Topic: Leaf springs: Ride Height Too High

[Building 3]

Has anyone run into the problem of the car sitting much too high after installation of new rear leaf springs?  We installed Drake leaf springs and now the car is much too high in the back. Some people have said that they will "settle in time." I am not sure about waiting a few years for the situation to correct itself. Any help from your experiences would be appreciated. My objective is to have the proper Ford ride height which had the car biased high toward the front, not the rear as it sits now. Thanks

[carlite65]

i have seen that quite often. did you let the car settle a bit before tightening the bolts??

[Building 3]

We installed the rear suspension while the car was on jack stands.  Then we installed the tires and wheels and lowered the car to the ground.  So, everything was tightened up prior to the tires and wheels going on.

[midlife]

Very common.  Tighten but not quite to torque all suspension bolts, then go on a drive 2-3 miles.  Upon your return, you'll see your suspension at the proper height, so go back under and tighten those bolts to spec.

[Richard P.]

I wouldn't worry to much, gravity will bring it down and it won't take a long time.  Fill your tank with fuel and drive your car.

[CharlesTurner]

As mentioned, this can usually be avoided by tightening the nuts when the car is on all 4 wheels with full weight in the car.  Also, it's important to torque the nuts properly, the specs are in the assembly manual and also in the shop manual.

[67gtasanjose]

As mentioned, this can usually be avoided by tightening the nuts when the car is on all 4 wheels with full weight in the car.  Also, it's important to torque the nuts properly, the specs are in the assembly manual and also in the shop manual.

+1  I do wheel alignments almost daily and I realize this step is often very inconvenient to follow 100% of the time.

Generally speaking...ALL suspension bolts, notably any going through a rubber insulator,  should be torqued while FULLY LOADED ONTO THE 4 WHEELS  and on a level surface, as already mentioned. A platform 4-post lift helps out tremendously. 

A good idea might be to leave these particular bolts loose until the car  has settled, then the car is moved/trailered  (maybe not driven) to an alignment shop, where all suspension height can be checked, confirmed and the final torque can be done as the wheel alignment adjustments are being made. Basically, you wish the rubber parts to be settled also, NOT having them torqued down into a "twisted" position.

I'll add one more thing to the discussion. NEW parts especially springs, that have been stored in their "unloaded" position will settle quite a bit over the first week or so. An installer could estimate this settling by adding a few hundred pounds of weight to the body, or in other words forcing some settling PRIOR to tightening all of the rubber insulator bolts. ...OR just "weight"  for it to settle by itself in a few days/weeks and then tighten them all down while "loaded".

Please, when I say "while loaded" I am talking about the car, not the nut behind the wrench 

[Hipo giddyup]

Not to throw in a monkey wrench, but I can't believe that workers on the assembly line would have retorqued later on or did they torque this components down with the car on all fours?? I too have had this issue and just bought new springs this summer. But after a few months and some miles with the kids in the back it had settled to an acceptable ride height.

[drummingrocks]

Yes, I've been there and experienced that too.  I've had mixed results.  On both of my cars, I installed Eaton (from NPD) springs that were the correct rate for the application.  They were supposed to be as close as you could get to the original ride height.

Both cars sat extremely high in the rear when the springs were first installed, and this was after we drove the car and let everything settle.  The full weight of the car was on the suspension when the bolts were tightened.  On my '66 fastback, upon deciding that it wasn't going to finally settle out to the correct height, we had a local driveline shop de-arch the springs.  The fastback now sits perfect, IMO.

My '69 Mach 1 was a different story.  It too sat very high in the rear with the new leaf springs.  After driving the car and letting it settle, we finally had these leaf springs de-arched too.  For a while, it looked perfect.  It did eventually settle, to the point that the rear end was noticeably sagging.  I had to remove the leaf springs again, and this time have them re-arched to bring back some of the ride height.

