Rear suspension ride is very hard

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   I have a 1968 AMX and the rear rides very hard. It would be nice too have a more compliant ride. The front is butter smooth, and wondered if anything could be done to the rear?
The current setup:

-Torque links with new polyurethane bushings. 
-New Go Package springs with stock rubber bushings
-Well worn KYB shocks. 

Does anything sound wrong?

Regards

Dono

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DAMX Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Nov/13/2017 Location: Silicon Valley Status: Offline Points: 195	Post Options Post Reply Quote DAMX Report Post Thanks(0) Quote Reply Topic: Rear suspension ride is very hard Posted: Nov/24/2021 at 10:32pm
	I have a 1968 AMX and the rear rides very hard. It would be nice too have a more compliant ride. The front is butter smooth, and wondered if anything could be done to the rear? The current setup: -Torque links with new polyurethane bushings. -New Go Package springs with stock rubber bushings -Well worn KYB shocks. Does anything sound wrong? Regards Dono

bikerfox Members Profile Send Private Message Find Members Posts Add to Buddy List Moderator Group Joined: Aug/02/2009 Location: USA Status: Offline Points: 4473	Post Options Post Reply Quote bikerfox Report Post Thanks(0) Quote Reply Posted: Nov/24/2021 at 11:17pm
	Three things that come out, for me: 1. poly bushings are known for lack of compliance and rigidity. rubber would be more forgiving. 2. are your torque links correctly ad- justed? there's info in your tsm about that. 3. which kyb shocks? gas-a-just or excel g's? i ran gaj on my sc and suffered from a stiff experience. for a street car, i would only use excel-g's.
	1969 Rebel SST (1970-1987) 1968 AMX (2005-2011) 1969 SC/Rambler (2011-2019) 1970 Javelin (2019 to ?)"Jane"

Mopar_guy Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Jun/07/2009 Location: Ohio Status: Offline Points: 4837	Post Options Post Reply Quote Mopar_guy Report Post Thanks(0) Quote Reply Posted: Nov/25/2021 at 7:38am
	From my experience, the shocks are my guess. I had the same issue and getting rid of the KYB's lets it ride nice. There's several threads on here about gas shocks and the rough ride they cause.
	"Hemilina" My 1973, 5.7 Hemi swapped Javelin

mbwicz Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Feb/20/2019 Location: Buffalo, NY Status: Offline Points: 2001	Post Options Post Reply Quote mbwicz Report Post Thanks(0) Quote Reply Posted: Nov/25/2021 at 8:40am
	Ross (401MatCoupe on the forum) has the tools to install rubber bushings in your torque links if the shock change doesn’t do enough for you. Mike
	1970 AMX, one step forward, one step back. Both steps cost time and money.

sweatlock Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Apr/28/2014 Location: Largo, FL Status: Offline Points: 3322	Post Options Post Reply Quote sweatlock Report Post Thanks(0) Quote Reply Posted: Nov/25/2021 at 9:10am
	Those polyurethane bushings in the torque links are preventing the suspension travel of the leaf springs. I agree that the shocks are definitely a contributing factor also - have Ross Peterson rebuild your torque links with rubber bushings as stated above and then set them up per the TSM, change out the shocks and don’t look back. This is what I did and it made a huge difference in ride comfort and I actually think it improved the handling.

DAMX Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Nov/13/2017 Location: Silicon Valley Status: Offline Points: 195	Post Options Post Reply Quote DAMX Report Post Thanks(0) Quote Reply Posted: Nov/25/2021 at 11:16am
	The torque links were installed to the TSM instructions, but I am hearing the dreaded poly squeak when the suspension try's too move. With these recommendations I will try. 1) Remove the shocks, and take a drive. 2) If there is little to no result from 1) then removing the torque links is the next step with the shocks installed. If 2) gets it is it very bad to drive without the torque links? I know the Javelins didn't have them. Thanks! Regards Dono

farna Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19692	Post Options Post Reply Quote farna Report Post Thanks(0) Quote Reply Posted: Nov/26/2021 at 6:39am
	The torque links work like upper control arm bushings. They are bolted up tight with the car sitting on the ground and the rubber twists as the car moves. Poly doesn't twist like rubber, so with the poly bushings torqued as the TSM specifies you are binding the rear suspension. IIRC the torque link mount on the body is slotted, so I don't know the correct installation for a poly bushed torque link. I'd say the bolt should be slightly loose so the link can pivot easily, but the slotted hole would mean the bolt moves, and it would beat the hole or bolt up when you hit the gas hard. If no slot that's what I'd do -- then the torque link would just work like any other upper link. The torque links aren't necessary, driving without them is fine. They are there as an addition to help control rear axle wind-up on hard acceleration. So unless you're drag racing/stoplight racing you won't even notice they aren't there -- except for the better ride.
	Frank Swygert

george w Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Jan/27/2013 Location: New Jersey Status: Offline Points: 2899	Post Options Post Reply Quote george w Report Post Thanks(0) Quote Reply Posted: Nov/27/2021 at 12:58pm
	What tires and tire pressures are you running ? Keep in mind that the factory pressure specs are 24 psi. You can run higher but the typical 30+ tire pressures of today's cars are not suitable for our cars.
	Long time AMC fan. Ambassador 343, AMX 390, Hornet 360, Spirit 304 and Javelin 390. All but javelin bought new.

DAMX Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Nov/13/2017 Location: Silicon Valley Status: Offline Points: 195	Post Options Post Reply Quote DAMX Report Post Thanks(0) Quote Reply Posted: Nov/27/2021 at 5:22pm
	Hello George, I like your simple approach! Going from 28 to 24psi did help a little. Regards Dono

Trader Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: May/15/2018 Location: Ontario Status: Online Points: 6917	Post Options Post Reply Quote Trader Report Post Thanks(0) Quote Reply Posted: Nov/27/2021 at 5:26pm
	Hate to be a party pooper, but tire pressure is based on a number of factors and when you deviate from factory, there are no "rules", you have to figure it out. My 17"x7" rims need 32 lbs of tire pressure to wear evenly on a 69 Javelin and need rotating every 5000 miles to keep some tread on the outside front corners. They last 25,000 miles before needing replacement. It's driven a little harder with softer tires. Use a dial Vernier to measure tread wear. Do this on my every day drivers also. The Sienna works best at 38 PSI, factory rims. 280,000 km AWD and no issues even though factory recommends 32 PSI. 2005 motorhome tires age out before wear out so they don't get rotated. Or damaged by a SS exhaust shield that sliced the sidewalls of front and rear tires!