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Thanks, guys, good to hear from some folks with more mileage. I'm not sure if I have the "shorter" version or not - I think I do, but I suppose I should ask CS.
I'm dropping the car off tomorrow morning to get the 8.8" rebuilt, and hopefully start to resolve the drivetrain vibration issues I've got.
Thanks, guys, good to hear from some folks with more mileage. I'm not sure if I have the "shorter" version or not - I think I do, but I suppose I should ask CS.
I'm dropping the car off tomorrow morning to get the 8.8" rebuilt, and hopefully start to resolve the drivetrain vibration issues I've got.
I know I'm definitely one of the first 5 guys that got the 8.8 done and I had 0 cleanance issues with the driveshaft I had a bit of vibration but turns out the shop that I used to set up the 8.8 was junk and had a buddy do my second one no issues perfect
So I've been tweaking the pinion angle on the 05 with the 8.8 and finally have this car as smooth as the 20 year old Toyota it replaced. In the end, it required 3 of the subframe washers described above under the front cradle mount and 1/4inch under the transmission mount to smooth this thing out. I'm simply amazed at how sensitive this car is to what I thought were very minor adjustments in the pinion angle. Insane....
Thanks, guys, good to hear from some folks with more mileage. I'm not sure if I have the "shorter" version or not - I think I do, but I suppose I should ask CS.
I'm dropping the car off tomorrow morning to get the 8.8" rebuilt, and hopefully start to resolve the drivetrain vibration issues I've got.
I had the 8.8" rebuilt a couple weeks ago. The pinion nut had either never been torqued properly, or had somehow backed off, which is why the diff was in such bad shape. So, everything was re-done with new gears, new bearings and seals, etc. Shop said they used Ford 75W-140, that they've had bad experiences using 75W-90 with the FRPP gear sets.
I talked to CS and they couldn't be certain which version of the adapter I had, as I had bought my parts about the time they were transitioning over. So, they sent me a new "short" adapter, and I had that installed along with the rest of the work. (Thanks yet again to Max and Kristie, who shipped the new adapter to the shop with nothing more than my word that I would ship back whichever adapter wasn't used in the end.)
For aligning the drivetrain, I told the shop to use the technique that Matt from VoodooChikin recommended (bolt the driveshaft in without the flex disk to see where that puts the carrier bearing, adjust things as necessary). I wasn't there to see it done, but the tech said the driveline was definitely not straight, that the carrier bearing was offset to one side. He loosened the tranny crossmember bolts and was able to shift that a little to get the carrier bearing to line up with the mounting holes.
I think fixing the diff was a big step in the right direction. Unfortunately, I still have vibrations from 40-45mph or so, and then again at 80ish; the vibes in the 40s don't feel a ton better than before, but the vibes at highway speed are much better, so I'm happy about that. The vibes in the 40s started when I installed the new flex disk and Voodoo refurbed driveshaft (still with the stock diff initially), so I'm not sure what my next step is. I think I want to check the driveline alignment myself when I get a chance to get the car up on a lift again - on the one hand I trust the shop put things right, but on the other hand I tend to want to see things with my own two eyes.
That sucks. Its bad when you replace the worn out stuff with new stuff and it doesn't work as good.
Wonder if you got your driveshaft back or if its a core?
From what I've heard, balancing a 2 piece isn't easily done but curious if it would make sense to balance the 2 halves of the factory shaft individually while its apart for the bearing swap?
Before I start, thanks for all who have posted in this thread with ideas and experiences, it's given me hope that there is a light at the end of the trans tunnel.
I bought this car 6 months ago and promptly ordered the CS 8.8 kit during the thanksgiving Black Friday sale with complete axels and DSS one piece aluminum shaft( I' didn't know of the 150mph issues until after I oredered it). I finally got around to installing it 2 weeks ago along with the red cradle bushings and a CS race engine and trans mounts, everything bolted up and seemed good for the 2 week break in period of low speed short drives around town. Saturday night I actually took it up to highway speeds and starting around 65-70 I got a nasty hum/vibration that only got worse with speed. Anything above 90 got scary and the dash was vibrating so I slowed down and made it home without issue. Sunday I lifted the car back up to confirm nothing came loose and all is good, I also rechecked the front cv to shaft clearance and it still at the limit of 5.75" which is where it was when installed. I have slight gear whine in 5th gear low speed low load situations but chalked that up the all the solid mounting, there is also what I've seen described as parade clunk if I blip the gas under same conditions.
