Underdog Posted February 20, 2009 Share Posted February 20, 2009 Was reviewing some pics of my last suspension install (swaybars)... and I noticed something I hadn't seen before. Here is the stock Legacy GT steel trailing arm, notice the 4-bolt pattern for mounting the hub? http://legacygt.com/forums/attachment.php?attachmentid=54221&d=1214065760 Now here is the inside of the Spec.B arm on my car. Notice that there are 4 bolts securing the hub, but notice the extra hole? http://img502.imageshack.us/img502/9793/img3249aj0.jpg I wonder if the spec.b hub unit has 5 tapped holes... Unclemat, perhaps you could shed some light on this? I could understand if the hubs change for the 6-speed since the rear diff and axles must be different, but what do the '06 spec.b's have, since they had the same rear diff/axles as I do, with these aluminum arms? The weird part is there is an extra boss for the 5th clearance hole on the steel arm, just with no hole drilled. You can see it in the first pic. I just want to make sure the arms don't fail prematurely because I'm concentrating stress on 4 bolt holes instead of 5. The Crimson Dynamo Link to comment Share on other sites More sharing options...
Guest Posted February 20, 2009 Share Posted February 20, 2009 No worries. I verified that and the part # for the hub is same regardless of trailing arms type. The extra hole is not used. There is other thing that worries me though. You said dealer ship used some hardware store bolts on the hub. They are probably not of required class. From the pic it appears they are 8.8 class. I pretty sure the stock bolts there are 10.9 class. You should replace them with correct bolts. Also it would be a very good idea to put anti-seize on them because steel corrodes in aluminum easily (metal "conflict") and the threads may strip if you remove them later. (btw, I have a spare set of these bolts if you're interested). Link to comment Share on other sites More sharing options...
Bolksey85 Posted February 20, 2009 Share Posted February 20, 2009 Is the hardware any different between the two? Link to comment Share on other sites More sharing options...
Underdog Posted February 20, 2009 Author Share Posted February 20, 2009 Whew... I was starting to freak myself out. Thanks for the info Unclemat. I am interested in the bolts, Let me check the rating when I install my RCE Tarmacs next week. I remember the tech saying he had to send his guy all over the place looking for the right ones, because I had raised the issue with him. When I zoom in on the pic, it looks like it could be 10.9... definitely will check though. Bolksey: Yes the flange of the trailing arm is thicker on the aluminum version, so longer bolts are needed. The Crimson Dynamo Link to comment Share on other sites More sharing options...
Underdog Posted February 20, 2009 Author Share Posted February 20, 2009 Okay... couldn't stand the thought of not knowing what was on there so I went out and crawled under the snow-covered car. Unclemat you were right, they are 8.8 bolts. If you want to get rid of your set, let me know. Otherwise I will just buy some through McMaster-Carr. Do you remember the specs on them? For some reason I recall M12x1.75, but I forget what length I need. Also, did you use flanged bolts, or just stick a washer under the head? The Crimson Dynamo Link to comment Share on other sites More sharing options...
Guest Posted February 20, 2009 Share Posted February 20, 2009 Don't f**k around with random bolts. Buy OEM ones. Flanged. I'll pm you once I check price. Mine are used and came with my trailing arms but I forgot about that and bought new ones. Only to discover the used ones afterwards. Link to comment Share on other sites More sharing options...
Underdog Posted February 20, 2009 Author Share Posted February 20, 2009 Oh, didn't see your edit and sent a PM. Not sure if these are the right ones but: http://www.mcmaster.com/#98093a761/=onylb When I compare to the 8.8 version the difference in tensile strength is 150,000PSI for 10.9 and 116,000PSI for 8.8. Plus I want to anti-seize the hell out of everything again. Have to pull my whiteline ball joints to replace them with the new revision. I hope this time it goes a little better! The Crimson Dynamo Link to comment Share on other sites More sharing options...
Bolksey85 Posted February 20, 2009 Share Posted February 20, 2009 Note to self: Buy LGTB specific hardware if I ever do this. Link to comment Share on other sites More sharing options...
Guest LGT-NY Posted February 20, 2009 Share Posted February 20, 2009 UD, you have anymore undercar pics of your susp? The photo above is the rear correct? What lateral links are those? Link to comment Share on other sites More sharing options...
Underdog Posted February 20, 2009 Author Share Posted February 20, 2009 I will try to dig some up and post them in my home thread (link to first post in my sig). 4BoxParts Adjustable Lateral Links. The Crimson Dynamo Link to comment Share on other sites More sharing options...
