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Dropping the Dana20

ymelnic1

New Member
Joined
Mar 7, 2013
Messages
43
Hey guys,

Does anyone have any instructions or a link to a video on how to drop the Dana20? Do I need to drop the tranny to get this done? I have a 74 automatic and need to drop the TC to rebuild.

Thanks!
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,724
you don't need to drop the tranny but their are watch outs. You need to remove the driveshafts and the cross member. set your parking brake and chock your tires. Support the transfer case so it doesn't tilt down. I recommend removing the fan. radiator is up to you. As motor tilts the fan takes out your radiator and fan shroud. Next remove the transfer case shifter, you need to remove the spring at the very bottom of the shifter then remove the boot at the inside floor and the boot under the floor board. under the boot inside there is a cover for the floor board unscrew that. next follow the shifter down and you will find the cover for the shifter ball. that unscrews and is spring loaded so you have to push down while unscrewing the cap. Then shifter pulls out the top, you want the transfer case in neutral while removing and installing the transfer case shifter.

Now back to removing the transfer case. Remove the speedometer cable from the transfer case. Now lower the transfer case, it will tilt down making it easier to remove bolts, choice is yours as to unbolting at the tranny end or the transfer case end of the adapter I prefer the tranny end. the transfer case end has a dowel in the bolt pattern that's hard to pull
back while the transfer case is attached under the truck. after you get the top hard to reach bolts out jack the transfer case back up and put a block of wood between the driver side valve cover and the firewall to keep the engine upright while removing the transfer case. Now you have to get support for the transfer case. personally I use a floor jack but it is really the wrong tool. the transfer case is extremely heavy while laying on your back and it isnt balanced, smart people make a platform for the jack to properly support the out of balance transfer case. As all the weight is overhead and heavily weighted to rotate towards the passengers side. as it comes off the transfer case wants to fall over and destroy anything in its path. this can smash and cut off parts of you between the transfer case. If the transfer case falls on a finger you will loose it, falls on your hand it will probably not work properly again. There you are warned. when putting it back in put the transfer case adapter in first then the transfer case.

You will need the tranny gasket to the transfer case adapter ( this is not a special gasket, standard gasket for the C-4 extension housing). the gasket between the adapter and the transfer case. the double lip seal for the spud shaft, the large o ring for the support of the double lip seal cover, and the transfer case 50 weight motor oil or synthetic 90 weight gear lube. more than likely the transfer case cover gasket. always replace the double lip seal when removing the transfer case no matter how good it looks.
When pulling the transfer case, the input gear gear may stay withe the spud shaft if it does it will drop individual roller bearings into the transfer case these roller bearing will need to be removed and replaced on reassembly. When you put the gear and shaft back into the transfer case . I think there are 13 rollers if my memory is correct grease them up on installation so they stay in place.
Reverse steps to reinstall.
 
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