I'm very interested in this! Any ideas or suggestions anyone? I not only want to know which 727 Torqueflight parts are the best and why, but also which of these best 727 Torqueflight parts interchange with the later 518/46RH/46RE, etc.? I want to build-up my 518 overdrive and I have heard that most all of the parts will interchange, (with the exception of the valve body) but I have not physically set-them side by side and compared them. I want to swap a 518 behind my Big Block 451 Stroker engine. Which parts will swap? Such as Hemi Clutch Drums, etc.?

I put some 92 Diesel parts in my 92 gas trans as far as the drum with more clutches and one of the four gear planatairs(?). Also went with an ultra bell.

Yeah, Thanks! I actually have a JW Ultrabell just like yours'! Can you give me more specifics on the parts that you installed in your tranny? I wanted to use this particular thread to build a list of potential parts for a build. Also, I love the way that you tig welded the factory brackets onto your Ultrabell. That is one of the reasons why I haven't went ahead and started to prep a transmission case yet, is because the Ultrabell didn't have the factory tabs cast into it.

Do any of the later 727s have the Hemi 5 Clutch Drum in them? Such as the ones from a 440 Motorhome? What about the Heavy Duty 618 behind a Cummins Turbo Diesel? Would it have a 6 Clutch Drum? I remember reading somewhere that these trannys had 6-Clutch Drums. What about which trannys had 4-Pinion Planetaries? It seems that I recall again reading somewhere that some of these transmissions had up to 6-Pinion Planetaries. Let's elaborate.

Robbins, please post some more pictures of your Ultrabell conversion. I love the way that you added the factory tabs, that's real ingenuity. Do you have shots of both sides? I assume that you took the donor parts off of 727 case? That alone makes me want to break my brand new Ultrabell out of mothballs!

There isn't much as far as hard parts that interchange , and your 518 will have many of the most up to date parts . you can put 5 clutches in a 4 clutch drum so there is no reason to add the rotating MASS of the $$$ hemi drum and it's rear clutch retainer to the 518.

Taking and upgrading to the 618/47RH would be more worthwile , there isn't a 6 clutch drum except for maybe in the 48RE ??? , upgrade to the diesel/V10 OD rear section , that has more clutches in its setup , I think it's the same outside hard parts just thiner steels and clutches , but not sure haven't compared them side by side . The diesel trans has a 5 pinion steel front planet , make sure the spline count is the same as your trans .

Then there is lockup vs. non lockup and adding the controls to turn off OD and apply lockup if you go that way ...

Thanks Johnahah! I have been doing SOME-MORE kind of researching this afternoon alone! You are correct with your statement about the 48RE. One article that I read from a Diesel Power type of magazine suggests that the 48RE has at least a 5-Clutch Front Drum, maybe more? And it has 6 Pinion Planetaries on all 3 Planet Gearsets! Here is a link to the article:

http://www.dieselpowermag.com/tech/dodge/0669dp_dodge_48re_transmission/index.html

Please check it out for confirmation. I already have a 518/46RH with Lock-Up (3-pin plug), but now I feel like I'm going to definately be searching the junkyards for a 48RE! I also found another thread on the MoParts forum that was a great tech article (or at least should be a tech article!) involving a Big Block/518 Conversion (using a JW Ultrabell) with lots of pics! Here is the link to the entire article:

https://board.moparts.org/ubbthreads/show...rue#Post3453311

Thank you very much for the information Johnahah!

The 48RE came out in the 2003 or 2004 model year , expect to pay over $1000 for 1 , probably more , I would just got out and buy the drum and the rear retainer, and maybe the planet sets .

FYI more pinions in the planets create MORE and DRAG on the rotating parts, which may not be a good thing .

Thanks again Johnahah! That is a good idea about the drag and such. That's exactly why I wanted to create this thread, for everyone's input and ideas for building a Jam-Up Street Torqueflight! Sure, I may take it to the Strip every once and awhile, but it will mainly be street driven. I guess that a person could go to either extreme, Heavy Duty Street, Street/Strip, or full blown Race. My ideal transmission should fall comfortably in between Heavy Duty Street & Street/Strip or somewhere there abouts. Here's another one of my stupid questions: Since I will be using a JW Ultrabell and not an adapter plate, do you think that I could re-use my factory original kickdown linkage? Personally, I don't see why not. Any thoughts? Please elaborate. Keep those great ideas coming and thank you!

When planning on installing later planetaries in an earlier 727 be aware that there were three different output shaft splines over the years. If you're looking for strength a 3-pinion steel planetary will be stronger than a 6-pinion aluminum planetary; the spline in the aluminum planet carrier is the weak spot, not the pinion count.

I'm actually building-up a 518 or 46RH for use in a 1996 Dodge Dakota. The engine will be a 451 Big Block Stroker engine coupled to the 518/46RH using a JW Ultrabell. I probably won't be drag racing it although I may take it to the strip after it's built just to see what it will do. I'm listening to everyone's comments and taking it all in. I want the tranny to be sturdy and not give any problems, that's one reason that I want to use the Heavy Duty parts. However, I do want it to run pretty good for a street truck too. I guess that I will have to reach some type of comprimise? I want to build a list of ideas with everyone else's help. We may go ahead and list them here so that they may help others in the future as well. Keep the great ideas coming and thanks.

Anyone tried a 518 front planetary (2,74:1) with the 1990-2000 Output Shaft to fit in a 727?
Would that work?

The geartrain in the 46/47/48 are completely interchangeable from 1994 and after when we went to a 30 degree front carrier to intermediate shaft spline. The problem is if you use any 48RE parts - the drive shell, frt. carrier annulus and some other parts are unique to 48. You don;t need those parts in a gas engine. Stay with the 46/47 parts - 47 got the steel front carrier with 5 pinions - over kill for most gas engines. The rest of the geartrain in the 46 is fine for what you are doing and so is the OD unit. The 46 frt drum is likely a 3 disc, could be 4 depending on application. Just swap out the front drum (clutch retainer) to a 4 disc and you are fine. Use the L/R drum retained with a snap ring and have the ORC race pressed on the L/R drum - this greatly reduces the ORC failures experienced by prior model year units without these improvements. Do not use a L/R drum without the race pressed on.

All 48RE had 5 disc front drums in production from 2003.5 - 2007, both in the diesel and SRT gas trucks. We never offered a 6 disc drum in production.

There is no factory 2.74 gearset for the 518 or for any 727-based transmission.

Sorry messed up with the 904 low gear set.

Neverless a 6 Pinion front Planetary from a Diesel can be installed in a 727?

Not necessary. A stock 3 pin will live to 750 hp forever. I've only hurt one at 900hp. It took over 300 passes. It striped the splines, didn't hurt the planets themselves. I put another stock one back in


Doug

Is there something weak about the expensive 2.74 ratio gear sets from AA?

Is it true that some OD unit gear sets for Cummins diesel transmissions are straight cut teeth for less friction drag, but give off slightly more noise?

Anyone know what the frictional horsepower percent loss
for a 727, 46, 47, or 48 is?

When the Chrysler press release for the new 8 speed Torqueflte came out last year
one of the things it said was that it was
98 percent efficient in any of the 8 foward gears,
which kind of astounded me.

My recollection on the A & A gearsets - the carriers are made of steel. That alone makes them stronger than the aluminum carrier. So "weak" - I don't think I would call them that.

None of the gearesets inside the trans proper are straight cut - the only ones that were straight cut were in the OD unit. We went to helical cut (I think 15 degrees) after launch to quiet them down while operating in OD. 15 degrees OD planetary and sun gear started in 1995 on 47, the 46 retained the 22.5 degree gearset in the OD.