121321 Cummins O-Ring | PAI

O-RINGPAI Part #: 121321OEM References: CUMMINS 3679139 CUMMINS 3949781 MACK 4333-1837803C91 NAVISTAR 1837803 NAVISTAR 1837803C1 Warranty: 2.0 year(s)

Warranty BackedPAI IndustriesFree Freight

JAK'S Part #JAKS-PAI-121321

Cross Ref3679139

Cross Ref3949781

Cross Ref4333-1837803C91

Cross Ref1837803

$3.99

In Stock — Ships Today if ordered by 3:00 PM MT

Secure Checkout 30-Day Returns Warranty Backed Ships Same Day

Not sure it's the right fit? Call a specialist

(720) 445-6249

Talk to a tech or text a photo of your part tag — we'll confirm fitment before you buy

Brand	PAI Industries
Part Category	Seals & O-Rings
Engine Make	Cummins
Condition	New
Stage / Tier	Standard

O-RING

PAI Part #: 121321

OEM References:

CUMMINS 3679139
CUMMINS 3949781
MACK 4333-1837803C91
NAVISTAR 1837803
NAVISTAR 1837803C1

Warranty: 2.0 year(s)

This part supersedes and cross-references the following OEM, dealer, and competitor numbers. Searching any of these will land here.

Number
3679139
3949781
4333-1837803C91
1837803
1837803C1

Don't see your number? We cross 1M+ OEM, dealer and competitor part numbers daily. Call or text (720) 445-6249 and a tech will match it by hand.

Cummins

Warranty Backed. Every part is covered against defects in materials and workmanship. Call a specialist for the coverage details on this part.

Complete The Job