Before I call CS I'm going to check drive shaft angles and try the cradle spacers and hope for the best. I guess this is more of a vent but after spending close to 5k I didn't expect any of these issues that never presented themselves with the worn factory stuff it replaced.
Before I start, thanks for all who have posted in this thread with ideas and experiences, it's given me hope that there is a light at the end of the trans tunnel.
I bought this car 6 months ago and promptly ordered the CS 8.8 kit during the thanksgiving Black Friday sale with complete axels and DSS one piece aluminum shaft( I' didn't know of the 150mph issues until after I oredered it). I finally got around to installing it 2 weeks ago along with the red cradle bushings and a CS race engine and trans mounts, everything bolted up and seemed good for the 2 week break in period of low speed short drives around town. Saturday night I actually took it up to highway speeds and starting around 65-70 I got a nasty hum/vibration that only got worse with speed. Anything above 90 got scary and the dash was vibrating so I slowed down and made it home without issue. Sunday I lifted the car back up to confirm nothing came loose and all is good, I also rechecked the front cv to shaft clearance and it still at the limit of 5.75" which is where it was when installed. I have slight gear whine in 5th gear low speed low load situations but chalked that up the all the solid mounting, there is also what I've seen described as parade clunk if I blip the gas under same conditions.
Before I call CS I'm going to check drive shaft angles and try the cradle spacers and hope for the best. I guess this is more of a vent but after spending close to 5k I didn't expect any of these issues that never presented themselves with the worn factory stuff it replaced.
This is definitely a hair pulling experience. I had the exact same situation on mine and luckily I was able to clear it up by changing the pinion angle. The car is smoother than I was ever able to get it with the stock 2 piece driveshaft so yes, there is hope.
But I hate to tell ya, checking the angle doesn't do much good because we don't have a published "optimal angle" to adjust to. I'd measure mine but the texture on the driveshaft doesn't really allow it to get that accurate of a reading but I'm guessing I'm somewhere between 2 and 2.5 degrees of pinion angle. I could maybe get to within a half a degree of confidence using the tools I have but its much easier to just start shimming it.
2 ways to do this, raise the transmission or lower the front of the cradle. You can raise the transmission with easily found washers, shimming the cradle will require the big "washers" or plates but CS has stacks of them as they supply them with their cradle bushings kits....Maybe you have the stock ones left over. I did and I used those between the car body and the cradle (to nose the pinion down a bit) without issue.
I still think the driveshaft could be too long. I don't know that we should have to compress the driveshaft so much to shoehorn it in the car. But of course, this is comparing the fit of the driveshaft with the many CV shafts I've installed over the years which (EDIT - typically) require no compression or extension to bolt them in because they're designed to go in that way. However, the Porsche 930 CV might not have ever been intended to operate at driveshaft speeds so who knows, maybe they're compressed for a reason...either way, I've never gotten an answer to the "why is my driveshaft so hard to install" question but I won't seek answers as long as the driveshaft is working as well as it is now. We'll see how long it last though...
Regarding the pinion noise, I've researched it because mine screams between 75 and 80, right where I drive the most. I found this thread about it for more info....
The thread referenced a Ford TSB about the noise and the bolt-on weight they supplied to help counteract it. The results have been decent for those who posted up about it and I found this one on ebay so I bought it. Its on the way, hope to have it this week and regain some of my hearing by the weekend.
http://www.ebay.com/itm/161986364755?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
EDIT - I'm currently running over the counter Ford organic fluid and additive which, once I get a few miles out of it, I may change to something else. I'd put a Ring and Pinion replacement on the to do list but the thread above pretty much said that the 8.8 is known for gear whine and some people have replaced their gearsets multiple times only to wind up with the same noise. Even though that's the first I've heard of this systemic pinion noise issue with the 8.8, I'll try the counterweight and fluid changes first before replacing ring and pinions because at the end of the day, its a Cadillac.
I dnt think I have room to go up with the trans, the aluminum 1 piece is so fat I had to bash the factory resonator and remove the gas tank shield just to make it fit and it's super close to the shifter. Shimming the cradle is my only option for making corrections.
As for length the shaft bolted up fine in its "resting" state, I didn't have to stretch or compress it to make it fit but like I mentioned before the instructions included a picture with a clearance photo and mine is at the max limit.
I dnt think I have room to go up with the trans, the aluminum 1 piece is so fat I had to bash the factory resonator and remove the gas tank shield just to make it fit and it's super close to the shifter. Shimming the cradle is my only option for making corrections.
