Help me please!

So how would I go about finding what I need? I did a little reading up on the amc 20 and if I have to replace the axle I don't think I want another one. Would rather find a Dana. Which one would you suggest?

 

Also, what do I need to specify to get the ubolts I need for the amc20, and will the same ujoint work?

 

Welcome from Utah.

 

Everywhere I've called about the ubolts says they only carry one type of ubolt for that and its the same one that don't work. Where in the heck can I get a part number I need or something?

 

on a 77 it has a Dana 20 t case it will be
4H-2H-N-4L
front to back
on the rear 20 if it is welded an u end up breaking some think it will most probably spin a hub before your axle shaft will break

 

Well I got it fixed. I took the yoke off and took it to O'reilly's and we found a perfect fitting ubolt for it. So I came home slapped the radiator in and hooked up the drive shaft. Cranked her up and headed out for a test drive. Within the first mile, she was officially dubbed Smokey. I mean that sucker smokes somethin terrible. The 304 was running great. Needs a clutch though. It's not engaging completely and it's grinding a little. Drove it a few miles up the road to my parent's house and me and my dad took a spin through the field. Then it ran out of gas. We went to town and got gas and then I headed home and halfway it quit and wouldn't crank again. Dad had to pull me home. Great test drive.

 

Congratulations! Perseverance overcomes adversity.

This is a 304? You need to check the hot idle oil pressure with a mechanical gauge, and test the compression.

This year came with the Prestolite electronic ignition, which is the most likely cause of "it just quit." The module is the usual culprit, although sometimes its the reluctor (sense coil in the distributor) or corroded plug between the two. Often these have the plug removed and are soldered together.

The usual MO for the module is it quits, then you put the hood up for a while or let it cool and it runs again. Don't spend a lot of money on the Prestolite gear - there are better junkyard and aftermarket solutions.

 

yep. Walked out this morning, turned the key and it fired right up.

 

When it quit, it didn't just die. It started losing power and I made it about a mile before it finally crapped out. Almost acted like it was overheated, but the temp guage doesn't work. So I don't know.

Also I noticed there is a box mounted on the right fender well, that has some kind of unk that has dripped out all down the fender and is hard like pine tar. There's only a bunch of wires coming out. Is this the 'brain box'. If so what's the proper name for that.

 

is the control modular (aka) brain box as u said that is more than likely ur prob

 

I wondered because I've got a buddy that had a 79 Bronco, and he had the same problem with a bad brain box. We were in the woods one night out of town and it would lose power and give out and he packed ice around it and it made it all the way home without dying again.

 

"Brain" is way too generous a term. All it does is replace the points - one input, one output - there's no computing involved like on a modern car.

The ECU (electronic control unit) from Napa that I have on my truck has been fine for as long as I've owned the truck (ca 3 years) so if you get a good one, they are moderately reliable. Your FLAPS can get you one, no problem. I found it easily on the Napa site, $54:



This is the view from the underside, normally facing the fender.

If the module you're referring to is the ECU, and the potting is coming out, then it's toast.

 

If potting is that gunk all over the fender and the frame, then yeah i'd say it's shot.

 

The black goop that they put in the can to cover and support the circuit board is called potting compound.

 

Could that be a likely culprit for the engine losing power and then dying?

 

Sure, but there may be more than one problem.

 

I would really like to know why it smokes so much. And I think I need a carburetor. Maybe a fuel pump?

 

See the other post about the smoke.

Instructions for checking the fuel pump are in the FSM, or search previous posts.