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Discussion Starter · #1 ·
This year's Winter project

This year's Winter project is the overhaul of the rear suspension on my 365BB. It was 15 years ago since the entire suspension on the car was last rebuilt...and with the "odd" handling issues that I was trying to resolve last Summer, the time seeem right to take a look/see at the suspension again. Here's the starting point:



As of today, the rear suspension is totally disassembled. So far, I have found that all of the rear shocks have little to no compression dampening. The outer bushing at the upright are OK, though show some signs of the rubber swelling. All of the inner (larger bushings) are very swollen...and offer little support to the metal inserts.

As the brakes hoses are now 11 years old, they'll be replaced, as well. SS braided lines, this time around...

The front shocks have been removed, as well. The condition is similar to the rear. No rebound remaining...and very, very stiff under compression!

More as this project progresses...

Regards,
David
 
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Discussion Starter · #2 ·
David: I would be interested

David: I would be interested in your progress. My Boxer had new springs, and shocks installed by the PO, a couple of years ago. I feel my car sits too low in the rear. The space seen between the fender edge and the top of the tire is much smaller in the back.

Should the space be the same, front and rear?
 
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Discussion Starter · #4 ·
David: I do recall those phot

David: I do recall those photos. At first I just ignored the lower rear........with new shocks, and all. But now I do think that it is not right.

I have coils over shocks, with a large "ring" nut where I can adjust the height. However, to raise the car any more would require compressing the spring, possibly too much......thus a stiff ride.
 
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Discussion Starter · #5 ·
Henry,
Seems that you have ad


Henry,
Seems that you have adjustable spring perches in your BB (Not OE)...Personally, I'd raise the rear (or lower the front), as it is desireable to have the rear either level, or slightly higher than the front. My car sits just shy of 0.4" higher in the rear than in the front. Although you will affect the spring pre-load a bit, as well as shock travel, the spring rate does not change if you raise the lower perches. Give it a try, and see...
Alignment does change with ride height adjustments.

Regards,
David
 
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Discussion Starter · #6 ·
When I first started to invest

When I first started to investigate, I put the car on my lift. With the wheels hanging, I was able to turn the springs by hand........one was even too loose. So I tightened the lower nut so the springs are just snug, with the wheels hanging.

It seems that I can't lower the front any more. I will then raise the lower perch in the rear. But to raise them I will be compressing the spring, much more than in the front. It would seem that I will have to compress the spring about 1-1.5 inches. How will this affect the ride?
 
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Discussion Starter · #7 ·
>>It would seem that I

>>It would seem that I will have to compress the spring about 1-1.5 inches. How will this affect the ride?<<

Hi Henry,

to answer the above, you won't know till you try it. What we do know is that improper suspension settings will make a car handle poorly. So until your suspension is set up correctly, it must be handling at a state that's less than optimum.

If the cars rake is not correct this can also seriously affect braking performance and characteristics.

Regards, JRV
 
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Discussion Starter · #8 ·
Thanks; My first impression w

Thanks; My first impression was that the new springs that the PO bought where too short in the rear, hence, the lower ride height.

I will turn the lower perch up, to where the body is level.
 
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Discussion Starter · #9 ·
David is corect about changing

David is corect about changing the ride height by adjusting the spring perchs. It will not change the spring rate. You do need to get the rake set correctly, and also, by adjusting the spring perches, you are changing the corner weights. Weight will be changed diagonally across the car.(Lf to rr)and(Rf to Lr) You should scale the car when you change the spring height setting, as the car will handle differently on right and left corners if the "cross weight" is not as close to equal as possible.On a street car cross corner weights should be within 30 pounds. Rons Mondail was weighted and found to be less that 5 pounds differance. Any good race prep shop has the platform and scales to do this quickly. I would not just raise or lower the ride height and rake without checking the corner weights after. It can produce evil handling problems
 
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Discussion Starter · #10 ·
Agree with Bob on the corner w

Agree with Bob on the corner wieght situation.

It might be wise to simply find a shop that can corner balance the car and have them adjust ride hieght & suspension geometry & corner balance all at the same time.

Regards, JRV
 
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Discussion Starter · #11 ·
Looked at your picture one mor

Looked at your picture one more time and noticed the sway bar. If you adjust the spring perches and don't corner weight the car, you can also cause the swaybar to pick up "preload". That will create more strange handling problems.Can't see in the pic if the swaybar has an adjustable link,down to the lower control arm, but, that is where you would adjust the bar for no preload when the car is sitting at the new ride height with the corner weights set.I can add more info about the correcting handling problems and suspension setup if anyone is interested. Bob
 
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Discussion Starter · #12 ·
Interesting to see what's

Interesting to see what's going on here. As you chaps know I'm about to pull the engine on my 512BB. It's all ready to come out but I've had to order a new crane because the one I have doesn't extend far enough.

I've been looking at the suspension wandering what to do. The problem is that I bought the car in a non-driveable condition (at least not legally) so I haven't had much chance to assess the handling. Nor would I know what to look for anyway, being honest. The question is, do I wait to get the car back on the road and fix only what needs to be done, or should I expect that things are pretty bad? I have no information to suggest that any work has ever been done in this area. A visual inspection reveals only a lot ot corrosion, especially on the shocks. Cost is not really an issue but I don't want to do things just for the sake of it. I thought I would at least remove the shocks and springs but should I perahps just go for the lot? I know it's not a clear cut question but your opinions would be valued.
 
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Discussion Starter · #13 ·
Jeremy and David, If the shock

Jeremy and David, If the shocks are Koni's, Send them to Koni and have them rebuilt and dyno'ed. It does not cost very much. I have my Penski /triple adjustable shocks rebuilt and dyno'ed for $400 with shipping both ways. Second, if you put a wrench on the suspension, why would you not install new bushings? Then have the car aligement done,caster, camber,toe and ride height set. Then do the final corner weight setup. Then drive the car without all the drama, because it will be handle right.If you can't figure out the corner weight deal, think of a small 4 legged table with a book on its top. Now cut one leg shorter. Short leg will have no weight on it,but the table still weights the same. Move the book over to the short leg and now that leg(short) weighs more than the leg across from it which is now up off the floor. Same thing with the 4 corners of a car, A light weight right front wheel(Short leg)will produce understeer in a left corner,and so on. Corner weights are very important and most people never set them.Ferrari made this stuff adjustable,ever wonder why?
 
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Discussion Starter · #14 ·
I changed all 6 shocks on my B

I changed all 6 shocks on my BBi as I was hearing a knocking from the driver left rear area. New Konis all around cost $140 per, and new shock-end bushing were about $20 each (if I remember correctly - caution - upper and lower bushings for rears are not the same). It made a world of difference in ride and handling. I did not remove the suspension parts to change bushings as I did not wish to have the car down for that long. I did have the springs sand blasted and painted (along with the green and red strip - front and rear). It is important to measure the spring height unloaded, and compare against the WSM specification.

Also - be careful when removing the lower front shock mounts (two bolts to provide swing clearance). There are spacers forward and aft that have a propensity for falling on the floor before you realize they are there. These are, of course, your camber/caster alignment shims. Also, when removing the rear brake calibers to provide clearance for the rear aft shock, there are shims between the caliber and the mount that set the geometry (parallel) the caliber (brake pad) to the rotor. When these drop to the floor, you won't know which was on top or bottom.

I chose to purchase new Konis rather than rebuild as they were available and comparably priced. I did not have such luxury on my 365 GTC/4, which necessitated rebuilding the load levelers.

Have fun.
 
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