727 to a 518 overdrive

S

Steve Grant

Member
I looked around on the seach engine here in the forum, can a IH 727 be made into an a518 tranny?? I'm curious if anyone has done anything to do this.
 
Nope...take at look at the bottom of the page in this link for a comparison of these units. The trans in the middle of the pic is a tf 727 "long tail" as used in most chrysler product apps. Pay attention to the rear of the case where the 4th gear guts are located:

transmission identification - crankshaft coalition wiki

IH 2x4 and fullsize 4x4 stuff uses a very short tail with a bolt-on yoke/output. Scout II uses a married transfer case which requires a tranny with a very "special" output shaft, unlike any other oem used.
 
Thanks for the reply Mike. I would like to have overdrive in my Travelall, its a '73, I was looking into getting the adapter plate for the 700r4, but as you know, the '73-prior had mounts on the side of the transmission, and the 700r4 don't. I would like to eliminate the divorced transfer case someday, I know the later dodge trucks had a 727, with a married 205, but that probably won't work with the IH 727. I toyed with the idea of a gear vendor od between the tranny and t-case, but was told you can't do that either. Appreciate your input sir, hope you have a merry Christmas!
 
Ok steve...ya say Travelall,...for some reason I thought you were dealing with/asking about a Scout II?? Sorry! Big difference!

Keep in mind, I'm just throwing shit out here, I have not done anything like this and certainly can't speak from the standpoint of experience...but let's do sum speckilatin'! And this would be a "cost-no-object" kinda deal using gearvendors stuff. But payback for the investment???...not in our lifetime!

We could do a "reverse" 727 conversion since your transfer case is divorced. We'd gut out the tranny (and of course do a total build-up in the process), and install a "long" chrysler-pattern output shaft and tailhousing setup. The only difference in the chrysler app 727 and the IH app is the output shaft "system" (and of course the bellhousing).

Once ya gotta chrysler-pattern tail on the tranny, then the gearvendors stuff should couple up just fine. But then you would have to move the transfer case and crossmember rearward, shortening the rear driveshaft, lengthening the front driveshaft. And we'd use the dodge motorhome output shaft and housing I have that has a bolt-on output yoke just like your existing transmission.

And we'd prolly have to have gearvendors do an "add and delete" adjustment to their kit parts selection depending upon exactly which one was selected.

I can see an ez $5k budget for this...ya game??

A divorced transfer case (or a 2x4 rig) always makes beerthirtytalkin' about this stuff much more viable!

This pic shows a comparison between the three common 727 outputs I deal with fairly often. The one on the left is a dodge motorhome without a parking brake setup on the tailhousing. The IH motorhome chassis (1310mhc/1510mhc) used a near identical setup, but of course, that transmission would have been an IH pattern bellhousing that would make this deal very simple if ya had one! It's approximately 6" overall longer than the one on your current tranny.

The center tail is the one you have currently, the 2x4 and 4x4 trannys for t'all are the same and both use a bolt-on yoke.

The tail on the right is a transfer case "adapter" as used with the married d20 on Scout II apps.

Divorced transfer cases are good and the 205 is massively strong!!! Makes doin' "stuff" much simpler!!
 

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And for comparative purposes, the tranny used for the "project" in this thread is the married 205 dodge you made reference to, only that one is a regular, non-electric/lockup 727. That gives ya an idea of what a 518 4x4 setup would look like if you calc'-in the additional planetary for 4th gear/od. Scroll to the bottom of that thread for an overall pic:

http://www.forums.IHPartsAmerica.com/transmission-tech/2043-t407-tf-727-diy-reseal.html
 
This shot compares the actual output shafts in the same order of the cases shown in the other pic...quite differnt!

The dodge takes a bolt-on yoke as does the IH fullsize unit in the middle. The Scout II on the right takes a 23 spline "bull gear" in order to mate with the married d20 transfer case.
 

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5k...whew. Im sorry for not saying what vehicle I drive. I've saw a pic of a bellhousing cut off of the transmission that was in the vehicle that person was driving, and taking it and welding it on to a tranny they were wanting to use.....in this case it was a 727 IH bellhousing to a a518 I believe. I think I saw that on the binder planet forum awhile back, I don't know if I would trust something like that, being its cast aluminum. I don't want to get rid of the 205, thats for sure. I thought about doing the setup in a Scout, but I would want a Dana 300, those are hard to find. Maybe I'll just gear it higher, I don't tow anything. Right now I have 4.10's in the truck. I know Travelall's aren't great for fuel mileage, I would like to get at least 13 mpg out it. Thank you for your input on Mike, its a big help.
 
Mike, that picture of the dodge tranny...you cant swap out the parts to make a married 205 could you??? Those pics you showed of the shafts, I know the dodge is longer, but could the shaft out out of that dodge tranny you refered me to could it work in a IH tranny, along with the 205 adapter, or totally different bolt pattern? I think I need to get into the tranny business...
 
steve grant said:
Mike, that picture of the dodge tranny...you cant swap out the parts to make a married 205 could you??? Those pics you showed of the shafts, I know the dodge is longer, but could the shaft out out of that dodge tranny you refered me to could it work in a IH tranny, along with the 205 adapter, or totally different bolt pattern? I think I need to get into the tranny business...
Click to expand...

I can't say for sure if what you propose would work steve...but when I conjured on this same concept while working with terry's tranny package I did spend some time in deep thought (and some parts interchange research) about this same thing!

