So over the winter I got some much needed work done on the V.

My stock clutch started going out and with that, the parade clunk we V1 owners all know and love eventually came back. I was guessing that the clunk came back because the clutch was slipping and the stock dual mass was causing deflection somewhere. The car, at that point, only had Creative Steel motor mounts, trans mount, diff bushing and diff block insert.

I decided to get a Diamond Stage 2 Clutch w/ the 15 lbs flywheel. Around the same time Revshift debuted with their Rear Cradle and Trailing Arm Bushings so I decided to get those along with their Flex Disc Coupler. I also had an original KARS III Anti-Wheel Hop Kit that I bought 4 years ago so I decided to get that put on as well. I then decided to also get the DSS Anti-Wheel Hop Axle Bars for good measure.

Overall, it sounds like a good combo to eliminate the rest of the stock rubber bushings in the rear, eliminate clunk, and reduce the wheel hop. The clutch has since been broken in, it grabs great, and engages instantly from the top. On a roll, the rear feels planted and the car feels like it's squatting when it's under load. I was impressed but still was not able to really put the hammer down due to winter road conditions.

That is, until this week, conditions have been dryer and a bit more friendly for some minor hoonage.

Here are the scenarios:

What I have noticed is I still have some parade clunk and an even louder shift clunk if do a light clutch dump, it kind of sounds like a bang now and less of clunk. I found that out by doing a 2k launch; the car hooked but I heard the bang as it hooked so immediately let off. I thought my 4th gen diff took a **** but it's fine.

If I do full WOT shifts, there's minor clunk shifting in 4th and the car squats and grabs. If I were to do a quick engine brake, I can feel immediate deflection and clunk but a light engine brake is fine. If I downshift without a revmatch in lower rpms, it clunks immediately. A downshift with a revmatch, it hooks and goes.

The Creative Steel mounts and diff bushing still look good, the KARS Kit is installed correctly (spacers were not installed because Revshift bushings take their place), the stock driveshaft was indexed correctly and does not feel out of alignment and the carrier bearing looks ok, I do have some minor vibration in the 30 mph range that was not there before but I chalked that up to the KARS kit making things more rigid.

So what am I missing? I've search around but I haven't found similar scenarios. Would the stock driveshaft still cause slop? What would still cause clunk when it feels like all the bases have been covered?

 

its the rediculous back lash in the stock diff. the more abuse they see, the wider the back lash gets. the case distorts and opens up the gear pattern.causes whine and clunk. the carrier bearing in the DS is also junk but most of your noise is that stock diff

 

I have a hunch the metal sleeve on the CS diff bushing shrinks in cold weather and causes clunk to come back. It may also get distorted over time if you drive it hard (like you do) while it is shrunken and gets knocked around. My hunch would be that a revshift diff bushing would take care of your slop.

 

This^

And remember, when it finally lets go at the strip....STOP! Don't be the idoiot rolling down the track trying to figure out what went wrong while leaking gear oil everywhere! Stop immediately and try to contain the spill, not pull a BP and ruin that lane, and a hour of everyones day.


and I'm done.

 

These are the times I wish I had a GroPro or some kind of camera to record what's going on underneath the chassis.

I just find it odd that it could make the kind of noise I'm describing, it was prominent and very distinctive (almost metal to metal loud clanking). Maybe I'm just being naive but it sounded way different than the normal clunk.

I guess the way to find out is to get a Revshift diff bushing and report back. Have there been people reporting the clunk came back with the CS bushing after some time?

Luckily I've had enough passes at the track and have see other cars in similar situations to not let this happen should the rear go out.

Rest assured I won't be taking it to the strip if I can't have it do a simple 2k dump on the street without it sounding like someone rear ended me.

 

Depending on how far I get this weekend, I might be able to tell you whether the 95A Revshift differential bushing helps. You were quoting me, up there, when you said that some people had reported that it felt like their Creative Steel differential bushing was giving out.

 

lol, I was counting myself among them. With the CS diff bushing, I got just a hint of a clunk on the coldest days. Now that the weather is warming up, the clunk is gone again. I'm thinking it's the metal sleeve.

