New leaf Springs and Shocks • The Dodge Challenger Message Board

by **tkdieter440** » 24 Oct 2003 12:32

A couple of weeks ago I decided to replace my worn out air shocks with a pair of new ones. Took my 73 Challenger into the local shock & muffler shop to have the work done. I have shock extensions on car now. and the air shocks that are suppose to work, the eye hole was to wide to fit into the extension and the shocks were not long enough if I tried to install them by removing the extension. They suggested that I replace the leaf springs (looked original) and put regular shocks on car. So after reading several threads posted on the site here I decided and ordered a pair of ESPO heavy duty leaf springs and a pair of KYB shocks. Well yesterday I had these new parts installed. Leaf springs went on relatively easy, considering I just watched them do all the work, but the shocks were 2 to 3 inches short without the extension, and I have the same proplem with the eye bolt hole being to wide to fit properly inside the extension.
I had to leave the garage to pick up my other Challenger I had at another shop getting the front end aligned and when I returned they had the shocks mounted and the car off the lift and outside the shop. I couldn't get a straight answer on how they got the shocks on, being they were almost 3 inches to short to start with, but it looks as though they sat on the rear of the car to compress the springs to get the shocks on. I have 15" tires on car and needless to say I have no clearance whatsoever and when I drove the car home on some bumps in the road I was getting some tire rub. Here are my many questions that hopefully someone can help me with and sorry about the long drawing out story.
Do I have the wrong Shocks??
Does anyone have the part number for the KYB shocks???
Do they make a longer style shock???
Do they make a different styled extension that will work with the new, what seems to be, wider eye bolt shock???
If so, a name brand or part number and where purchased?
Does anyone recommend machining the thickness on the eye bolt to the size of the old shocks that fit inside the extensions? its about a 1/8" - 1/4" difference.

Last summer on my other 73 Challenger I installed new leaf springs I purchased from Year One, heavy duty ones also. I don't have extensions on those air shocks and I have plenty of tire clearance, although I have 14" tires on this car, but still, I am sitting well above 3" over the tires. I do not see any differences between the 2 cars, except the shock extension on the one. Well I didn't sleep too well last night tossing and turning trying to figure out whats wrong here, but I need to go to work now, so if I don't respond to any answers, I will when I get home. If you need to see a picture of the extensions I can attach one somehow, I think.
Troy

by **dave-r** » 24 Oct 2003 15:13

When all the weight is off my rear wheels the shocks are only around a half inch or so short. So it sounds to me as if your new shocks are the wrong length and they sat in the trunk to get the shocks on. You will be able to tell this easily by taking the shocks off the lower mounts while the car is on the ground. It they come off with great difficulty and the car suspension rises when they do come off then they were too short.

Your suspension height is mostly due to the rear springs. Check the car is at the right height without the shocks. It could be that the springs have more height than stock to make up for the fact that these springs will settle after a few weeks.

If the suspension is the right height and the tyres still rub then the wheels have the wrong offset or are too wide.

The bottom shock mount should be the right size for the eye in the shock. If it is not then you have the wrong shock or the wrong mount.

by **tkdieter440** » 24 Oct 2003 17:09

Thanks Dave, I am headed back to the shop to take the shocks off.

by **tkdieter440** » 27 Oct 2003 13:23

After doing some investigating and realizing and confiming I don't know anything about working on cars, it looks as though I do not have the proper back spacing on my rims and my tire size isn't working out either.
I ended up using the KYB shocks, for now, with the extensions but with the wrong backspacing on the rims I am still rubbing.
They way I look at at I have three options,
1 - buy new rims with the correct back spacing
2 - buy new lower profile tires (present tires 255-60-15)
3 - buy new air shocks and install

For now, I have opted for the air shocks. Winter is almost upon us here in Wisconsin, and I need to put car up for storage, so I have a while to decide or change my mind.

Is there a thread on here that explains how to measure for the correct back spacing on wheels, If I do decide to buy new rims?
Troy

by **dave-r** » 27 Oct 2003 14:11

You might want to try the search facility on here to find any other threads about wheel size.

Back spacing (or offset) is measured by laying the wheel face down and putting a straight edge accross the wheel rim from side to side (not across the tire). You then measure the distance from your straight egde to the back of the wheel where it contacts the brake drum. I will try to find a drawing of this tonight.

I would guess a 4.5 inch back space would be ideal for you but you should be able to look at where the tire is rubbing and see how far in the tire needs to move to stop it rubbing.

For example if you feel moving the wheel in an inch each side would do the trick, measure your back spacing and add an inch to get the offset for your new wheels.