Help needed: Swapping out motor in fullsize Bronco

93redzj

93redzj

Well-Known Member
Joined
Aug 29, 2005
Location
Albemarle
Heres the deal, I have an '81 Bronco and I need to swap the motor out. I already have the motor im putting in, Ive just never swapped a motor before and have no clue what im doing. Basically I would like some help from people who have swapped motors before. Tips and Tricks or if anyone wants to actually lend a hand that would be great. Thanks for any and all help. Oh yeah and the motor im putting back in is a 302 if that matters.
 
93redzj said:
Heres the deal, I have an '81 Bronco and I need to swap the motor out. I already have the motor im putting in, Ive just never swapped a motor before and have no clue what im doing. Basically I would like some help from people who have swapped motors before. Tips and Tricks or if anyone wants to actually lend a hand that would be great. Thanks for any and all help. Oh yeah and the motor im putting back in is a 302 if that matters.
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Labeling all the wires with tape helps to where they go back to.
 
i see you are putting in a 302. are you taking out a 302 also? what year is the 302 that you are putting back in place of the old one. older 302 engine's are 28oz. balance newer ones are 50oz. balance. just make sure you keep the harmonic balancer and flywheel with the same engine that it came with. you dont want to mix them up. if you do you will be out of balance which will cause vibrations and bearing failure. also carb? or efi? stick? or automatic?
 
broncomania said:
i see you are putting in a 302. are you taking out a 302 also? what year is the 302 that you are putting back in place of the old one. older 302 engine's are 28oz. balance newer ones are 50oz. balance. just make sure you keep the harmonic balancer and flywheel with the same engine that it came with. you dont want to mix them up. if you do you will be out of balance which will cause vibrations and bearing failure. also carb? or efi? stick? or automatic?
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Well I definately didnt think of all that, but to answer your questions: Yes im replacing a 302 with a 302, the one Im using came out of an 84 GT, its a roller motor, carbed, and from what one of my buddies said, it was set up for a manual tranny but the bronco is an automatic. Can anyone help with changing the rear main seal as well? I seen a write up on fullsizebronco.com it had pics as well but it didnt help to much. Thanks for the help so far on what to look for and things to do.
 
If you have a digital camera take all kinds of pictures of the engine compartment. It really helps when you are getting down to the end of the job and can't remember exactly how a wiring harness was routed.

Plastic baggies (and labelling them) to hold various bolts/nuts can help too. All alternator bracket bolts in one bag, power steering in another, etc.

The longer the job takes the more this will help. Everythings obvious the first day. If it takes a week or two to button it all up, then things tend to get a little foggy.
 
Before you put that thing in make sure you change the rear main. It is about 1000 times easier to do when the motor is out of the truck. I would also put on a new oil pump and and if you have the extra cash I would put on a new water pump. Make sure you put on the flex plate before you start putting the motor in. Make sure there isn't going to be a balance issue with switching from a flywheel to a flexplate.

my final advise is to NOT CUT ANYTHING. This leads to more headaches that are really worth it.
 
Yeah I was trying to figure out how to do it, ive never change the rear main seal on a vehicle, and im guessing Ive got the 2 piece seal and will have to take the oil pan off? Im not sure though, I saw a write up of a rear main seal change on fullsizebronco.com I think by a guy called bronkozilla or something like that, he had pics and everything but that part of my motor doesnt look like his, his was a 1 piece seal and just popped right off with a screw driver, that same part of my motor has no seal there nor a place for the seal to be so Im guessing its behind it?? :confused:
 
On the earlier motors, it's a two-piece seal. The oil pan has to come off, and the main caps have to be loosened at least. You shouldn't have to remove the crank, just loosen the caps and roll the seal out, roll the new one in.

Technically, anything after 83 should be a one-piece seal, but it's possible you got a leftover motor.

You'll want to replace the oil pan gasket while you have the pan off, too. There should be a one-piece reinforced pan gasket for that motor, but if it's a pre-84 block, I dunno what the part number is.

Get a picture of the crank/rear main seal area.
 
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