I swapped the 302 with a 351W and ruined the AOD transmission. I was told the 5.8 flexplate wouldn't work and that caused the failure. My question is... will the original 302 flexplate work on the 351 with the original transmission? In looking for new 351 flexplates, most say they work with 302 or 351 AOD combo's. Just curious. FYI, the 351 originally had an E40D behind it.
Ken
Qtband

 

It depends on what year the 302 is, the 351 uses a 28oz. balance weight and the newer 302s use a 50oz. balance weight. It is very obvious visually when looking at the two flex plates if one has a 50oz weight.

the 351 flex plate should not have hurt the AOD they are the same size and the trannys are interchangable. The most likly cause of damage to the AOD is inproper line pressure from a miss adjusted TV (throtel valve) cable. there is a special procedure explained in the haynes manual for setting the proper line pressure for the AOD tranny.

 

The 305 & 351 are both 1991's.
qtband

 

thats your problem, the flex plarte from the 302 is a 50oz, the 351 is 28 ounce.

you could have also done engien damage tot eh crank bearings becaue you were turning a 28oz balancer on the front of the crank and a 50oz on the rear. not good.

also the AOD TV cable needs to be adjusted corretly too, very common to blow a trans with a misadjusted TV cable.

what exactly happened to the trans?

also teh AOD will bolt right up to a 302 or 351, they both use the same bolt pattern, there is a 157t and a 164t flywheel but either can be used as long as you use the right bellhousing

 

the 351 you put in had an e40d tranny so the flex plate that was on the 351 should work just fine with the aod.

 

OK. The transmission shifts into first. You take off and shifting into second only occurs at a higher RPM. No shifting into 3rd or OD. Right now the 351 flexplate is on the 351 connected to the AOD and I have the problem. I adjusted the TV cables and it had no affect on the transmission. I have been told by others who have made this swap that the flexplate needs to be changed and I should install one that came from a vehicle that had the 351/AOD combo, such as a Crown Vic Cop Car, etc. What should I do?
Qtband

 

I can't see any way that a flexplate is going to affect your shift points.

 

yeah flex plate affecting shifting??? thats a new one-1st I have heard that-heard the 20oz and the 50oz differences before

 

If you feel that you must investigate the flex plate issue further my suggestion is that you make a trip to your local parts store and have them pull the part number for the flex plate on the 351 (you already know the vehicle make and model) then ask them to pull the part number for a flexplate from an 88 F-150 with the 351 and an AOD. the crown vic and all other 302 (5.0) cars that had the AOD will have a 50oz flexplate that will distroy your 351 if you install one of those.

http://www.transmissioncenter.org/cl...FSFNZwodUlhSaQ

check out the above web site they have all the reasourses to answer all your questons about parts. poke around they also have the instructions on how to properly adjust your TV cable and what ever conversion parts you will need to use an AOD in any application.

 

the flexplate on a 351 with an e40d will not work with an aod....you need a flexplate from a 351 with an aod like an 89 crown vic....the flexplate from the e4od pushes to far into the convertor on an aod and ruins the trans

 

an 89 Crown wont work either since Ford put 50oz balance on the 302 in 87...

 

some crown vics had 351's and that is the fklexplate that is needed