| SLIPPED VIBRATION DAMPER |
Incorrect Timing On
1984 4.9L (300 CID) 6 Cylinder Gasoline Engines
It's been reported that a number of 1984 Ford E & F trucks and Bronco vehicles with the subject engine may suffer from timing that is off by more than 4°, thus resulting in poor performance. The reason may be that the vibration damper bonding may have slipped.
The figure below will help you to determine the correct location of the timing mark. Do no, however, mistake the monolithic notch for the timing mark. the monolithic notch is located 180° from the keyway.
The AERA Technical Committee |
| NOISY TIMING GEARS |
Timing Gear Noise On
1965-76 Ford 6 Cyl. 3.9 & 4.9L (240 & 300 CID) Truck Engines
It has been reported that a timing gear noise problem exists (loud whining sound) in 1965-76 Ford 6 Cyl. 3.9 & 4.9L (240 & 300 CID) truck engines. The problem appears to be caused by the design and material selection of the gears.
When this condition is encountered, it is suggested that a set of dissimilar metal timing gears be installed.
The AERA Technical Committee |
| 4.9L CAM BEARING HOUSING BORE CHANGE |
Revised Cam Bearing housing Bore On
1985-87 Ford 300 CID (4.9L) Engines
The Form Motor Company has revised the cam bearing housing bore on
Ford 300 CID (4.9L) engines manufactured after June 4th, 1985.
Previously all four housing bores measured 2.1440. The late style
block with the casting number E1TE-6015AA, has the following cam
bearing housing bore dimensions:
Location Part # Bore Diameter
1 E5TZ-6261A 2.1590
2 E5TZ-6262A 2.1440
3 E5TZ-6262A 2.1440
4 E5TZ-6261A 2.1590
AERA members are cautioned to check each cylinder block's cam
bearing housing bore for positive identification.
At this time the revised design cam bearings are available only
through Ford Motor Company. They will be made available through the
aftermarket during the 4th quarter of 1987.
The AERA Technical Committee
September 1987 - TB 449R
(Please destroy original TB 449)
##END## |
| INTAKE & EXHAUST VALVE LENGTH CHANGE - '85 ENGINES |
Intake & Exhaust Valve Length Change On
1985 Ford 4.9L (300 CID) Engines
Ford Motor Company has changed the length of the intake and
exhaust valves used in the company's 1985 model year and later
4.9L (300 CID) engines. The earlier style valves had an overall
length of 4.810 long while the later style are 4.750 long.
The Ford Motor Company part numbers for these valves are:
E5TZ_6507A for the intake valve and E5TZ-6505A for the exhaust
valve.
The change in valve length was necessitated by a change in the
engine's rocker arm styles. The 1985 model year and later
engines are using the boat style rocker arm configuration that is
similar to the Ford 351W and M series engines.
At this time, AERA is not aware of any aftermarket suppliers for
these new length valves.
(Insert Illustration)
The AERA Technical Committee
December 1986 - TB 412
##END## |
| GUIDELINES FOR CRANKSHAFT THRUST FLANGE SURFACE FINISH |
Guidelines For Crankshaft
Thrust Flange Surface Finish
The AERA Technical Committee offers the following information regarding guidelines for crankshaft thrust flange surface finish. Failure to follow these recommendations while remanufacturing crankshafts may be one leading cause of premature thrust bearing failures.
Correct surface preparation for bearing surfaces has been changing through the years. The current requirements for the thrust surface of 12 Ra and less (smoother is better here) must be met with the use of today?s commonly found lightweight oils. Many engines now have smaller thrust bearing surface areas than 20 years ago. Those smaller surfaces are still expected to carry the load or even higher loads per square inch than years ago.
Most current, original equipment service manuals, do not supply thrust surface finish information. Looking at service information published 20 years ago when we didn?t see a lot of thrust failures occurring we found several listings. Remember also, this was before lock-up torque converters, hydraulic clutch systems and small thrust bearing surfaces.
Occasionally, the required thrust flange surface finish is published in factory service manuals with a RMS number. Below is such a listing of specifications from an original equipment 1977-78 Ford engine specifications manual. Those older specifications are no longer suggested for engine rebuild practices.
Engine Application Thrust Flange Front Rear Finish
300, 302, 351 W car & truck 35 25 RMS
351M, 400 car & truck 25 20 RMS
361, 391 truck 20 10 RMS
460 car & truck 25 20 RMS
477, 534 truck 20 20 RMS
To convert into Ra multiply RMS by 1.11
In the middle 80?s Michigan 77 called out in their failure analysis guide, rear thrust surface finish of 15 Ra or less for passenger car applications. They also suggested a 10 Ra or less when applying to heavy duty or highly loaded thrust surfaces. The higher the load, the smoother the surface finish requirement. The smoother the surface finish, the more bearing surface available.
AERA shops that produce a thrust surface finish of 6-8 Ra consistently, report no premature crankshaft thrust wear problems.
Note: It may be advantageous to recommend using the same brand of engine oil in an engine. Doing so is one method of eliminating the possibility of a negative reaction between the different additive packages from each oil company.
