Dodge truck transmission swap

[66chargertoy]

I am helping a friend from work change the automatic transmission out of a 1993 250 Cummings Dodge truck. It's a two wheel drive that the transmission gave up. He found another working transmission that came out of a four heel drive unit. Question is , is it difficult to swap out the tail end of the junk transmission and match it up to the four wheel drive unit. If this all works out, I am thinking that maybe I will buy this truck off of him for personal use. Should tow my 66 Charger with no  problems .
Denis                   

[GPULLER]

I would say the output shaft would have to be changed, that will involve pulling the two trannys a part.  Get a big clean work area and tear them a part.  Lay all the parts out in the order they come out of each trans so you know how they go back together.  Take your time and it will be OK.  I was leery of tearing down a 727, then I did, it wasn't bad as I thought.  I aways think "It ain't the Space Shuttle" should be able to figure it out.

[66chargertoy]

Both transmissions are overdrive and from a 1993 truck. Could you just pull the tail section out of each and switch them . Someone told me also this morning that the reverse rod would be tricky to reconnect.
Denis

[RD]

on OD units, you can just remove the rear OD tailshaft housing unit as there is a intermediate shaft that is the same length for all OD transmissions that rides in between the OD unit and the front housing internals.  On 727's the output shaft is the same from the front housing to the rear housing, but in OD transmissions they have been separated due to the OD unit configuration.  BUT, AND THIS IS BIG TIME IMPORTANT... you have to make sure that the trans you are pulling from is the same 47RH that you have, and not a 47RE.  

Secondly, that intermediate shaft will need to slide into the OD unit perfectly.  If it is off you will need to realign the OD clutches so that the shaft will slide in all the way into the 3 bushings of the OD carrier.  to realign those clutches, you will need to remove the tension from the 800 ft/lb spring (e.g. YOU CAN LOSE YOUR LIFE IF NOT DONE RIGHT) and put in an alignment tool or another intermediate shaft to get it lined up.  Then you have to press the unit back together and put in the retaining spring. (its a arduous process, that has steps to it, but if you plan on doing it, I will just copy from the book and send it to you email on how to get it done.  You will need a press and a tool that mounts to the OD unit to push the spring down).

Thirdly, each output shaft on OD units have selective rings that are used to adjust the endplay.  If your selective ring is not the same as your former selective ring, you may end up with too much or too little endplay which can easily and quickly shorten the life of your transmission.  They are color coded so you can just check the colors to see if they are the same.  They are located on the output shaft behind the governor assembly if my memory is correct (been a month or two since I did a OD overhaul).

Lastly, if you do not feel comfortable with it.. just take both transmissions to a trans shop and tell them that you know its possible for it to be done and just have them do it so you have a warranty on labor

hope that helps.

[Tilar]

I aways think "It ain't the Space Shuttle" should be able to figure it out.

Funny you said that... I always said "Give me a service manual and the parts and I could put the Challenger back together.

[RD]

Both transmissions are overdrive and from a 1993 truck. Could you just pull the tail section out of each and switch them . Someone told me also this morning that the reverse rod would be tricky to reconnect.
Denis

not sure what you are talking about when you say "reverse rod".  They are most likely talking about the park rod.  to alleviate that fear, all you have to do is slowly rotate the output shaft, at the back of the housing, while pulling on the tailshaft housing away from the front case.

[66chargertoy]

Thanks for the great replies . I think that the best course of action,especially after reading RD's post, will be to convince my buddy to just put both transmissions in the back of his other truck and go see my tranny guy and get him to do the switchover. Pulling the transmission out a second time from a 3/4 ton truck because you thought that you could do the job doesn't sound like fun. Sometimes tis a far better thing to admit defeat then to lie about your victories because sooner or later the stinking truth comes out and covers you from head to toe
Denis

[Cooter]

Thanks for the great replies . I think that the best course of action,especially after reading RD's post, will be to convince my buddy to just put both transmissions in the back of his other truck and go see my tranny guy and get him to do the switchover. Pulling the transmission out a second time from a 3/4 ton truck because you thought that you could do the job doesn't sound like fun. Sometimes tis a far better thing to admit defeat then to lie about your victories because sooner or later the stinking truth comes out and covers you from head to toe
Denis

Amen! I couldn't have said it better...There's a commercial that I love to use to explain to customers when they "Have a guy that will do it for WAY less"....


Remember that commercial where the guy calls his doctor on an operation, and the doctor is telling him something like "Just make a tiny incision just below the 3rd and 4th Thorasic" and the guy says "Uh Doc., Shouldn't YOU be doing this?

Classic truth...Good thing doctors don't have to ever worry bout people coming into the emergency romm with their guts hangin' out talkin' bout "Hey Doc., I had this guy I know try to take out my Gall Bladder..I think he did something wrong, can you help me?"