How should the Piston Ring Set and pistons be laid out for matching during the side clearance check, end gap measurement, and engine assembly on a Subaru Forester?

Lay out the pistons and new ring sets to match each ring set with the corresponding piston and cylinder during the side clearance check, end gap measurement, and engine assembly. Before installing the rings, check the piston ring side clearance by placing a new ring in each groove and using a feeler gauge beside it, ensuring to check at several points around the piston and using the correct ring for each groove, as they differ. A typical clearance for compression rings is around 0.0015 to 0.004 inch (0.038 mm to 0.101 mm), and if excessive, new pistons will be necessary. The ring end gaps must also be verified, assuming the side clearance has been confirmed. Insert the top ring into the first cylinder, squaring it with the cylinder walls using the piston, and position it near the bottom of the cylinder. To measure the end gap, use feeler gauges between the ring ends until the correct gauge slides in with slight drag; typical gaps range from 0.010 to 0.020 inch (0.25 to 0.50 mm) for compression rings and up to 0.030 inch (0.76 mm) for oil ring steel rails. If the gap is too small, carefully file the ring ends to avoid contact during operation, ensuring to file only by pushing the ring from the outside end of the file towards the vise. Excess end gap is not critical unless it exceeds 0.040 inch (1.01 mm), and it's important to double-check the ring type. Repeat this process for each ring in the first cylinder and the remaining cylinders, keeping rings, pistons, and cylinders matched. Once the end gaps are checked and corrected, install the rings on the pistons, starting with the oil control ring, which consists of three components: first, insert the spacer/expander into the groove, then install the upper side rail without using a piston ring installation tool to avoid damage, and finally, install the lower side rail, ensuring the upper rail spin stopper aligns with the side hole in the piston. After installing the oil ring components, verify that both side rails rotate smoothly in their grooves. Next, install the middle ring, ensuring the identification mark faces up, and use a piston ring installation tool for both the middle and top rings, being careful not to confuse them. Finally, repeat the procedure for the remaining pistons and rings.

