Anyone ever drop the trans on an Expedition/F150 4wd of the 1997-2002 variety? 4r100 trans.
My truck is shifting pretty hard into 3rd under light throttle and I know it’s just a matter of time before it gets worse. Another summer of towing the boat all around will most certainly kill it. Right now the plan is to pick up a junkyard trans (found one in Binghamton with 42k for $650 in less than 5 minutes, will search more thoroughly when I’m ready to go this route). I don’t want to get rid of the truck because it runs/looks perfect and only has 80k on it. New tires, shocks, brakes and exhaust in the last year. At the same time I don’t really feel like dropping 2k+ for a rebuild on something I will probably keep another couple years.
Asked Carnut about swapping it but he’s real busy. I swapped the trans on my old Fiero myself so it’s one of those jobs I could probably do over the weekend with a couple friends helping with the brute force part but wanted to get an idea of what’s involved from someone who’s done it. One big difference is I won’t be able to bear hug an 4r100 into place like I did the little Muncie 4speed on the Fiero.
i just did the transmission on my 1998 4x4. its pretty staight forward just look at it and see what needs to come off. first start with the drive shaft, then transfercase and then front crossmember holding up the front axel( or shift on the fly hub locker). i would advise that you tie up the transfer case to the crossmember thats is right behind it because at this time you can not take it out. you can leave the locking hud up in place the reason for taking the crossmember down is to get the front drive shaft out. next take of the starter due to the fact the starter bolts go through the tranny bell housing. so right now you should be looking at a bare tranny mounted to the engine block and a a crossmember supporting the tranny. next get a tranny jack to support the rear of the tranny before you start to remove the crossmember bolts.after the crossmember are out and tranny supported crack every bolt but don’t take them out. start by taking out the hardest to get at bolts first and work your way around. i would recomend that you leave in one bolt on each side of the tranny bellhousing untill your ready to drop the tranny out of the truck. make sure all the wires are disconnected from each side i believe there are 3 plugs and you need to disconnect the shifter cable and the 4x4 shifter rod. if you have electronic 4x4 then i believe there is one more plug. the tranny should just drop out and the torque converter will be still attatched to the flywheel there is a wrench that will fit the end of the converter and be carefull not to strip the nuts on the back of the flywheel between the engine block and flywheel cause if you do your screwed and tyhat thing aint comming off good luck;)
You have tio watch which trans you have, i think there was a few diff ones(4R75W, AOD) I had a similair problem w/ a 98 F150. I’m told it’s common. The servo/piston for the 3rd gear accumulator gets screwy. Before replacing it, check it checked out. Good place is wholesale transmission and have scott/bill check it out. They quoted me like 250 to replace the servo piston and fix the problem(valve body has to come out to get to that servo). He even said if he dropped the pan and it was full of shaving he would stop and just charge me for a drain/fill.
fyi-For years on first startup/drive/trip mine wouldnt shift into 3rd untill real high rpm–only once then it was fine
^ That servo piston issue is on the 4r70w and I guess it’s real common. I’ve got a 4r100 which I’ve never seen anyone mention having that problem. After 2003 the 4r70w became the 4r75w, but I guess Ford didn’t bother fixing the servo piston issue because there are still 100’s of posts complaining about it.
I’ll probably take it somewhere for a diagnostic anyway, just to be sure before diving into a swap, but I’m pretty confident they’re going to come back telling me it’s rebuild or replace time.
Jay, knowing you and your mechanical incline…you should have no problem doing this swap. They are very straight forward, but…HEAVY. tranny jack would ease the process if you are working alone or you will come back posting on how you were sucessful but half pinned under your car throughout the process
