Input on OEM LCA part numbers

Cscribble · 11-18-2023, 06:06 PM

The last couple of days I was digging through part numbers for the LCAs on the GD chassis and I found most of my info seems legit, I can't seem to figure out what the LCAs where made of and if there where any variances between them. I'm about 90% sure all the numbers are specifically USDM numbers but maybe some of them are also JDM numbers and/or shared.

I know there are at least two style aluminum LCAs, the straight one that doesn't add caster and the slightly curved one that does add caster, but there are a few others as well. Reading through some older posts on a couple different forums there are also the Type-C, SPT, and maybe another that I can't think of off-hand.

If you've got any information to add to this comment below. I know there's a lot of misinformation around about the LCAs so I'd hope to not spread more so it'd be great to link to a legit source but if not I'll add a notes column to the file. I went straight to the SoA website and went to the OEM parts section to check the models and superseded numbers. I'm mainly looking for whether it effects caster and what material its made of but if there's other information that's relevant or interesting that'd be cool too.

Also, does anyone know why some of these have small tabs coming off the arm of the front bushing? It seems like just right side has this small tab with two holes in it but not all versions of the right.

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Cscribble · 11-18-2023, 06:24 PM

FYI, OpposedForces is down.

cueball89 · 11-18-2023, 08:14 PM

https://forums.nasioc.com/forums/sho...&postcount=245
I look for the shape of the endlink mounting tab. The increased caster and flipped hurricane bushing makes a pretty nice difference.

IIRC there was a sensor that mounted to the front control arm on some cars. Can't remember what sensor it was...

Cscribble · 11-18-2023, 10:39 PM

Quote:

Originally Posted by cueball89

https://forums.nasioc.com/forums/sho...&postcount=245
I look for the shape of the endlink mounting tab. The increased caster and flipped hurricane bushing makes a pretty nice difference.

IIRC there was a sensor that mounted to the front control arm on some cars. Can't remember what sensor it was...

That post you linked was one I read through last night.

I don't have the LCAs in hand or pictures so I can't identify them by sight. The images from SoAs parts site are just drawings.

A sensor? interesting. I was thinking something to direct air towards the disc up until I realized the tab was only on one arm and not the other side. I still can't imagine a sensor that would only fit on one side though.

REX_WGN · 11-20-2023, 02:30 PM

What cueball89 posted is essentially the two main differences to the GD years aluminum arms. It's generally known as "caster-adding" with the bend on the front side and non-caster adding with the other. However, they are both add more positive caster; just so happens one adds more than the other. I believe it's fastwrx.com or one of the other OG parts websites (still active) that points this out. I'll keep the general consensus terminology below.

The other major difference between the aluminum arms are the rear bushings. 04-07 STI have the "coveted" bushing. All other aluminum arms offered or on any GD model have a different rear bushing - smaller crush tube, hence more rubber. They also have different rubber and metal sandwich washers - the ones that go in front and behind the rear bushings. I'll call these STI rear bushing and non-STI rear bushing below, respectively.

SPT aluminum arms are the non-caster adding body with non-STI rear bushing. There's part numbers for them in one of the old STI PDF catalogs.

06 WRX sedan arms are the same as the SPT aluminum arms.

04-06 STI arms are the caster adding body with STI rear bushing. These are the best arms to get if you want a pure oem setup.

07 STI arms are the non-caster adding body with STI rear bushing. Why Subaru decided to switch the final year GD STI back to the non-caster adding body is unknown.

There are width differences between GG (wagon) and GD (sedan). Perhaps that's why you are seeing so many part numbers.

As far as I know, all other GG/GD arms are steel with rear bushings that are the same in physical design as the non-STI rear bushing (including sandwiching hardware) EXCEPT they are liquid-filled.

Two more last points I want to make as it's somewhat important (semi- GD related):

GC Aluminum arms were also offered or came on certain GC models. Since GG models are the same track width as GC, these arms were used to upgrade for GG owners (I'm one of them) that wanted to maintain track width. Just have to change the front bushing to the longer GD front bushing. The rear bushing design is similar to the non-STI bushing but has the odd voids in them. If you google STI (Group N) transverse bushing, you'll see the design I'm talking about.

JDM Forester STIs had non-caster adding body with non-STI bushing pressed in Forester housings (angled version).

Sorry - I do not have a part numbers list but it's looking like you're tackling that amazingly for our 20-year old chassis during these times.

I made a thread about Forester housings and ALKs. It's floating somewhere.

