DS Loop / DS clearance issue (pics)
Thread Starter
Joined: Oct 2006
Posts: 2,608
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From: Webb City, MO...out in the garage
DS Loop / DS clearance issue (pics) yes i searched, and found no help...
i've got a tunnel-mount torque arm w/driveshaft loop, M6, and a Moser 9" rear. the issue i was having (back when the car ran) was everytime i'd stop moderately to hardly OR when i went over a dip/bump at speed (45+mph), there would be a sound almost like an old phone ringing. i determined it could only be my driveshaft hitting something, but wasn't 100% certain and i never really investigated after a couple brief peeks under the car showed nothing, i just modified my driving style to not allow this sound to happen.
well, time passed and i since forgot the problem...until yesterday. i was under the car (no tranny, motor, front end) unhooking stock fuel lines when i saw my DS loop. it had powdercoat missing on the front, top edge. i checked my DS and it had scarring about 3/4 of the way around the front of it just before the tranny yoke. here's a pic of the loop:
here it is from the back side looking forward:
what do i need to do to remedy this problem? i really don't see anywhere to make adjustments. the driveshaft was centered in the loop perfectly as i remember. the TA mount is bolted directly to the body, i.e. no shims to remove to raise it up, adding clearence. the car HAD stock springs/shocks, with all UMI rear suspension, but will now have QA1 coilovers up front and the rear might get some kind of lowering springs due to the 20" CCW's, unless i can trade them off for some 18's or 19's before i modify the suspension.
any ideas guys? this can't be the only car like this...
thanks,
ben
i've got a tunnel-mount torque arm w/driveshaft loop, M6, and a Moser 9" rear. the issue i was having (back when the car ran) was everytime i'd stop moderately to hardly OR when i went over a dip/bump at speed (45+mph), there would be a sound almost like an old phone ringing. i determined it could only be my driveshaft hitting something, but wasn't 100% certain and i never really investigated after a couple brief peeks under the car showed nothing, i just modified my driving style to not allow this sound to happen.
well, time passed and i since forgot the problem...until yesterday. i was under the car (no tranny, motor, front end) unhooking stock fuel lines when i saw my DS loop. it had powdercoat missing on the front, top edge. i checked my DS and it had scarring about 3/4 of the way around the front of it just before the tranny yoke. here's a pic of the loop:
here it is from the back side looking forward:
what do i need to do to remedy this problem? i really don't see anywhere to make adjustments. the driveshaft was centered in the loop perfectly as i remember. the TA mount is bolted directly to the body, i.e. no shims to remove to raise it up, adding clearence. the car HAD stock springs/shocks, with all UMI rear suspension, but will now have QA1 coilovers up front and the rear might get some kind of lowering springs due to the 20" CCW's, unless i can trade them off for some 18's or 19's before i modify the suspension.
any ideas guys? this can't be the only car like this...
thanks,
ben
I Dont Know What Might Be Causing It To Rub...you Could Always Heat The Mounting Bracket That The Loop Is Mounted To And Bend It Up Just A Hair Looks Like It Only Hit Mostly On The Front Underside..or Take The Mount Off And Squeeze It In A Vise Just Enough To Elongate It You Wont Have Any Side To Side Movement In Your Driveshaft, Well At Least We Hope Not...
Thread Starter
Joined: Oct 2006
Posts: 2,608
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From: Webb City, MO...out in the garage
well thats a pretty good suggestion, but i'm not the biggest fan of bending/cutting on aftermarket stuff that *should* work right to begin with.
i'm thinking something isn't right and i dunno what. i don't want my $400 PST driveshaft to get ruined when it goes in because of something simple. i'm sure someone else has encountered this before...
i'm thinking something isn't right and i dunno what. i don't want my $400 PST driveshaft to get ruined when it goes in because of something simple. i'm sure someone else has encountered this before...
On The Tree
Joined: Dec 2005
Posts: 151
Likes: 0
From: South Dakota
I installed that same torque arm and noticed some very close clearances as well. It's hard to tell when it was up in the air though as all of the suspension wasn't fully loaded correctly.
