Carolina Broncos

****ATTENTION potential 4R70W installer**** If you intend to reference this thread in accomplishing your installation, I STRONGLY urge you to carefully read through the ENTIRE writeup. Modifications were made along the way so everything is not necessarily is perfect operational order.

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This article will guide you, step by step, through the installation of a 4R70W automatic transmission into a Early Bronco with a C4 automatic, D20 J-shift transfer case, and 302 engine.

I used info in the following threads to gain general information regarding different aspects of the swap.

http://www.classicbroncos.com/forums/sho...t=4R70W+ZF

http://classicbroncos.com/forums/showthr...p?t=184809

http://classicbroncos.com/forums/showthr...915&page=3

http://classicbroncos.com/forums/showpos...tcount=194

http://classicbroncos.com/forums/showpos...ostcount=1

The C4 has served me well but with the 35" tires, 4.56 gears and my personal requirement to make this rig drive to events, I was forced to install something with overdrive. With the C4, my RPM sat around 3,000 @ 60MPH which was unacceptable to me. I have no desire to travel faster than 60 because this huge rolling brick becomes a massive drag device and MPG go even further down the toilet. I prefer to see my RPM cruise around 2300 RPM and with the 0.7 gear ratio of the 4R70W, I was able to achieve that goal.

Below is my list of parts which I have added as of the conclusion of the project which totaled $1,980.00

4R70W-junkyard-'99 AWD V8 Mountaineer -$320 + $30 core
starter-junkyard-'99 AWD V8 Mountaineer-$ Included w/ transmission
converter-junkyard-'99 AWD V8 Mountaineer-$ Included w/ transmission
flexplate-junkyard-'99 AWD V8 Mountaineer-$ Included w/ transmission
ZF crossmember-BC Broncos-ZF-$125.99
ZF adapter-BC Broncos-50-4303-$441
controller-Baumann-OS1-$565
harness-Baumann-HPF2 or HPF2A-$ Included w/ controller
shift cable-Lokar-ACA-1808-$52
Lokar Dipstick -$$105.90
JB Fab Twin Sticks-$149.03
Aux cooler lines-$23.99
Adapter seal 471950-$18.36
Misc fitting, bolts, and other crap-$59.61
14 quarts of trans fluid and trans filter:$90.00

Got the 4R70W from a 1999 Mountaineer AWD (also referred to a 4WD or 4x4) 5.0 with 100K miles from a local salvage yard.








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To prevent having to gut the transmission to replace the output shaft as required for other 4R70Ws utilizing the Advanced Adapters 4R70W to D20 adapter, I specifically utilized the AWD 4R70W variant as its shaft length is sufficient to use the ZF to D20 adapter while only needing to cut 1/2" from the end. Eliminating the transmission dissasembly is very appealing as is the flexibility of using a ZF adapter for potential future upgrades if need be. The other advantage of using the ZF variant is the cost being less than the other adapter.

I measured 1/2" from the end of the shaft and used some blue painter's tape as a guide. My cutoff wheel worked well but I was careful to constantly rotate the shaft as I was cutting so as to prevent an angled cut.



After the cut, the shaft came to 5.938"




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I chose to do the cut first before pulling my C4 from the Bronco in case I botched something up and had a useless transmission. With the cut successful, the dissassembly could commence.

I measured the distances of the front and rear driveshafts for reference before and after the installation of the 4R70W. My lengths are different than stock as I have a 4-link in the rear.

Front: 24-3/4"
Rear: 35-7/8"

Since I don't own a transmission jack, I just used cargo straps on the front and rear to lower the transmission assembly to the floor.

Next, I pulled the flexplate only to find that, after doing so, it was actually an AOD plate as depicted by the AOD stamp on the back. This makes sense as my motor was from an 89 Mark VII. Just wish I had noticed this before I removed the flexplate. Now I have a spare if anyone is interested.



Here is my C4 next to the 4R70W



Since my 4R came already pulled, I do not have mounting bolts for transmission to engine nor do I have a dipstick. The length of the 4R mounting bolts is different than the C4 by about 0.465" which is due to a difference in the bellhousing thickness. This means you need to pickup six 7/16 x 2.25" bolts and start figuring out what you are going to do about a dipstick.

First order of business is to remove the D20 from the C4. In doing so, the spud shaft (D20 input shaft) decided to stay with the C4 intermediate housing instead of come out with the D20 and the roller bearings all ended up in the bottom of the C4 case. I had a garage covered in gear oil, so be careful.

