Clutch/Dash Panel - High Effort/Cracking
Article No. 86-20-10DASH PANEL CRACKS AT CLUTCH MASTER CYLINDER (6.9L(D)/7.5L)
CLUTCH - HIGH EFFORT - DASH PANEL CRACKING/MISSHAPED RELEASE LEVER (6.9L(D)/7.5L)
CLUTCH - INCOMPLETE RELEASE
- DIAGNOSIS (6.9L(D)/7.5L)
LIGHT TRUCK 1983-86 F-250/350
The 6.9L(D)/7.5L clutch systems may exhibit three interrelated durability/performance concerns:
^ Dash panel cracking at clutch master cylinder:
This typically is caused by high pedal efforts.
^ High pedal efforts:
This typically is caused by binding up of the clutch release lever/throw out bearing/transmission input bearing retainer, or excess wear of the disc.
^ Clutch not completely releasing:
This may be caused by several conditions:
- High pedal effort creating system deflections which lower "effective" system travel.
- Restricted pedal travel reduces the ability to fully "stroke" the system.
- Free play in the system can use up some of the pedal travel before the system begins to react.
These conditions are discussed individually in this TSB article. Check the vehicle for all three conditions.
Dash Cracks
Cracks located at the clutch master cylinder should be serviced by installation of a dash panel reinforcement kit (part number 7K509). This kit includes detailed instructions and parts to mount the reinforcement. When ordering the reinforcement kit, the vehicle should be inspected to determine if stud extenders will be necessary. If needed, they must be ordered separately.
Check master cylinder studs and determine length of threads currently extending beyond nut. If less than 1/8", stud extenders are required (85-9-38).
When performing the dash panel repair, be sure to:
^ Seal dash panel "dish" where service actions have created need, such as welding burn-out of sealant (adjacent to master cylinder).
^ Service high pedal effort concerns.
^ Adjust pedal freeplay as necessary.
Figure 9:
(See Figure 9 for general reinforcement information only.)
High Pedal Efforts
1. Raise vehicle on a hoist.
2. Remove the release lever as follows:
a. Push the release lever forward to "compress" the slave cylinder. As an aid, reinstall the plastic retainer strap, if it is still present.
b. Pry off the retainer clip and slave cylinder.
c. Remove the release lever by pulling slightly in a rearward direction.
Figure 8:
d. Inspect the lever for wear at the "tips" of the "fork". Evidence of excessive wear at this point indicates incorrect lever geometry (see Figure 8).
This can result in binding of the release bearing. For 1984-86 vehicles, obtain a replacement fork. For 1983 vehicles, obtain a replacement fork and pivot stud.
3. Remove the transmission from the vehicle as outlined in Section 16-24 of the 1983 or 1984 Light Truck Shop Manual.
4. Inspect the clutch bearing contact area of the input shaft bearing retainer (7050) for galling or gouges If there are any indications of abnormal wear to the surface of the retainer, discard the retainer and oil seal (7052).
5. If required, obtain a new cast iron bearing retainer and install a new oil seal into the bearing retainer. Install the retainer assembly to the transmission assembly using a new gasket (7051). Torque attaching bolts to 15-25 ft.lbs. (20-34 N-m).
6. Remove the clutch bell housing.
7. Remove the pressure plate and disc.
8.Inspect the Belleville spring fingers on the pressure plate for excessive wear and grooving. Check pressure plate face for evidence of excess wear and heat.
9. Inspect the disc for evidence of excess wear and heat.
10. Inspect the flywheel for evidence of wear and hot spots.
11. Replace clutch components as required.
12. Reinstall the clutch bell housing.
13. Reinstall the transmission.
14. Reinstall the slave cylinder.
Clutch Not Completely Releasing
Diagnosis for inadequate clutch release (hard shifting/ gear grinding).
Diagnostic Procedure
Check the rod motion of the clutch housing mounted slave cylinder. With the clutch pedal pushed through its full travel, the slave cylinder pushrod should move the minimum distance specified below, against the clutch release lever (7515) head. Hydraulic slave cylinder must be installed on clutch housing and actuated against the release lever head for this test or breakage of the slave cylinder may occur since the internal spring will fully extend the piston before the pedal is stroked.
Minimum Slave Cylinder
Application Rod Motion
6.9L Diesel and 13.5 mm (17/32")
7.5L Gas Engines
If the slave cylinder rod moves at least the minimum distance, then the hydraulic system and the in-cab mechanical components are functioning properly. Continue to troubleshoot for clutch disengagement problems due to the clutch pressure plate, clutch disc, release bearing or the release lever.
See Section 16-01 through 16-04 of the 1983-86 Shop Manuals.
Inadequate Slave Cylinder Travel Diagnosis
^ Clutch pedal stroke restriction:
Check the clutch pedal travel with a tape measure. Measure the distance between a chosen spot on the front edge of the seat and the pedal. Measure at two positions: pedal fully up and pedal fully down. The difference between these two measurements equals the pedal travel. Minimum acceptable travel is shown below:
Application Minimum Pedal Travel
6.9L Diesel and 165.1 mm (6-1/2")
7.5L Gas Engines
Figure 7:
If pedal travel is low on 1984-86 vehicles, remove the pedal stop (see Figure 7). If pedal travel is low on vehicles without a stop, look for excessively thick floor mats and carpeting limiting travel.
