Vibration at 35-60 km/hr - UMI suspension install

[pontiacgp]

read this thread about pinion angle and some run extreme angles but they don't mention any problems with vibrations. They do mention premature u-joint failure for extreme angles tho.

http://www.chevelles.com/forums/showthr ... 996&page=2

 

[cat herder]

Ya know, there are TWO u-joints, don't forget that the angle at the front joint changes as well when pinion angle changes. Put a 1/4~3/8" spacer (stack some washers) under the trans mount and see if the vibration changes.

 

[Pontiac455]

Put the original arm back on and the vibration will be gone. The front joint is at to great an angle and is binding. This is why the sell adjustable uppers, to change pimion angle. If it wasent doing this prior to u changing the control arms what else would it be? U measured the arms and said they were too long so yer right. Pinion angle is off.

 

[Captain Calais]

Emailed UMI and got a response. They made a mistake and are replacing my control arms with adjustable ones. amazing customer service with them. This should solve all my problems!

Don't know if the upper was just for the wrong vehicle, or they were defective, but they weren't the right size and UMI was great to deal with and solve this issue.

Thanks for your guys' help.

 

[UMI Sales]

I apologize for the shipping error (A-body uppers instead of G-body). We're building your new ones now and will get them to you asap. Then your car will work fantastically. That Roto-Joint non adjustable is one of my favorite pieces.

ramey

 

[pontiacgp]

I also had a great response from UMI when I had a slight issue with a part It's great that you actually get to talk to the people in charge who make decisions without delay.

 

[khan0165]

I'm noticing a re-occurring trend where ordering rear control arms is a dodgy adventure. Most of the mix-ups I've heard about were when ordering from a 3rd party dealer. Seen this from Hotchkis, BMR, TRZ, etc...

but the Abody and Gbody arms are so similar, seems to be a common mix-up. Happened to friend of mine ordering Hotchkis arms for his Abody, and got Gbody arms instead. And happened to someone I know ordering thru TRZ as well

... wonder if part numbers are similar too?

 

[G_Body_Enthusiast]

i looked at UMI and for their regular non adjustable uppers for 68-72 a-bodies the part number is 4015. for the regular non adjustable g-body uppers the part number is....3016. i dont think you could confuse those. i guess. i dont know how they do their pick/pack where ever it is they keep their parts ready for shipping but i dont think they'd be easily confused.

not sure about the other companies though. could be a problem in packaging of the parts? if the package says X part number but the parts are for another app that'd explain it i think. if the number and parts match but arent the right parts for your app that'd be more of a pick/pack issue. accidents will happen when you deal with parts that look a lot alike at a glance.

i saw that happen quite a bit with the hand assembled plate heat exchangers at this place i worked at. each size exchanger had different types of plates for them, some thicker some thinner,some made of stainless, some made of titanium. even the gaskets were very similar but didnt fit all the plates, only specific plates. there's was a lot of corrections that had to be made because of this. it's just human error. people stock parts in the wrong location and you think they're the right ones but they arent but you dont know that till management rechecked the order while you were working on it and caught the mistake.