I had to completely drain the D20 and remove the inspection cover to retrieve the 13 roller bearings. Used wheel bearing grease to make them nice and sticky and put them back where they belong.



After cleaning up my garage and finishing the bearing issue, it was time to swap the new spud shaft and bearing on the old drive gear.

Here is the old assembly...



The snap ring holding the drive gear on the spud shaft was a real pain the butt since it had no eyelits for snapring pliers. Advance Adapters does not include a new snap ring so destroying it was not an option. I ended up opening it up enough with my snapring pliers to get one end just out and over the spud shaft spline. Then I slowly worked it with a couple of flathead screwdrivers. I tweaked it a little but felt comfortable it was still usable. Someone correct me if I am wrong, but there is not much axial load on that snap ring anyway.



Drive gear removed from old spud shaft and bearing.



Next I had to mate the retainer, seal, bearing, and new spud shaft which are all a pressed fit.

I mated the bearing and shaft first. Since I do not have a press, I opted to place the spud shaft in the freezer for 30 minutes and the bearing in the oven @ 350 degrees for 30 minutes. The two mated like a couple of horny high school kids! Slid right on with no force whatsoever. I would use caution with the bearing in the oven. It was not until after I did this that I called Nachi and asked what the temperature tolerance of the bearing was. Turns out it is 220 deg. F. Keep in mind that is while under load not static in a oven. They are just concerned about deformation under stress so take that for what is worth.



Next is the seal installation into the retainer.

Set the oven to 350 degrees F for the retainer and throw the shaft/bearing assembly and seal in the freezer. Please make sure the shaft/ bearing assembly is cooled before placing it in the freezer!

While the oven is heating up, lay a light coat of blue RTV gasket maker on the retainer where the seal will rest.



Make sure orient yourself with how you will place the seal. You will not have a lot of time once the parts are hot/cold. The open end of the seal is to face the transmission.



Place the retainer (yes, with the blue RTV) in the oven @ 350 degrees for 30 minutes.

Once the parts are cooked, you can install the seal into the adapter ring.

I used a spare piece of 2.5" exhaust tube and a mallet to drift the seal in evenly.



I used the depth function of my caliper to verify it was fully seated all the way around. Next I sprayed a coat of silicone lubricant on the seal lips just to make sure it would stay happy for the duration.



Next is mating the retainer / seal assembly to the bearing / spud shaft assembly.

We want to heat the retainer assembly in the oven at 200 degrees F for 30 minutes to prepare it to be mated the the bearing / shaft assembly. I was concerned about the temperature limits of the seal. I called National and found this seal has a tolerance of -40 / +220 degrees F. The transmission does have the ability to reach the upper end of this spectrum but I seriously doubt that temp would ever reach this seal.



Now the bearing had to be secured in the retainer with the large inner snap ring provided by Advanced Adapter.



Next the drive gear was installed on the new spud shaft assembly and the darn snap ring was reinstalled. It is not any easier installing it now than it was during removal.



I used blue RTV in the channel of the adapter where the new O-ring seats.



Then installed the new O-ring. I also added a coating of silicone to the OD of the O-ring once it was installed to reduce friction during installation to the D20 housing.



*** EDIT: Some folks (including me) have been trimming the gasket that goes between this assembly and the D20 case thinking it goes over the assembly and not under it. Before installing this assembly, install the gasket and no trimming will be necessary. The gasket is dummy proof so it will only go on one way.

After the gasket was on (in theory ), I installed the assembly and gave it a slight tap with the mallet to seat.

Now my D20 is complete with new spud shaft, retainer, and bearing!



Next, I installed the ZF adapter ring. All 6 holes line up in all configurations but the adapter does have a dimple that goes at the 12 o'clock position. The 6 allen head bolts secure it to the D20 case.



The gasket that goes between the ZF adapter and the transmission is dummy proof too, but not as obvious. Just be careful to make sure that all 6 holes are lined up. The ZF adapter has 6 sets of 3 holes each for multiple clocking options. I just did as others have in the past and went with the middle of the three holes.The normal torque rating is 45 ft-lbs but since this is an aluminum adapter, I decided to reduce that to 30 ft-lbs. Advanced Adapters does not provide torque specifications in their installation instructions so this seemed like a good strategy. I ended up stripping out 3 of the holes!

