Although I focus great attention on how a transmission is built, installation and proper adjustment after the unit is installed are just as important to durability and longevity. To get longevity and durability, a transmission must be properly installed and adjusted, which means a methodical approach to getting a fresh transmission into service. Let’s begin the installation discussion with a few removal points; that’ll get you off to a good start.
Removal
Transmission removal is on par with transmission teardown (see Chapter 3) because it is a forensics study in why the transmission may have failed to begin with. Ask yourself, “How was the transmission installed?” “Was everything in proper adjustment?” How was the transmission functioning when it was time for removal?”
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Installation
Transmission installation requires great levels of care.
Torque Converter
Torque converter  installation, although it sounds simple, is an easy step to mess up. It’s mostly about feel because you cannot see the components to ascertain fit. Not only must the converter slide onto the input shaft and pump stator, it must also fit squarely into the pump and engage the drive gear. If it doesn’t seat properly, you risk severe pump and torque converter damage before even getting started. Believe me, a lot of us have made this mistake—don’t you make it.
As you are seating the converter, rock it on the stator and feel for proper input shaft, pump, and stator engagement. Then do the hand-fit check. If your hand can fit between converter and bellhousing, it is not seated. Feel for a solid bottoming out and do the hand-fit check. Then rotate the torque converter and see how it feels. If there’s binding or noise (grinding), it is not properly seated. Again, perform that hand-fit check between converter and bellhousing.

If the transmission failed, removal is a part of learning how and why failure occurred. Sometimes failure isn’t due to transmission problems, but instead due to poor initial installation and adjustment.

This is an opportunity to check out a transmission’s condition before teardown. What leaks and why? Are the kickdown and shifter linkages properly adjusted? Does the throttle valve (vacuum modulator) function properly? What condition is the transmission mount in? Is there a transmission cooler? What about driveshaft and slip yoke? What color is the transmission fluid?
After the converter is seated, use a fabricated retaining device, even if it’s a simple piece of band iron, to keep it in place.
Cooling System
Before installation, check out your transmission’s support system. The cooler lines and cooler must be flushed thoroughly to remove any particulates caused by transmission damage. Tom’s Transmissions uses a system called Hot Flush HF345S, which pressure-flushes transmission coolers and lines with a quick-reversing hot-fluid action that slams fluid back and forth to dislodge any debris that can harm a fresh transmission. Particulates are trapped in super-fine filters that ensure damaging debris won’t harm your new transmission.
What shape are your transmission cooler lines in? I’ve seen so many cars with patchwork transmission cooler lines connected together in pieces— easy spots for destructive debris to accumulate. I strongly recommend against using hose between transmission and cooler. Hard-line your system from transmission to cooler, using a minimal amount of hose. Under ideal circumstances, you hardline 100 percent of your transmission’s cooler lines.

