my opinion.

    If you take car to a car wash for this, I would have someone tail you in chase car – just to make sure you get there and back ( . . . not saying you won’t).

    On trip there and back, try to get transmission to operate in all modes (normal upshifts, WOT upshifts, downshifts, etc.). If anything is not acting normal, make a note of it.

    After trip, re-check at transmission fluid level.
    ATF expands roughly 15% from “cold” to “Hot” so some change higher is to be expected. Any foam or fluid loss is not to be expected. Foam indicates an overfill condition or contamination.

    Cardboard is an excellent method of looking for leaks – if you don’t have a lift. Minor fluid leaks can occur only when car is off OR only when car is running – so checking for both is helpful.
    If you got spray or more than drips - then see the four possible areas mentioned at beginning of this post.
    BudW
     
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  3. BudW

    BudW Moderator Staff Member

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    An automatic transmission uses hydraulic pressure to operate. Matter of fact – it uses a hydraulic computer to operate it (the valve body). It must have a certain level of fluid – or it will not operate correctly – which is what it sounds like you’re describing.

    You might also have a stopped-up filter, but I don’t that is the case here.


    Metal transmission cooler lines tend to rub together and leak – or crack and leak – which I suspect is what you have (possibly). The brass fittings between the transmission case and cooler lines also have a tendency to crack.

    I try to make a point of anytime I’m under a car, mine or anyone else’s, to check the metal lines and make sure they are not rubbing anything (themselves, brackets, oil pans, etc. – for those are the area of most common leaks are found.

    The non-lockup transmissions, a person can cut the metal line (a tubing cutter works well in this case) at the crack or rub-through), take a piece of 5/16” rubber fuel line and hose clamps and make a trouble-free patch.

    Chrysler went to lockup transmissions mid-year 1978. A person can do the same thing on a lockup transmission – but the rubber hose patch does not take well long-term because of the higher pressures (7-10 PSI vs. 70+ PSI). A rubber patch can get you back on the road – but it will start to leak again, shortly.
    The best patch for a lockup transmission cooler line is a metal tubing splice or just replace the entire line with another metal line.
    This is a transmission line splice kit available from AutoZone – but a person might be able to get something cheaper from your local hardware store.
    Line splice.jpg


    On a different note, I have an active leak coming from my ’77 wagon, coming from either the front pump seal or front pump to case gasket/O-ring. Either case, it will require transmission removal to fix.

    I have been keeping an eye on this concern, for if it is the front pump seal, it will give out on me somewhere at a snap of my finger. You can tell when that happens for there will be a one to one half foot wide swath of red/pink fluid leak behind the car from where it pumped out all fluid in a very short distance.

    Right now, when my car is cold and is transmission is about 2 quarts low of fluid, car will not engage into gear – or will engage for a short distance, then act as if you pushed in the clutch petal, then bang back into gear again (when fluid catches up).
    Driving (any) car with low fluid level is hard on an automatic and will wipe out a clutch pack in no time and that is not considering bearing/bushing damage from lack of sufficient fluid.

    Sense I have a supply of parts in my garage (8 Chrysler automatics . . . I think), my plan is to rebuild a lockup A999 transmission I have, and install it into the wagon (to replace the non-lockup A904) for better fuel mileage. The A999 has the good (desirable) first gear set – and I don’t think the ’77 A904 has that gear set in it (but it might).

    Either way, swapping out a transmission over a weekend is better for me, than to have a car disabled for a week or more and have wife get on my case (for an X number of times) – but not everyone can do it that way.

    If your transmission needs to come out (and hopefully not), I wouldn’t get another transmission first. In my case, I already have the extra transmission taking up space in my garage.
    BudW
     
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  4. JLN5thAve

    JLN5thAve Well-Known Member

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    That is the best guide I have gotten. Thank you!! I knew about the cardboard trick, and will be cleaning her off under the hood and the undercarriage - then set out leak hunting. I am hoping it is merely a drip that can be fixed with stop leak.

    Very informative - contained information that I did and didn't know. Thank you BudW -
     
  5. Dr Lebaron

    Dr Lebaron Well-Known Member

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    Forgot the easiest fix-leaking pan gasket.
     
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  6. JLN5thAve

    JLN5thAve Well-Known Member

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    Yessir that’s another one... my next step is rebuild the carb sadly, cause it’s leaking around the top of the carb, and I also need to fix a messed up vacuum leak somewhere. Then it’s clean the engine compartment and the underside to check for leaks..

    Power steering pump leaks as well - and I am nervous to rebuild that thing.
     