On the surface, I really see no reason why it would not. The mating "pattern" on the rear of the 727 cases are all the same for the various tailhousings or transfer case adapters.

The dodge 727 with the married 205 is near identical internally to what you have right now (it does have the partial throttle kickdown valve body and associated input shaft same as the later Scout II).

So... (I know where you are going!) it might be possible to put all the dodge guts (or whatever is different) inside your existing IH-pattern 727, and convert it to a married 205 (dodge version). With that, ya can install the appropriate gearvendor setup.

So what we need to verify this is a complete dodge pullout (pre-518) version 727. Ya got one in yore pocket?? I'm sure I could come up with just the tranny and adapter portion, but all my s.s. Checks for the coming millennium are already spent.

I have at least two complete "married" 205 cases broken down into service parts (either chev or Ford, not sure which as I got 'em in pieces), along with misc. Couplers of a few different patterns. I'd have to spend some quality time with the various spicer parts lists for those to determine exactly what I got on the shelf.

Next...yore gonna suggest that I try this and install in my super-tow rig currently undergoing resurrection! I will if you will front the financing and then you can write off the fail if it doesn't work!! If it does work, then we'll go into the conversion-production bizz and sign on as a gearvendors dealer!

Or maybe terry the plastic bawl dude would donate his package to us for a trial fit and front the costs...I bet his is still on the pallet on his shop floor!

Folks have been cutting off powerglides and such for years and doing bell conversions, that is a major part of the drag race parts bizz. But all those casting for that stuff now are done from scratch and set up with proper alignment dowels and all so the centerline of the bell and main case can be established accurately...that is imperative and those tranny packages go for $4k and up depending upon the output of the motor going in front.

If someone with a complete machine shop capability and jigging cut the bells off a dodge 518 and an IH 727, then did a swap, that is certainly in the area of what high-end race prep folks do. But again...I could see an ez $4k just to build that kinda case with decent internals. For a pro, welding the case castings is very doable, the problem is alignment...and maintaining alignment while connecting the two parts!
 
Im going to try to get a older 727 from a dodge truck soon, but this is a long term thing im thinking about. Understand the money thing, I'm unemployed, I'm a diesel/heavy equipment mechanic looking for work....real drag man. I could get a IH 727 from phil coonrod, I work for him once in while stripping trucks, so then I dont have to yank mine (daily driver). Thats why I was wondering about the 518....if the rear of it bolts up to a 727. But if I could get the married set up on my 13 letter shit spreader, then save up the the g.v. I'll go that route. Believe me, if I were Rich, I would front the money and then some the conjure something up to help out the fullsize truck guys and the Scout guys, I own a '76 Scout. I wish the 518 tailend could bolt up, that would be slick.
 
Mike,
what years in dodge trucks had the married t-case, I might go searching around the bone yards Tuesday for fun to see what some of these outfits might have. Is the married 205 the same spline as a Dana 300? A friend of mine has a Jeep 300, which is the six bolt round not the texas style, in his Scout, he thought that maybe I could go the route of using a the adapter and shaft like what hes got. Just throwing that out there. I still think I'll go the route of the dodge set up. I would think the 205 has a larger spline count then the 300 from the Jeep.
 
Again steve, I'm just blowin' stuff out here , I have no experience in doing this!

But...here's a shot of a GM th350-spec'd input shaft for a married 205, I have no idea what m/y combo this came from, just parts on my shelves! You can see that the input shaft is massive and so is the coupler which is "sealed" to the shaft when it's slid home over the "o" ring on the shaft.

I also have a Jeep 727/d300 output shaft here now that is going into a 727 for a club member so he can install a d300 in his sii. But I don't have his actual 727/300 coupler or tc adapter/tail housing as he forgot to put 'em in the box with his other parts.

The 205 input shaft in that pic is noticably larger in all dimensions as compared to similar, but much lighter-duty 727-to-d300 stuff.

I'm not knowledgeable about which m/y dodge 727/205 packages to look for, but anything that is a 727 which was pulled from a diesel I'd have to say would be suitable.

Go to the gearvendors website and do a product look up for a dodge 727 4x4 and go backwards and see if they give a range of dodge m/y for the kit application.
 

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Cool Mike, thanks for your help on the this stuff, I'm going to go look around some boneyards around the denver area, to see what I can find. I just wanted to throw around some ideas to you, pick your brain if you will. I hope you had a merry Christmas!!!
 
90 to 93 diesels had an a518 with a 205 attached, all dodge automatics are 23 splined output shafts ,all diesel 205's have a spline adapter installed right from the factory and it just slides on. Usually the conversion bellhousing will bolt on at the pump . All dodge 205 tcases are bolted directly to the tcase except the late 60's and really early 70's power wagon. If you want to run a 727 all the dodge internal parts are interchangeable and the short output shaft from the IH or an amc/Jeep version including the extension housing will fit. The only hard part for a od swap will be finding a conversion bell housing or adapter plate .
 
Thanks coolpete. I'm looking to do a married 205, so you and Mike's help is appreciated. Once I get this swap done in the future, I'll do a gv od. I was hoping that the od on the rear of a 518 would swap to the back end of the 727, but I guess I was dreaming :)
 
I know this is a couple months old but 727's are also used in amc's and there was a guy in michigan that was experimenting with the 518 guts in a 727. Here's his info if you want to give him a shout.
Donato's transmissions
john donato
3096 w. Maple st., wixom mi 48393
248/624-4964

*delete if it's inappropriate to post this info here.
 
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