The AERA Technical Committee |
| DETONATION COMPLAINTS |
Detonation Complaints On
Ford 4.9L (300 CID) Engines
Resolving detonation complaints on Ford 4.9L (300 CID) engines can go beyond selecting the right piston and making sure that the cylinder head has not been resurfaced below specifications. A worn distributor can also result in detonation.
Mechanical distributors used in these engines rely on plastic bushings to pivot the advance weights. Over time these bushings can wear allowing ignition timing to advance to the point at which the engine will detonate.
The correct timing specifications are:
Static distributor setting 8^ BTDC maximum
2000 rpm, distributor vacuum off & plugged 21^ BTDC maximum
2000 rpm, distributor vacuum connected 33^BTDC maximum
These specifications may not apply to engines equipped with electronically controlled distributors.
For additional information see AERA EXPO '92 Technical presentation: Changing Compression Ratios in Today's Engines, by Clarence Clark.
The AERA Technical Committee |
| REVISED LIFTER ADJUSTMENT |
Revised Hydraulic Lifter Adjustment Procedure On
1962-65 Ford V-8 Engines
The Ford Motor Company recommends a new procedure for adjusting hydraulic valve lifters on 1962-65 3.6L, 3.9L, 4.3L, 4.7L, and 4.9L (221, 240, 290 and 300 CID) engines.
Instead of turning down the rocker arm studs an additional one and one-half turns after the clearance between the push rod and rocker arm has been just barely eliminated, the new procedure calls for tightening the rocker arm studs just an additional three-quarters of one turn.
This looser adjustment is overcoming lifter bottoming trouble and thereby correcting noisy lifters and rough engine operation.
The AERA Technical Committee |
| OIL PRESSURE LOSS |
Oil Pressure Loss On
Ford 4.9L (300 CID) Engines Built On August 1, 2 And 3, 1983
A small quantity of light E & F trucks and Bronco vehicles may have mismachined camshaft journals which could cause premature bearing wear and subsequent loss of engine oil pressure. Low oil pressure concerns, with or without engine noise, may be a result of this condition on subject vehicles built on the above dates.
To determine if a camshaft is suspect, inspect the journals and lobes for any excessive wear, chatter or unusual pattern on the surface finish. Pay particular attention to the #1 lobe or the 2nd and 3rd bearing journal.
If any of the described conditions exist, replace the camshaft and bearings. If the camshaft does not show excessive wear or irregularity of the surface finish, check the oil pump for damage and proper operation.
The AERA Technical Committee |
| TIMING GEAR NOISE ON 240 & 300 CID ENGINES |
Timing Gear Noise On
Ford 240 & 300 CID (3.9 & 4.9L) Heavy Duty Engines
A number of AERA members report they are finding high timing gear noise levels on Ford 240 and 300 CID engines. Timing gear whine is normally associated with insufficient lubrication or insufficient gear lash. While gear train noise may not cause any mechanical problems, it may lead to customer dissatisfaction.
Increasing the amount of direct lubrication to the timing gears will reduce or eliminate timing gear noise. This can be accomplished by inserting a 1/8 X 1/2 long roll pin into the oil galley orifice at the front of the block, just above the
camshaft timing gear. Maintain a 1/8 clearance between the tip of the roll pin and the camshaft timing gear.
The roll pin directs oil onto the gear teeth, thus reducing noise levels and possibly extending the service life of the timing gear set.
The recommended timing gear lash for these engines is .002-.004. This figure should be maintained even though lubrication to the gears is increased. Insufficient lash may lead to increased gear train noise level and early failure.
The AERA Technical Committee |
| OIL PUMP HOUSING CLEARANCES |
Oil Pump Clearance Caution
Some AERA members report they are having problems with inadequate
clearance between the oil pump housing and the crankshaft or
connecting rods on some engines. The engines most seriously
noted for this are the Chevrolet 292 CID six cylinder and Ford
300 CID six cylinder, 302 CID V8 and 400 CID V8 engines.
The problem is not with the cylinder block but with the oil pump
housing. Some aftermarket oil pump housings have extra material
cast into them that interferes with the crankshaft or connecting
rods on long stroke engines. As an example, there have been no
problems with the 250 CID Chevrolet six cylinder connecting rods
clearing the oil pump housing, but installing the longer stroke
292 CID crankshaft in that same block may create a clearance
problem.
A visual inspection should be made when the oil pump is being
installed to insure that there is a minimum of .060 clearance
between all points on the oil pump housing and all points on the
oil pump housing and all points on the crankshaft and connecting
rods. If there is inadequate oil pump housing clearance,
remounting the oil pump may solve the problem if you can move the
oil pump away from the crankshaft. If not, remove the oil pump
and remove material from the oil pump housing until adequate
clearance exists. Be sure to adequately clean the oil pump
before reinstalling it on the block.
Although this clearance problem is more likely to be found on the
above engines, it is a good practice to check for this condition
on all engines you assemble.
The AERA Technical Committee
July 1986 - SPB 134
##END## |
