Automotive Technical Newsletter Archives - Page 19 of 20 - Transmission Digest
January 2002 Issue

Issue Summary:

Mismatching wires of the turbine-shaft-speed sensor on Mazda 929 R4A-EL can cause major headaches.

A timing problem can cause delayed reverse in an E4OD.

In some two-wheel-drive Ford pickups with the E4OD transmission, stacked upshifts can result from the use of a 4×4 wiring harness.

We have information on the new A350 unit in the Lexus GS 300.

Incorrect drive and/or driven sprockets can cause gear-ratio errors in Ford AXODE/AX4S/AX4N units.

December 2001 Issue

Issue Summary:

In a Nissan RE4FO4A or Villager 4F20E, slipping or no second gear may be caused by insufficient spring tension on the 1-2 accumulator piston or a stuck 1-2 accumulator regulator valve.

We have in-depth information on retrieval of diagnostic trouble codes for Nissan vehicles.

Harsh upshifts on electronically controlled Nissan transmissions may be caused by a faulty dropping resistor or a poor connection at the resistor.

In Toyota Previas with four-cylinder engines and A46DE transmissions, stacked shifts or no passing gear may be caused by a broken wiring harness or faulty throttle-position sensor.

GM introduced a new-design overrun roller clutch into the THM 4L80-E as a running change beginning in March 2001. We cover the parts affected by this engineering change.

November 2001 Issue

Issue Summary:

n Acura Legends with G4, L5 & PL5X transaxles, grinding or bind-up in reverse could be caused by incompatible reverse-selector components on the countershaft.

In the BMW ZF-5HP-18, a bind-up with the selector in Manual 2 position, 1st gear, could be caused by a broken D-clutch one-way checkvalve assembly.

A broken clutch-pressure-control spring may cause flared or harsh upshifts on Honda A4RA/B4RA.

We also illustrate Ford CD4E air-check passages.

In 1996-98 Ford E4OD or 4R100, slipping or no reverse and/or no engine braking in Manual 1 or 2 can be caused by a misplaced BS1 checkball.

In earlier E4OD models, slipping or no reverse or no engine braking in Manual 1 or 2 can be caused by misplaced BS1 and BS6 checkballs.

October 2001 Issue

Issue Summary:

1997-2000 Ford F-150/F-250 pickups with 4R70W transmissions may have driveline vibration and rear-seal leaks.

Cooler leaks on 2000-01 Ford Explorer/Mercury Mountaineer four-door vehicles with 5R55W transmissions may be caused by contaminants on the cooler tubes.

On 2000 Cadillac Devilles, Eldorados and Sevilles and 2001 Oldsmobile Auroras with 4T80-E transaxles, slipping in fourth or no fourth gear with code P0734 may be caused by a warped lower-control valve-body channel plate.

No movement or delayed engagement in a BMW with the ZF-5HP-18 may be caused by a shrunken bypass ball.

We have furnished typical relay checks for Chrysler’s 41TE, 42LE and 42RE transmissions. Once the operation of a relay is understood, any relay can be checked with ease.

September 2001 Issue

Issue Summary:

This month’s issue covers a variety of complaints on Mercedes Benz vehicles, including harsh reverse or delayed reverse engagement in 722.3, 722.4 & 722.5 units, and slipping on take-off on models equipped with the rear-pump-elimination kit.

In AX4S/AXODE units, solenoid-wire connectors installed on the wrong solenoids may cause harsh shifts, a clicking noise and tie-up on shifts.

We have listed the vehicle-harness repair kits that are available for several different Ford transmissions.

Failure of the exhaust-brake system on Isuzu NPR/GMC Forward Tiltmaster vehicles could be caused by elevated line pressure and premature transmission failure.

August 2001 Issue

Issue Summary:

In the General Motors THM 4L80-E/4L80-EHD, no converter clutch, trouble code 68 in Overdrive and trouble code 39 in Drive 3 may be caused by an incorrectly installed TCC enable valve.

A blown fuse in 1991-95 Cadillacs equipped with the THM 4T60-E can cause 3rd-gear starts before or after overhaul.

In Saturn MP6/MP7 units, delayed or harsh reverse engagement and repeat failures of the external filter seal may be caused by a broken spring or bore wear.

The new center support for the Ford A4LD will retrofit as long as the new selective No. 4 and No. 3 thrust bearings are used.

July 2001 Issue

Issue Summary:

General Motors’ new-design pump-and-rotor assembly for 1994 and up 4T60-E models must be used with the tapered rotor because of some passage changes in the pump.

We have information on retrieval of Nissan diagnostic trouble codes – how to receive the signal from the A/T control unit and to indicate a detected fault by illuminating the malfunction indicator lamp (MIL).

General Motors has new-design solenoids for the 4T80-E, so we are showing the ways to identify them. Previous-design solenoids no longer are available.

Bind-up in reverse and 3rd and/or wrong-gear starts in the Ford 5R55E may be caused by a crack in the inner race for the center-support caged needle bearing.

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.

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.