1990 Jaguar Sovereign

Transmission problem
1990 Jaguar Sovereign 6 cyl Two Wheel Drive Automatic 162000 miles

where can I look first to solve this problem
February 18, 2009.

Transmission malfunctions may be caused by poor engine performance, improper adjustments, or failure of hydraulic or mechanical components. Always begin by checking fluid level, fluid condition, linkage and cable adjustments. Perform road test to determine if problem has been corrected. If problem still exists, several tests must be performed on transmission. See TESTING.

Before performing road test, warm engine to normal operating temperature. Ensure fluid level is correct and in good condition. Ensure shift linkage and throttle cable are properly adjusted.
Road test vehicle and check for abnormal noise, vibration and clutch slippage. Specified clutch and brake are applied in designated gear. See CLUTCH & BRAKE APPLICATION table. Drive vehicle with shift lever in " D" position.
On Jaguar models, ensure upshift and downshift speeds are correct in relation throttle position. See SHIFT SPEED SPECIFICATIONS table.
On all models, slipping or excessive engine speed during shifts usually indicates clutch or brake slipping problems. Unless an obvious condition exists, transmission should never be disassembled until hydraulic pressure tests have been performed.

CAUTION: DO NOT perform torque converter stall speed test for more than 5 seconds or transmission may be damaged.

Apply parking brake. Block all wheels. Connect tachometer and start engine. Ensure A/C is off. Warm engine to normal operating temperature. Place shift lever in " D" position.
Fully depress brake pedal. Fully depress accelerator for 2-4 seconds and note maximum engine speed. This is the torque converter stall speed. Allow transmission to cool for 2 minutes before repeating torque converter stall speed test.
Ensure torque converter stall speed is within specification. See TORQUE CONVERTER STALL SPEED SPECIFICATIONS table. If torque converter stall speed is not within specification, refer to TORQUE CONVERTER CLUTCH OPERATION under TROUBLE SHOOTING for possible causes.
If torque converter stall speed is less than specified, check for low engine output or defective torque converter one-way clutch. If torque converter stall speed is greater than specified, check for slipping clutch.

Information not available from manufacturer.

Dave H
Nov 2, 2009.