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Hey Yall! Long time lurker first time poster, I've got quite a situation on my hands. Picked up this truck from Montana last weekend and drove it all the way back home to Idaho mostly without a hitch. It's a 1983 F250 that at some point got a 7.3 IDI swapped into it along with a ZF5. The swap seems fairly shabby and about half way I noticed a slight leak starting at the input shaft, said welp thats a bummer and kept it topped off on the way home. The ZF5 already had issues with reverse and growling noise when the clutch was depressed so I figured I'd replace it or rebuild it once it got home. Upon a deeper look there were a few leaks and the synchros were all but destroyed so I grabbed a replacement off a buddy and dropped the old one out.
This was my first time pulling a ZF5 so I was ready to take pictures and notice everything, from the begining I saw the yoke was fairly loose, having almost 3/4" of play before engaging the clutch. Continuing on I found that the transmission had writing on it and clearly did not match the transfer case, so my assumption that the whole drivetrain was swapped at the same time was incorrect. The rear axle had a tag on it that said 91 F250, so I operated under the assumption that the rest of it was the same truck.
Once I dropped the trans I found shavings of what was once a pilot bearing sitting in the flywheel, which at a minimum explains the input shaft leak. I went to order a replacement clutch and flywheel because the ring gear was chewed up bad, but I can't seem to figure out what the original flywheel came from. It isn't a dual mass like the stock one should be, and it doesn't have any aftermarket identifiers that would make me think it was an upgraded SMF. It looks to me like a T19 flywheel, which could explain some of the issues with the pilot bearing destruction and the throwout. It could also be the original flywheel that came on the engine if it was in a bricknose.
I'm not eager to but the wrong flywheel, especially because I've heard about incorrect balancing damaging engines. I spent awhile trying to assess what what year the engine is but the serial number isn't helping much. It's clearly a N/A 7.3, the serial is in an image below as well in case anyone can help.
My main question is if anyone recognises this flywheel and has an idea of what SMF kit I should buy instead, and if I need to replace my harmonic balancer to match. Thank you so much and appreciate the replies!
How can you clearly see its a 7.3? I have a 6.9l in my truck that was built by Dealers Diesel or Reviva. Interestingly the valve cover decal says 7.3. I was told that all their 6.9 and 7.3 engines got the valve cover decals that say 7.3. I actually ordered the engine from Dealer's but received it from Reviva. They changed their name mid order.
I'm wondering what engine you originally had in your truck? 1983 would be early for a 6.9l, but if late in the year could have been I guess?
On the flywheel maybe cross check the different engines and look up the part numbers on Rockauto.com and see if they are cross compatible. There are different ZF5s for different engines. IIRC the 460 and the diesels are not compatible. Check compatibility on Rockauto.com and compare part numbers. That's all I have for you. Hope you get it straightened out. Let's see what others say...
Thanks for your reply BigBlue2! You made me doubt myself LOL So I double checked and verified the rest of the serial number is a 7.3. Great question, I was wondering the same thing. It seems like it would have had the 6.9 since it has the DIESEL Fender tags, but that can be misleading too. Even the guage cluster seems to be from another truck with a gas engine, which ne er worked because they didn't connect any of the gauges. Off topic but I was thinking about that too, I'd assume the guage sets would have to be different for the 300, 351, or 460.
Anyways, I did try to search up the part number on the flywheel in a couple places but it must be a serial number of some kind because I can't find a trace. The other T19 flywheels I can see don't have that odd chunk missing, thats why I wanted to get a bit of confirmation. I think at this point that it isn't the correct flywheel because of the pilot bearing situation and the clutch play, but I'm too unsure to go to a single mass zf5 kit from LUK quite yet.
I recommend the LUK SMF kit. I put one in my '88 after the stock DMF, and a replacement DMF crapped out. The truck was a wee bit louder, but OMG! the clutch was like butter! Pedal feel was greatly improved, it felt like driving a car, not the heavy heavy clutch the DMF had. My '93 came with what I believe to be a Southbend SMF, pedal sucked as bad as the DMF did on the '88. That ended up with a LUK clutch when I dropped the ZF6 in, and magically the pedal feel was where it should be.
I'm not going to say I've pushed it to its limits, but have certainly towed a few heavy trailers with both trucks, and the LUK clutch has been trouble free. If you can't identify the flywheel, you may have trouble getting a clutch that bolts up correctly, may be easier to just swap it all to LUK
Flywheel confusion.