Genuine Subaru Forester Piston Ring Set

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33 Piston Ring Sets found

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Subaru Forester Piston Ring Set
Part Number: 12033AC330
$146.82 MSRP: $214.65
You Save: $67.83 (32%)
ADD TO CART
Product Specifications
- Manufacturer Note: STD
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2014-2018 Subaru Forester | 2.0XT Premium, 2.0XT Touring | 2.0L H4
View related parts
Subaru Forester Piston Ring Set
Part Number: 12033AB340
$161.57 MSRP: $236.22
You Save: $74.65 (32%)
Ships in 1-3 Business Days
ADD TO CART
Product Specifications
- Manufacturer Note: STD
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2004-2013 Subaru Forester | Forester Sports, L.L.Bean, X, X Limited, XS, XT, XT Limited | 2.5L H4, 2.5L H4 DOHC Turbo, 2.5L H4 SOHC, 2.5L H4 Turbo
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Subaru Forester Piston Ring Set
Part Number: 12033AC350
$146.82 MSRP: $214.65
You Save: $67.83 (32%)
Ships in 1-3 Business Days
ADD TO CART
Product Specifications
- Manufacturer Note: OS 0.50
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2014-2018 Subaru Forester | 2.0XT Premium, 2.0XT Touring | 2.0L H4
View related parts
Subaru Forester Piston Ring Set
Part Number: 12033AB360
$161.57 MSRP: $236.22
You Save: $74.65 (32%)
Ships in 1-3 Business Days
ADD TO CART
Product Specifications
- Manufacturer Note: OS 0.50
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2004-2013 Subaru Forester | Forester Sports, L.L.Bean, X, X Limited, XS, XT, XT Limited | 2.5L H4, 2.5L H4 DOHC Turbo, 2.5L H4 SOHC, 2.5L H4 Turbo
View related parts
Subaru Forester Piston Ring Set
Part Number: 12033AC250
$141.26 MSRP: $206.52
You Save: $65.26 (32%)
Ships in 1-3 Business Days
ADD TO CART
Product Specifications
- Manufacturer Note: OS 0.25
- Replaced by: 12033AC940
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2011-2014 Subaru Forester | 2.5i, 2.5i Limited, 2.5i Premium, 2.5i Touring, X, X Limited, X Premium | 2.5L H4, 2.5L H4 DOHC
View related parts
Subaru Forester Piston Ring Set
Part Number: 12033AC240
$146.54 MSRP: $214.23
You Save: $67.69 (32%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Manufacturer Note: STD
- Replaced by: 12033AC930
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2011-2014 Subaru Forester | 2.5i, 2.5i Limited, 2.5i Premium, 2.5i Touring, X, X Limited, X Premium | 2.5L H4, 2.5L H4 DOHC
View related parts
Subaru Forester Piston Ring Set
Part Number: 12033AC340
$146.82 MSRP: $214.65
You Save: $67.83 (32%)
ADD TO CART
Product Specifications
- Manufacturer Note: OS 0.25
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2014-2018 Subaru Forester | 2.0XT Premium, 2.0XT Touring | 2.0L H4
View related parts
Subaru Forester Piston Ring Set
Part Number: 12033AD230
$146.50 MSRP: $214.18
You Save: $67.68 (32%)
Ships in 1-3 Business Days
ADD TO CART
Product Specifications
- Manufacturer Note: STD
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2017-2018 Subaru Forester | 2.5i, 2.5i Limited, 2.5i Premium, 2.5i Touring | 2.5L H4
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Subaru Forester Piston Ring Set
Part Number: 12033AD410
$135.57 MSRP: $196.48
You Save: $60.91 (31%)
Ships in 1-3 Business Days
ADD TO CART
Product Specifications
- Other Name: Ring Set-Piston
- Manufacturer Note: STD
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2019-2021 Subaru Forester | Base, Limited, Premium, Sport, Touring
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Subaru Forester Piston Ring Set Std
Part Number: 12033AA760
$178.10 MSRP: $260.38
You Save: $82.28 (32%)
Ships in 1-3 Business Days
ADD TO CART
Product Specifications
- Other Name: Piston Ring Set
- Manufacturer Note: STD
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 1998 Subaru Forester | Base, L, S | 2.5L H4 DOHC, 2.5L H4 DOHC (New EVAPO)
View related parts
Subaru Forester Piston Ring Set
Part Number: 12033AC930
$146.54 MSRP: $214.23
You Save: $67.69 (32%)
ADD TO CART
Product Specifications
- Manufacturer Note: STD
- Replaces: 12033AC240, 12033AC390
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2011-2016 Subaru Forester | 2.5i, 2.5i Limited, 2.5i Premium, 2.5i Touring, X, X Limited, X Premium | 2.5L H4, 2.5L H4 DOHC
View related parts
Subaru Forester Piston Ring Set
Part Number: 12033AD710
$128.08 MSRP: $185.62
You Save: $57.54 (31%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: RING SET-PISTON
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2025 Subaru Forester | 4 Cyl 2.5L, 4 Cyl 2.5L Hybrid
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Subaru Forester Piston Ring Set
Part Number: 12033AD700
$128.08 MSRP: $185.62
You Save: $57.54 (31%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: RING SET-PISTON
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2025 Subaru Forester | 4 Cyl 2.5L, 4 Cyl 2.5L Hybrid
View related parts
Subaru Forester Piston Ring Set
Part Number: 12033AD690
$128.08 MSRP: $185.62
You Save: $57.54 (31%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: RING SET-PISTON
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2025 Subaru Forester | 4 Cyl 2.5L, 4 Cyl 2.5L Hybrid
View related parts
Subaru Forester Piston Ring Set
Part Number: 12033AD430
$135.57 MSRP: $196.48
You Save: $60.91 (31%)
Ships in 1-3 Business Days
ADD TO CART
Product Specifications
- Other Name: Ring Set-Piston
- Manufacturer Note: OS 0.50
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2019-2021 Subaru Forester | Base, Limited, Premium, Sport, Touring
View related parts
Subaru Forester Piston Ring Set
Part Number: 12033AD420
$135.57 MSRP: $196.48
You Save: $60.91 (31%)
Ships in 1-3 Business Days
ADD TO CART
Product Specifications
- Other Name: Ring Set-Piston
- Manufacturer Note: OS 0.25
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2019-2021 Subaru Forester | Base, Limited, Premium, Sport, Touring
View related parts
Subaru Forester Piston Ring Set
Part Number: 12033AD250
$146.50 MSRP: $214.18
You Save: $67.68 (32%)
Ships in 1-3 Business Days
ADD TO CART
Product Specifications
- Manufacturer Note: OS 0.50
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2017-2018 Subaru Forester | 2.5i, 2.5i Limited, 2.5i Premium, 2.5i Touring | 2.5L H4
View related parts
Subaru Forester Piston Ring Set
Part Number: 12033AD240
$146.50 MSRP: $214.18
You Save: $67.68 (32%)
Ships in 1-3 Business Days
ADD TO CART
Product Specifications
- Manufacturer Note: OS 0.25
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2017-2018 Subaru Forester | 2.5i, 2.5i Limited, 2.5i Premium, 2.5i Touring | 2.5L H4
View related parts
Subaru Forester PB000811 Ring Set
Part Number: 12033AB010
$183.81 MSRP: $268.73
You Save: $84.92 (32%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: Piston Ring Set
- Manufacturer Note: STD
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 1999-2002 Subaru Forester | Base, L, S | 2.5L H4 SOHC
View related parts
Subaru Forester Piston Ring Set
Part Number: 12033AC940
$141.26 MSRP: $206.52
You Save: $65.26 (32%)
Ships in 1-3 Business Days
ADD TO CART
Product Specifications
- Manufacturer Note: OS 0.25
- Replaces: 12033AC250
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2011-2016 Subaru Forester | 2.5i, 2.5i Limited, 2.5i Premium, 2.5i Touring, X, X Limited, X Premium | 2.5L H4, 2.5L H4 DOHC

