518 Swap questions.

Transmissions and Rear Ends

  1. MBDale

    MBDale Well-Known Member

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    Hey guys,

    My Aspen RT has a 360 LA with a 727. I’m thinking of a Overdrive Swap. If I want to change the transmission to an overdrive unit do I look for the ‘88-‘92 non lock-up 518 (so I can the same converter as my 727), or can I run a A500 (42RH)?? I’m thinking the 518 because it came behind a 360 right?
     
  2. kkritsilas

    kkritsilas Well-Known Member

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    A500 should work as well. There are not many A500s around. The A518 is stronger, but possibly overkill for stock small block, 318 or 360. The A518 never came behind a 360, it came behind a Magnum 5.9L (which is a 360 block), but I don't know if the balancing of the LA and Magnum are the same. I do know one of the belhousing bolts did move slightly. It would be better to get a lock up vs. non-lockup transmission if possible if you are doing a lot of highway driving. Also, the A500 will be more efficient (less power loss) than the A518 (Just like the A904/A998/A999 is more efficient than the A727, and for the same reason).
     
  3. 80mirada

    80mirada Well-Known Member

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    A-518 entered production in 1989, for the 1990 model year, and was used behind 318 and the 360 starting 1991. The Magnum 318/5.2 wasn't available until the 1992 model and the Magnum 360/5.9 followed in 1993. I have a 1989 (1990) production 518, they were OD only until 1992, all 500s are OD and Lock-up.
     
  4. Duke5A

    Duke5A Well-Known Member

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    How is your motor built, how heavy is the car and what is the intended usage?

    I ate three 500's behind a 400 HP 360 in my heavy Fifth Avenue. These were stock builds mind you. A 500 could be made to live behind 400 HP.

    The 500 has the advantage of being smaller and more efficient. It'll put more power to the ground and has a slightly lower first gear than the 518. It would be my choice for a car that sees daily driver duties and cruising.

    Depending on your usage you may or may not want lock-up. The 518 can be found in a non-LU variant, but these were only built during the first two years of the 518's existence. The 500 was never produced without LU. The easiest way to tell if a 518 has LU is to look at the overdrive plug. If it has three pins it has LU, if it has only two then it does not.

    Overdrive and LU are both electronically controlled by powering up solenoids with 12v. You can either do this by hand with switches, or automate it with a vacuum switch and a couple of pressure switches. I did this to my car and it isn't complicated at all. I can help with this if you want.
     
  5. MBDale

    MBDale Well-Known Member

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    I’d really appreciate the help and advice Duke5A!! My 360 makes 400 HP. As per dyno. A 500 has come up locally for sale, it was behind a early 90’s Dakota. This got myself reading on Overdrive swaps. Ideally I’d like a 2-pin 518 because then I could use my new 3000 stall from my 727. If I can’t find one, I’ll go with a 3 pin. One of my questions is that I found a 1995 Ram with a blown 518. Would that 518 being a 1995, would it still be a 46RH transmission? I’m betting it be a 3 pin though. And that’s ok. To answer your question about intended usage and weight, the cars is being used on the street, full interior, no AC, weekend driving, some strip time. It’s an Aspen RT, I’m guessing @ 3600 lbs. Thanks for everything!
     
  6. 89.Fifth

    89.Fifth Well-Known Member

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    I also picked up an A500 not too long ago. My plan is to build it up and put it behind a nice mild 318. I would love to see any pics or diagrams of how you got all the wiring and solenoids going. That in my mind is the hardest part to get right.
     
  7. Duke5A

    Duke5A Well-Known Member

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    @MBDale Yeah, that would be a 46RH. 1995 was the last year for the hydraulic models. It's also a lock-up unit. You'll need to find one from 1990 I think. Don't be so quick to toss LU though. Goes a ways for fuel mileage.

    @89.Fifth The wiring is stupid easy. Don't be at all intimidated by it. One adjustable vacuum switch, one 5 amp fused 12v supply, and one pressure switch (or two if you have LU).
     
  8. MBDale

    MBDale Well-Known Member

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    You might want to check out 42RH Swap: ‘80 Volare. Under transmission section.
     
  9. 8T2TOP

    8T2TOP Well-Known Member

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    Don't forget about floor pan work and different trans member and mount, cooler lines,cooler drive shaft mods..
     
  10. MBDale

    MBDale Well-Known Member

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    The trans just might have to be a Lock-Up unit, I’m at work right now and get home Monday the 19th. I’ll find out more next week. Have a guy checking his auto yard for me. He’s just out of town a little way. This 3 weeks out and 1 at home is killing me. Nightshift too. Hopefully this project is done in December. I’ll make a post next week and see where we’re at.
     
  11. Duke5A

    Duke5A Well-Known Member

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    My Dad's Diplomat coupe has a non-LU 518. He wanted it without LU for the same reason as you. Just the year before he spent $600 on a nice Turbo Action converter for the 727 that was already in the car. I looked around for a couple weeks and eventually found one on Craigslist about an hour north of us. Was already pulled and sitting in a junkyard. $100 and gas money brought it home and I think he put $800 into it at a shop for a basic refresh.

    If you've already seen the 500 how-to then you know exactly what needs to be done tunnel wise. The mods are exactly the same between the 500 and 518.

    If you're going to be under the car with a welder already it's a great time to add sub-frame connectors.
     
  12. Aspen500

    Aspen500 Well-Known Member

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    Not sure if you were talking about the 500 or 518 but, my 1996 Dakota is only electronic for OD and lock up, 1st thru 3rd uses the TV ("kickdown") cable and will work even if the trans is unplugged. Just some useless trivia:D
     
  13. BudW

    BudW Moderator Staff Member

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    One thing that is overlooked is the torque converter. Sometime after the Magnum engines came out (mid ‘90’s?), Chrysler finally moved the balance weights from converter to the flexplate. Also, they changed the torque converter hub from a slot (which is known item to crack) to a flat.
    TC slot vs flat hub.png

    A727 A518 flat pump gear.jpg

    The Torque converters and front pump gear sets will interchange as a pair (ie: slot converter with slot gears, and flat converters with flat gears). The flat converters give significantly less trouble than the slot design does, and I highly encourage anyone looking at a trans rebuild to go with a flat converter (unless you already have an expensive race-only torque converter).


    The A518 (46RH, etc.) is heaver and would be excellent if a person has a high HP car or constantly drives hard. If you have a stock or mild 318 and looking for mileage, the A500 (42RH, etc.) would be recommended because of the better first gear ratio.

    Personally, I do recommend going with lockup converter – even if you have lockup disabled. Lockup does give about 10% better fuel mileage and reduces a lot of heat buildup inside of the torque converter. My 400 stroker build, will have a working lockup system (once I decide to go with overdrive (A518) or without (A727). At this point, I’m leaning towards the big block A518.

    I hope this helps.
    BudW
     
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  14. MBDale

    MBDale Well-Known Member

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    Just a quick update here guy. I’d like to also thank everyone for their advice, help and experience on this. I’ve also got a A518 3 pin lined up to pick up when I get home from working out of town. Hopefully have some pictures here soon. Thanks!!