Yanmar knuckle gap

   / Yanmar knuckle gap #1  

truffalo

New member
Joined
May 20, 2025
Messages
1
Tractor
Yanmar 2420d
I bought a 2420d two years ago, and have put about 30 hours on it. I recently topped up the front axle gear oil. The next time I drove it, I noticed it leaking past the knuckle seals, right and left. Steady drip. This drew my attention to the gap at the knuckle, between the bevel and final housings. On both knuckles the gap was tight on the outside, towards the tires, and wide enough on the inside I could see over the top of the seal. I want to say 3/16", but I didn't measure or take pictures before I took it apart. I do have a picture of the seal on the final housing. Note how the seal is worn through, to the metal, on the tire side of the housing. The seals feel new. The guy I bought it from said he rebuilt the front less than a year before I bought it. The gears look great, so that checks out. The bottom of the bevel housing is worn badly, on the inside edge. There must have been bad grinding before he rebuilt it. I don't worry about that wear, since that part doesn't seem to sit on anything. The bevel housing is worn some where it mates with the seal, but that's probably less of an issue than the uneven gap.

I'm thinking of putting shims between the final head and steering arm, between the outer bolts, to close the angle, straighten the gap. Thoughts? Other things you'd look out for?
 

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   / Yanmar knuckle gap #2  
I bought a 2420d two years ago, and have put about 30 hours on it. I recently topped up the front axle gear oil. The next time I drove it, I noticed it leaking past the knuckle seals, right and left. Steady drip. This drew my attention to the gap at the knuckle, between the bevel and final housings. On both knuckles the gap was tight on the outside, towards the tires, and wide enough on the inside I could see over the top of the seal. I want to say 3/16", but I didn't measure or take pictures before I took it apart. I do have a picture of the seal on the final housing. Note how the seal is worn through, to the metal, on the tire side of the housing. The seals feel new. The guy I bought it from said he rebuilt the front less than a year before I bought it. The gears look great, so that checks out. The bottom of the bevel housing is worn badly, on the inside edge. There must have been bad grinding before he rebuilt it. I don't worry about that wear, since that part doesn't seem to sit on anything. The bevel housing is worn some where it mates with the seal, but that's probably less of an issue than the uneven gap.

I'm thinking of putting shims between the final head and steering arm, between the outer bolts, to close the angle, straighten the gap. Thoughts? Other things you'd look out for?
Yes, post this in the YANMAR section and ample enough people will help. (y)

 
   / Yanmar knuckle gap #3  
Looks like your sealing surface has rust on it thus making the seal wear out.

Dont shim anything unless it's out of spec.
 

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