Posted By: poorboy
3.9 V6, does a modern V6 bolt to the transmissions? - 10/24/22 06:23 PM
My coupe has a 91 3.9 V6 with an AX15 5 speed. I'm currently running the early 90s throttle body injection.
This motor has around 170,000 miles and is showing its age. Last year, the rear oil seal started leaking, I didn't know until it was tore apart it had a rope seal. According to what I've read, you can't replace the rope seal without removing the crank and pressing the new rope in place. The rope seals are pretty hard to find these days. As it was, I removed the rope seal and installed the standard replacement seal, and sure enough, it leaks worse then the old rope seal leaked.
We have made it through another driving season, so once again I am facing that rear seal again. Currently the motor is going through about a quart in 500 miles, most of that through the rear seal, but it also has a hint of blue exhaust. and the famous blue haze valve seal leak on start ups.
Good used 3.9 are hard to come by around here. Rebuilding the one I have is an option, but I'd rather not go that route if I don't have to. This is the 2nd 3.9 in this car, the 1st one would have been better to rebuild, but its long gone.
Both the 3.6 and the 3.7 V6s are readily available here. Will either bolt up to my AX15 trans and bell? Then will one of those motors be adapted to run off the throttle body EFI, and would it be worth the effort? This car has been driven 100,000 road miles in the last 12 years, I am no opposed to installing a more modern V6, but I would really like to keep a standard trans rather then an auto trans. I am also not opposed to upgrading the EFI system if it can be done without all those modern interconnected things I don't have, the current system was from the 90 Dakota donor with 200K miles on it now.
I'm not interested in installing any V8 (hemi or SB Mopar), the car is light, and I'm getting old. The V6 with the standard stick shift is about all the thrill I can handle anymore.
Thoughts and suggestions?
Thanks Gene
This motor has around 170,000 miles and is showing its age. Last year, the rear oil seal started leaking, I didn't know until it was tore apart it had a rope seal. According to what I've read, you can't replace the rope seal without removing the crank and pressing the new rope in place. The rope seals are pretty hard to find these days. As it was, I removed the rope seal and installed the standard replacement seal, and sure enough, it leaks worse then the old rope seal leaked.
We have made it through another driving season, so once again I am facing that rear seal again. Currently the motor is going through about a quart in 500 miles, most of that through the rear seal, but it also has a hint of blue exhaust. and the famous blue haze valve seal leak on start ups.
Good used 3.9 are hard to come by around here. Rebuilding the one I have is an option, but I'd rather not go that route if I don't have to. This is the 2nd 3.9 in this car, the 1st one would have been better to rebuild, but its long gone.
Both the 3.6 and the 3.7 V6s are readily available here. Will either bolt up to my AX15 trans and bell? Then will one of those motors be adapted to run off the throttle body EFI, and would it be worth the effort? This car has been driven 100,000 road miles in the last 12 years, I am no opposed to installing a more modern V6, but I would really like to keep a standard trans rather then an auto trans. I am also not opposed to upgrading the EFI system if it can be done without all those modern interconnected things I don't have, the current system was from the 90 Dakota donor with 200K miles on it now.
I'm not interested in installing any V8 (hemi or SB Mopar), the car is light, and I'm getting old. The V6 with the standard stick shift is about all the thrill I can handle anymore.
Thoughts and suggestions?
Thanks Gene