7 1/4 axle seal option

-

64longroof

FABO Gold Member
FABO Gold Member
Joined
Dec 2, 2011
Messages
185
Reaction score
98
Location
Kentucky
Both in this forum and on the big video sharing platform, the Precision 9569 S axle seal is mentioned as useable on the 7 1/4 differential. Here are my caliper measurements....yes, the old factory seal is deformed, but rotating it within the caliper jaws , without getting near the section of the seal I deformed, did not change the measurement shown in picture below. As I read it, the 9569 S is 0.8 mm wider diameter than factory original.
Given this, do I try to jam the bigger one into the axle housing? That risks compromising the rubber part of seals geometry. Maybe?
The axle diameter is 3.39 cm, vs. 3.30 for the 9569 seal inner diameter. This nearly 1 mm difference allows for 0.5 mm of seal lip flex around the axles circumference.
Would that amount of lip flex sufficiently seal the axle? Any mechanical engineers reading this?
Thanks for comments, and any corrections to my caliper readings.
Perhaps this info. will help a few folks out there

IMG_20250809_203111016_HDR~2.jpg


IMG_20250809_203221966_HDR~2.jpg


IMG_20250809_210634094_HDR~2.jpg


IMG_20250809_210742983_HDR~2.jpg
 
PS, the only other seal option seems to be NOS , which is a very old leather seal.
 

Rock auto
Also keep in mind the outer part of the seal has sealer that gets smashed upon installation

Screenshot_20250809-230635.png
 
Thanks to both of you,
Is Jim at DMT referring to James at Detroit muscle technology? Can't find this on his website.
 
Are you talking about the foam pieces I used on the Dart? Yes Jim has (had) them. I have a bunch too since he sent me a stack of them.
 
-
Back
Top Bottom