 

for what its worth ill say this. ive had 3 stock diffs in my car..including a gen4. when new out of the crate it has what feels to be about 10-12 thousands of back lash. after 10k miles it turns into about 30 thousands..and so on. when i broke my last cv before the 8.8 went in i could literally turn the drive shaft a 3rd of a full rotation before the axles were affected.

this is where most of the drive line clunk is from. i set my 8.8 to .006 and have ZERO CLUNKS and ive been beating on her daily.

 

Ugh..doomed from the start. My car hasn't seen a lot of abuse, most daily driven miles. It's only seen the track twice and survived minus the typical wheel hop. No burnouts or hard launches. Over time I got the mods that should have reduced this stuff from happening.

Another thing that I've noticed is weight transfer from front to rear and vice versa, it's noticeable when shifting while coasting. What could that be a sign of?

 

Get an Auto V2...problem solved.

 

The clunking/banging that you describe in higher gears could also be caused by a bad carrier on the driveshaft center support. Once that rubber carrier degrades, the shaft will sag in the middle at the joint and under the right conditions it will hammer away like mad. Google cts-v carrier bearing and youll see what I mean. This is just in conjunction with diff lash and the diff bushing. I replaced the diff bushing and about 98% of my clunk disappeared.

 

Soooon.....well it will still be a Manual.

Yea, looks like I'll have to look into driveshaft options. If I were to accelerate then clutch out to neutral, it's also noticeable.

At 89k and still making close to stock power, I would have never thought a carrier would go out. The V1 driveline is such a sloppy bitch.

 

In for how this turns out. I'm in chicago also and just got motor mounts and cradle bushings in 95A, trying to eliminate some sloppiness too. Keeping my fingers crossed for now.

 

I saw this video online and wish I could do the same for my car to see what's going on.


I'd imagine that it's probably the same if not worse. The bearing itself isn't making any noise. Some of the vibrations are coming from the Revshift Flex Disc but it's nothing horrible. I was skeptical at first as I did see a thread where someone complained about vibrations and then shattered theirs, they however, installed it wrong.

If anything, the stock flex disc may have dampened the issue enough to where it wasn't noticeable while my stock clutch was slipping and the dual mass flywheel was throwing it's dead weight at the driveline.

You're going in the right direction. What part of Chicago? I'm on the NW side.

 

You bought a V1, trying to get all the odd little noises out is like trying to train squirrels to do tricks. It can be done, but you might kill all the squirrels out of frustration and change animals.

 

I don't think you're going to like 95A motor mounts. My 87A motor mounts transmit noticeable vibration at idle.

 

I'd accept the noises if they weren't damaging in the long term. I knew buy changing out to stiffer motor mounts, trans mount, rear bushings, etc that there would be more road noise and some vibrations. I'm fine with that. The KARS Kit transmits a particular "howling" noise that I'm sure the more traditional Cadillac owners would love, it doesn't bother me though. What I'm not fine with are mysterious noises and odd clunking that are a step above the typical V1 nonsense.

87A, are those Creative Steel mounts?

 

Yes. Please note that my engine is cammed, and I had zero vibration thanks to the Slowhawk tune with the stock mounts.

With the Creative Steel mounts, at idle, I have enough vibration to see the steering wheel vibrate slightly when I let go of it. As soon as I exceed 1000 RPM, however, all of that goes away. I'd put this vibration at the bleeding edge of my tolerance level.

 

Yea, good point, I'm not cammed.....yet. Stock, the CS mounts have some vibration but nothing extreme. It's more noticeable now with a lightened flywheel and a grip happy clutch. If I clutch out slowly on take off, I can see the hood vibrate slightly.

I ordered a Revshift 95A differential bushing for now. If my CS bushing has failed, I'll know right away with the replacement Revshift. I'm going to have to go underneath the car anyway to check everything again and report back. I have to route a hose for the stock vent also.

In addition to researching for a new driveshaft, I also read that someone managed to break a differential bolt which would cause a clunk.

 

*cough* V2 *cough cough* do it now *cough*