Transmission TECH/TALK Archives - Page 24 of 25 - Transmission Digest
June 2001 Issue

Issue Summary:

When a 4L60-E fails from lack of lubrication, the cause may be that the lube-from-cooler passage in the pump stator was not drilled completely.

We also have information on the bellhousing changes in the 4L60-E units in Camaro and Firebird models, along with the converter applications. None of the parts listed will interchange with previous-design parts.

In vehicles with the Ford CD4E and Mazda LA4A-EL, high-gear starts in manual low after replace-ment of a valve body or computer could be due to the difference in solenoid firing order between 1994-and-earlier and 1995-and-later vehicles.

In a Mazda/Ford GF4A-EL, no 4th gear after rebuild could be caused by installing the forward and coast drum from a G4A-EL. We also have infor-mation on harsh upshifts.

We have identification of lower valve bodies on Mercedes-Benz 722.5 units showing the differences between the models that have rear pumps and those that don’t.

Also included are information on and functions of the vehicle-speed sensor on the Isuzu NPR/GMC Forward Tiltmaster.

May 2001 Issue

Ford’s 5R55N has a tab added to the new-design pan gasket to prevent the roll pin in the manual link-age from falling out.

Different procedures have to be addressed on the assembly of the low sprag in Ford 5R55N units.

On a Mercury Villager or Nissan Quest with 4F2OE or RE4FO4A, when the malfunction indica-tor lamp is lamp on and codes are stored but there are no drivability or transmission concerns, the cause may be a malfunctioning throttle-position sensor.

DaimlerChrysler changed the driveshaft yoke on A518/A618 units, so after rebuild it may not fit the output shaft.

No reverse and a 3-neutral shift after overhaul of a BMW ZF5-HP-30 may be caused by misassembly of the A-/C-clutch housing.

Shift shuttle on General Motors trucks and vans with 4L80-E transmissions probably means that the connectors for the input- and output-speed sensors have been switched.

April 2001 Issue

Issue Summary:

When a vehicle equipped with the THM 4L60-E will not start in Neutral, the cause may be the Park/Neutral switch or the C1 or C2 repair harness.

Trouble code P1870 in THM 4L60-E units usually results from slippage of the torque-converter clutch. Proper procedures for assembly of the front pump on the Ford 5R55N are important, because some misassemblies can occur if the technician does not refer to the manual.

For example, the outer pump gear must be placed in the pump body with the ID marks facing down.

March 2001 Issue

Issue Summary:

Beginning at the start of production for the 1998 model year, the Ford 4R100 was offered with two different torque-converter-clutch application strategies – PWM and non-PWM versions. We cover the parts affected on V-10 gasoline and diesel applications.

Harsh shifts when a Mazda/Ford GF4A-EL/GF4EAT gets hot and the pressures get erratic may be caused by a faulty pressure-control solenoid.

A worn governor valve can be one cause for late or no upshifts or no upshift after kick-down in a Chrysler A500/A518.

Undefined gear-ratio-error codes stored on vans and trucks with 4L80-E transmissions may be traced to an output carrier without a speed-sensor exciter ring.

February 2001 Issue

Issue Summary:

Incorrect installation of knock sensors can cause high line pressure and result in code 43 being stored on GM trucks and vans with gasoline engines.

Using a long bellhousing bolt in a shallow hole when re-installing the 4T65-E in a 1999 or later Oldsmobile Intrigue can damage an engine-oil passageway.

Watch your step in replacing the park/neutral switch on Cadillacs with 4T80-E transmissions. It can be tricky.

Installing incorrect drive and/or driven sprockets on Ford AXODE/AX4S/AX4N can cause several fault codes to be stored.

Oil venting from the filler tube on Ford
AODE/4R70W could be caused by the conical screen in the case being blocked.

On a Chrysler A-518, no or late third gear may be because some grooves for the direct-clutch inner seal were cut too deeply into the direct drum.

We also have provided updated information on gear ratios for the 1997-99 4T60-E.

January 2001 Issue

Issue Summary:

Ford 4R44E/4R55E/5R55E units with delayed Reverse may require removing a checkball.

Some 1996 and later Ford E4OD models may not upshift. If the PCM is commanding the transmission to make the upshifts, the BS2 checkball in the main valve body is missing.

In the Ford 4R44E/4R55E, intermittent or no TCC application could be caused by replacement of the inner pump gear with one from an A4LD.

When wires are removed from the case connector on 4R44E/5R55E units, determining the cavities to which the wires must be returned can be confusing. We list the pin numbers and colors of wire and the terminals to which you should connect them.

In the General Motors 4L30-E, a complaint of slipping or no 2nd gear before or after overhaul may be because of a barely perceptible crack in the 2nd-clutch housing.

Chrysler A500/42RE may have no Reverse or a bind-up on the 3-4 upshift after a rebuild because of incorrect assembly of the overdrive direct-clutch pack. This is due to the differences in the pressure plate or the steel clutch plates.

