[Jelphree]

I just got home and freeway driving its pretty annoying. My dash is rattling like crazy. I punched it just to check the car. I down shifted to 5th and HOLY SHIET!!! Acceleration is HUGE!!! I hit 100+ mph in no time. The vibration was prominent is the rear, as if I was sitting on a massager. It was vibrating hard during deceleration and the sound resonating.

I don't doubt the performance gain on this drive shaft, but I'm seriously going to check it tomorrow. I hope I didn't get a defective shaft.

SOJDM or ACPT, can you guys chime in on this? Anyone in the LA/OC area have this dive shaft give some pointers? I'd love to compare the characteristics of your car versus mine.

Thanks guys.

[QuickSilverSTi]

Mine was smooth as silk - I had no vibration at all at any speed. I would park it and take a look underneath. Make sure your shift linkage/wires are zip tied out of the way and the install was to spec. I had mine installed at P-Tuning.

[Jelphree]

Quicksilver, thanks for the input.

I'm going to try the thinner outrigger bushings and what they do. I've read that the thicker bushings have a HUGE amount of NVH. We'll see if this does the trick. I'm praying that the drive shaft isn't the problem.

[SoJDM.com]

Sometimes if the driveshaft is unbolted and reclocked 180 degrees that will help. An old trick used frequently on metal driveshafts.

[SoJDM.com]

Also, make sure the two flanges meet perfectly flush. We seem to have one vehicle with a driveshaft that has a defective flange.

[Jelphree]

I switched out the thicker outrigger bushing for the thinner ones and I got a new noise to deal with. It's a clicking sound once I get into 2nd.

I'm going to try SoJDM and Icereaperx303's suggestions tomorrow after I buy a jack and jack stands.

Now I'm wondering whether the cf drive shaft is balanced, because this install/modification has been a nightmare.

I hope repositioning the shaft works tomorrow.

[bbong]

Mine seems good as well, took it up to 85mph so far, no vibrations, smooth as silk.

[wrrrx]

Oy, the vibration reports make me a bit nervous- I have a track day in a week and half, and I want everything to be "smooth as silk" too.
Hmm, since my car is still at PDXTuning, mebbe I'll swing by and drop off the d/s for them to install...

[Mustangkilla]

I was able to take a little bit off with a burr and then i was able to bolt it up fine... You can see it if you bolt it up and take it back down the marks that the differentials input shaft makes.. The amount of material that i took off was very minimal and didn't affect any balance issues, considering the method of balancing consisted of offset washers welded to the metal ends(as far as i can see), im sure the couple tenths of a gram i took off wont hurt... Brought the car up to about 100 mph and it was dead smooth!!

But boy o' boy does the car feel different, power shifts into 5th are butter smooth, and all in all just feels sooo much more responsive.. Even after all the small issue's, i still feel its worthy mod..

[Icereaperx303]

Glad it worked out. Didn't really have any tools to do this to mine and didn't feel comfortable take away some material hehe. Just hope to get another in a few weeks.

[Got2Boostit2]

Originally Posted by Mustangkilla

I was able to take a little bit off with a burr and then i was able to bolt it up fine... You can see it if you bolt it up and take it back down the marks that the differentials input shaft makes.. The amount of material that i took off was very minimal and didn't affect any balance issues, considering the method of balancing consisted of offset washers welded to the metal ends(as far as i can see), im sure the couple tenths of a gram i took off wont hurt... Brought the car up to about 100 mph and it was dead smooth!!

But boy o' boy does the car feel different, power shifts into 5th are butter smooth, and all in all just feels sooo much more responsive.. Even after all the small issue's, i still feel its worthy mod..

MKilla,
Sounds good! I'm jealous....

[Jelphree]

I just finished unbolting the shaft, turned it 180°, and bolted it back on. It made no difference. The flange did not sit flush until the nuts and bolts were torqued in. I did have those marks on the yolk after it was installed.

I also noticed that the shaft was hitting the chassis, right where the rear floor is located. It made a small rubbing mark on the under-body. I'm guessing this is why the vibration/shaking is occurring. The shaft seems shifted a little bit to the left if you were looking at it straight upwards. What I mean is that the gap between the shaft and the rear diff mount is bigger than the left side.

My plan tomorrow when I get home from work is to hammer the under-body in to give some clearance. For the people who installed the shaft themselves, did you have this issue?

I will post pictures tomorrow. SoJDM and ACPT have given me some feedback and have been very helpful with this ordeal.

I'm going to have a few beers now...

[949]

i have a question for everyone.

how far is your ds from the area where the parking brakes are to the ds?
how far is the ds from the parking brake lines that are comming out of the cars floor to the undercarriage?

[Mustangkilla]

Originally Posted by Jelphree

My plan tomorrow when I get home from work is to hammer the under-body in to give some clearance. For the people who installed the shaft themselves, did you have this issue?

For MY04 I had no clearance issues with the undercarriage, plenty of room all around, i even started the car while in the air and watched the shaft spin to make sure it was good all around..
As far as the E brake cable, that was very close maybe a tenth or two of an inch, I figured its got some padding on the cables cover.. The cable is pretty tight to the undercarriage, i tried moving it around to gain clearance it wasn't happening. Ill be back under the car this weekend to see how things look and install my redesigned diff. protection plate thing, ill snap some pics..

[949]

so at least now i know im not the only one with the ebrake close to the ds.

you can move the cable only after you unbolt and take off the two clamps that keep them in place. there are two on each side of the car for the left and right ebrakes. you do have to be a bit imaginative to make it stay after you unbolt it.

i wonder if it hits the ds while spinning fast tho?