Possible solution to a non computer 4 speed

[Robyn]

Well here she goes again.

Off on another damned fool crusade.
In my quest to come up with my goal of the ultimate cool Burb I have decided as many of you have been reading to do a turbo 6.2 swap and to keep it all non computer.

The tranny was limited to a 700R4 (too light) or a 400 (no Overdrive)
Yesterday while chatting with a local tranny parts supplier about the early allisons to see if any had OD I was informed that the early (94-96) Dodge 618 tranny was basically a hydraulic shifted 727 with the OD controled by an electric signal and also the Lockup too.

Some serious digging tuned up a company that makes an adapter that will allow a chevy SB to bolt to a Dodge 618 box :D

The fine details of getting it in the rig are easy. Will have to use a Dodge 241 T case along with the tranny and do a little fab work on the cross members and drive shafts, BUTTTTT this will be easy to do.

Getting the OD and the Lockup to work can be done with a few simple pressure switches run off the governor pressure port and an adjustable vacuum switch to give part throttle dropout of the lockup.

This package will give good service and should be fairly simple to do.

The question keeps coming up as to why not do a 700R ?????

The 700R is simply too light and too spendy to build and then marginal on a turbo diesel.

The 618 is basically the old 727 monster with an output overdrive.
Easy to work on and cheap to build. A transgo shift kit and its pretty well bullit proof.

This may well be an interesting little idea.

We shall see.

Robyn

[JohnC]

More than likely the GM body will reject the Mopar box as foreign tissue.

[DmaxMaverick]

I think this isn't common because the front shaft is on the wrong side of the Dodge 241. I could be wrong, but it sticks out in my mind, and haven't looked into it.

I agree with John. Transplant rejection may be an issue.

[arveetek]

I wouldn't mess with a Dodge tranny. They're not any stronger than a 700. You of all people know that a properly built 700 will stand up to a lot of abuse.

Remember when I asked advice of you on rebuilding my 700 a while back? Well, I just went with a new TC, and I haven't had any more issues. That's a total of 12 years, and over 100,000 miles on a USED 700R4, with the last 4 years behind a heavily modified 6.2L turbo.

Casey

[Robyn]

The newer Dodge T cases are on the same side as the GMs.

The 518/618 tranny is the same basic box as the 727
A 727 tranny is a great box. The only issue is that they need a shift kit to get rid of the soft mushy shifts.

A Mopar box can be built really tough for a small fraction of the cost of building a "K" case 700

The internals are far simpler as the OD on the Mopar is a output shaft unit that is seperate of the main box.

The 700 can be built up but it will never be any larger partswise than it is from the factory.

Even with the best aftermarket tech and parts the 700/4L60 is marginal behind a turbo diesel.

Might be fine in a small rig like a Blazer (2 door Tahoe) but not a 2500 Burb with 37" rubber.

The 400 is a great box and I may still use it, buttttttt having the OD without the need for computer control would be a nice perk.

Back in the 70's the 904's and 727's were the first auto trannies I got into.
Tough, simple and cheap to build.

The mid 90's 518/618 uses a cable throttle pressure control and the main 3 speed box is all hydraulic controled with a governor.

I have already started the Burb on some anti rejection additive in the fuel and the oil as well as some topical rub applied to the paint surfaces. :D

This will definately be an interesting swap. I can't find any company that offers an adapter to do this. (Possibly a bad omen :eek: )

I am, as I write this, designing an adapter to get the GM engine and the Mopar tranny intimate.

I have an old Cast Iron powerglide adpter ring that I am thinking will give me a good jumping off spot to get things close.

Once the bellhousing is able to mate up the rest will fall into place quickly.

My plan is to turn up a shaft in the lathe that will just fit into the two rear main saddles and then reduce the diameter so it will slide through the input shaft bushings in the front pump on the Mopar.
This will align the tranny perfectly to the crank centerline and then I can scew with getting the bolt holes and dowel pins where they need to be.

Once this is done the converter connection will need to be done.
The Mopar converter has the ring gear on the OD so this will need to come off and be discarded.
An adapter crank pilot device will be needed as well as the possible relocation of the drive bolt lugs on the front of the converter and or possibly redrilling the flex plate.
I am going to try and keep an off the shelf converter if at all possible.

With the 4" body lift that the Burb has I am fairly sure there wont be any issues with getting things into the chassis. But thats what they made hammers for. :rolleyes:

Too soon to have all the answers in the bag, but, its coming together.

One little weak spot was the Mopar plastic cooler line connectors :eek:
This will have to change.

*** Casey***
For the average folks working on their rig I would not even recommend this approach.
A 700 is a direct (or at least close) bolt up and can work fine for most applications if not thrashed hard.

What I am going to attempt is going to push even my skills to the upper limits.
If not for the fact that I have the Mill, Lathe and other machine tools available I would not even consider this idea.
To hire a shop to do it would be very very costly.