^ Cross-shaft attachments loose:
Attaching nuts between the pedal and pedal shaft and also between the pedal shaft and lever should be checked for looseness. If loose, tighten (see Figure 7).
^ Clutch Pedal Linkage Adjustment:
Disconnect the cotter pin (380699-S) and the master cylinder pushrod from the clutch lever (7A554). Refer to Figure 7.
For 1983 Only - Push the master cylinder pushrod forward until it is seated in the pushrod pocket in the master cylinder and check the alignment of the hole in the pushrod with the stud on the clutch lever (7A554).
If the pushrod hole misaligns from the clutch lever stud by more than 1/8 inch in 1983 vehicles or by more than 1/16 inch in 1984 and 1985 vehicles, then the in-cab linkage is mispositioned. Adjust the pedal linkage.
1983 Models - Use of Adjustable Service Pushrod
1. Remove the cotter pin (380699-S) from the clutch lever (7A554).
2. Remove the existing 7641 pushrod from the clutch master cylinder.
3. Replace the pushrod with an adjustable pushrod.
4. Adjust the pushrod as follows:
a. Adjust the pushrod until freeplay between the pushrod and master cylinder piston is just eliminated.
b. Back off one-half turn.
c. Tighten the jam nut.
d. Assure that the bleed port for self-adjustment located in the master cylinder is uncovered. With the slave cylinder mounted, push the clutch release lever (7515) toward the slave cylinder with the palm of the hand.
e. If the lever can be moved, then the bleed port is uncovered and the rod adjustment is correct.
f. If the release lever cannot be depressed, shorten the master cylinder pushrod until the release lever can be moved.
1984-86 Models - Adjustment of Clutch Release
1. Disconnect the cotter pin, the master cylinder pushrod, and the bushing clutch lever.
2. Disconnect the clutch lever (7A554) from the pedal shaft on the clutch pedal assembly by removing the attaching nut and prying the clutch lever off.
3. Check for evidence of a tight fit between the lever (7A554) and the shaft (7506).
a. If the fit between the lever and the shaft did not create clearly defined spline cuts in the lever, then replace the shaft (7506).
b. If the fit between the shaft and the lever created clearly defined spline cuts in the lever, do not replace the shaft (7506).
4. Discard the clutch lever (7A554) (the spline pattern in the hole of the discarded clutch lever will not allow repositioning on the pedal assembly shaft). If the shaft is to be replaced, remove the pedal overcenter spring (7B572). Remove the nut attaching the clutch pedal assembly to the pedal shaft and remove pedal from shaft. Remove the pedal shaft (7506) from the pedal support (2L252). Discard the pedal shaft (7506).
5. Attach a new clutch lever (7A554) to the master cylinder pushrod with the bushing and the cotter pin.
6. Place the clutch pedal (7519) up against the upper stop on the brake and clutch pedal support bracket (2L252) and allow the overcenter spring to hold it in place.
7. Attach the new clutch lever (7A554) to the shaft of the clutch pedal assembly with nut N620483-S2, making sure that the clutch lever (7A554) is not pushing or pulling the master cylinder pushrod. Torque the nut to 40-50 ft.lbs. (54-67 N-m). Check the clutch system for proper operation.
PART NUMBER PART NAME CLASS
E3TZ-7K509-A Kit - Dash Panel CG
Reinforcement
*N803891-S Stud - Hollow, Extender S
*34671-S8 Nut RS
*375674-S36 Washer SG
E6TZ-7515-A Lever - Clutch Release B
E3TZ-7B602-E Pivot - Clutch Release C
Lever (Converts 1983 Models to Accept E6TZ-7515-A Lever)
E5TZ-7550-G Clutch Disc (6.9L (D)) V
E6TZ-7550-B Clutch Disc (7.5L) V
E5TZ-7563-B Clutch Pressure Plate V
(6.9L (D), 7.5L)
D9ZZ-7548-A Hub and Release Bearing A
C5TZ-7050-H Input Bearing Retainer A
(T19)
8MTH-7051-B Gasket B
C5TZ-7052-A Oil Seal A
E3TZ-7641-B Pushrod - Master A
Cylinder (Adjustable)**
E4TZ-7506-A Shaft - Clutch Pedal*** B
E4TZ-7A554-A Lever - Clutch Pedal** B
Shaft
* Use with E3TZ-7K509-A if master cylinder stud requires extension.
** 1983 models only.
*** 1984-86 models only.
OTHER APPLICABLE ARTICLES: 85-5-26
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: SP7050A86 - Repair cracked dash panel and high pedal effort - welding not required.
TIME: 4.6 Hrs. - 4x2 5.5 Hrs. - 4x4
OPERATION: SP7050B86 - Repair cracked dash panel and high pedal effort - including welding of dash panel.
TIME: 5.1 Hrs. - 4x2 6.0 Hrs. - 4x4
Supplement: Remove and reinstall PTO - Use "Actual Time" DLR. CODING: Basic Part No. 7050 - Code: 14