  7. BudW

    BudW Moderator Staff Member

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    I would agree, the pan gasket is the most likely leak and easiest one to fix - but rarely leak more than a drip.

    I highly suggest replacing it with the new style reusable pan gasket, instead of the cheap cork ones that comes in many filter kits. The reusable ones hardly ever leak – especially if the pan is flat to begin with.

    Always change the filter anytime the pan is off – unless you know how old the existing filter is!

    When an oil pan is off (engine or transmission) or valve cover is off, always, always, always check how flat they are at the bolt holes. Many people over tighten the pan/cover bolts which distorts the pan, squeezes out the gasket and makes the leak that much worse. If there are any bolt hole dimples, get a piece of wood (a 2x4 works well) and shape it like this:
    2x4.jpg
    Take a small hammer, a body hammer works well if you have one, and lightly tap it down flat. It doesn’t take much. A little work with this part saves a ton of grief later.

    With the re-useable gasket, no sealant is needed.

    The problem with the transmission pan gasket replacement – is it can be messy.


    Most P/S pumps can be resealed fairly easily. There is a front shaft seal (which is not common to leak) and the can O-ring (which is common to leak). Make a post in steering section and I can give details for it.
    BudW
     
  8. AJ/FormS

    AJ/FormS Well-Known Member

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    Hang on, he drove it 5 miles slipping and lurching, Common drop the pan and witness the carnage.
     
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  9. BudW

    BudW Moderator Staff Member

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    It still sounds more like a lack of sufficient fluid level to me, plus he mentioned that fluid is going somewhere.

    Then again, he might have what is known as a religious transmission now (aka holy, or case full of holes) but I don’t think so. The A904/998/999 series is not known to blow up like the A727 series are (in high HP scenarios).
    BudW
     
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  10. 4speedjim

    4speedjim Well-Known Member

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    I agree, I sounds like low fluid level, Too low! Which pan gasket and filter would he use? The 42re/A-500? He has a 998/999 series tx right? Them gaskets are the best thing ever. The last one you'll ever buy. Try that and see if tx still works ok. Or get one from JY and rebuild that if your driving the car. $100-$150 should cover a good used trans.
     
  11. BudW

    BudW Moderator Staff Member

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    The Chrysler reusable pan gasket (which are by far the best pan gasket I have seen or used) part numbers are:
    4295875AC for A904/A998/A999 (will also fit 30RH (newer name for A904), 31RH (newer name for A998), 32RH (newer name for A999), A500 (4-speed OD version of A999) - which is also known as 40RH/42RH/40RE/42RE/44RE) – which MSRP as of today is $25.35 (US).

    2464324AC for A727 (will also fit 36RH & 37RH (newer name for A727) and A518 (4-speed OD version of A727), A618, A818, 46RH, 46RE, 47RH, 47RE and 48RE) – which MSRP as of today is $39.80 (US).

    The transmission filter is the same for all 1967-1993 above mentioned transmissions – which is Chrysler part number 3515996 – which as of today is $12.95 (US).
    The 1994 and newer filter is bigger/thicker and better – but will not fit within our oil pans.
    The filter looks like:
    3515996.jpg
    If you open the package and filter looks different - then keep looking.
    There is a smaller version of same filter – but I doubt you can find one now. They interchange and if you did find the smaller version – why use it, if the bigger version fits and will filter better?

    My local parts store sells a transmission filter kit (fits all transmissions listed above, until 1993) for $9.00 (US). I would use it over the Chrysler filter (and save a few bucks) and toss the cork or black paper gasket’s.
    Then get the Chrysler pan gasket (listed above).

    I recommend replacing the filter anytime the pan is off.
    I also recommend adjusting both bands anytime the pan is off. Both don’t take long to do. Band adjustment procedures is listed in sticky section.
    BudW
     
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  12. BudW

    BudW Moderator Staff Member

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    I would bet a $5 dollar bill, that he has either the A998 or A999 transmission.
    An A727 would be a special order and seldom found on cars that are not police or taxi's.
     
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  13. Dr Lebaron

    Dr Lebaron Well-Known Member

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    On a personal note, for me, reusable gaskets suck dead donkeys on old stuff.
    Leak city.
    Much rather do the job once than 2 or 3 times.
     
  14. JLN5thAve

    JLN5thAve Well-Known Member

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    I am hoping I don’t have to replace anything on the transmission, but I plan on cleaning off the undercarriage within the next couple of weeks to pinpoint the leak.

    I am glad for the high quality responses to this.