rumblefish360
Well-Known Member
The reply above is accurate. Chrysler used a rubber rectangular pad approximately an inch thick above and below the leaf springs. Under the rubber was a plate just like the older cars have but also above the rubber. The rear ends U boots are longer and attach in the same manor as the older models sandwiching the rubber between the metal which dampens the vibrations for a smoother ride.
This was also done at the K frame. The K frame was redesigned a little bit and round rubber biscuits are sandwiched in between the frame and K frame.
Last but not least….. the transmissions cross member was redesigned and moved about 6 inches and was also given smaller round rubber biscuits to limit vibrations.
All in all, the goal for a smoother and quieter driving car was met and I think the road really nice.
HOWEVER - As far as performance goes, they kill the off the line and gear change hits because the rubber gives way unlike the older suspension. So if your upgrading a ISO suspension car, you should loose the rubber biscuits and work in the older stuff.
In the K frame, the police package has “Hy-durometer” bushings that are less flexable and the MoPar community has had a few fellas make aluminum biscuits.
On the rear end, it’s ether removal of the perches and weld in the older one and use older springs or weld up the big hole where the leaf spring locating on is and then get small pin locator springs installed.
Small locator springs are ether stock, SS springs or most every aftermarket manufacturer made spring. But you must check with them!
Also, the trans cross member rubber bushings should be replaced. The worst case is you use a stock of washers. (Don’t do that, really!) But a nice round piece of stock, cut down to the proper thickness would work excellent!