I called Advanced Adapters and they suggested I Helicoil the damaged hole. Of course I had no Helicoil set in the garage. Now I can add $30 to the cost of the conversion for a Helicoil kit.

I went ahead and used Helicoil in all six holes because I know they are all weak and the last thing I want is to strip out another hole especially after it is installed and I go back after a few hundred miles to retorque.




I marked the gasket to the ZF adapter to make sure it didn't rotate during mating to the 4R70W. To my surprise, it slid on rather easily and I had it bolted in no time.



This is a good time to install the flex plate to the engine.

You will need to make cuts on the webbing and the rear boss to make room for the shifter bracket and allow the inner flag of the D20 to move fully forward.



This is a good point to start the controller installation along with the transmission end of the Lokar shifter.

My controller came with 5' of length which gave me the option of placing it pretty much anywhere in the cab. Some folks want to have it where they can read the display for temp, speed, gear selection, errors, etc. Since I intend to use my Autometer trans temp gauge inline at the cooler, I really don't have a need to have the controller in sight at all times. For me, it was between the Tuffy center console and the glove box. I chose the passenger wall of the glovebox so I could at least glance at the display when troubleshooting on the fly rather than looking down into the console. Also, the controller is not waterproof so the glove box is a much higher and safer place.

I used a 1-5/8" hole saw to get through the back of the glove box to route the cables directly to the passenger side hole in the upper corner of the firewall which in not in use for my configuration.



I used the mounting screw that holds the glove box to the frame on the passenger side to hold the controller. It seemed quite secure, so I didn't bother with the second mounting point on the controller.

All the harnesses were routed through the firewall except the vehicle harness which was left in the cab and plugged in to the RJM harness. Having this harness connect to the RJM harness is awesome since it eliminates the need for multiple splices.



I loomed the three exterior harnesses and routed them to the tunnel area. The four wires for the neutral safety switch and the backup lights needed to be spliced to the vehicle. I was a little disappointed that the harness does not come with the square connector native to the Bronco. I ended up cutting my connector off, leaving plenty of pigtail in case I ever needed it in the future, and soldering the four wires to my Bronco harness.

Looking at the Bronco connector, the Red/Blue wires are for the NSS. The male connector goes to IGN START and the female goes to STRT RELAY. The Black/Red wires are the backup lamps. The male connector goes to 12V IN RUN and the female to BKUP LAMP.



That is as far you will want to go with the controller until the transmission in installed and you can continue routing the cables.

Next you want to pull the pan and swap out the old filter. I cut open the old filter to make sure there was no debris to be concerned about; it looked good.

The Lokar shifter directions are pretty good although they do not mention the electrical connector. Before removing the NSS, I marked its position because I know the mounting holes are elongated which suggest it has some adjustment.

Here is the before pic...



The 21mm nut (not the size stated in the directions) holding the selector shaft in place was super tight. I used a 12mm wrench on the outer part of the shaft where the old linkage went to hold it in place. Pulled the roll pin and swapped out the old shaft for the new one.

http://i288.photobucket.com/albums/ll176...040721.jpg

The new linkage will have to come off to slide on the NSS. Remove the bolt and not the three allen head screws.



The after pic...

Time to get it installed!

I consider the stock clocking position to be the middle clocking position since this brings the D20 shifter flags to an angle equal to the top of the bellhousing (level).





I don't have a transmission jack and, if I did, it wouldn't be much help with all my lift; nothing can get high enough. I just use a floor jack, 2 cargo straps and a cinder block.

I left the D20 off to keep things on the level and as light as possible.

The only clearance issues I had were with the bellhousing and the pan. The bellhousing had what looked like some sort of tab sticking out on the driver's side.; it was hitting my header.



I cut it off...



and bolted her on...

Please make sure BEFORE you tighten the bellhousing mounting bolts you ensure the torque converter studs are through the flexplate!



Here you can see how my passenger header collector is hitting the pan. I have a set of ceramic coated headers that drop down slightly more than this set and I hope they will clear the pan.



Next install the D20 gasket and the D20.

With the pans of the 4R70W and engine leveled axially, I had everything pretty well stuffed under the Bronco with plenty of clearance while not sacrificing to much D20 to differential angle.





