7.3 flywheel is it the same as the 6.9

[86F2506.9]

Ok now my question is are the flywheels from the 6.9 to the 7.3 interchangable with each motor i ask this because im converting my 7.3idi to stick and since i have my t19 laying around i wana put my 4spd in the truck or is there more involved stuff that i need to change truck use to be auto with the e4od

 

[itsacrazyasian]

same, they interchange.

There was little talk once about the imbalance between the two. But personally have used a 6.9 c6/flywheel behind my 7.3 and use a 7.3 zf5 flywheel behind a 6.9 before.

 

[towcat]

same, they interchange.

There was little talk once about the imbalance between the two. But personally have used a 6.9 c6/flywheel behind my 7.3 and use a 7.3 zf5 flywheel behind a 6.9 before.

+1
there are differences in the ford p/n for the harmonic balancers BUT.....IH has no difference in their catalog. I've sucessfully done combinations of all sorts between IDI's and transmissions over the years and never had a phasing balance issue.

 

[86F2506.9]

Well i try'd putting my 6.9 flywheel on my 7.3 and its not sitting flat against and wont sit back in to line up with the starter

 

[towcat]

Well i try'd putting my 6.9 flywheel on my 7.3 and its not sitting flat against and wont sit back in to line up with the starter

post a pic of the back of your crank.
betcha you still have the adapter mounted on the crank.
if the crank mount surface doesn't look like the one in the pic, you still have more work to do.

 

[sle2115]

post a pic of the back of your crank.
betcha you still have the adapter mounted on the crank.
if the crank mount surface doesn't look like the one in the pic, you still have more work to do.

What he said!

 

[Agnem]

Kind of funny really. In the Ford manuals it specifically says not to use a 7.3 flywheel on a 6.9, but guess what the part number is for a 1987 6.9 with a ZF-5 from the factory? Yup. The 7.3 flywheel part number.

 

[sle2115]

Kind of funny really. In the Ford manuals it specifically says not to use a 7.3 flywheel on a 6.9, but guess what the part number is for a 1987 6.9 with a ZF-5 from the factory? Yup. The 7.3 flywheel part number.

I'm running a single mass on mine, but it was listed for the 87 6.9 and newer 7.3's with a 5 speed. It's aftermarket of course, but I found the same thing in my search for a flywheel.

 

[icanfixall]

This sounds like you have the late stamped steelflexplatewith the welded on gear. Between this and the crank is a 1 inch spacer. It needs to be removed so the new standard tran flywheel can be mounted directly to the crank. Just lightly tap it with a small hammer and it will fall off the crank. Be sure to use some kind of thread sealant on the crank bolts or oil will leak out past the threads. The torque used on the crank bolts is 47 lbs and its very important to reach that amount. I use blue loctite as a sealant and thread locker here.

 

[sle2115]

This sounds like you have the late stamped steelflexplatewith the welded on gear. Between this and the crank is a 1 inch spacer. It needs to be removed so the new standard tran flywheel can be mounted directly to the crank. Just lightly tap it with a small hammer and it will fall off the crank. Be sure to use some kind of thread sealant on the crank bolts or oil will leak out past the threads. The torque used on the crank bolts is 47 lbs and its very important to reach that amount. I use blue loctite as a sealant and thread locker here.

I knew you'd be in on this one...I remember the flywheel issues from the past! lol

 

[OLDBULL8]

When you remove the 1" spacer, seem's like you would have to change the bolt length. Never changed from automatic to manual, so I don't know. Wouldn't the bolts bottom out on the rear main if you didn't ?

 

[typ4]

Bolts need to be used from the flywheel he is putting on.

SAVE THAT SPACER. and bolts , they are needed from time to time.

 

[icanfixall]

Boy howdy is the above true.... I went thru hell when I installed my BTS trans... They had a machine shop create a new spacer for my trans flexplate swap.. The spacer was made about 3/8 inch too thin...You guessed it... The bolts were too long and bottomed out against the main bearing radius... Now try to remove said bolts with the end thread rolled over.... I did manage to save the bolts and the crank... Just think how much of a mess it would have been to ruin the crank... Turns out the crank material is much harder than the bolts... So I chased the threads and ground off the first thread... Works fine... I had no idea of the proper spacer thickness but I sure found it out in ahurry. I now have two spare spacers.... Just in case ever happens... The reason for these spare spacers is ford no longer makes them. I did a nationwide search... None to be found. Also on a similar note... The nut that holds down the rear section of the valley pan is no longer made either... I bought 11% of what Ford had left in stock... Another just in case someone has lost theirs because they do grow leggs and walk away sometimes... Some here have even posted about oil leaks back there because they didn't install that funny looking nut with a 3/8 inch hex hole in it..... That hole is for the vally drain and if the nut isn't there you get an oil leak and crap gets into your engine....

 

[86F2506.9]

Thx everyone for the info im at work at the moment but guna figure it out when i get home at 430

 

[Diesile]

.........Just don't put a 7.3 FACTORY turbo flywheel (dual mass or after market) on a 6.9 or 7.3 n/a or the other way around. Different balance for the factory turbo IDI.