N Sperlo
N Sperlo UberDork
4/26/12 8:41 a.m.

A friend blew his transmission and its asking me to replace it. Anything I need to know up front? Who's experienced with these hunk-o-junks? I believe its the FWD version, so no transfer case to worry about. As easy as a drop-n-swap?

Duke
Duke UberDork
4/26/12 8:56 a.m.

It should be that easy - it's probably worth dropping the whole engine and trans out as a package. The issue is going to be finding a used one that isn't equally used up. The average lifespan for those (41LTE, I believe) with the average maintenance (which is to say, NO maintenance) appears to be about 100k-120k miles. They do better if you change the fluid regularly.

N Sperlo
N Sperlo UberDork
4/26/12 9:02 a.m.

Awesome. Thanks.

He'll be buying a $200xx transmission and we will rebuild the old one because he is a courier and wants a spare. Ill be looking things over/changing out the filter making sure everything looks OK. Not that it makes much of a difference. Last time it was the second transmission that was the winner.

iceracer
iceracer UltraDork
4/26/12 10:09 a.m.

FWD transmissions are no where as easy as a RWD to change.

N Sperlo
N Sperlo UberDork
4/26/12 10:31 a.m.

In reply to iceracer:

Already know that, but thanks.

turboswede
turboswede PowerDork
4/26/12 10:59 a.m.

There are a lot of updates that were performed on those A604's over their lifespan. Not only internally, but with the firmware that controlled the solenoids that replaced the hydraulics used in the old-style torque-flites.

Also, I believe the body controller needs to be set to a default mode to learn the driving habits and shift points, etc of the new transmission.

Use the proper fluid.

Find someone who has access to the Chrysler FSM's and TSB's and use that to determine what should be done on the rebuild to make them fairly reliable (and to check the work of the rebuilder)

The older 3-speeds were scaled down torqueflights and were stupidly simple and strong. Not efficient or particularly nice, but they generally just work.

As to the actual swap? Not much too it. Lots of room in the engine bays of those caravans compared to the smaller cars. Engine/transaxle were installed from the bottom as a single unit, so that might help you determine how you want to attack the problem.

Sky_Render
Sky_Render Reader
4/26/12 11:10 a.m.

Use a heavy-duty cherry picker to raise up the entire front of the vehicle. Drop the engine, transmission, and K-member out of the bottom.

And never, ever, EVER use anything other than Mopar ATF+4 in a Chrysler transmission.

N Sperlo
N Sperlo UberDork
4/26/12 11:11 a.m.

In reply to turboswede:

Excellent. I'll look into that. You've been a great help.

Thanks to you as well, Sky.

patgizz
patgizz UltraDork
4/26/12 2:58 p.m.

i wouldnt bother dropping everything, it's relatively not awful when the exhaust crossover is out of the way

Ranger50
Ranger50 SuperDork
4/26/12 5:55 p.m.
iceracer wrote: FWD transmissions are no where as easy as a RWD to change.

HorseE36 M3. Don't start out with a chip on your shoulder and they are not anywhere hard. More parts? Sure. Hard? Heck no.

As to a Caravan, you will just need a jackstand, block of wood, floor jack and a tiedown strap to remove a transmission after it is already on stands in front. No need to pull the exhaust crossover if you have the proper sized impact swivel and most times you don't even need that.

And yes when it's all installed, you will need to do a reset on the TCM. If you don't, the adapted shift parameters will take your new trans and turn it into a steaming pile of crap that needs rebuilding. Install NEW cooler lines. They are cheap, $20 for the bundle. You CAN use the LubeGard supplement with plain old DM3, but ATF +4 is just as cheap.

As to the actual rebuild, you will need some special tools to get it apart and back together. ALWAYS replace the solenoid pack. There are some updates, but nothing spectacular, especially if it is newer then '00.

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