A518 Overdrive Questions

[ChallengerHK]

I'm guessing ChallengerHK's name is Carl too? I think it is but just making double sure.
I've decided to go Manual/Hemi. Still, nice to know how you put a A518 into our E-Bodies with factory linkage.

No, I'm David. Going down the same road you were when you started this thread and trying to determine what option to go with.

[PlumCrazyChris]

I'm putting a 518 in my 70 Challenger and have been researching it for quite a while.  I now have a tranny and bought a transgo shift kit to put in it before it goes into my car.  I hope to see the car that Wild R/T modified for the 518 fairly soon.  The car is here in the Austin area.  I think I have a pretty good handle about what needs to be done.  I just hope my early 90 trans holds up.  We'll see. My motor is pretty tame at this point, but a stroker rotating assembly is in the future.  Apparently the later models have received many mods to strengthen them.  So a 95 is the one to get.  And there is no need to worry about the lockup failing.  Neither it nor the OD will engage at WOT, and will drop out if you stomp on it.  They only engage at light throttle at cruising speed.  I have a friend with a 550 hp 408 in his 97 Ram RT daily driver and his 518 handles it no problem with over 100,000 miles on it. 
I have a couple of articles from some earlier magazines pdf'd detailing the mods to the trannys and whats needed to install them.  If anyone would like to get them, sent me an email.   

Like Wild R/T said, trimming the case and modding the lower crossmember is all thats needed to bolt one up in an Ebody or 72 and later Bbody.  Then route your pressure switches for the LU and OD, and your vacume switch to unlock, cut your driveshaft and your all set.

I have yet to identify the specific part # or application for the two pressure switches and the mount bushing, but am closing in on them.  I have found a supplier that has variable pressure switches, so you could dial in when your LU and OD occur.  I don't have a price yet though,  they may be pricey. 

I'd be happy to share what info and pictures I have with anyone that would like it.  Just let me know.  When I'm done, I'll post the pics and story.

Cheers,

PlumCrazyChris
Austin, TX
Newsletter Editor Mopar Muscle Cars of Austin
www.mopar.org
70 Challenger 340 Convertible
70 Challenger

[PlumCrazyChris]

No, I'm David. Going down the same road you were when you started this thread and trying to determine what option to go with.

Hey David, I'm from the Raleigh area and know several mopar guys down there.  I wonder if you know any of them?  How bout James Ayscue in Fuquay or Sammy Wood out near Benson??  They are both ebody guys.

[Jacksboys]

I'd be happy to share what info and pictures I have with anyone that would like it.  Just let me know.  When I'm done, I'll post the pics and story.

Hello Chris,

I would love to see as many pics as you can get, showing all of the modifications you have to make.  I have an A500 in my garage and I am debating on if I want to do this swap with my 904.

Also, does you Challenger have the Slap-stick shifter?

[tactransman]

PCC, the really only update difference between an early 518 and the later is in '91 1/2 they went to a 14 element low  sprag and beefed up the case in the back.(definitely better  ) There is a bigger OD planet bearing also but that can be updated to any tranny. The biggest reason I went with a '90 tranny was to have a non lock up and that makes you unlimited in the stall converter range. IMO a lock up converter is weaker than a non lock up,with the lock up clutch being in it,they have to make the sprag smaller to leave room for the lock up clutch. Pics would be great too by the way.

[ChallengerHK]

Definitely pics.  And did we come to any consensus about whether cutting the case is acceptable? I assume that it would be up to a given horsepower/torque point, but is this a good assumption?

[tactransman]

Definitely pics.  And did we come to any consensus about whether cutting the case is acceptable? I assume that it would be up to a given horsepower/torque point, but is this a good assumption?

I think that cutting on the OD housing is OK. Just make sure your driveshaft is perfect as far as straight and balanced.

[tactransman]

These guys have the switches and a good article on the install.

http://www.transmissioncenter.net/SwapInformation.htm

[PlumCrazyChris]

If ya'll want to send me a message to my personal email, I'll be happy to reply to you with my info.  I'd rather not do it through this server. 

Terry, I got a lot of my infor from PATC, I just don't want to spend over a hundred dollars for the same switches I can get for $8 each at O'Reillys.  If you know the application for those switches, I'd be much obliged.

Chris

[tactransman]

Chris,I am pretty sure those switches are from around mid 1980's Chevy PU with a 700R4,I'll see if I can round up some OEM part #'s.

[PlumCrazyChris]

Another thing I have not seen mentioned in this thread is the requirement for a 3/8" cooler lines.  The way to make these things survive is to get cool fluid to the overdrive unit.  Drilling the valvebody to allow more fluid to pass and adding a separate cooler with bigger (than 727) lines, A518 and A500s have 3/8" lines stock is the way to do it.  Just take the lines off the donor vehicle and they should work fine with only minor alteration.

I had found a thread on a different forum where a guy discussed all the mods he made to 518s to handle high performance applications, but didn't book mark it and of course....I can't find it again.

Terry if you have any tips, in addition to the ones in the article I sent you, I'm all ears.

Chris

[ChallengerHK]

I noticed that the one I just picked up has a deep trans, pan and I'm assuming that part of the reason is the need for more fluid.  To those who have them fitted, is that pan a problem for regular street driving? I was going to replace it with the stock 727 pan, but now I'm thinking that's maybe not such a good idea.

[PlumCrazyChris]

Chris,I am pretty sure those switches are from around mid 1980's Chevy PU with a 700R4,I'll see if I can round up some OEM part #'s.

That'd be great Terry!  I think I'd be interested in the 50 and 52 psi switches.  I've found a vendor that sells them, but haven't been able to contact them yet.

[tactransman]

 The 518 uses the same performance mods as a 727. It is a very tough tranny. I have not seen any mods to the valve body that increases cooler flow,do you have info on that?

[PlumCrazyChris]

Its not a problem at all.  You really need that deep pan, the later model ones I'm told have even deeper pans.  Lots of people upgrade their 727s to deeper pans with fins or tubes going through them to keep them cool.  Several manufacturers have kits for that with longer pickups.