Skip to product information
SKU:
NLT2T00128
Ships for free in 2–4 business days.
Access Hole Cover 3903463 for Cummins 4B 6B 6C ISC Engines
$22.99
In Stock
$22.99
Sale price
$22.99
Regular price
This is a replacement gear-housing access hole cover for Cummins 4B, 6B, 6C and ISC-series engines. It replaces reference number 3903463 and closes the service opening in the engine gear housing.
Estimated delivery between
Let Northline Parts Do the Heavy Lifting for You!
Not sure which part you need? Our team can help you find the right replacement.
Parts Support Hours: Monday–Friday, 8:00 AM–5:00 PM CT
Live Chat: Available 24/7
I reached out for some replacement head bolts and they responded quickly with a few questions and cautionary information and is sending me some bolts. Great customer service! Thanks
Edward H. — Verified customer
Compatible Models
We do our best to list all compatible models. Although this may be the part you need, your exact model may not appear below.
Compatible equipment / model
| Application | Fitment Details |
|---|---|
| Primary application | Cummins 4B 6B 6C ISC Engines |
Product Overview
The engine access cover closes the gear-housing access opening to keep dirt and debris out while containing oil mist inside the engine housing. A missing, hardened or damaged cover can allow contamination into the housing or create seepage around the access opening. Replacing the failed component can restore normal operation without changing unrelated parts that are still serviceable.
Part 3903463 is a gear-housing/access-hole cover used on Cummins 4B, 6B, 6C and ISC-series engines. Matching listings also pair it with seal 3903475, so inspect the existing cover and seal before installation.
Key Features & Performance
- Closes the Cummins gear-housing access opening
- Matches reference number 3903463
- Inspect the mating seal and opening condition during installation
Part Numbers & Specifications
- Part Type: Engine Access Cover
- Reference / Part Numbers: 3903463
Before You Order
Match the original part number whenever one is available. Also compare voltage/connector style on electrical parts, hose/port layout on fuel and cooling parts, and the machine or engine serial/build information. If any of those details differ from your original component, verify fitment before installation.
Frequently Asked Questions
What should I match before ordering?
Start with the original part number, then compare the machine or engine model and the physical configuration shown in the listing.
When should this part be replaced?
A missing, hardened or damaged cover can allow contamination into the housing or create seepage around the access opening.
Is this a genuine OEM part?
This listing is for a replacement part. OEM and manufacturer reference numbers are provided to help identify fitment; they do not indicate that the product is manufactured by the original equipment manufacturer.