As for length the shaft bolted up fine in its "resting" state, I didn't have to stretch or compress it to make it fit but like I mentioned before the instructions included a picture with a clearance photo and mine is at the max limit.
I've got a carbon one piece so I can't speak for how well the aluminum shaft will work by shimming it. I'm glad yours installed easily because I had to bolt mine into the car before tightening the cradle bolts because it wasn't going in with the cradle fully seated.
Maybe the aluminum shaft is larger in diameter than the CF piece because I have no clearance issues with it at all. The only clearance issues I had was with the exhaust hitting the diff because the diff is so much bigger than the Gertrag.
What kind of exhaust are you running???
Reason I ask...I had my stock exhaust modified (by the local hack, no waiting muffler shop I admit...$40, what do you do) to go around the diff and now the car sounds like **** because the pipes are no longer the same length and the system lost its tune. Didn't see that one coming but I've made an appointment with the "quality" muffler shop in town who'll take the time to make it right again.
This is definitely a hair pulling experience. I had the exact same situation on mine and luckily I was able to clear it up by changing the pinion angle. The car is smoother than I was ever able to get it with the stock 2 piece driveshaft so yes, there is hope.
But I hate to tell ya, checking the angle doesn't do much good because we don't have a published "optimal angle" to adjust to. I'd measure mine but the texture on the driveshaft doesn't really allow it to get that accurate of a reading but I'm guessing I'm somewhere between 2 and 2.5 degrees of pinion angle. I could maybe get to within a half a degree of confidence using the tools I have but its much easier to just start shimming it.
2 ways to do this, raise the transmission or lower the front of the cradle. You can raise the transmission with easily found washers, shimming the cradle will require the big "washers" or plates but CS has stacks of them as they supply them with their cradle bushings kits....Maybe you have the stock ones left over. I did and I used those between the car body and the cradle (to nose the pinion down a bit) without issue.
I still think the driveshaft could be too long. I don't know that we should have to compress the driveshaft so much to shoehorn it in the car. But of course, this is comparing the fit of the driveshaft with the many CV shafts I've installed over the years which (EDIT - typically) require no compression or extension to bolt them in because they're designed to go in that way. However, the Porsche 930 CV might not have ever been intended to operate at driveshaft speeds so who knows, maybe they're compressed for a reason...either way, I've never gotten an answer to the "why is my driveshaft so hard to install" question but I won't seek answers as long as the driveshaft is working as well as it is now. We'll see how long it last though...
Regarding the pinion noise, I've researched it because mine screams between 75 and 80, right where I drive the most. I found this thread about it for more info....
The thread referenced a Ford TSB about the noise and the bolt-on weight they supplied to help counteract it. The results have been decent for those who posted up about it and I found this one on ebay so I bought it. Its on the way, hope to have it this week and regain some of my hearing by the weekend.
EDIT - I'm currently running over the counter Ford organic fluid and additive which, once I get a few miles out of it, I may change to something else. I'd put a Ring and Pinion replacement on the to do list but the thread above pretty much said that the 8.8 is known for gear whine and some people have replaced their gearsets multiple times only to wind up with the same noise. Even though that's the first I've heard of this systemic pinion noise issue with the 8.8, I'll try the counterweight and fluid changes first before replacing ring and pinions because at the end of the day, its a Cadillac.
Good Luck and keep us posted....
I'm curious to see your results with the mass damper. It may not do anything if the frequency is different in our V's than in a mustang due to the mounting setup that we are using, but should be a worthwhile option to look at.
The OEM's typically use mass dampers to get rid of unwanted noises as a last ditch effort due to the add in weight. I've also seen torsional dampers installed inside the driveshafts that accomplish a similar goal at a lower weight penalty.
I'm curious to see your results with the mass damper. It may not do anything if the frequency is different in our V's than in a mustang due to the mounting setup that we are using, but should be a worthwhile option to look at.
The OEM's typically use mass dampers to get rid of unwanted noises as a last ditch effort due to the add in weight. I've also seen torsional dampers installed inside the driveshafts that accomplish a similar goal at a lower weight penalty.
I'm curious too!!
I've seen NVH dampers in the past that bolt to the car and I'd bet they'd be pretty well tuned for the vehicle they're being bolted to. But as this one bolts directly to the diff, I'm hoping that its more diff specific and tuned for it irregardless of what kind of car the diff is in.....we'll see.
