gingrass179
Full Access Member
Putting a 6.9 in my truck is the flywheel the same? Thx
6.9 7.3 flywheel the same?
- Thread starter gingrass179
- Start date
Knuckledragger
blowing chunks and grabbing porcelain
Yup.
gingrass179
Full Access Member
sweet...i heard there was a difference
junk
Full Access Member
I technically think the 6.9 and 7.3 are supposed to be balanced slightly different, but lots of guys are running 6.9 flywheels on their 7.3's and vice versa with no ill effects. I have a 6.9 flywheel on my 7.3 in my 89 and it works fine.
gingrass179
Full Access Member
dang well i dont want any vibrations im going to be balancing it etc
junk
Full Access Member
if your balancing anyway I definitely wouldn't be concerned.
Knuckledragger
blowing chunks and grabbing porcelain
If you are using a transmission appropriate for the flywheel and if you are balancing the entire rotating mass (harmonic balancer, rods, pistons, crank, flywheel), it won't matter a lick. Your machine shop may have some trouble doing the balance, I had to give mine a couple of chunks of lead so they could get the counterbalance to match up.
icanfixall
Official GMM hand model
The flywheels are the same but they are differant.. Now feel free to ask why this is so. They bolt up directly to the cranks on each engine. Some you need to remove a spacer oe add a spacer but they are the same but differant... Some are balanced differantly but they are the same but differant. See where this is going. The only issues we have learned is the fylwheels being drilled off center so they had lots of runout causing horrible vibrations. This has happened twice in this forum and it was hell to diagnose too. Quality controll has slipped these days everywhere. Another reason to do your own work but check others workmanship on what you buy. A terrible way to do business isn't it..
austin92
Full Access Member
Reviving this thread instead of starting a new one. With as old as this is, you can see I've been through the search function. I have a southbend OHD kit that's been sitting in my closet because I've been too lazy to order the flywheel they said they could get when I bought the clutch. Now they can no longer get the flywheel, but they said they can redrill mine to fit their clutch. Problem is, my truck is my dd and I can't afford to have my flywheel gone for a week or 2 so I was going to buy a new one. They tell me that the 7.3 and 6.9 have different crank patterns but most forums say they're the same. So, I have a 6.9 with a zf5 and need to know what flywheel to buy. Pressure plate bolt pattern won't matter as southbend clutch is redrilling it
This is what I'm leaning towards. Looks like a single mass and it's listed for my year (83)
Sent from my iPhone using Tapatalk
You must be registered for see images attach
This is what I'm leaning towards. Looks like a single mass and it's listed for my year (83)
Sent from my iPhone using Tapatalk
icanfixall
Official GMM hand model
Any flywheel for a 6.9 or 7.3 fits every idi crank flange. End of that story. Only issues come up about a turbo flywheel on any non turbo engine. But even a turbo wheel easily bolts to the 6.9 or 7.3.
austin92
Full Access Member
That's what I read, I just figured south bend knew what they were talking about
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
IDIBRONCO
IDIBRONCO
I'd guess that they're confusing the 7.3 IDI with the 7.3 PSD. The PSD has 10 flywheel bolts while the 6.9/7.3 IDI have 9. There's suprisingly few people these days who know the difference. They think that a 7.3 is a 7.3.
austin92
Full Access Member
Yeah I told a new guy here at work what I drive and he was like "at least your strokin and not ******" I didn't even try to correct him....
So, is there any depth difference between the t19 and zf5 flywheels? I read some things about adding/removing spacers? What about starter rings? Do I need to match a part number on my starter to the tooth count on the new flywheel?
Sent from my iPhone using Tapatalk
So, is there any depth difference between the t19 and zf5 flywheels? I read some things about adding/removing spacers? What about starter rings? Do I need to match a part number on my starter to the tooth count on the new flywheel?
Sent from my iPhone using Tapatalk
IDIBRONCO
IDIBRONCO
I'm not sure about the depth of the flywheels. If I had to guess, I'd say no. I know you can use the same starter on either one. I believe that the starters are the same even for the automatics. The flywheel (flexplate) for the c6 doesn't use any spacers as I recall, it's just the one for the e4od that uses a spacer.
austin92
Full Access Member
I appreciate the info. Looks like this will be fairly easy. South bends info had me all worried lol. I was calling some part stores this morning. Everyone was special order and over 250$. Out of curiosity I asked about an 87 6.9 zf5 flywheel, 1200 freakin dollars!!!! Why such a huge price difference?
Sent from my iPhone using Tapatalk