This is the BC Bronco's ZF crossmember. As you can see, there is about a 3" gap between the crossmember and the bracket. There is a bit of offset even after adjusting the transmission bracket all the way to the passenger side. Either the transmission is cocked or the ZF crossmember is not welded in the correct position. I even thought I may have the crossmember backwards but that was not the case.



Ideally, I would like to re-weld the crossmember and add an extension piece to properly connect the two. Info on that is located here http://www.classicbroncos.com/forums...light=4R70W+ZF. In the mean time, this is my solution. It's not pretty, but it is functional.



Once Everything was bolted in I started on my driveshaft measurements. I took measurements for static, compressed, and extended.

My measurements, after taking them a million times, came to the following:

Rear Compressed: 31"
Rear Static: 31-15/16"
Rear Extended: 32.5"
Rear Max Travel: 1.5"

Front Compressed: 27-3/4"
Front Static: 28-7/8"
Front Extended: 29-3/4"
Front Max Travel: 2"

Not a as much movement as I expected and not sure how much the 4-link plays in to that equation.

In the end, I found the difference between my front and rear shaft lengths, 3-1/16", was much more than I had originally thought so my dream of having interchangeable driveshafts was over.

Lastly, I plugged in all my connections and fired up the computer.

Twin Sticks!

JB sticks may require you to trim the tunnel cover all the way to where the angled plate and the horizontal plate meet. This was still not enough. I did not want to continue to trim so bending the sticks was my next step. I think these sticks were made based on zero body lift as the outboard bend was at the base of the stick instead of a couple inches higher where it would be more ideal.

I straightened this stick and moved the bend up a couple inches. This was about 2 hours of trial and error fitting but finally got it to work.

Sadly, all I have is a propane torch so I had to resort to this method to bend the sticks. ;D



Also had to bend the sticks forward as I trimmed the tunnel cover back all the way to where the aft angled portion meets the horizontal portion and was not willing to trim any more.

Long story short, the j-shift sticks are installed after a LOT of work. I am hopeful that JB will use the notes I sent him today to iron out the kinks and possibly have a bolt on 4R70W / ZF / D20 J-shift twin stick setup available for purchase in the very near future.

Next I installed the Lokar transmission dipstick (XTD-3AODFM). The beauty of this flexible setup is I can mount it anywhere.

I chose the firewall cubbie area so as to keep it off the headers and still easily accessible. Had to use a couple of nuts as spacers to move it slightly forward off the firewall so I could remove the stick without hitting the upper ledge of the firewall.

There is so much crap in my engine bay that it took a bit of doing just to drill the self tapping screws into the firewall. Sadly, this was the easiest thing I did all day and it took about an hour. :-X



The Lokar column shift linkage (ACA-180 was lots of fun too. When I purchased this item I failed to realize that it is designed for a GM column NOT a Ford column. This created my first issue with this install below.

This shows the column shifter and the bolt that came with the kit. The hole in my Ford shifter is way too big!



Lokar includes special bushings to adapt this bolt for a GM application so I had to ditch the bushings and come up with a solution.

My solution was to use the bushing that was originally used with the C4 shifter linkage. I would recommend obtaining a new one from one of the vendors though.

Had to drill it out with 21/64" to get enough meat out of the bushing to allow the 5/16" bolt to fit.



Reinstalled the bushing on the shifter and installed the Lokar hardware. Make sure you install the heim on the back side of the column shifter or your angle will be bad going to the 4R70W.



Now down to the 4R side of the shifter linkage. I had to re-clock the adjustable Lokar arm that was originally clocked to the 8 o'clock position to the next position clockwise (approximately 9 o'clock).



In the process of finding the right position, I cut about 3/8" off the rod. I think I could have gotten away with not cutting it at all.

Unfortunately, I stripped one of the set screws holes so Lokar is sending me a replacement.

Once connected, I ran the shifter through the full range with the key on to observe the position indication in the display window of the computer.

For some reason, it only took 10 quarts to fill the transmission. I don't recall if I ever drained the torque converter. I think that would account for the other 3.

A few loose ends to include the cooler lines, exhaust, driveshafts, install aux cooler, center console, twin stick boot,etc.

At this point you are going to want to test drive and being to figure out the programming. I suggest having someone else drive and you program. It is a LOT easier.

Please feel free to contact me with any questions.

This Tech article was adapted from my complete installation write-ups located at

http://classicbroncos.com/forums/sho...48#post2148448

and

post 113
http://www.cb4x4.com/forums/showthre...ighlight=4r70w