A518 Overdrive Questions

[ShelbyDogg]

Here is the circuit without having to decipher the transmission center's text.
It's hard to draw with a mouse but its good enough.

If I were really picky, I would use 2 oil pressure sending units, like the ones used for the guage on a rallye dash.   I would build a circuit in a box with 2 potentiometer knobs on the front.  One knob to adjust when to shift into OD, the other for when to lock-up the converter.  The pots would just adjust what pressure level each circuit kicks in.   The circuit is very simple but the cost would go up.
The sending units are $23-$25 each, then if you build the board and box, you'll have at least $100 in your labor and parts. We are making a simple circuit, complex by trying to overthink this.  We just need to find their source for the 44 PSI and 50 PSI switches.  They are probably around $8 each.

Chris,   With these cars being as old as they are. I don't put in aftermarket seats.   I'll probably take a reclining mechanism out of a new seat and weld it into a stock type Cuda Bucket. That way all the Ferd and Chubby guys will think its a stock seat.

[tactransman]

Rob,the way I see it with that circuit,you will not be able to have lock up without OD,is that the way you want it? You probably wouldn't want it to lock up unless you were in OD but I was just checking.

[tactransman]

In my case, I would only want lockup to kick in in 4th gear after hitting 50 mph

Then it looks fine to me.

[ShelbyDogg]

So Terry,

If TransmissionCenter's circuit is installed to see governor line pressure,  does governor line pressure ever hit 44 to 50 psi in the other gears?   I was thinking that the Tee should be off of the 3rd gear clutch pack so it can only hit LU and OD when in 3rd gear and when vacuum goes above the sending unit's setting.

I'm also thinking that we need adjustable pressure switches because we always turn up the pump pressure when installing the shift kits.  The TransCenter says that its one PSI for every MPH so the 44 psi sender should kick in at 44 MPH.  I don't see that staying the same after we start turning the pressure screw on the VB.   With adjustable, we can tweak them till it shifts the way we want it to.  Your thoughts on that?

[dmk67]

i would like to do a 518 swap but with limited funds i would like to see pics of how to modify my slap stick linkage before investing in buying a trans any pics of a successful linkage swap

[tactransman]

So Terry,

If TransmissionCenter's circuit is installed to see governor line pressure,  does governor line pressure ever hit 44 to 50 psi in the other gears?   I was thinking that the Tee should be off of the 3rd gear clutch pack so it can only hit LU and OD when in 3rd gear and when vacuum goes above the sending unit's setting.

I'm also thinking that we need adjustable pressure switches because we always turn up the pump pressure when installing the shift kits.  The TransCenter says that its one PSI for every MPH so the 44 psi sender should kick in at 44 MPH.  I don't see that staying the same after we start turning the pressure screw on the VB.   With adjustable, we can tweak them till it shifts the way we want it to.  Your thoughts on that?

Rob,so you are wondering if the gov. pressure gets high enough like in a full throttle upshift in 1st or 2nd for the LU or OD to kick in? That is a good question,if I get one in here I will throw a gauge on it and see.

[tactransman]

any pics of a successful linkage swap

Soon ,probably soon. I am not going to have a slap stick in mine,but a few people are going to be tackling it in a little while.

[dmk67]

with a 518 attached to a 318 eng in a 91 dodge p/u would you have to change the bellhousing to fit a 440 eng

[tactransman]

with a 518 attached to a 318 eng in a 91 dodge p/u would you have to change the bellhousing to fit a 440 eng

Yep, check out this thread       http://www.cuda-challenger.com/cc/index.php?topic=25669.0

[PlumCrazyChris]

Well I just recieved my pressure switches.  I got the 44psi, the 50psi, and what was listed as a 54psi, but arrived as a 52psi.  Not too happy about that.  But they cost me ~$20 total for all 3 and shipping.  That $119 kit was a tough nut for me to swallow.  I knew I could find them cheaper (he says very self satisfied

I still need to find a source for the vacume switch, the local shivie dealer wants $49 for it.  Anyone find one cheaper? 

I pulled my tranny open last weekend and found it has been rebuilt and the clutches look good.  Now I don't want to mess with it.  but I will install the transgo kit I got.  The kit was listed for the 518, but doesn't appear to be anything different then the 727/904 kit.  I'm pretty disappointed in that, it was $53.  Its pretty much a filter, some drill bits and instructions where to drill.  I already have drill bits and know where to drill, and filters are a lot less than $53.  Save your money boys and check out the old mopar muscle mag articles for the shift kit info. 

I've got a spare crossmember that will likely get cut up for the conversion, but the one I saw fabbed from 2"x2" square tubing in the Moparts truck section looks a lot better and easier then remaking an old one.  You got to check out this thread if your considering this mod, especially if you have a big block.  Totally archive worthy.

http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=3453311&an=0&page=1&gonew=1#UNREAD

I'm off to my mopar meeting.

Chris

[ntstlgl1970]

That crossmember pictured won't work in a passenger car, way too low. US car tool made one for a dart that was a very low profile design. I emailed the guy and he said he might have some parts to make one up, but I haven't heard from him since.

[PlumCrazyChris]

I didn't say that one would work in my car, I said I like the design better than cutting up my original crossmember.  Its a elegant and pretty easy way to do it.  I don't think one for a dart will work in your ebody.  Bbody and Ebody are the same, but I don't believe Abody crossmembers are.

[ntstlgl1970]

Sorry was thinking of a different car. Anyway, here is one they built for reference.
http://www.uscartool.com/img/70Challenger/index.html
page 7 and 8

[PlumCrazyChris]

I'm getting close, my motor is about finished, just need to put the accessories on it.   I think I'll pull the 904 out of the Challenger and trial fit the 518, that way I can trim the trans as necessary and mock up the linkage and see whats required to get the slap stick to work. 

I can also measure the drive shaft and send it out to get cut and balanced. 

Is anyone else still working on their trans conversion?

Chris

[Jacksboys]

Please take as many pics as you can