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Caterpillar 177-9953 is the 24 V brushless alternator with a threaded drive shaft (pulley not included), heavy duty frame. It is used on Caterpillar 320C, 320D and 325C excavators and 950H wheel loaders. This aftermarket version has the same mounting and electrical connector as the original, so it plugs in and bolts on where the old one came off.
Sold as one unit. Check the number on your old part, or in the parts manual for your machine, before ordering.
| Part Type | Alternator |
| Replaces | Caterpillar 177-9953 |
| Type | Brushless alternator, shaft drive (no pulley) |
| Voltage | 24 V |
| Fits | Caterpillar 320C; Caterpillar 320D; Caterpillar 325C; Caterpillar 950H |
| Condition | New, aftermarket |
| Stat. HS-Code | 851150 |
Caterpillar machines
Check the part number on your old unit before ordering.
| Caterpillar Part No.(SPM Part No.) | Fits |
|---|---|
| 177-9953(SPM-HEP-3121) | Caterpillar 320C, Caterpillar 320D, Caterpillar 325C, Caterpillar 950H |
Battery not charging
A charge warning light or flat batteries every morning point to the alternator once the belt and wiring check out.
Noise
A worn bearing whines or grinds.
Low voltage at idle
Weak output shows as dim lights and slow electrics at idle.
Fit with a new belt
Change the belt and check the tensioner when fitting the alternator.
We check what other aftermarket sellers charge for this same part. Their prices on the date we checked:
| Seller | Price | Checked |
|---|---|---|
| eBay (10 aftermarket sellers) | USD 246.16 to 352.77 | 7 Oct 2026 |
| SINOCMP | USD 399.00 | 7 Oct 2026 |
| Spare Part Mart | USD 196.93 | Today |
Our price of USD 196.93 is 20% to 51% less than these sellers.
Found this part cheaper somewhere else? Send us the listing and we will beat it by 5% under our Price Beat Guarantee. Every order is also covered by our 30 day money back guarantee.
No. It is an aftermarket part made to fit in place of Caterpillar 177-9953. It is not made by or affiliated with Caterpillar; the Caterpillar part number is used only to show what it replaces.
It fits Caterpillar 320C; Caterpillar 320D; Caterpillar 325C; Caterpillar 950H. Machines change parts between serial number ranges, so check the number on your old part or in your parts manual.
It has the same mounting and electrical connector as the original. Check the plug and terminals match your old part, and test it before putting the machine back to work.
Yes, we ship worldwide. Shipping is calculated at checkout, and every order is covered by our 30 day money back guarantee and price beat guarantee.
Prices depend on your postcode.
In USD for the quantity selected. The exact cost is confirmed at checkout.