Technically stock parts "work" (given they aren't broke) but we change them for aftermarket anyway. I would say tweak the loop larger somehow and try to double check that you get a bit more clearance, besides, it gives you another reason to be in the garage.
Technically stock parts "work" (given they aren't broke) but we change them for aftermarket anyway. I would say tweak the loop larger somehow and try to double check that you get a bit more clearance, besides, it gives you another reason to be in the garage.
I'm guessing you are running a 3.5" drive shaft from PST? My suggestion is to swap the drive shaft out for a 3" Chrome Moly drive shaft. Your drive shaft is sitting centered in the loop like you mentioned but when you hit bumps is when the suspension is traveling and forcing it into the loop. Since the drive shaft is larger in diameter this is causing the rubbing issue. I run a 3.5" drive shaft as well with my Strange S60 and it is close, but changing to a 3" shaft should cure your issues.
Hope that helps,
Ryan
Hope that helps,
Ryan
Thread Starter
Joined: Oct 2006
Posts: 2,608
Likes: 0
From: Webb City, MO...out in the garage
I'm guessing you are running a 3.5" drive shaft from PST? My suggestion is to swap the drive shaft out for a 3" Chrome Moly drive shaft. Your drive shaft is sitting centered in the loop like you mentioned but when you hit bumps is when the suspension is traveling and forcing it into the loop. Since the drive shaft is larger in diameter this is causing the rubbing issue. I run a 3.5" drive shaft as well with my Strange S60 and it is close, but changing to a 3" shaft should cure your issues.
Hope that helps,
Ryan
Hope that helps,
Ryan
my problem seems to be up/down clearance issues. seems to me motor mounts would cause side-to-side issues, but i agree that bad mounts might cause something like this. mine are fine though.
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Verdad Gallardo Get what I'm saying? I've got an UMI tunnel mount and DD SFCs. And I only have 3/8" of clearance on the top and mine doesn't rub. You make alot of power in an M6 with a 9 inch. No doubt that you're putting some stress on that area, though you make no mention of the noise on hard shifts.
Thread Starter
Joined: Oct 2006
Posts: 2,608
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From: Webb City, MO...out in the garage
nope, no noise during shifts....and i'll be making a lot more power than my sig indicates in about 4 weeks. i do see what you're saying...and i know parts tend to not work together when they're all aftermarket, but i still think something isn't right.
i wish there was some way to add/remove shims, that would take care of this issue i believe, or an adj. DS loop.
i wish there was some way to add/remove shims, that would take care of this issue i believe, or an adj. DS loop.
well this issue is occuring with a STOCK driveshaft...that's why i wanna remedy it now, so i CAN run a PST driveshaft
my problem seems to be up/down clearance issues. seems to me motor mounts would cause side-to-side issues, but i agree that bad mounts might cause something like this. mine are fine though.
my problem seems to be up/down clearance issues. seems to me motor mounts would cause side-to-side issues, but i agree that bad mounts might cause something like this. mine are fine though.
Thread Starter
Joined: Oct 2006
Posts: 2,608
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From: Webb City, MO...out in the garage
all mounts are good, and relatively new. the car itself only has 30K on it, and was bone stock until ~24K.
I just took off my Umi tunnel mount TA. It did not hit the top off my DS loop, but it did rub the bottom of the loop with the suspension fully dropped. Sounds exactly what your sounded like over huge dips/bumps. Try shimming it down a bit.
Are you sure its the top? Paint might just be chipped from the vibrations etc? I think its close enough that it shouldnt rise to much with the suspension loaded but the DS will drop alot while the suspension is suspended..
Thread Starter
Joined: Oct 2006
Posts: 2,608
Likes: 0
From: Webb City, MO...out in the garage
yes. i am 100% certain it is the top. it's not paint, it's powdercoat...that stuff doesn't vibrate off, it's baked on and very hard. plus where the coating is chipped off, the metal is scratched up from the DS rubbing it.
I was looking at the first picture and think it was on the top and bottom. If it's just the top the bend the loop up or shim the tranny down (remember to check you driveshaft and pinion angles if you shim the tranny).