Trailing arm front bushing flex
 

Hi, I have an issue with my passengers side trailing arm.
The trailing arm is brand new and I have installed new bearings and set the end play according to spec. Everything seems tight where the spindle is, but when I lift on the wheel the trailing arm assembly it looks like it's twisting or flexing at the front bushing. I checked the shims and tightened the bolt to eliminate any slack. Also added more shims just to make sure there was were no gaps.
Any ideas on what could be causing this as the drivers side does not do this.

Thanks

A GOOD PHOTO of the trailing arm bushing as it is right now installed in your car would be GREAT. The better quality of photo you post..the better I can see what you have...so PLEASE not out of focus photo(s).

IF your shims are tight....and they do not move.....and this is a NEW trailing arm (as you stated)...the trailing arm BUSHING ITSELF should NOT flex . BUT...what you are 'saying' can be also a bit deceiving.

Because...IF the trailing arm bushing IS NOT moving....BUT you can see that the arm can flex WHILE the bushing is still solid and NOT moving.....then that is why I would like to see your trailing arm bushing.

The trailing arm will move ...it HAS TO.....due to moving all three axis (X,Y and Z).

And I am ASSUMING that your trailing arm bushings are rubber.

DUB

Are you using rubber front bushings or poly? Were they installed by you or the trailing arm supplier? There will be a certain amount of flex in that joint due to the natural arc of the trailing arm travel.

I have been restoring my 74 corvette for the last couple of years and have replaced a lot of items.
The frame was replaced, differential is rebuilt, differential cross brace is new. Shocks, leaf spring, struts, and a lot more.

I will take a picture tomorrow of the trailing arm.
The bushings are rubber.

I did another check today on everything that I thought might be a problem.

Differential is rebuilt so I checked to make sure there was no end play on the shafts and they are okay.

I also took the half shaft off and made sure the universal joints were okay even though they are all new.

Then I pulled the spindle out to check the bearings as I was the one that did the rebuild of the trailing arms.
I did find around .015" of end play, so tomorrow I will fix this and put everything back together and double check to see if this helps.

Thanks for the info.

If you simply have the new trailing arm hanging from the front bushing/pivot point, you can grab the arm and flex it in big circles with no problem, even with all the shims in place and the bolt snugged down tight. You have so much leverage by grabbing the arm at the spindle that there is no rubber bushing that will feel tight with that moment arm. I have brand new arms hanging in my photos in my rear suspension drop thread, and I can twist them and move them in every direction. That's completely normal. Nothing will tighten up until you install the other 2 links of the suspension (half shafts and rod ends).

Lars