December 2000 Issue

Issue Summary:

Most of the vehicles we are working on have computer-controlled transmissions, so we will be bringing you the latest types of checks to help in diagnosing the vehicles’ transmission problems.

The 4L60-E and 4L80-E transmissions used in General Motors C/K trucks can be stuck in fail-safe. One of the causes could be a blown fuse but the replacement fuse also blows. We have a check procedure and the common cause for that problem.

Sometimes scan tools can give incorrect information on GM THM 4T80-E units with diagnostic trouble code P056 stored. You should access the codes through the onboard diagnostic system on Cadillacs.

Mazdas equipped with the R4A-EL transmission may exhibit normal 1-2 and 2-3 upshifts but no 4th gear. The cause could be a faulty or misadjusted inhibitor switch, a faulty theft-deterrent system or a grounded wire harness leading to the inhibitor-signal fuse.

Nissan Maximas equipped with the RE4FO2A may have only a 1-2 shift and the reverse lamps do not illuminate. The cause may be that the connector for the auxiliary air-control valve has been switched with the inhibitor-switch connector.

November 2000 Issue

Issue Summary:

No forward engagement in a Ford E4OD may occur because the plastic-caged low roller clutch was installed incorrectly.

An A4LD in Ford light trucks may require shift-lever PRNDL adjustment because the cable-assembly locking tab is not fully seated.

If you have a Chrysler A-604 with a broken tapered snap ring in the underdrive/overdrive reaction plate, be sure you install the late-type snap ring.

We have corrections for bind-up or 2nd-gear starts on KM-177, and a pump-gear change on KM 175.

In Ford Probe 4EAT and Mazda G4A-EL units, a
4-2-3-1 shift pattern after rebuild may be caused by reversed shift solenoids.

We also have the procedure for FIPL (fuel-injection pump lever) sensor adjustments on the Ford E4OD.

October 2000 Issue

Issue Summary:

This month’s Tech/Talk covers a variety of complaints and fixes, leading off with a Saturn that moves forward in all gear selections. The problem is caused by a mismatch of the manual valve and manual-valve link.

A missing rubber-coated sleeve in the overdrive-servo assembly of a 4R70W may result in burned forward clutches.

Torque-converter discoloration in a 4T60-E may be caused by a melted plastic spring retainer in the to-cooler fitting.

A weak or collapsed 4th-apply piston return spring in 4L60 and 4L60-E units may be the cause of burned 2-4 bands.

We also have information on a Subaru Justy ECVT that has no ratio change from low.

Mismatching manual valve to case in G4A-EL units will result in either no reverse or movement in neutral. Mismatching reverse and forward drums will cause stacked shifts.

A complaint of no movement in any range on a Subaru RE4-style transmission may be caused by an incorrectly installed lockup-control valve and spring.

Shift-solenoid and lockup-solenoid wires that are connected backward on Mazda MPV R4A-EL units will produce a 1-3 upshift in Drive.

September 2000 Issue

Issue Summary:

Some overdrive planetary gearset changes that were made in 1995 Chrysler A518 models can create service concerns. We have covered those changes from the previous-design straight-cut (spur) gears to the 15° helical-cut gears.

In the middle of the 1997 model year, GM changed the transaxle case, channel plate and check-ball locations on the THM 4T40-E. Those changes are noted along with the illustrations.

August 2000 Issue

Issue Summary:

In some instances, the Park/Neutral position switch on General Motors 4L60-E cannot be removed. Related problems may occur, such as the dash indicator showing either an improper shift or no shift, or no back-up-light operation.

A speed-sensor-harness repair kit now is available for General Motors 4L80-E and 4L80-EHD. Part numbers are included.

The location of the rear lube seal and orifice on General Motors 4L80-E and 4L80-EHD is still a problem for many technicians. We have illustrated this location.

Premature failure of the 3-4 clutch in General Motors 4L60 and 4L60-E units usually is associated with vehicles used for police, taxi or other heavy-duty service.

No upshift from first gear after overhaul of a Chrysler A500SE (42RE) may be caused by excessive wear on the overdrive-piston support where the low-reverse drum rides.

After rebuild, some Chrysler 42RE vehicles may have a 1-2 upshift shuttle that may lead to an incorrect diagnosis as a valve-body problem.

July 2000 Issue

Issue Summary:

The checkball locations are similar in Chrysler 42RE and 47RE transmissions, but we have illustrated some differences. None of the individual parts will interchange with those of previous design levels.

Chrysler A500/A518 with no 3-4 shift before or after overhaul may not have the right computer for the vehicle.

We also have center-gearbox differences on General Motors 4L80-E/4L80-EHD center-lube transmissions. Notice that none of the parts listed will interchange with any previous-design-level parts, and none of the previous-design-level parts can be used in the units with center-lube design.