Engine swap this weekend, advice pls
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Engine swap this weekend, advice pls
I will taking the 302 engine from a 78 Fairmont and replacing the 302 in my 81 F150. My question is wll the car 302 that had a C4 attached bolt right up to the truck trans which is a AOD type automatic trans. Are the flex plates the same? It's the only place I think I could get some kind of unwanted surprise.
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From: Huntersville
Engine swap this weekend, advice pls
The AOD flexplate is AOD specific. Make sure to use the AOD flexplate behind what ever engine is going to be installed in front of the AOD.
Also, balance weights changed right in that time period. Make sure the engine you use has the right balance weights. This could cause some problems. I think the change was in 82 but it's something to be aware of.
Clint
Also, balance weights changed right in that time period. Make sure the engine you use has the right balance weights. This could cause some problems. I think the change was in 82 but it's something to be aware of.
Clint
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Engine swap this weekend, advice pls
check the crank balencer and it should tell you and then you match up the plates..
- Chad
www.xfoa.net founding member
- Chad
www.xfoa.net founding member
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I have installed engine with the AOD flexplate, I matched up the AOD flexplate position with the C4 position on the crank and I'm getting a crazy shuddering vibration at idle. When you say crank balancer do you mean harmonic balancer? The weights on the flexplates are different too, the AOD weight is larger. Should I have purchased a AOD flexplate with the matching weight to the C4? By AOD specific do you mean the bolt holes or the depth of the starter ring gear? Help!
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I think that is your problem the weights should be the same probably why you feel the vibration. What weight flexplate was on the 302 (your donor motor) in the car? The flexplate originally on the new donor engine would the aod converter mate up to it? You may be able to use it I don't know worth a look, otherwise, I believe your old motor in your truck used the 50oz and the new one used 28oz so you need a 28 oz aod flexplate, let me know if the aod and c4 flexplates are identical as far as converter mounting points. Good luck, looks like your almost there
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They are the same diameter and number of teeth, the only thing I'm not sure of if the ring gear offset for the starter. I guess I will be busy again this weekend. I don't know what I was thinking, I knew they were different weights and it made no sense to put a heavier weight on the '78 302 engine, I guess I was more concerned with the 'must use a AOD flexplate on a AOD' thing.
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If they are identical as far as how far they come off the motor as in its not gonna press the converter in too far or keep it too far out and not seat right, again if they are identical then use the old flexplate that came with the motor you installed as mentioned because you know it is supposed to go with the motor, and the only real concern is keeping the motor balanced it has little to do with the tranny. Again I am not 100% sure but if it bolts to the aod then go for it, I would double check to be sure as I am sure you will. Good luck and let us know when you have that thing up and running without any problems, later
Last edited by jwtaylor; Sep 30, 2003 at 07:08 AM.
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From: Huntersville
When I put in my AOD I used the AOD flexplate that matched my engine imbalance. The AOD flexplate is stamped AOD on it somewhere. It has to be the right weight to match the engine imbalance, the right tooth count to match the transmission and have the right offset at the torque convertor which is where the AOD spacific comes in.
I pulled a c-6 out to put in my AOD. The c-6 flexplate was the right imbalance, the right tooth count for the transmission but was not the right offset for the AOD. It would not let the rub bushing on the torque convertor come through enough. So the confertor would not be supported there. Now maybe this does'nt matter. But it was told too me when I was doing thid swap that it did matter so that is why I said that Bout the AOD specific,
Clint
I pulled a c-6 out to put in my AOD. The c-6 flexplate was the right imbalance, the right tooth count for the transmission but was not the right offset for the AOD. It would not let the rub bushing on the torque convertor come through enough. So the confertor would not be supported there. Now maybe this does'nt matter. But it was told too me when I was doing thid swap that it did matter so that is why I said that Bout the AOD specific,
Clint
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From: Huntersville
Look for an early 90's F150 with a 351 engine and an AOD. I bought mine new from Autozone for about $40. Worth the money for a new one if you can afford it. I hope I did'nt mislead you the first time and cause you the extra work. I'll be more clear on any help I try to give.
Good luck
Clint
Good luck
Clint
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From: Atlanta, Georgia, USA
Good call on that one Clint. Very lucky indeed that the 351's always used the 28.2 weight, and still were mated to an AOD. The tougher one is to find a C4 flexplate that has a 50 oz. weight on it. It's actually impossible, but B&M makes them for $105. It's nice to use production parts, because $105 for a flexplate really adds a few cubic dollars to the budget. TK
*edit*
in a bind, you could hot wrench the balance weight off an AOD 'plate, and arc-weld the lighter weight in place of the 50 oz. weight. I've never done this before, but as long as you weld it to the same spot, it should work the same.
*edit*
in a bind, you could hot wrench the balance weight off an AOD 'plate, and arc-weld the lighter weight in place of the 50 oz. weight. I've never done this before, but as long as you weld it to the same spot, it should work the same.
Last edited by TorqueKing; Oct 1, 2003 at 10:45 AM.
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I took the day off work cause I couldn't wait to get it done, dropped the trans and took off the flexplate to match up to 28oz one and it is exactly the same dimensionally. Replaced everything and it is running again. It's running like a dog because I took off all the smog crap and have more vacuum nipples plugged than I thought possible, but it is RUNNING!!!Thanks for all the support, i appreciate it.