You described the exact symptoms my car has. I had my mechanic check the motor mounts and he said they are fine. Car has 97k. He did day the rear carrier bushings were shot. The car is really annoying to drive. Anyone come up with anything on this?

 

I have the same drivetrain slop,i can definitely tell its coming from the rear motor mount,

 

Can I ask how you know it's coming from the rear motor mount? I ask, as I too have this issue. It's quite annoying having to treat the throttle pedal like an egg when driving this thing to avoid the bucking, makes the car quite a bit unstable for auto crosses. The rear mount on my car looked good when I had the transmission out, got a good "test" to check it?

I've done the front motor mount, the beatrush rear diff bushings, and the torque solutions driveshaft bushings. I'd really love to fix this as at the moment my civic can be more enjoyable to drive around in.

Anybody with a car that has A) not had the transfer case off, and B) is on a stock tune/car that has this? I'm wondering if there is something to do with the way the engine mounts get torqued up Or maybe something with the tune.

 

I kinda fixed this issue by using my ingalls engine torque damper. Though I have to adjust it quite often, at least for summer and winter, because I think temperature affects the damper itself, when it gets really hot it gets softer (without changing the setting) and stiffer in cold.


And also my opinion is that as the clutch wears, it has different engagement properties. Because as my clutch wears, I have to constantly adjust the stiffness of the damper to get it just right, where it's just stiff enough to stop any jerking/chatter, but not stiff enough to cause cabin vibrations.


it could be caused by a glazed flywheel though, but the ingalls allows me longer use of my clutches where before I would replace clutch when it starts chattering, but now if I just tighten it a tiny bit when it starts to chatter, then it won't chatter anymore. I really enjoy the adjustability.


I'm not really sure what the real issue is though, but this is how I deal with it.


Do any of you guys already have like a master bushing set installed?

 

Had a similar issue with the older evos. Changed the propshaft bushing and helped alot. Also might want to check your back lash on the rear diff, huge issue with Evos especially the older ones. Had to tear down the rear diff and readjust the pinion gear to proper adjustments.
Hope this helps. Heard the polyurethane bushings makes it worse and puts more pressure on the other OEM rubbers, as the polys are mainly for racing.

Cheers

 

Thanks for the ideas guys. I've tried the TS driveline bushings which had no effect unfortunately. I added the rear diff beatrush polyspacers and that only really helped get rid of the sonic boom on hard shifts. I do have a whine now thats coming from the rear that started as soon as I did the spacers. Makes me wonder if it is the rear diff and the poly spacers just made it so I could hear it.

Could it be that I need to reshim the rear to fix A) the noise and B) the slop? I did want to go and rearrange the plates back there anyways.

Lately I have started to think it may be ISCV tune related as the engine seems to be shaking around when lifting. I have an '05 with the throttle hang issue which seems to have the engine "unsure" of what to do when lifting after say 50% throttle. Still messing with the settings per the threads on here without a ton of luck. I will report back though if I ever get it dialed in right.

Thanks all for the suggestions

 

I have the TS bushings for the driveshaft & poly bushes from front to rear & still have backlash, sloppy shaft, jerking, bouncing etc. I'm going to believe the only way to fix the issue & what I'm going to lead it to is the rear diff pinion gears or surrounding parts inside are worn out.... I may be guessing, but it could be correct. Think about it, the problem occurs from the driveshaft so where does the driveshaft connect to the rear diff? & the one in front connects to transfer case? But the noise comes from the rear... By the way poly bushes increases the noise of the rear & front diff, transmission, road noise, exhaust sound etc... That could be the downside of poly bushes, but they are way better then rubber in terms of, reliability, performance, etc ! Need good & strong stuff for our type of cars.

 

I've had every part of my drivetrain upgraded except the driveshaft. I plan to do this eventually. I have all torque solution mounts in the engine, poly bushings on the rear diff and Buschur hard mount mustache bar. The only time I get backlash is in 1st and 2nd gear when driving slowly, which I expect due to the stiffening I've introduced into the car.

I also get the oscillation at low speeds that require me to ride the clutch or put it in nuetral to stabilize it, but this is normal when you start to really stiffen the chassis and drivetrain. As you stiffen the chassis drivetrain, it's not able to absorb those oscillations. Same thing with a racecar and how jerky they are at slow speeds.

The u-joints on the driveshaft will harden over time. At this point the drivetrain will not be able to absorb the shock and will transmit it back to the chassis.

 

Heard the DSS driveshaft helps eliminate this problem....anyone with a DSS shaft to comment?? The DSS shaft uses one mounting point rather than two like OEM.

From DSS:
"We are proud to introduce our new 2-piece driveshaft for the Evolution VII / VIII / IX with AYC Differential. This shaft uses an Aluminum front section with a Chromoly rear section with a specially designed hanger bearing and bracket that eliminates the violent hanger lag that occurs when power is put through the factory shaft. Our driveshaft uses 1 hanger bearing, instead of the 2 on the factory shaft, and features greasable/replaceable u-joints instead of the non-serviceable type on the factory shaft. We also include an Aluminum conversion plate for the rear and all necessary hardware to make this a bolt-on affair."


Cheers

 

^ that could be another one & even old/busted coils may even need changing, as this can effect with acceleration & so on.

 

Just an update...changed out the rear diff mounts to Teflon mounts. Improvement in the shifting of the car and less "thump". I was surprised because I thought it would cause louder thumps but I still have some OEM rubbers on other mounts, I guess that helps. Had no choice but to go with the teflon since the TS poly mounts I ordered didnt fit so beware it said "evo 8 and 9" but didnt fit my evo 9 (JDM). (

However, still a slight thump when backing off the throttle and then back on hard again. None the less an improvement.

Cheers

 

Have noticed the rear diff is louder now with the install of the Teflon bushings...right on the money EvoTurboTurk

 

I did mention in the other post that rear diff could be on its way out if the driveshaft is bouncing, sloppy, etc but I believe its not the only cause this problem. Many cases rear diff will be fine & other things could be causing it to jerk, bounce, sloppy, backlash, etc or it could be normal for AWD & 4WD cars to do this. Shouldn't need to worry about it, until it breaks or not . I have been in new cars that are AWD & 4WD, that do these. However you won't be able to notice it as much due to the vehicle being alot bigger, etc, if you concentrate on it during take offs, etc you will hear it.

 

Any update? Had anyone sort out the issue? I got basically same problem, its so annoying to drive it everyday. Thinking at doing motor mount next, the rear one is not that good.

 

For DD bounciness, some of it will be drivetrain gear wear, and some will be due to bushings becoming compressed and/or deteriorated. As you suggest, trying to reduce bounce with bushings is the easiest place to start. Inspect and replace what looks bad.