Drivetrain play

[Mid_Life_Crisis]

My car suddenly feels like the rear motor mount is missing or something. When I shift or take my foot off the gas, it feels like the engine is rotating several degrees and I usually hear and feel a thump from under the car. It has been raining here so I got under it only briefly last night, by jacking up and supporting one side of the car. The rear mount looks fine.
Where do I start looking for loose pieces? What is the most likely next culprit to check?
Thanks in advance.

 

[SallySpeed3]

Maybe the other mounts?

 

[8.5MS3]

^^+1 look for leakage. other mounts are fluid filled.

 

[Sport6]

Is it the stock rear mount? If so make sure the rubber hasn't ripped away in the center.

Get under there, not under the motor just in case, and push the motor back and forth. If one is broken you should be able to move the motor with some ease.

Biggest one is to check the tranny mount because the rubber can pull through that too.. easiest one to chek is probably the passenger side mount as its right on top of the motor.

 

[meicalnissyen]

Hey mid,

Its nasty out, just find some one who can use a clutch without hurting themselves, and have em rub the engagement point in 1rst and rev with the ebrake on. while you watch for motor movement

 

[Mid_Life_Crisis]

Last night it finally stopped raining so I checked "that mount" the one under the battery that scares us so much. I got a quarter turn out of the bolt. Not enough to be the source of the movement.
Finally got it on a lift this morning at a local shop and got a good look at the rear mount. My aftermarket dogbone was in perfect shape, but the bushing in the factory side is shot. I asked the mechanic (the owner of the shop) what I owed him for the diagnosis and he told me to forget about it. I said, "no, I won't. This is your business, you just did what you do for a living here, I'm paying you something for your time." He smiled and asked, "how's 20 dollars sound?" Worked for me. Checked the brakes while it was up in the air and they're good for a while. Nice to have a local mechanic shop that isn't out to gouge you for every cent they can. Now I just need to order the part and I'm good to go. Comforting feeling to know the engine isn't about to fall out.

 

[Jackis]

So, I didn't get it precisely, what bushing exactly was broken? You said rear motor mount was nice, so what was bad?

 

[Kain]

You have the TRZ dogbone? I have the CP-e 70 duro and noticed in the last couple of weeks a thud when shifting harder than normal. I checked for leaks in the engine bay near the driver and passenger mounts, but nada. I find it hard to believe the bushing in my rear mount is shot since the mount is pretty new and doesn't see that much abuse.

 

[Mid_Life_Crisis]

So, I didn't get it precisely, what bushing exactly was broken? You said rear motor mount was nice, so what was bad?

The dogbone that I replaced the factory piece with is fine. The problem is that there is a short "arm" for lack of a better word that is bolted to the tranny/motor with three bolts. The open end of the dogbone mount attaches to it. There is a large bushing in the end of that arm at the attachment point. This is the bushing that is shot.

 

[Mid_Life_Crisis]

You have the TRZ dogbone? I have the CP-e 70 duro and noticed in the last couple of weeks a thud when shifting harder than normal. I checked for leaks in the engine bay near the driver and passenger mounts, but nada. I find it hard to believe the bushing in my rear mount is shot since the mount is pretty new and doesn't see that much abuse.

It's not the bushing in your nice new mount. It's the bushing you bolted it to.

 

[Mid_Life_Crisis]

I know there's a full manual on this site somewhere, but I can't fnd it. Anybody know where it is?

Never mind. I found it.

 

[Jackis]

Oh well. Hard to understand w/o lifted car in front of me
Looks like it is transmission mount bushing you're talking about...

 

[Mid_Life_Crisis]

Oh well. Hard to understand w/o lifted car in front of me
Looks like it is transmission mount bushing you're talking about...

If you want to be technical about it, the passenger side is an engine mount and the other two are tranny mounts. We usually just call them passenger, driver, and rear to avoid confusion.

 

[Kain]

Bah, I wonder how much that rear mount arm is...

 

[Jackis]

Thanks for clarification!

If you want to be technical about it, the passenger side is an engine mount and the other two are tranny mounts. We usually just call them passenger, driver, and rear to avoid confusion.

So, according to you, rear motor mount doesn't actually hold motor? I thought it does...

 

[Kain]

The rear mount holds the motor laterally to prevent it from rocking back and forth. It's not weight-bearing.

 

[Mid_Life_Crisis]

Thanks for clarification!

So, according to you, rear motor mount doesn't actually hold motor? I thought it does...

The motor and tranny are bolted together as an assembly. It might be that the rear mount is actually attached to the engine, but I thought it was the tranny. I could be wrong. Now you see why we call them passenger, driver, and rear.

 

[Jackis]

Ok, thanks anyway! I have only "rear" reinforced and after reading this forum, I'm thinking now about getting another two

 

[Mid_Life_Crisis]

Bah, I wonder how much that rear mount arm is...

Short money.

http://www.mazdapartscenter.com

part # cc3139010

 

[Sport6]

Short money.

http://www.mazdapartscenter.com

part # cc3139010

Save 70 cents and get it at onlinemazdaparts.com

http://www.trademotion.com/partlocator/index.cfm?action=getJointLocator&siteid=214264&Sectionids=0,2453&groupid=51840&subgroupid=4102&componentid=&make=22&model=Mazda%203&year=2007&graphicID=5417286&callout=6&catalogid=2&displayCatalogid=0

Though I don't know what shipping would be.