727 to 518rh trans gearbox upgrade?

Started by budder, March 19, 2017, 03:43 AM

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budder

Ok I have a torqueflite 727 mated to my mopar 440
I have been offered a 518rh, so far I worked out I will need a adapter plate if I want to mate it with the 440.
Or could I just take the over drive of and put it on the 727. Hm?

budder

I have looked on the web and answered my own question.
But I found tis it looks quite interesting.
http://board.moparts.org/ubbthreads/ubbthreads.php/topics/35994/2.html

budder

So is this a 2wd or a 4x4 box? I know it says it's a 4x4 but it looks like a 2wd one.
Look at this on eBay  http://www.ebay.co.uk/itm/252811591269

stanDman111

sure looks like a 2 wheel drive unit to me ?

Rickf1985

That is a two wheel drive but a 904 is a light duty unit used on AMC cars and and dodge cars and Jeep CJ's. It would never hold up to your unit. There was the 904 which was a non lockup and a 999 which was a lockup torque converter. You need something based on the 727. Look for a 47RH, I am not sure what you would need for adapters. They were used in just about all of the pick-up trucks prior to the computer controlled transmissions which were the 47RE and 48RE. I would think you would be able to find a flexplate that would bolt up but I have never done it with a 440.

budder

Rick it was advertised as a 518 then he changed the listing.

khantroll

An a518 is an early generation 46rh, and as Rick said a 904 is a light duty version. You either need what is called an ultrabell adapter or the PTAC adapter set. The Ultrabell is cheaper, but it's still about $400. The Ultrabell requires grinding the cast bellhousing on the transmisison.


I'd post a link to the Ultrabell, but my work computer doesn't like the manufacturer's site. I'll update it if I can find an alternative source. Jegs carries all of them but the one we need.


Here is a link to the PTAC adapter:


https://transmissioncenter.net/shop/chrysler-big-block-361-383-400-413-426-440-to-dodge-small-block-518-transmission-6-bolt-crank/


No matter which way you go, you'll need one of these to control the OD:


https://transmissioncenter.net/shop/patc-727-to-518-46rh-conversion-kit-click-here-for-727-to-46rh-swap-wiring-diagram/




Here is a thread of someone doing the swap, albeit it in a car and not a motorhome:


http://board.moparts.org/ubbthreads/ubbthreads.php/topics/35994/big-block-a518-overdrive-conversion-lots-of-pics.html






Rickf1985

I can tell you the 47rh is a very strong transmission and can be built even stronger because they used them in the Cummins Diesel pickups. Guys have modified the engines on those trucks up to 800 plus HP and pushing 1,000 ft/lbs. of torque. And they do not go easy on them. Granted the transmissions do not last 100,000 miles but I know of several that are going on 70,000 with over 500 hp going through them. Keeping them cool is the biggest thing, they will last a long time if you keep them below 250 degrees. I run synthetic oil in my Diesel pickup which has a 47RE in it.

budder

So I'm on the look out for a 47rh. If any one knows one available in good condition and can help ship it back to the uk that will be cool. W%

budder

Quote from: khantroll on March 20, 2017, 09:26 AM
An a518 is an early generation 46rh, and as Rick said a 904 is a light duty version. You either need what is called an ultrabell adapter or the PTAC adapter set. The Ultrabell is cheaper, but it's still about $400. The Ultrabell requires grinding the cast bellhousing on the transmisison.

I'd post a link to the Ultrabell, but my work computer doesn't like the manufacturer's site. I'll update it if I can find an alternative source. Jegs carries all of them but the one we need.

Here is a link to the PTAC adapter:

https://transmissioncenter.net/shop/chrysler-big-block-361-383-400-413-426-440-to-dodge-small-block-518-transmission-6-bolt-crank/

No matter which way you go, you'll need one of these to control the OD:

https://transmissioncenter.net/shop/patc-727-to-518-46rh-conversion-kit-click-here-for-727-to-46rh-swap-wiring-diagram/


Here is a thread of someone doing the swap, albeit it in a car and not a motorhome:

http://board.moparts.org/ubbthreads/ubbthreads.php/topics/35994/big-block-a518-overdrive-conversion-lots-of-pics.html



I think I would like to manualy switch into od then do it automatically. The bell housing looks the better option the other set up looks quite expensive for what you get. ;) 

khantroll

Hi Budder,


I agree, and if and when I do this swap I'll be going for the UltraBell. As for manually switching in the OD... the setup also controls torque converter lockup. My personal preference would be to have it act "factory", but hey, the point of customizing things is to get what you want  :)ThmbUp


I've got a friend with a rat rod and a similar setup, but he's got manual switches. It's funny to watch him drive down the road flipping switches.  :D  He loves it though.