OD auto for a small block??

[dusterdoug]

Exploring ideas after my buddy got his Brand X car running with a OD auto; goes mid 11's at gets 20 mpg. Grrrrrrrrr...

What is the auto behind the small block Durango/Dakota/Ram? A 518A or something...?? These are just a 727 with a 4th gear, right?

I'm sure someone in the aftermarket makes a 2500-3500 converter, BUT what about a manual valve body?? Prefer a reverse VB, but that's probably too much to ask.

What do you know? What are you running in this arena??

Thanks, as usual!!

 

[fishy68]

Depends on the year and which engine was used in the Ram/Durango/ Dakota as to which trans it has. If it's a conventional magnum engine it could be a a500 or a518. It it's a 3.7, 4.7, or Hemi engine it's a 45re or 45rfe. The A500 is basically a 904 with and o.d. unit and the A518 is basically a 727 with an o.d. You can get an older A500 that does not use a lockup converter and is real easy to find parts for. I just sold one at the Indy swap meet in fact. They do need some beefing up in the o.d. unit to handle high power but when done work great. Not sure if anybody makes a manual vb for them. Try calling Chris Andrews of Andrews Racing trans. (google search for the ph. #) Chris is super sharp on all Mopar transmissions so I'm sure he can help.

 

[dusterdoug]

Wow! Good info, Fishy! I'm liking the idea of that A-500/904 deal! Was going to do a 904 for the mass reduction, anyway.

I'll find him and call him. Thanks!

 

[dusterdoug]

Fishy, do you know what years the "older A500" were??

Thanks again!

 

[dgc333]

The A500 and A518 started in the mid late 80's. The designation was changed to 42RH and 46RH in the early 90's (same tranny with some internal improvements) in the mid/late 90's the tranny added more electronic controls and became the 42RE and 46RE. There is also a 44RE which is a 42RE with more clutches to give it more capacity and is found behind v6 4x4 Dakota's and Durangos (maybe some jeeps too).

All the A500's had lock up torque converters but the early A518's didn't. You don't want a 42RE or 46RE because there is not a controller available to make these work on a retrofit into an older car.

NOTE: either an A500/42RH or A518/46RH will require that you cut the torsion bar cross member and the floor to expand that area for clearance with the OD section of the tranny.

 

[fishy68]

If I remember right 95 was the last year for the hydraulically operated A500's and A518's but I made a typo in that I said the older A500 can be found with no lockup. I meant the A518 can be found with no lockup. All A500's I've ever seen were lockup. Sorry about the mis-information. I was real tired last night and just boobed up.

 

[inkjunkie]

i spoke with Chris a short while ago about the 518. limited in valve body choices, if you look to http://smrtrans.tripod.com/smrtransmissionsintro/id5.html they have a reverse manual vb available. keep in mind, that if you run a od with a loose convertor you very well might have some issues with the convertor slipping on the road, spoke with several shops about it. one of which was http://www.ultimateconverter.com/home.html
probably will not be much of an issue, unless you are pushing some torque. you end up with a compromise, if you run a tight convertor with the od you might be lacking in stall, if you run a typical 9.5" convertor it does not contain enough fluid to not slip while cruising at 2200 rpm or so. an od simply takes a percentage of the gear out. 4.10 would become a 2.82 with the 518 .69 od. you would be trying to cruise at 2200 rpm, so cruising with a loose convertor will be a problem. and as mentioned you need to do a bit of surgery to get the 518 into the car. what it comes down to is if you want to run a loose convertor, and to run mid 11's with a small block, you probably will have to, you might want to look outside the Mopar box for a trans. the picture is of what it took to get a gm4l80e in a Dart. The Dart will have a 572 Hemi in it, with a crossram and efi from FastMan EFI on it. The 4l80 is a very stout unit, that takes very little in the way of upgrades to get it to live at 700-800 hp. you can run enough stall to keep your car happy at the strip yet be able to run a lockup convertor so you can drive it on the street. there is a few trans brakes available for it also. i have done a bit of research on this nighmare, and for me, this was pretty much the only solution. while you could also run a t-56 out of a viper, I wanted an automatic. the 4l80 is strong. you can get one with a manual valve body from http://www.jakesperformance.com/4L80E.html for $2100 that is claimed to live behind 750 hp. $500 or so for the QuickTime bellhousing, my buddy that owns a trans shop quoted me $1000 for a convertor. There is no reason why you cant run 10's and still get decent fuel mileage, if you are willing to step out of the era that our cars were built and into this decade. I have seen more than a few 5.0 Stangs that ran low 10's and still got close to 20 mpg on the freeway......
Disclaimer....the above is just my opinion. While I understand that the above will constitute the rape of my Mopar product, it is mine to do as I choose to. So if you are a purist and have an issue with what I am doing, why did you read this after the title told you not to?