Guest Posted February 20, 2009 Share Posted February 20, 2009 Oh, didn't see your edit and sent a PM. Not sure if these are the right ones but: http://www.mcmaster.com/#98093a761/=onylb When I compare to the 8.8 version the difference in tensile strength is 150,000PSI for 10.9 and 116,000PSI for 8.8. Plus I want to anti-seize the hell out of everything again. Have to pull my whiteline ball joints to replace them with the new revision. I hope this time it goes a little better! I am not positive that stock bolts are 10.9. 10.9 is sometimes worse than 8.8 depending on application. In a critical application like this I'd stick to whatever Subaru engineers meant there to be. Link to comment Share on other sites More sharing options...
Underdog Posted February 20, 2009 Author Share Posted February 20, 2009 Gotcha, I'm instant messaging with Jeremy @ FredBeans now... The Crimson Dynamo Link to comment Share on other sites More sharing options...
Underdog Posted February 20, 2009 Author Share Posted February 20, 2009 Okay... According to Jeremy there is a different P/N between the stock GT and spec.B bolts. The spec.B bolts are #901000285, $1.17 ea, qty.8 required. Now I just need to know if they are grade 8.8 or 10.9, he couldn't check because it's special order. Unclemat, could you (or anyone with spec.b trailing arms) check that for me? No sense in replacing the bolts I have if they are the same spec... The Crimson Dynamo Link to comment Share on other sites More sharing options...
Guest Posted February 20, 2009 Share Posted February 20, 2009 You can't check because OEM bolts have some funny numbers that I don't know if they correspond to class, probably not because I've seen 7, 8, 10, 11. Anyway I think they have "11" stamped on the heads. Link to comment Share on other sites More sharing options...
Underdog Posted February 20, 2009 Author Share Posted February 20, 2009 Gah... I'm not sure what to do... I guess for $10 plus labor time I should just do it. Think if I just pull one at a time I can replace it without undoing the axle lock nut? I wonder if I even have room around the CV boot to get a socket... The Crimson Dynamo Link to comment Share on other sites More sharing options...
Guest Posted February 20, 2009 Share Posted February 20, 2009 Yes, if you do one at the time you'll be fine. There should be room for socket & extension. Link to comment Share on other sites More sharing options...
PeterJMC Posted February 20, 2009 Share Posted February 20, 2009 Did you notice any difference when going from the regular trailing arm to the aluminum spec B one? Link to comment Share on other sites More sharing options...
Guest Posted February 20, 2009 Share Posted February 20, 2009 Might be in my head but yes I do think the suspension is reacting bit faster. I'd say trailing arms swap makes more sense than LCA swap - the difference in unsprung weight removed is fairly significant. Link to comment Share on other sites More sharing options...
Underdog Posted February 20, 2009 Author Share Posted February 20, 2009 Tough to say... probably more placebo than anything. Between the upper lateral link and trailing arm, you cut about 7lbs from the suspension per side. The pieces are beefier and stiffer (by reasoning, not measurement) which probably helps somewhat, but for a daily-driven car this is moot. I'd say this is probably the worst modifications you can do in terms of bang-for-the-buck. However, you do save some additional weight by removing all the dollars from your back pocket! I paid ~$1,250 for all the spec.B aluminum components. LINK edit: Unclemat beat me to the punch... +1 to what he said. The Crimson Dynamo Link to comment Share on other sites More sharing options...
Long Island Legacy Posted February 20, 2009 Share Posted February 20, 2009 Tough to say... probably more placebo than anything. Between the upper lateral link and trailing arm, you cut about 7lbs from the suspension per side. The pieces are beefier and stiffer (by reasoning, not measurement) which probably helps somewhat, but for a daily-driven car this is moot. I'd say this is probably the worst modifications you can do in terms of bang-for-the-buck. However, you do save some additional weight by removing all the dollars from your back pocket! I paid ~$1,250 for all the spec.B aluminum components. LINK edit: Unclemat beat me to the punch... +1 to what he said. Everyone loves to see nice shinny bits instead of cast parts under the car too. Do you have a side by side comparison of the arms? Link to comment Share on other sites More sharing options...
Underdog Posted February 20, 2009 Author Share Posted February 20, 2009 Nothing side-by-side since I didn't do the arm installs, unfortunately. Some other pics here... I will take more when I put in the Tarmacs soon. The Crimson Dynamo Link to comment Share on other sites More sharing options...
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