DIY Network

Transmission Swap: Remanufactured Transmission A 1985 Chevy El Camino gets cured of the hesitation blues with a remanufactured transmission. From "Weekend Mechanic" episode WKM-406

(Continued from page 3)

Installing The Remanufactured Transmission

With the old transmission removed, Bruce is now ready to install the remanufactured transmission (figures K and L) into the vehicle. Using a remanufactured transmission saves money as compared to replacing with a new one or paying to have this one rebuilt. It also avoids risks inherent in replacing our transmission with a used or salvaged one--where the history and condition of the replacement would not be known. Remanufactured transmissions typically come with full warranties (usually in the range of 36 months or 75,000 miles) and installation parts.

Figure K

Figure L

The exterior of the old transmission shows evidence of fluid leaks.

• To transfer the throttle-valve cable, remove the retainer plate bolt, unhook the cable from the valve rod, and pull the cable out. Then attach the supplied seal to the cable and hook the end of it to the valve rod in of the new transmission. Carefully slide the cable into the socket and fasten it down. Verify the installation by pulling on the spring end of the cable.

  Important: An improperly adjusted or defective throttle valve cable can result in loss of downshifting and possible transmission damage.

• Next remove the retainer tab for the speedometer gear housing and pry the gear out of the old transmission.

• Before installing it into the new transmission, replace the old seal by pulling the gear apart, removing the worn seal, and installing a new one that was supplied with the re-manufactured transmission. Reassemble the gear and then also replace the O-ring by pulling it off using a small hook and sliding a new O-ring down over the gear and onto the shaft.

• The speedometer gear can be installed into the new transmission.

• The retainer tab slips into a slot on the side of the housing and is fastened down.

There are two cooler lines. We have one that's the inlet and one that's the outlet. The actual cooler is mounted inside of the radiator tank. Attach the flush kit tube to the inlet line and tighten it down. Slip the bottle over the cooler outlet line and flush. It's a good idea to dump the liquid and re-flush it several times--until the foam looks white and clean.

Figure M

• While we've got the transmission out, we also check for any signs of cracking around the crankshaft bolts and inspect the flywheel teeth.

• Before installing the new transmission, make sure that the mating surface (figure M) is clean and free of debris, which would prevent it from tightening up properly.

• With the transmission lined up with the bell housing, install the bolts. The tape placed around the universal socket extension helps keep the tool from flopping around.

• The flywheel-to-torque converter bolts goes on the same way that they came off by using the pry bar to rotate the flywheel and line up the bolt holes. The torque converter cover goes back on and is secured with the fasteners.

• The flushed cooler lines are installed into the new transmission and the fittings are tightened down. To prevent stripping threads, it's always a good idea to hand tighten first and then use a wrench.

• The new mount is installed along with the cross member. The bolts go on and the transmission mount is secured. The cross member bolts are installed "nuts up" through the frame and tightened down.
  

  Figure N

• With the new transmission secure, the jack is removed. The torque converter clutch (figure N) can be re-installed, snapping it into the new transmission TCC solenoid. The torque converter clutch is the electrical circuit that applies voltage to the torque converter located at the front of the transmission.

• Now the speedometer cable can be re-installed, slipping it into the new transmission and locking it down. Secure the speedometer line to the cross member using a zip-tie. Mount the bracket to the floor pan and secure it. It's always a good idea to tie up loose lines using zip-ties.

• Next, a new vacuum modulator hose is installed and the vacuum modulator is connected to the new transmission. With everything connected to the new transmission, the driveshaft can be re-installed, slipping the two yokes together and securing the universal joint with the u-bolts.

• With the driveshaft back on, reinstall and secure the brace that we removed earlier.

• Now it's just a matter of re-installing the exhaust pipes that we removed earlier to gain access to the transmission, then replacing transmission pan and TV cable.
  

• With the transmission pan bolts loosened and removed, the old steel pan comes off.

• Carefully fit a new gasket onto the aluminum pan, and raise the new pan into position (figure O).

• Install the pan bolts and tighten them down (figure P).

Figure O

Figure P

Figure Q

Installing the Throttle-Valve Cable

• Slip the TV cable through the bracket and snap the housing into the bracket (figure Q).

• Hook the end of the cable up to the carburetor throttle linkage, and pull it back to secure it.

• Adjust the throttle to wide open, then the TV cable automatically adjusts to the proper length.

• The end of the vacuum modulator hose connects to the T-fitting of the intake manifold vacuum line.

Figure R

Replacing the Transmission Fluid

With the installation complete, we're ready to start adding the new transmission fluid. With this transmission totally empty, it will take about 11 quarts to fill it.

Use a transmission funnel for adding the fluid (figure R). A transmission fluid funnel is longer than a typical oil funnel and designed to reach lower fluid tubes.

You won't want to add all 11 quarts at one time because it could leak out the vent at the top of the transmission. Instead, we start by putting 6 about quarts into the transmission, then starting the engine and letting it run for a little bit--allowing the fluid to work its way into the system. Then shut the engine back off and add a couple more quarts. Keep repeating that process until the transmission is close to being full.

When we get close to being full--when we're close to the level on the dip stick-- run the gear selector through the gears. This also helps disperse the fluid throughout the system. After that, come back and do one final check with the dipstick.

Avoid rushing this process because, if you overfill, it's difficult to get fluid back out.

Weekend Mechanic DIY FYI : Most automatic transmission fluids are petroleum based, but some are high-performance synthetic blends. Both are designed to reduce transmission temperatures and improve shifting.

Test Drive and Followup

With the remanufactured transmission installed, the vehicle drives and shifts nicely, without the hesitation that was noticeable before.

During these first weeks, i'll be sure to check for any signs of leaking and spots on the driveway and tighten up the tranmission pan if needed. It's also important to check and fill the transmission fluid for a couple of weeks after installing a new transmission.

1 | 2 | 3 | 4

GUESTS :

Roger Schmidt
Z-Barn
Knoxville, Tenn.
www.zbarn.com