Rear end Bottoming out. opinions? Options

[TravisG]

Hi All,


My 73 914-4, just got on the road (IMG:style_emoticons/default/driving.gif) , will bottom the suspension in the rear when I take off in 1st gear quickly. It will also bottom out at speed if I go over a good size bump. At rest, It sits lower in the back than the front. OK, Now the question: Is it the springs, the shocks, or a combinations of the 2? The car is not bouncy when driving, just bottoms out when driven hard. Also where is the best place to get the springs or shocks?

Thanks in Advance

[SLITS]

Springs or if you have adjustable perches they are set to low. I have a couple of cars with weak springs. Replace them and it will come back up to normal ride height.

Oh, if the springs are weak, sometimes you will see lots of negative camber in the rear wheels .... take a pic of the back as it sits and post it or if the wheels are angled in at the top ... weak springs period.

[Sleepin]

Take all the coke out of the trunk! (IMG:style_emoticons/default/blink.gif)



the 914 is a pretty good smuggler car....(IMG:style_emoticons/default/biggrin.gif)

[SLITS]

Take all the coke out of the trunk! (IMG:style_emoticons/default/blink.gif)



the 914 is a pretty good smuggler car....(IMG:style_emoticons/default/biggrin.gif)

You bad man Mr Plick!

[Sleepin]

I don't know whose car this is, but maybe I should have said "take all the guns out of the trunk".

(IMG:http://i171.photobucket.com/albums/u307/Sleepin1974/103_0092-1.jpg)


(IMG:style_emoticons/default/lol-2.gif)

[SLITS]

I don't know whose car this is, but maybe I should have said "take all the guns out of the trunk".

(IMG:http://i171.photobucket.com/albums/u307/Sleepin1974/103_0092-1.jpg)


(IMG:style_emoticons/default/lol-2.gif)

Val's ?

[r_towle]

go jogging...

Rich

[TravisG]

Not much camber on the rear wheels, would have to put a level on it just to notice. The rear fender lip comes down to within 2 inches of the rim, covering the top of the tire.

Here is a pic of when I bought it, It seems to sit just a little lower now on 4 bolt fuchs.

[TravisG]

seems my pic didn't post (IMG:style_emoticons/default/confused24.gif) once I figure this out, I will post pic

[Sleepin]

Read this thread on how to post a pic Travis:

http://www.914world.com/bbs2/index.php?showtopic=83268

[TravisG]

(IMG:http://i583.photobucket.com/albums/ss278/TravisGElliott/NewImage.jpg)

Thanks for the link Eric. I hope this works now. This is the pick of when I first saw the car, Bad engine and all. It was love at first sight.

[SLITS]

That looks like about stock stance for a Teener ... they were set higher in the front due to the front trunk.

The rear could be a little low. Now as to bottoming out ... there is really nothing to bottom out in the rear except for the muffler to hit the ground.

If you hear a thunk on acceleration, it could well be your motor mounts. The two little rubber donuts have seperated and you motor will jump on acceleration. Motor will move around a bit on bumps too! Easy test is to have car on lift and put a pry bar between engine bar and engine ... pull down on the bar ... if the engine goes up ... the mounts are bad.

If you push down on the rear fender and the car keeps bouncing ... it's the shocks. If it comes up and stops ... they're prolly good.

[Sleepin]

I would dial down the front height as well!

[lynn478co]

I would dial down the front height as well!

ahem!!!!.....






(IMG:style_emoticons/default/rolleyes.gif)

[TravisG]

Motor mounts and trans mounts are all new. Just put in rebuilt 2.0 about a week ago. I can push down on corner of car and it comes back up, not bouncy.

When I take off with a little wheel chirp, I hear a quick thud, like it has hit a bump stop. Same sound when I go over a small two lane bridge at speed. It is downhill to the bridge and then a slight level off section. It always bottoms out, even worse with a passenger.

I figure the stock springs must be shot, but being new to the porsche world, I figured the vast knowledge of the list (IMG:style_emoticons/default/pray.gif) might know have other opinions.
All responses have been greatly appreciated.

After removing the cargo from the hidden compartment in the trunk (IMG:style_emoticons/default/lol-2.gif)

[SLITS]

You could reasonably test the springs with a known weight. Depending on who you want to argue with, they are either 90 lb/in or 100 lb/in. Generally black paint and one or two green stripes on one coil of the spring. This assumes the stock springs are still on and haven't been changed.

If the trailing arms bushings are worn out, the inner trailing arm mount ovaled or inner mount nut loose .... you'll get some banging around .... and if loose enough, some exciting handling.

So, if you place 90 lbs on top of the spring, it should depress one inch.

[SGB]

If you think the springs are original, then they are sure to be shot....

I'm afraid to disassemble my trailing arm bushings. Its sure to be wa-aa-ay gone on my 3 or 400k miles car that has had almost everything ELSE repaired or replaced. Chris Foley is the place to go for trailing arms. That will be the good part of finding out how far gone mine are- new arms/ bushings from Tangerine Racing...

[srb7f]

I find it hard to believe that your car truly bottoms out as you have described.

There lots of things that move when the car does the things you describe, and all of them could make noise.

Start simple, with the trailing arms and the bushings between them and the body. Check the status of your rear wheel bearings for excessive play in and out. Check the upper and lower shock bolts.

I would also check the status of your CV joints. Buy a bunch of CV grease, then take off the half-axle shafts, disassemble, and check the inside of the CV joint for deep pits. Re-pack them if they look OK, but replace if they have deep pits worn in them on the inside of the grooves for the bearings. If one of them lets go completely, you won't be able to drive the car.

It's a little hard to describe, but I believe the Haynes manual explains it fairly well. It'll be pretty easy to see once you get them apart.

[TravisG]

I replaced all the cv joints and the boots when I put the new engine about a week ago. It not just a sound that I hear, I can actually feel it bottom out. I have had other cars (non Porsche) that would hit the bump stop and that is what it feels like.

Maybe I should say that the suspension is running its full travel to avoid any confusion about the bottom of the car hitting the road.

I plan on replacing the rear springs, as the shocks seem to be fine (using the push down on the corner and release test).

Is there a practical and simple way to lower the front?

[benalishhero]

I find it hard to believe that your car truly bottoms out as you have described.

There lots of things that move when the car does the things you describe, and all of them could make noise.

Start simple, with the trailing arms and the bushings between them and the body. Check the status of your rear wheel bearings for excessive play in and out. Check the upper and lower shock bolts.

I would also check the status of your CV joints. Buy a bunch of CV grease, then take off the half-axle shafts, disassemble, and check the inside of the CV joint for deep pits. Re-pack them if they look OK, but replace if they have deep pits worn in them on the inside of the grooves for the bearings. If one of them lets go completely, you won't be able to drive the car.

It's a little hard to describe, but I believe the Haynes manual explains it fairly well. It'll be pretty easy to see once you get them apart.

Mine bottomed out until I replaced original springs ,so it's possible.