Jonb42

Just to give a quick overview of my ? Or problem. I have a 99 gs with. 2jzgte vvti IPT race built trans. T67 single trd lsd rear diff lowered with d2 coilovers megan rear lover control arms toe arms and traction rods. I have poly diff mounts and poly upper rear control arm bushings. I have a 1 piece driveshaft with forged isolater couplings attaching it to the flange on the trans and the diff. All this work was done at the same time when we swapped the motor from my old gs (crashed) to this one. The problem I have which I'm not sure is a problem or if its a semi normal thing to have with a solid driveshaft Is on the highway doing between 80 and 90-95 there is a vibrating sound similar to a wheel bearing sound but not as intense. It's a low pitched rumble. I'm wondering if there is a problem or if anyone else has experienced a similar issue. I like the idea of never having to replace the rubber isolators. Before I go through that headache of buying new rubber isolators (the one ones I have are cracking) and swapping in my old driveshaft to see if the problem stops I was hoping for someone to tell me it's normal. I don't cruise between 80 and 95 anyway. I either blow through that speed range or am not in it at all so it doesn't bother me besides the fact that idk 100% if the driveshaft is the problem. Thanks for the input if any.

99 GS3

iTrader: (14)

I'm running a 3.5" aluminum one peice shaft with a billet flange adapter and it's buttery smooth over 140+ still, no vibration. I had it high speed balanced when built to eliminate any issues. Alot of shaft shops don't have a high speed/high rpm balancer, So it they only balance it on a typical balance machine you may have vibration at higher rpm/speeds.

Do you know what the highest rate they ran it at on the balancer?

VIP161

iTrader: (3)

Im currently having a 3" single piece driveshaft made for my 2JZGTE GS430. Ive visited several shops that have told me about car owners experiencing your symptoms that were cause by an unbalanced or improperly balanced driveshaft.

Quick question, is replacing the rubber isolator with an aluminum one really necessary?

Jonb42

I bought the driveshaft from driftmotion. They require the aluminum isolators to adapt the driveshaft to the flanges. I think that the vibration is either being caused by the angle of the u joints or being unbalanced. I had the driveshaft shortened by a shop that has a very good reputation in north nj. They said they balanced it after shortening it. http://www.markwilliams.com/driveshafttech.aspx. This is a link someone sent to me explaining how the angle of the joints effects harmonic vibrations. I think I'm just gonna try raising the rear of my car a inch. If that doesn't stop the noise I'm gonna order new rubber isolators and go back to my factory driveshaft. Or upgrade to a carbon fiber or aluminum driveshaft. I haven't looked into the options or had the car on a lift tha I can check the joint angles on yet.

99 GS3

iTrader: (14)

Raising the car doesn't effect the driveshaft angles any because it's an irs.

But I'm confused, you bought a steel shaft from driftmotion, but then you had it shortened locally? Why did you have to do that, did you mis-measure the diff-to-trans length when you placed the order? How fast did the other shop spin it up when balancing it?

What diameter is the shaft you currently are running?

99 GS3

iTrader: (14)

The aluminum flange adapters are mainly to convert the Toyota 3 bolt diff and auto trans flanges to a standard 4-bolt pattern so you can run solid body spicer joints which will hold tons of power.

The stock rubber guibos can help absorb driveline transfer and vibrations. But high quality, well built and balanced one piece shafts and/or solid adapters can be indistinguishable to the cabin when done correctly.

Jonb42

I ordered the driveshaft for the car I crashed. I never installed it. I'm not sure if I just straight up measured it wrong. I don't think so. But in any case when I wen to install it in the new gs it was too long. I'm not sure what rpm it was balanced to but as I said they have a good rep. I'm going to be doing the bearings in the rear this weekend. The rear left is shot. I have poly upper control arm bushings and pillow ball mounts on every rod connecting to the axel carrier. I'm hoping that the noise is the bearing being amplified because of the solid bushings. I should know ny Monday. Ad if that's not it I'm gonna go back to oem and order a carbon fiber driveshaft in a couple months. I'll post the outcome as soon as I know. Hopefully we don't get to much snow in jersey this weekend and I can work on my car.

TTurboPimp

iTrader: (12)

sounds like a balancing issue to me

kdick91

I had this *EXACT* same problem... In my Trans Am. I had just replaced the bearings and axles in my rear end and did *not* reshim as it appeared the backlash was tight between the ring and pinion. I noticed you put in a TRD LSD. The shims set on the differential have to be checked with the wear of the ring and pinion or if you change nearly any component in the differential. Did you have the differential shimmed or where the shims just tossed back in when you put the diff back together? If so, I am 99% sure that is your issue. I had my driveshaft balanced, my transmission mount changed between poly and rubber, wheels balanced, rotors, changed, EVERYTHING! Checked backlash between the ring and pinion... too tight. Reshimmed, dead quiet. Hope this helps!

Jonb42

Turned out to be the balance. Swapped back the stock driveshaft and the vibration is gone. I thnk that its because they balanced it without the aluminum couplers. I ordered new rubbers for the stock driveshaft and am calling it a day. For now at least. Thanks