The Hot Flush system from Tom’s Transmissions is an outstanding transmission purification system (left). Using a hotflush, high-pressure surge system, it removes all impurities, which are trapped in a filter (right).
Linkages
Inspect manual shift and kickdown linkages for integrity and proper adjustment. Remember, transmission failure isn’t always due to internal problems; there can be external ones like improper kickdown and manual linkage adjustments. Improper manual linkage adjustment is an easy mistake to make because a lot happens between your hand and the manual shift valve down under, especially with a column shifter.
Manual shifter adjustment needs to be on target per your Ford Shop Manual. Whether it is a console or column shift, Ford gives you plenty of room to adjust. Your adjustment should be in the middle of Ford’s adjustment range.
Vacuum Modulator And while I am on the subject of adjustment, vacuum modulator and control pressure should be a part of all this. Using a pressure gauge and following Ford’s numbers, adjust the vacuum modulator. Most vacuum modulators are already properly adjusted. But you want to be sure with a new transmission. Never leave one to chance.
Also make sure you have a working vacuum modulator and a reliable vacuum source. An engine with a lumpy camshaft and 14 inches of vacuum isn’t going to deliver a reliable vacuum signal, which causes the transmission to shift erratically. So if you’re having transmission problems with a roughrunning high-performance engine, check your vacuum signal first before blaming the transmission.
Inspection
While your transmission is out, it is time to inspect things like your engine’s oil pan gasket and rear main seal for leaks. And if you’re going to take care of these items, now is the time to do it.
What about your starter? What is the starter drive’s condition? What about your flexplate? The ring gear should be free of damage and runout.
What about the block plate? Is it the right one for your application? While your driveshaft is removed, inspect the slip yoke for scoring and abnormal wear.
What about universal joints? This is the time to se rvice your driveshaft and make it serviceable.
Next is the transmission crossmember and mount. A fresh mount keeps things secure around the driveshaft’s centerline.
And finally, what about your speedometer cable and drive gear? This is the time to inspect and make sure you have the correct drive gear and make sure your speedometer cable is in top condition.
Flexplate Installation
Step-1: Inspect Flexplate
First inspect the flexplate, checking for runout and ring gear damage. If all is true to mark and there are no cracks around bolt holes, the flexplate may be reinstalled.
Step-2: Install Reinforcement Plate
Ford calls this the flywheel reinforcement plate (PN C2OZ- 6A366-A), which must be installed with the flexplate. And like the flexplate, it installs only one way.
Step-3: Check for Leakage (Critical Inspection)
While your transmission is out, check for rear main seal and oil pan leakage. Now is the time to correct any engine problems.
Step-4: Line Up Correctly
When you’re preparing flexplate for installation, get all of the holes lined up in both flexplate and reinforcing plate because they only install one way. Use a reference mark to ease installing the reinforcing plate, flexplate, and crankshaft.
Step-5: Use Thread Locker
Always use a high-temperature thread locker on crankshaft bolt threads to both secure and seal because these bolts thread directly into the crankcase.
Step-6: Torque Bolts
Torque bolts crisscross to 75 to 85 ft-lbs in thirds: first, to 28 ft-lbs, then to 56 ft-lbs, and finally to 75 to 85 ft-lbs. Don’t forget thread locker.
Step-7: Check Fitment
If you have fitment problems, check sizing and bolt-hole patterns. Torque converters are sometimes mislabeled or misboxed to where they’ve no chance of fitting your application. They either won’t fit the pilot or the transmission input shaft and stator. If a torque converter does not fit, do not force it.
Step-8: Use Correct Flexplate Size
Most common flexplate sizes for C4 transmissions are 157-tooth (left) and 164-tooth (right). Each calls for its own bellhousing size. There’s also a smaller 148-tooth flexplate (not shown here) for Mustang II and Capri.
Step-9: Install Block Plate
This is a one-size-fits-all adjustable block plate for small-block Fords, available from Mike’s Transmission. This block plate fits 157- and 164-tooth applications.
Step-10: Use Transmission Fluid
Service the torque converter with 1 or 2 quarts of transmission fluid prior to converter installation. This primes the pump and gets prompt lubrication to transmission internals on start-up. You don’t have to use Type F on old Ford transmissions anymore. Dexron III and Mercon IV are suitable fluids.
Step-11: Lubricate Pump Drive
Converter pump drive should be lubricated with transmission lube prior to installation to prevent seal damage.
Step-12: Install New Transmission Mount
Install a new transmission mount in order to minimize movement around the driveshaft’s centerline. Also check driveshaft, universal joints, and slip yoke condition.
Step-13: Adjust Shifter
Proper shifter adjustment is important to operation. Move the manual valve shift into Park; then, place shifter in Park. Secure linkage and tighten adjustment. Adjustment should fall in the middle (as shown).
Step-14: Inspect Speedometer Drive Gears
Speedometer drive gears on transmission and cable should both be inspected for abnormal wear or damage. Install a new O-ring while you’re at it and lubricate generously with transmission assembly lube.
Step-15: Check Drain Plug Location (Critical Inspection)
Torque converter drive stud and drain plug alignment are very important. Get this wrong and you wind up with a distorted flexplate. Make sure drain plug is located at the right hole and not up against the flexplate.
Step-16: Run Transmission Lines
Transmission cooler lines should be hard lines between cooler/radiator and transmission. Keep the number of joints minimal.
Step-17: Inspect & Adjust Kickdown Linkage (Critical Inspection)
Inspect and adjust the kickdown cable or linkage. Replace the neutral safety/ back-up light switch if necessary. Check for proper operation and continuity.
Step-18: Fill Fluid
Although vintage Ford automatics once called for Type-F fluid, they can get away with using Dexron III or Mercon IV these days. Type-F was more about friction enhancers than anything.
Step-19: Don’t Drain Torque Converter (Professional Mechanic Tip)
Down the road, when the time comes for transmission service, never completely drain your torque converter for two reasons. First, you want fluid in the converter to prime the pump and ensure lubrication on start-up; second, some transmission professionals never completely change fluid due to the risk of “shocking” seals.
Written by George Reid and Republished with Permission of CarTech Inc