Ultimately, it's hard to say exactly what to do.  But I will echo what others have said: be absolutely sure the car has settled before attempting to have the springs re-arched or de-arched.  In the case of my '69, it came back to bite me in the end.

[67gtasanjose]

Not to throw in a monkey wrench, but I can't believe that workers on the assembly line would have retorqued later on or did they torque this components down with the car on all fours?? I too have had this issue and just bought new springs this summer. But after a few months and some miles with the kids in the back it had settled to an acceptable ride height.

Keeping in mind these cars were mass produced AND Ford engineers having the ability of figuring out any rate of settling for post production...Much more would be possible for them to "get it right" than any aftermarket manufacturer would have at their disposal. "Getting it right" could  have involved adding (a pre-determined) weight to the body for setting up alignments and forcing the "end settlement" into the calculations. PLUS the line had undercar pit areas where inspection and final torque values were most likely set. Question: Just when do you think all those paint daubs and crayon scratch marks went onto such suspension/steering parts? My thoughts those marks and daubs would be put on just before or just after the alignment process. Maybe Jeff, Bob or somebody more familiar with the line process can help with that detail. Assembly lines were not our backyard garage or restorer shop facility. My understanding is we are attempting to duplicate the results of the assembly line process, not the actual process the car went through when it was 1st built.

My thoughts are still the same on installing any new springs. Use either original, confirmed good or re-arched springs or BUY A GOOD QUALITY CONCOURS APROVED AND VERIFIED HERE AT THIS SITE set of springs, front and rear, Install them loosely bolted in, where going through any bushings, add weight evenly as needed to bring the ride hight down to specs, set the alignment and torque everything to specs and finally add any of the markings you found FROM YOUR OWN EXAMPLE when you took the car apart. At least you should be closer that way than installing and waiting for the sellting to occur. If is doesn't settle in a few days/weeks/months...begin the process again. Example A below tells the story best!


 

Yes, I've been there and experienced that too.  I've had mixed results.  On both of my cars, I installed Eaton (from NPD) springs that were the correct rate for the application.  They were supposed to be as close as you could get to the original ride height.

Both cars sat extremely high in the rear when the springs were first installed, and this was after we drove the car and let everything settle.  The full weight of the car was on the suspension when the bolts were tightened.  On my '66 fastback, upon deciding that it wasn't going to finally settle out to the correct height, we had a local driveline shop de-arch the springs.  The fastback now sits perfect, IMO.

My '69 Mach 1 was a different story.  It too sat very high in the rear with the new leaf springs.  After driving the car and letting it settle, we finally had these leaf springs de-arched too.  For a while, it looked perfect.  It did eventually settle, to the point that the rear end was noticeably sagging.  I had to remove the leaf springs again, and this time have them re-arched to bring back some of the ride height.

Ultimately, it's hard to say exactly what to do.  But I will echo what others have said: be absolutely sure the car has settled before attempting to have the springs re-arched or de-arched.  In the case of my '69, it came back to bite me in the end.

Richard.

[Building 3]

Thank you.  I learned a lot.  It seems like this is a common problem. So we will check the suspension and loosen it if needed.  We will also add sand bags to where the rear seat will go.  4-80# bags. It will sit like this for a month or so while the rest of the car is being finished. I will report back on the results. In all of the Mustang and other makes car shows that I have attended I have never seen a rear end of a car where it is too low, only too high.  So I guess getting rear leaf springs at the proper height is difficult.

When we finally get around to the alignment shop, how much fuel do you usually put in the tank?  I am thinking that Ford did not fill up the tanks at the factory, but only put a few gallons in it.  At 5 gallons, that would add 30# to the rear of the car, while a full tank of 16 gallons would add 96#, so it's only 66# difference between the two. Any suggestions? Thanks

[carlite65]

my old time front end man used to recommend 1/2 tank of fuel. he would also have me sit in the car for the final check.

[Building 3]

That's what we will do.  Thanks!