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1-20 of 33 Results

Subaru Forester Piston Ring Set

Subaru Forester Piston Ring Set maintains cylinder pressure in a tight seal. Every spark is transformed into confident forward action. The Piston Ring Set, known among Subaru loyalists for its durability, has a triple barrier in each boxer cylinder that traps combustion gases, sweeps stray oil, and directs heat into the block where it can cool the pistons. The outcome is a Forester engine that revs easily both in city streets and mountain trails and has earned a balance of efficiency and safety awards that have helped the Forester win top SUV honors. Since it integrates with factory specifications from the first generation up to the present, this Piston Ring Set fits into various Forester trims, whether a base model from the late nineties or a modern turbo XT, allowing Subaru owners to achieve consistent compression with reduced oil consumption without a complex adjustment process. The ductile iron tops, which are high-strength and have plasma-moly faces, withstand intense temperatures generated by Subaru turbo power. The narrow 1 mm and 2 mm profiles reduce friction to achieve faster throttle response and fuel economy. Each ring of the Piston Ring Set is installed on a break-in, with less downtime and more assured everyday driving. Exact control of oil also lowers blow-by, making catalytic converters cleaner and avoiding subjecting passengers to noxious fumes, which directly increases overall vehicle safety. This small yet crucial Piston Ring Set, together with the all-wheel-drive grip that Subaru is known for, makes the crossover even more reputable in terms of lasting performance. Selecting a genuine Piston Ring Set during the overhaul process is a prudent precaution. True Subaru metallurgy perfectly matches the Forester block, and the Piston Ring Set has been vindicated over the miles. Drivers who invest in this engineered match experience quieter starts, more consistent idle, and long-term peace of mind knowing their Forester powertrain will be sealed and strong.

Our website stands as the go-to online destination for OEM Subaru Forester Piston Ring Set. With complete lines of genuine Subaru Forester Piston Ring Set available at unbeatable market prices, we ensure top quality, reliability, and durability. Each part comes backed by the manufacturer's warranty, reinforcing your trust in our offerings.

Subaru Forester Piston Ring Set Parts Questions & Experts Answers

Piston Ring Set
12033AB340
Q: How should the Piston Ring Set and pistons be laid out for matching during the side clearance check, end gap measurement, and engine assembly on a Subaru Forester?
A:
Lay out the Pistons and new ring sets to match each ring set with the corresponding piston and cylinder during the side clearance check, end gap measurement, and engine assembly. Before installing the rings, check the piston ring side clearance by placing a new ring in each groove and using a feeler gauge beside it, ensuring to check at several points around the piston and using the correct ring for each groove, as they differ. A typical clearance for compression rings is around 0.0015 to 0.004 inch (0.038 mm to 0.101 mm), and if excessive, new pistons will be necessary. The ring end gaps must also be verified, assuming the side clearance has been confirmed. Insert the top ring into the first cylinder, squaring it with the cylinder walls using the piston, and position it near the bottom of the cylinder. To measure the end gap, use feeler gauges between the ring ends until the correct gauge slides in with slight drag; typical gaps range from 0.010 to 0.020 inch (0.25 to 0.50 mm) for compression rings and up to 0.030 inch (0.76 mm) for oil ring steel rails. If the gap is too small, carefully file the ring ends to avoid contact during operation, ensuring to file only by pushing the ring from the outside end of the file towards the vise. Excess end gap is not critical unless it exceeds 0.040 inch (1.01 mm), and it's important to double-check the ring type. Repeat this process for each ring in the first cylinder and the remaining cylinders, keeping rings, pistons, and cylinders matched. Once the end gaps are checked and corrected, install the rings on the pistons, starting with the oil control ring, which consists of three components: first, insert the spacer/expander into the groove, then install the upper side rail without using a piston ring installation tool to avoid damage, and finally, install the lower side rail, ensuring the upper rail spin stopper aligns with the side hole in the piston. After installing the oil ring components, verify that both side rails rotate smoothly in their grooves. Next, install the middle ring, ensuring the identification mark faces up, and use a piston ring installation tool for both the middle and top rings, being careful not to confuse them. Finally, repeat the procedure for the remaining pistons and rings.