I found this as well and thought awesome it will help. Well i have the 3 speed 3L80 but a serial number of 601xxx so not very helpful. as for year who knows. I have a date of OCT05 stamped on it but I'm guessing thats when it was rebuilt into the 1097 and went from a 6.2 to the 6.5If your unit has the M1097R1 HMMWV, NSN 2320-01-346-9317, with a retrofitted engine, check the serial number before ordering a new transmission for the vehicle. ...www.psmagazine.army.mil
If your unit has the M1097R1 HMMWV, NSN 2320-01-346-9317, with a retrofitted engine, check the serial number before ordering a new transmission for the vehicle.
- M1097R1 HMMWVs with serial numbers between 500000 and 549000 require the 3L80 transmission
- Those with serial numbers between 570000 and 599000 need the 4L80E/4L85E transmission.
So basically sounds like you have a 3 speed truck, which would put you at 1993 or earlier I think?
I'd suggest just putting 1990 and calling it good. It puts your truck at over 30 years old which is more than enough for historic license plates in pretty much every state. There is no way for anyone to accurately verify the exact year, and putting it as a newer vehicle doesn't give any benefits in any state as far as I am aware.