Note that greasable u-joints are physically weaker (due to the grease journals drilled through them), and those with the grease fitting screwed in between the trunnions even moreso, due to the wedge effect of the threads exactly where material is missing. They are also less durable, due to their seals constantly being blown out by the grease being pumped through them. Studies have shown that the dirt that is invariably introduced during greasing is more detrimental than NOT repeatedly adding grease. A sealed u-joint (which should be greased before installation, and can be re-greased by disassembly later) is stronger & lasts longer.
See also:
Dana/Spicer Expert for U-joint ID by Dimensions
.
.
.
For other TSBs, check
here.
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TSB 97-20-15 U-Joint Identification
Publication Date: SEPTEMBER 29, 1997
LIGHT TRUCK: 1990-1996 BRONCO
1990-1997 AEROSTAR, ECONOLINE, F SUPER DUTY, F-150-350 SERIES, RANGER
1991-1997 EXPLORER
1997 EXPEDITION, MOUNTAINEER
ISSUE: Available U-joints for driveshaft service are not always identifiable through model application charts. Some customers may request greaseable U-joints as a personal preference.
ACTION: Refer to the following Service Information for availability of U-joint with grease fittings.
SERVICE INFORMATION
TO IDENTIFY U-JOINT BY MEASUREMENT:
Remove the old U-joint.
Measure U-joint using the following measuring procedure.
Remove bearing cups.
Remove excess grease from bottom of bearing cups and trunnions.
Remove seals from bearing cups and trunnions.
Reinstall bearing cups on trunnions.
Measure as follows, permitting a tolerance of ±0.005" at Dimension "G" with Dimension "D" and "E" at ±0.003".
Outside Snap Ring Style
A) Measure "G" dimension and record.
B) Measure "D" dimension and record.
C) Measure "E" dimension and record.
Identify U-joint part number using reference dimensions in the Light Truck Cross Reference Chart found at the end of this TSB article.
TO IDENTIFY GREASEABLE U-JOINT FOR SERVICE:
For customers who demand greaseable U-joints due to their specific vehicle duty cycle, refer to Light Truck Cross Reference Chart.
Greaseable U-joints are typically recommended only for vehicles which operate 100% of the time in a high grit environment (e.g., coal mines).
NOTE: GREASEABLE U-JOINTS DO NOT CONTAIN END PLAY THRUST WASHERS AND MAY CAUSE NOISE/VIBRATION/HARSHNESS (NVH) CONCERNS ON CERTAIN APPLICATIONS.
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Information Only
OASIS CODES:509000, 590000, 597997
