Slight clunk

[Kaldar142]

So I have a slight clunk when I first press the gas, it's not really something you hear but more so something you "feel".

Everything in my rear suspension is upgraded, except the UCA differential bushing. That or the so called "play" that is in the UCA / mounting bracket are the only things I can think of that would cause this...

I was thinking of adding one of those stepped spacers that steeda sells.

Thoughts?

 

[Flash_of_Yellow]

So I have a slight clunk when I first press the gas, it's not really something you hear but more so something you "feel".

Everything in my rear suspension is upgraded, except the UCA differential bushing. That or the so called "play" that is in the UCA / mounting bracket are the only things I can think of that would cause this...

I was thinking of adding one of those stepped spacers that steeda sells.

Thoughts?

Check for slop in the ring/pinion. I had an old truck that was like that. Let go of gas and feel a bang, hit the gas and feel another. It was just play in the gears. How many miles you got? When did you last check that fluid?

Also, from your sig pic it looks like you track the car. My local mustang shop told me that it was imperative to check/change the rear diff fluid if I'm going to track it a lot or I'll tear up the gears quick. So, another pointer to your rear end.

 

[Kaldar142]

I just had the rear end rebuilt less than 2000 miles ago and I changed the fluid and diff cover 2 weeks ago. The car itself just turned 40k.

Fwiw this "jerk" happened before & after my rear was rebuilt.

 

[Vapour Trails]

I have that to a degree as well, I'm thinking play in the UCA attachments.

 

[Kaldar142]

I mean it's really not that bad, I'm just very particular about these things.

Plus after driving the Z06 around, it makes the jerk much more noticable

 

[EagleStroker]

Plus after driving the Z06 around, it makes the jerk much more noticable

But seriously, you say you haven't touched the UCA bushing meaning it's the OE? If I'm not mistaken your running rod end LCA's correct? I had this when I had just the Metco lowers (rod/poly combo) and when I replaced the mount, added the spacer, and put in a poly adjustable UCA voila! Might not be the same for your but I can't imagine the bushing mis-match not causing it.

 

[Kaldar142]

I have a CHE poly UCA but oem bushing on the differential.

I think I'm just going to switch to steeda comp. Uca and spacers along with the upgraded differential mount. Hopefully it goes away after that

 

[kevinatfms]

the spacers from UMI helped me, installed them with the FR500 bushing in the OEM arm and my clunk went away.

 

[Cookiemonster]

same thing happens to me (more so when im gettin on the gas). If i ease into it i don't feel the clunk at all, but if i just floor it its like a kick in the back.

 

[Shotokan1509]

Are your LCA's rod ends on both ends? When I blew out an LCA bushing it clunked, and the entire car shifted when laying into the gas & letting off... did not immediately appear bad when installed but they were beyond toast when removed.

 

[UMI Sales]

the spacers from UMI helped me, installed them with the FR500 bushing in the OEM arm and my clunk went away.

Hello
Thanks for suggesting UMI Performance! Like mentioned above the factory mount has a lot of play in it! And we manufactured both spacers and a new mounting bracket (to help adjust instant center) for faster weight transfer. Below is a link to show you what all we have to offer!

http://www.umiperformance.com/catalog/index.php?main_page=product_info&cPath=12_131&products_id=344

http://www.umiperformance.com/catalog/index.php?main_page=product_info&cPath=12_131&products_id=341

If you have any other questions feel free to ask!
Thanks
Brad

 

[Kaldar142]

I think i'll have to try that spacer out...hows the installation?

 

[kevinatfms]

not bad, just gotta take the UCA off and put them on the outside of the OEM bracket, or buy the bracket they sell and dont need spacers since they make the bracket with the 14mm hole.

 

[Kaldar142]

So if i'm taking off the UCA i might as well just upgrade to the Steeda comp. uca while i'm at it

 

[kevinatfms]

yeah i guess it would be to proper thing, why not just get everything from UMI, they have an adjustable one too. see if you can get them to give you a discount on all your UCA parts.

 

[RedMosesSC]

I get the same "clunk" but only when i apply lightly throttle when cruising, i have the Steeda UCA & Mount so i dont think that will solve your problem, if its the same as mine. I had the Clunk on my 07 GT Vert and i also get it on my 06 Saleen S281SC.

I discussed this on other forums before and the best answer ive heard that seems most logical is "Pinion Slap", theres enough play in the drive line to cause the clunk.

Are you on a stock drive shaft? U Joint? Im not sure if a 1 piece shaft will take care of the issue but it about the only thing in the rear i have not changed, on both cars.

 

[marksti]

shoulda left it stock

 

[UMI Sales]

yeah i guess it would be to proper thing, why not just get everything from UMI, they have an adjustable one too. see if you can get them to give you a discount on all your UCA parts.

Hello
Thanks for the suggestion! When you are ready feel free to give me a call. And I will be more than glad to see what I can do for you. Below is a link to show what all we have to offer.

http://www.umiperformance.com/catal...cPath=12_131&zenid=g9taib4neui8mspthnaer4ma67

Thanks
Brad