And the other reason is it's OFF THE WALL and it keeps my mind sharp and gives it something to think about that requires deep intense thought.

Best

Robyn

[arveetek]

Even with the best aftermarket tech and parts the 700/4L60 is marginal behind a turbo diesel.

Might be fine in a small rig like a Blazer (2 door Tahoe) but not a 2500 Burb with 37" rubber.

Robyn

I think my HD 2500 pickup towing a 5th wheel might put a bit more strain on the 700 than a big 'burb with big tires:

http://rides.webshots.com/photo/1165036867029465272wuEVDd

So I will still argue that a 700 would work great for your application.

However, your other reasoning makes much more sense! "Why do it? Because it hasn't been done and because I can!" Now that's a good reason! :D

Casey

[EWC]

What about the kit that replaces the electronics and shifts like the TH400 ? Transgo , I think , advertises this on their website but I haven't checked into it as I plan on using the GM ECM for my 4L80E .

[Robyn]

The base plan for the project was to do away with the electronics totally
The 6.2 will be fueled with a 4911 DB2 pump.
The tranny is to be non "Electronic"
The front differential is to be converted to cable shift.

The "Beast from Hell" that will work under the worst possible conditions without worry of a comoputer failure or other electrical issue that is the cause of so many breakdowns.

Simplicity, plain and simple.

As far as the 700 goes, after breaking several and litterally scattering one all over the street behind a 6.2 N/A Im not all that impressed with the little GM OD box.

The only tranny I have had apart with smaller innards would be the tiny little C4 Ford.

The 700 has just too many "Tiny" parts. The complex input drum assembly is aluminum with a steel shaft pressed into the splines.
The aftermarket units have a hard steel ring pressed over the outer diameter of the splined hub to keep it from spreading, but they are still very small.

The 700 is fine for a grocery getter and such but I am not going to spend big $$$ on another one when I can do the Mopar unit very cheap and make it live easily.

If you are yanking a 5er around with a 700 calling the gears, I hope luck is with you all the way. If you drive it right it will likely last, but at this juncture I have a clean piece of paper to work with.

My project rig does not have to run tomorrow or next week.
I have a body, frame, two axles and such to fit anything in that I want to.

This thing has the potential to be whatever I choose at this point.

With some hours of thinking, a little machining and whatever "Bastardapt" I turn out this thing will come together.

My feeling is that I can bolt together a rig that can take pretty much anything I can throw at it and hold together.

best

Oh and the because I can, is definately a good reason. :D

Robyn

[DmaxMaverick]

Why the push for the OD, Robyn?

With 37" tires, unless you upgrade to 4.56, or deeper, gears, you won't/can't use an OD anyway. Under this condition, any of the non-electronic OD boxes will have issues. A 4L80 will handle it, but it's electronic. The 700 will do it, if built well, and it has a deeper 1st gear.

Have you considered something in the neighborhood of an AT545? No durability issues there. They are plentiful, and a bell housing is available to make it a direct fit. And, I don't think you'd have rejections issues with it.

[Robyn]

Maverick
I looked into the 545, the issues with that box are, NO park lock.
These Allisons are basically for medium duty trucks with air brakes or some other "Reliable" means to secure the rig when parked.

Currently the rig will run down the road in 3rd at about 2500 RPM at just about 50 MPH
Poor little diesel creature is gonna be Howling at freeway speed :eek:


Too fast considering what will happen in the upper reaches (65 and over) with the diesel.

I have not checked the ratio yet but I suspect its not what the tag in the glove box says. (3.73)

The Mopar box has basically the same ratios as the 4L80 with a 2.45-1.45-1.0 and a .69 OD

As yet things are still in a state of flux and the plan may change again.

If I go with a 400 box there are adapter issues to get the tranny bolted up to the 241 case. The overall length is an issue (short)
A 700 will require similar mods as the output shaft on the tranny is smaller and the adapter to the T case is different.

An AT 545 will require even more work to get it to speak to the T case
(possibly use a divorced 205)

The 518 Mopar used with its own married 241 T case is 3.5" longer and will fit close to original mounts.

Some work required with the Mopar but this has been done by a few locals that have installed the 4BT cummins in their Burbs.

I would rather do a little mod here or there to fab a bracket to fit rather than try and get the gear boxes to mate together.

Any of it is possible with enough time, $$$$ and amounts of metal shavings on the floor around the lathe and the mill.

Cost wise, the Mopar is cheaper to buy, far cheaper to build to a very reliable level and overall should be very easy to get into the truck.

I know that many folks have a real issue with swapping "brands" when it comes to mixing and matching engines and stuff in their rigs.

I think a big O'l V10 from a Viper would look kewl under the hood, but who can afford to feed the beast..

We shall see, we shall see.