Cscribble · 11-20-2023, 03:43 PM

Quote:

Originally Posted by cueball89

IIRC there was a sensor that mounted to the front control arm on some cars. Can't remember what sensor it was...

That tab is apparently for the light adjustment sensor on Xenon facelifted cars with adjustable headlights. I only found one article that mentioned this though.

Quote:

Originally Posted by REX_WGN

SPT aluminum arms are the non-caster adding body with non-STI rear bushing. There's part numbers for them in one of the old STI PDF catalogs.

06 WRX sedan arms are the same as the SPT aluminum arms.

04-06 STI arms are the caster adding body with STI rear bushing. These are the best arms to get if you want a pure oem setup.

07 STI arms are the non-caster adding body with STI rear bushing. Why Subaru decided to switch the final year GD STI back to the non-caster adding body is unknown.

There are width differences between GG (wagon) and GD (sedan). Perhaps that's why you are seeing so many part numbers.

As far as I know, all other GG/GD arms are steel with rear bushings that are the same in physical design as the non-STI rear bushing (including sandwiching hardware) EXCEPT they are liquid-filled.

Two more last points I want to make as it's somewhat important (semi- GD related):

GC Aluminum arms were also offered or came on certain GC models. Since GG models are the same track width as GC, these arms were used to upgrade for GG owners (I'm one of them) that wanted to maintain track width. Just have to change the front bushing to the longer GD front bushing. The rear bushing design is similar to the non-STI bushing but has the odd voids in them. If you google STI (Group N) transverse bushing, you'll see the design I'm talking about.

JDM Forester STIs had non-caster adding body with non-STI bushing pressed in Forester housings (angled version).

Sorry - I do not have a part numbers list but it's looking like you're tackling that amazingly for our 20-year old chassis during these times.

I made a thread about Forester housings and ALKs. It's floating somewhere.

I didn't have any luck looking for the old SPT catalog. It does seem from the info I've gathered that the parts listed in the pic I posted would be 11, 12, 24, and 25 would be the SPT arms. SPT parts specifically would have their own part numbers but the models would line up with info I've seen in a few different posts.

I'm not extremely concerned about the rear bushing because I personally have the Whiteline ALK but it does help to explain why there are so many different part numbers since they list the LCA with all the bushings.

Cscribble · 11-20-2023, 03:53 PM

Immediately before I hit post I had a realization about why there's so many differnt part numbers for the right and so few of the left.... Some of the right side LCAs had the extra tabs for the headlight adjustement sensor and some didn't. The fact there where so many on the right has seemed extremely odd to me for years, now I know why lol

I might go through my list and note which ones have the tab and which ones don't but to do that I'll have to look at the style of headlight on that perticular model. It's not important to me but I may do so just out of curiousity.

Cscribble · 11-20-2023, 03:53 PM

Immediately before I hit post I had a realization about why there's so many differnt part numbers for the right and so few of the left.... Some of the right side LCAs had the extra tabs for the headlight adjustement sensor and some didn't. The fact there where so many on the right has seemed extremely odd to me for years, now I know why lol

I might go through my list and note which ones have the tab and which ones don't but to do that I'll have to look at the style of headlight on that perticular model. It's not important to me but I may do so just out of curiousity.

REX_WGN · 11-20-2023, 04:44 PM

Quote:

Originally Posted by Cscribble

I'm not extremely concerned about the rear bushing because I personally have the Whiteline ALK but it does help to explain why there are so many different part numbers since they list the LCA with all the bushings.

Then hopefully you are using the correct washer if you have aluminum arms. If you have steel arms, then you're good to go.

Take a look at point #3 of my thread here.

Cscribble · 11-20-2023, 05:09 PM

Well aware of the washer situation but thanks for the point about it.

11-18-2023, 06:06 PM	#1
Cscribble Scooby Newbie Member#: 454595 Join Date: Sep 2016 Chapter/Region: MWSOC Location: Neosho, MO Vehicle: 2002 WRX Silver	Input on OEM LCA part numbers The last couple of days I was digging through part numbers for the LCAs on the GD chassis and I found most of my info seems legit, I can't seem to figure out what the LCAs where made of and if there where any variances between them. I'm about 90% sure all the numbers are specifically USDM numbers but maybe some of them are also JDM numbers and/or shared. I know there are at least two style aluminum LCAs, the straight one that doesn't add caster and the slightly curved one that does add caster, but there are a few others as well. Reading through some older posts on a couple different forums there are also the Type-C, SPT, and maybe another that I can't think of off-hand. If you've got any information to add to this comment below. I know there's a lot of misinformation around about the LCAs so I'd hope to not spread more so it'd be great to link to a legit source but if not I'll add a notes column to the file. I went straight to the SoA website and went to the OEM parts section to check the models and superseded numbers. I'm mainly looking for whether it effects caster and what material its made of but if there's other information that's relevant or interesting that'd be cool too. Also, does anyone know why some of these have small tabs coming off the arm of the front bushing? It seems like just right side has this small tab with two holes in it but not all versions of the right. * Registered users of the site do not see these ads.