I haven't been able to find a picture of this part on a car, the TSB number or the instructions for it so I'm not sure how it was initially intended to be installed. I'll assume the closer to the diff I get it the better off I'll be so I'll attempt to install it between the bushings and the diff. The challenge here will be clearance. If I have to bolt it to the bottom of the mounting bracket and there are 2 sets of bushings separating the weight from the diff, I have no idea how effective this will be but I'll damn sure give it a shot.
I've seen NVH dampers in the past that bolt to the car and I'd bet they'd be pretty well tuned for the vehicle they're being bolted to. But as this one bolts directly to the diff, I'm hoping that its more diff specific and tuned for it irregardless of what kind of car the diff is in.....we'll see.
I haven't been able to find a picture of this part on a car, the TSB number or the instructions for it so I'm not sure how it was initially intended to be installed. I'll assume the closer to the diff I get it the better off I'll be so I'll attempt to install it between the bushings and the diff. The challenge here will be clearance. If I have to bolt it to the bottom of the mounting bracket and there are 2 sets of bushings separating the weight from the diff, I have no idea how effective this will be but I'll damn sure give it a shot.
Any opinions on this are appreciated....
From the picture of the ebay post. the holes end of the piece goes towards the rear of the car and sandwiches in between the front ear bushings. I'm not sure if it would go on the top or bottom bushings. Use your judgement to get enough driveshaft clearance and go with that. I'm not sure about our exhaust though, there could be interferences. Good luck. It looks like it weighs about 3-5lbs.
From the picture of the ebay post. the holes end of the piece goes towards the rear of the car and sandwiches in between the front ear bushings. I'm not sure if it would go on the top or bottom bushings. Use your judgement to get enough driveshaft clearance and go with that. I'm not sure about our exhaust though, there could be interferences. Good luck. It looks like it weighs about 3-5lbs.
I'll wind up putting it in any way it'll go LOL! I thought I read that it weighed in at over 9lbs but don't quote me on it. I hope to get it on the car for testing the way the exhaust already is. If it works, I can have the exhaust routed around it (I hope) if need be as it needs to be rerouted anyway....
Finally got around to shimming the subframe today. I ended up using 1/4" spacers (roughly 2 CS washers) in the front and all the low speed issues are completely gone from whine to parade clunk. The entire driveline seems tighter, unfortunately the highway speed vibration only moved from onset at 60 to 75mph. I'm not sure if I have enough threads on the subframe bolt to stuff another spacer in there so I might try going up on the trans next. At least I'm making progress so I'm not ready to give up on the aluminum one piece yet.
Finally got around to shimming the subframe today. I ended up using 1/4" spacers (roughly 2 CS washers) in the front and all the low speed issues are completely gone from whine to parade clunk. The entire driveline seems tighter, unfortunately the highway speed vibration only moved from onset at 60 to 75mph. I'm not sure if I have enough threads on the subframe bolt to stuff another spacer in there so I might try going up on the trans next. At least I'm making progress so I'm not ready to give up on the aluminum one piece yet.
Glad its starting to work out for you. I'm running 3 plates right now and so far so good but i'm with you on this one, I'm going to take one out and raise the trans a 1/4" just in case.
Finally got around to the damper install. As you can see, this thing is freakin huge and weighs every bit of 10 lbs.
As built by Ford, this lump hangs down below the diff by a full 1.5" and even below the exhaust which made this the lowest thing under the car. Luckily, it cleared the exhaust but was too low to work as far as I was concerned. Based on the images I've found of the Cobra front diff mount, it had to be built this way to clear it. As the CS mount isn't as big as the stock Cobra mount, I was able to section the mounting bracket a little over an inch and move the weight forward about another inch. With these mods, it's just about even with the diff.
Did this solve my problem? Yes and no...it didn't get rid of the whine but it reduced its intensity and moved it down the mph scale to where it isn't so much of an issue.
How fast have you had your car with the new setup?
Only to 80mph before I let off, at that point it was obvious the vibration wasnt going away. I contacted CS today and ordered some more shims and voiced my concern about the issues I was having, Max was very helpful and mentioned the laser alignment tool if there is no improvement with adding another spacer.
What we need are these black washers shown here....
I used the cradle shims because that's what I had and I also wasn't sure how firmly the rear diff bracket located the diff itself in the cradle. I had to take the front diff mount off to put the damper on and quickly realized that the rear bracket doesn't hold the diff firmly at all. We should have no issues adjusting pinion angle off the front bracket and leave the cradle where it is as long as the bolts will thread. I'd be concerned that if we used more than one washer, the bolt would be at enough of an angle to where it wouldn't thread but we'll see.
I also guess we could use different length bushings to do this as well.
01-08-2016, 04:04 PM