I am just about ready to start ripping the drive train (engine, trans, tcase) from the burb and get it ready to go.

I need to find a home/s for the 454 and 4L80 to help finance the project though.
The current times are not bringing many calls on this stuff either.

Later

Best
Robyn

[DmaxMaverick]

Maverick
I looked into the 545, the issues with that box are, NO park lock.
These Allisons are basically for medium duty trucks with air brakes or some other "Reliable" means to secure the rig when parked.

Currently the rig will run down the road in 3rd at about 2500 RPM at just about 50 MPH
Poor little diesel creature is gonna be Howling at freeway speed :eek:


Too fast considering what will happen in the upper reaches (65 and over) with the diesel.

I have not checked the ratio yet but I suspect its not what the tag in the glove box says. (3.73)......

Hmmmm. According to your speed/RPM/tires, you have 5.51 gears. I think something's amiss. At 55 MPH in direct, you should be seeing 1860 RPM's with 3.73 gears, which is close to optimum. Supports the TH400, but 1st gear would be way too tall, IMO. In OD with 3.73, you'd be at about 1300 RPM's at 55. Too slow, and too little power to keep it going (bad idea, unless you have the power to run at 90 MPH all the time). Have a look at THIS SITE (http://www.4lo.com/calc/gearratio.htm) for the calculations. You will need 4.56 gears, or lower to be able to take advantage of OD. With 4.56's, you would be turning 1700 RPM's at 60 MPH, and 2000 RPM's at 70 MPH.

If you already have a 4L80E, a stand-alone controller would be a lot cheaper, and easier, than messing with a tranny/TC swap. It is electronic, but reliably so. It would solve your durability concerns, and you'd have the OD/TCC. You could "kit" the tranny for non-electronic operation, but you lose some of the "automatic" functionality.

True about the 545. No parking pawl. But, many of them can be had with a parking brake at the tail housing. It would work well with a divorced TC. The 205 would be my TC choice, in any case.

[Robyn]

Maverick

I have got to jack the beast up and rotate the wheels and count the pinion turns to be sure.

I scarfed up a 518 tranny with a Tcase this afternoon with 80K on it from a fellow for $125 and its nice.

The Box ix from a 93 and is a RH drop. The 94 and later Dodge saw the drop on the same side as the GM trucks.

I will just swap the input (23 spine from the 241D tcase into the GM box and make a little adapter to clock things the right way so they will bolt up.

Took the beast out today for a quick spin and I was wrong. The OD was engaging, just the lockup was not as I was not going fast enough.

The Dodge 518 will work sweet in this thing and I can select if I want the lockup in 3 or 4 as well as turn it off around town. The OD can also be selectively controled too.

The OD on these will not work unless the box is in 3rd already and then the control oil pressure is available to the solenoid to activate the OD when the solenoid is grounded

The yards all wanted big Buckos$$$$$$$$$$$$$ :eek: for a married set.
I placed an ad on Craigs list last night and this fellow called today and was only 15 minutes away.
SWWWWWEEEEEEEEEEEEEEEET

The best part is that I dont have to pull it out and it is fairly clean too.

Later

Robyn

[convert2diesel]

Robyn:

If what you say is correct, you could effectively by-pass the OD pressure switch, have a cab mounted rocker switch and end up with a "7 speed" (14 if you include the Xfer case). :D. Doubtful if it would be useful unless you intend on doing some heavy towing but would be cool non the less.

Bill

[Robyn]

This might be possible but the basic tranny is a 3 speed just like the old Torqueflite. The tranny must be in 3rd before control is available to allow the OD to be used.

If you crunch the numbers, using the OD with any of the other gears really would not give you much.

More of a mess than anything else.

The original setup had the OD and the lockup run by the ECM.
BUT seeings that the rest of the tranny is haydraulically run as in past models the OD and lockup can function great via the use of governor pressure to opperate two selected pressure switches that correspond to MPH

If tire sizes are not way out in left field, each pound of governor pressure equals 1 MPH
Simply selecting a pair of switches with the PSI rating that will activate the OD and lockup when desired is the ticket.

Very basic

The late 46RE and 47RE trannies are "Electronic" the early ones were designated 46RH and 47RH for Hydraulic.

Around 96 they went to ECM control on the beasts.

This will be a fairly easy swap and should perform quite well.

The Old torqueflite is easy to work on and requires very few special tools as compared to the new stuff.

Transgo makes a wonderfull shiftkit that just about makes these trannies bomb proof.

Yesterday I was under the Burb looking around at thingS, OMG with the 4" body lift there is enough room between the tunnel and the tranny/Tcase to stuff a cow in there.

There will be no problem getting at any of the bolts on things at all.

I can use the GM factory fuel lines that bolt to the bell housing and not have any issues at all.

This is definately starting to get interesting.

Keeps my mind very active, not to mention my doodle pad :D

Best

Robyn