Diff mount going bad?

[mindspin311]

Now, Ive only had my car for 5 days, so I am still getting used to the clutch. But, I have noticed that on 1-2 shifts, if I dont get the timing perfectly, I can hear a decent thud from the rear of the car. I figure it has to be a diff mount. Thoughts?

[TristanHunter]

The rear diff bushing is usually responsible for the thump when the load on the diff changes. Your best bet would be to jack up the back of the car and inspect it so you know for sure.

[mindspin311]

Thats what I figured. Ill try and get under it at some point and take a look at it.

[Torxuvin]

It is the rear diff mount most likely. I had exactly the same issue. Other things to check are the guibo, rear subframe and rear shock mounts. You would hear noise over bumps too with the subframe and rsms though. Let me know if you need another set of eyes or hands. I'm in Midtown. Congrats on the car.

[mindspin311]

It is the rear diff mount most likely. I had exactly the same issue. Other things to check are the guibo, rear subframe and rear shock mounts. You would hear noise over bumps too with the subframe and rsms though. Let me know if you need another set of eyes or hands. I'm in Midtown. Congrats on the car.

Thanks!

Yea, no noises over bumps. Just the thud during my sh**ty shifts.

[Vas]

Like others have stated, jack up the car and take a look at the rear mounts.

Also do you know if your car still has the CDV installed?

[mindspin311]

Like others have stated, jack up the car and take a look at the rear mounts.

Also do you know if your car still has the CDV installed?

I was never told it was removed. So it must still be there.

[Vas]

I would remove it if I were you.

[mindspin311]

I would remove it if I were you.

Yea, I've heard is a no-brainer to do. Ill add it to my to-do list!

[mindspin311]

OK, is there any reason to buy a modified CDV vs. just removing and reconnecting the lines?

[derbo]

OK, is there any reason to buy a modified CDV vs. just removing and reconnecting the lines?

There is no reason to buy a modified one. Its the same as removing it and reconnecting the line.

[Sockethead]

OK, is there any reason to buy a modified CDV vs. just removing and reconnecting the lines?

No there is no reason whatsoever. You'll see why when you get under there...
If you really want to leave that piece in there you can just drill out the center of the existing one. I did that while my car was still under warranty.

[mindspin311]

No there is no reason whatsoever. You'll see why when you get under there...
If you really want to leave that piece in there you can just drill out the center of the existing one. I did that while my car was still under warranty.

Awesome, thanks guys.

Sent from my Nexus 5

[bloodspatteranalyst]

IDK how helpful this would be for you, but my rear diff mount is shot too. I have an AT, no clunks when the gears shift, but a clunk when switching between gears while stopped (when going into reverse, for example). The whole car kind of drops at the back end, and is accompanied by a nice little clunk in the rear of the car. It's pretty terrifying for passengers who aren't expecting it. Haha.

I have been delaying its repair because I'm waiting until I can get hold of a bushing tool, but the mechanic said not to worry because "the bushing isn't going anywhere". I might be losing a little bit of power to the wheels, but that's something I can live with for a while.

[mindspin311]

So, I was thinking... If Im going to replace the diff mounts, shouldnt I just go ahead and knock out engine and trans mounts as well?

[NoVAphotog]

So, I was thinking... If Im going to replace the diff mounts, shouldnt I just go ahead and knock out engine and trans mounts as well?

Might be a good idea. Here is some recent info on the matter from my inquiry on the matter:

http://www.zhpmafia.com/forums/showthread.php?13129-Engine-Transmission-mount-(or-something-different)-inquiry

[mindspin311]

Might be a good idea. Here is some recent info on the matter from my inquiry on the matter:

http://www.zhpmafia.com/forums/showthread.php?13129-Engine-Transmission-mount-(or-something-different)-inquiry

Yea, I dont notice the shifter moving at all. Just the thud from the rear.

Any holy smokes thats a lot of options for mounts. I would probably go with OEM M3 versions. This isnt a race car, just a daily.

[LivesNearCostco]

You certainly can, especially if engine and/or trans mounts are old or cracked. But there's not much overlap in the work other than raising the car safely. Diff bushings require removing exhaust and diff (or rear cover of diff). Engine mounts and transmission mounts require supporting engine or transmission temporarily with a jack or brace.

The big bonus would be combining either one with a guibo or CSB replacement. Both of those require removing exhaust and in my case, disconnecting driveshaft from diff required me to loosen the CSB support, though not sure that's always true.

Well one overlap, if you remove exhaust to do diff bushings it makes it easier to do the transmission mounts, but is not required.


So, I was thinking... If Im going to replace the diff mounts, shouldnt I just go ahead and knock out engine and trans mounts as well?

[scooby24]

I was never told it was removed. So it must still be there.

No CDV. It was drilled out.

[scooby24]

Yea, I dont notice the shifter moving at all. Just the thud from the rear.

Any holy smokes thats a lot of options for mounts. I would probably go with OEM M3 versions. This isnt a race car, just a daily.

You're welcome. ;-)

I did the shifter bushings with aftermarket, pivot rod...carrier plastic (whatever it's called)...everything on the shifter. It was a bitch, but well worth it. Compare the way your ZHP shifts to 95% of other ZHPs and you'll see how good you got it now.

It's subtle after getting used to it, but feeling the oem rubber in every other e46 is like a wet noodle.

Also, guibo is likely OEM, but I inspected it when doing the shifter, zero cracks and rubber was still pliable. Wouldn't worry about it. Transmission bushings are a wash since you have the M3 engine mounts that are new. There's not much movement there I'd guess.

[mindspin311]

You're welcome. ;-)

I did the shifter bushings with aftermarket, pivot rod...carrier plastic (whatever it's called)...everything on the shifter. It was a bitch, but well worth it. Compare the way your ZHP shifts to 95% of other ZHPs and you'll see how good you got it now.

It's subtle after getting used to it, but feeling the oem rubber in every other e46 is like a wet noodle.

Also, guibo is likely OEM, but I inspected it when doing the shifter, zero cracks and rubber was still pliable. Wouldn't worry about it. Transmission bushings are a wash since you have the M3 engine mounts that are new. There's not much movement there I'd guess.

Yep, no slop in the shifter. Makes sense about the engine mounts, gave it a few hard revs in neutral and the shifter barely flinched.