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mine is a 1 piece 4" aluminum shaft rated at 500hp. they will make whatever you want though. It's like a german CV joint that mates to a porsche. They sent an adapter and I had to get it milled down to clear the shifter too. They said they updated their blueprints for future cars based on my experience but who knows.


cheapest option would be to have just modified the 2 piece stock driveshaft from the start :)
 

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Had this exact same issue. My issue wasn't abated until I purchased a CV driveshaft from DSS.
Those bastards told me I couldn't get a CV on that end. Said it wasn't strong enough. Once I balanced my shaft, it worked fine up to 120 mph so, I'm not really sure why it didn't work for you. My V8 does place the transmission in a slightly different position I guess.

Plenty of other people have gotten this working without vibration using the drift motion setup. It's pretty close to the same as the DSS with adapter setup. It's not clear why it works for some people but not others.

Ant did you ever check runnout on the shaft and adapter?
 

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Those bastards told me I couldn't get a CV on that end. Said it wasn't strong enough. Once I balanced my shaft, it worked fine up to 120 mph so, I'm not really sure why it didn't work for you. My V8 does place the transmission in a slightly different position I guess.

Plenty of other people have gotten this working without vibration using the drift motion setup. It's pretty close to the same as the DSS with adapter setup. It's not clear why it works for some people but not others.

Ant did you ever check runnout on the shaft and adapter?

the CV was a new thing for them. probably didn't have that part sourced at the time you asked.


I think my issue may have been runout from the local shop that shortened the shaft. When I measured it, it seemed like quite a bit but I don't really have much experience to tell how much is too much. That shop was too far away to go back though as I couldn't drive the car above 40mph lol.
 

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other things I noticed:

my low mileage AR5 has some play in the output shaft - maybe some AR5 transmissions are better than others in this regard.

the solstice transmission mount is super flexible. I bought another and filled it with poly window glue but haven't installed it yet.

I think in my situation these 3 things together caused the issue
 

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Discussion Starter #26
Well, with the crossmember in, there is only 0.2 degrees difference in driveline angle from the transmission output flange, and the differential flange. I think its safe to say the angle is no longer a factor.

While the car was on a lift, I put it on cruise control in 5th gear, to make the car continuously vibrate. The computer was confused and was constantly coming on and off the gas.

I noticed that the output shaft comes in and out with throttle input. Is this normal?

Here is a video:
https://youtu.be/ZnE038rF2_U

Ant did you ever check runnout on the shaft and adapter?
That is the next thing I want to check, but I don't have the means for that. When you say runout, are you talking about the flange face, like a brake rotor spinning in a bad wheel bearing? Or are you talking about the output shaft having some up and down play?

other things I noticed:

my low mileage AR5 has some play in the output shaft - maybe some AR5 transmissions are better than others in this regard.

the solstice transmission mount is super flexible. I bought another and filled it with poly window glue but haven't installed it yet.

I think in my situation these 3 things together caused the issue
My AR5 was from LKQ and said to have 86k miles. It shifts beautifully, however before install I did notice that the output shaft had a tiny bit of play. I was told that amount of play is normal, and nothing to worry about.

I also noticed that the brand new (said to be OEM Pontiac) transmission mount was extremely flexible, and the transmission moves around a decent amount because of it. Those gaps where I mentioned putting washers, surprisingly create no play or movement, and the transmission is held secure there.

I may try filling it with polyurethane
 

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While the car was on a lift, I put it on cruise control in 5th gear, to make the car continuously vibrate. The computer was confused and was constantly coming on and off the gas.
you need to press TRAC OFF i think

That is the next thing I want to check, but I don't have the means for that. When you say runout, are you talking about the flange face, like a brake rotor spinning in a bad wheel bearing? Or are you talking about the output shaft having some up and down play?

Just search runout gauge on ebay. I already had one for my bicycle disc rotor but they are only like $25
 

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https://www.amazon.com/gp/product/B007XZIT5I/ref=oh_aui_search_detailpage?ie=UTF8&psc=1




Is the one I use. Was using it on my drill press the other day. Discovered that if you use the flutes into the bits you get a bunch of wobble but if you stick it farther in so it's just the round part, there's almost none.

I noticed that the output shaft comes in and out with throttle input. Is this normal?
Seems kind odd to me. I'd expect the CV joint to move in and out, not the output flange. I wonder how much thrust movement is acceptable? I can't find the end play specs.

I don't think much of how that guy used the exhaust for his magnetic mount.
 

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Discussion Starter #30
you need to press TRAC OFF i think
This is true. I had trac off, but I think the computer for cruise control was confused with the car being in the air, since the rear wheels were moving and the fronts were not.

That W55 transmission mount looks way better than the GM one. I would try to poly fill the GM one next and see if that helps. That's a significant difference between polish_man's setup and ours.
I definitely want to try this, but I don't think this is related to the vibration, so I will wait until after I get this issue sorted out.


Seems kind odd to me. I'd expect the CV joint to move in and out, not the output flange. I wonder how much thrust movement is acceptable? I can't find the end play specs.
That's what I am trying to figure out. Is that kind of thrust movement at the output shaft considered normal? Or should I be looking into that as a potential culprit?



Apparently some people have issues with the nut holding the output flange onto the shaft backing out or getting loose. However its similar to an axle or something where one side of the nut gets punched into a little recess on the shaft, to prevent it from backing out, so I find that unlikely.

I would like to check that nut regardless, but I am unable to find the torque spec for it on any website, or using AllData. Anyone have any information on that? I don't want to just crank on the nut and end up destroying a bearing or something from over tightening a nut that was perfectly fine.


Its getting to the point where I might have to pay a transmission or drivetrain specialist to diagnose this. I would hate to spend the money, but I am unable to figure this out and am starting the school semester in less than 3 weeks, and am going to need my car in good working order.
 

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Discussion Starter #31
Update, I tightened the output flange nut a little, about as tight as I could get it. No difference made, running out of things to check.

Any other suggestions from anyone?
 

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Did you ever figure this out? My car recently started shaking like a mofo at around 60 mph to the point where I am highway cruising at 50mph. Installed AR5 about 6 or 7 months ago and everything was fine up until about a week ago. Ima shove the whole thing off a cliff.
 

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I'm using a single piece driveshaft shop one. It was working fine so I'm thinking a weight may have fallen off? Does that even happen? In any case, I'm headed over to a driveline shop today during lunch to see if we can figure it out.
 

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I'm hoping it'll just be in need of a rebalance.
That solved my problem. In your shoes, I'd be tempted to ditch the one piece, find a stock 2 piece and have someone mod the transmission end with an original AR-5 CV joint (or one like it). I wish I'd gone down that route when I did this.
 

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Put the car on the lift. Vibrations were NOT as obvious as under load but still vibrated at aroun 65ish or 70ish. Noticed two weights had fallen off of the DS so uninstalled and got it re-balanced. Diff mounts looked good and nothing jumped out other than the drivers side axle maybe making a sound here and there. Took it out on the highway, same issues. Money spent, box checked, problem unsolved. Rant over. Next.
 
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