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11-18-2023, 06:24 PM	#2
Cscribble Scooby Newbie Member#: 454595 Join Date: Sep 2016 Chapter/Region: MWSOC Location: Neosho, MO Vehicle: 2002 WRX Silver	FYI, OpposedForces is down.

11-18-2023, 08:14 PM	#3
cueball89 Scooby Specialist Member#: 90513 Join Date: Jul 2005 Chapter/Region: Tri-State Location: NY	https://forums.nasioc.com/forums/sho...&postcount=245 I look for the shape of the endlink mounting tab. The increased caster and flipped hurricane bushing makes a pretty nice difference. IIRC there was a sensor that mounted to the front control arm on some cars. Can't remember what sensor it was...

11-20-2023, 02:30 PM	#5
REX_WGN Scooby Guru Member#: 107618 Join Date: Feb 2006 Chapter/Region: Tri-State Location: NY Vehicle: 06 GG WRX / 09 FXT @florencedestinedfxt	What cueball89 posted is essentially the two main differences to the GD years aluminum arms. It's generally known as "caster-adding" with the bend on the front side and non-caster adding with the other. However, they are both add more positive caster; just so happens one adds more than the other. I believe it's fastwrx.com or one of the other OG parts websites (still active) that points this out. I'll keep the general consensus terminology below. The other major difference between the aluminum arms are the rear bushings. 04-07 STI have the "coveted" bushing. All other aluminum arms offered or on any GD model have a different rear bushing - smaller crush tube, hence more rubber. They also have different rubber and metal sandwich washers - the ones that go in front and behind the rear bushings. I'll call these STI rear bushing and non-STI rear bushing below, respectively. SPT aluminum arms are the non-caster adding body with non-STI rear bushing. There's part numbers for them in one of the old STI PDF catalogs. 06 WRX sedan arms are the same as the SPT aluminum arms. 04-06 STI arms are the caster adding body with STI rear bushing. These are the best arms to get if you want a pure oem setup. 07 STI arms are the non-caster adding body with STI rear bushing. Why Subaru decided to switch the final year GD STI back to the non-caster adding body is unknown. There are width differences between GG (wagon) and GD (sedan). Perhaps that's why you are seeing so many part numbers. As far as I know, all other GG/GD arms are steel with rear bushings that are the same in physical design as the non-STI rear bushing (including sandwiching hardware) EXCEPT they are liquid-filled. Two more last points I want to make as it's somewhat important (semi- GD related): GC Aluminum arms were also offered or came on certain GC models. Since GG models are the same track width as GC, these arms were used to upgrade for GG owners (I'm one of them) that wanted to maintain track width. Just have to change the front bushing to the longer GD front bushing. The rear bushing design is similar to the non-STI bushing but has the odd voids in them. If you google STI (Group N) transverse bushing, you'll see the design I'm talking about. JDM Forester STIs had non-caster adding body with non-STI bushing pressed in Forester housings (angled version). Sorry - I do not have a part numbers list but it's looking like you're tackling that amazingly for our 20-year old chassis during these times. I made a thread about Forester housings and ALKs. It's floating somewhere.

11-20-2023, 03:53 PM	#7
Cscribble Scooby Newbie Member#: 454595 Join Date: Sep 2016 Chapter/Region: MWSOC Location: Neosho, MO Vehicle: 2002 WRX Silver	Immediately before I hit post I had a realization about why there's so many differnt part numbers for the right and so few of the left.... Some of the right side LCAs had the extra tabs for the headlight adjustement sensor and some didn't. The fact there where so many on the right has seemed extremely odd to me for years, now I know why lol I might go through my list and note which ones have the tab and which ones don't but to do that I'll have to look at the style of headlight on that perticular model. It's not important to me but I may do so just out of curiousity.

11-20-2023, 05:09 PM	#10
Cscribble Scooby Newbie Member#: 454595 Join Date: Sep 2016 Chapter/Region: MWSOC Location: Neosho, MO Vehicle: 2002 WRX Silver	Well aware of the washer situation but thanks for the point about it.