Rear shocks
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Lahti411
- Posts: 128
- Joined: Sat Jan 29, 2005 2:23 pm
Rear shocks
Does any of you guys happen to remember how thick the KYB rear shock cartridge body is? I bought a while a go a pair of Gabriel-brand 3/4 ton truck shocks as i couldn't find anyone selling the KYB shocks for U.S. trucks. I tried to install the Gabriel shocks to my car today but the cartridge body is so thick (56mm) that it was rubbing against the rear trailing arm. So obviously i can't use those... I found some other brad available and asked how thick would these shocks be. The vendor told they are 50,35mm thick so i think these might fit. Any opinions?
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wshawn
- Posts: 209
- Joined: Thu Dec 27, 2007 6:36 am
I couldn't source KYB ones in the UK either so found some Sachs gas shocks that fit the front 3/4 ton Ford Econoline van, '75-'91 for £60 for the pair.
I had to pack out either side of the lower bush with some washers but they are working fine and are an imprpovement on the oil filled ones that were on there.
I had to pack out either side of the lower bush with some washers but they are working fine and are an imprpovement on the oil filled ones that were on there.
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raygreenwood
- Posts: 11910
- Joined: Wed Jan 22, 2003 12:01 am
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herr_sparky
- Posts: 145
- Joined: Wed Oct 24, 2001 1:01 am
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Lahti411
- Posts: 128
- Joined: Sat Jan 29, 2005 2:23 pm
While tinkering with the rear suspension i desided to change the rear coil springs as my car had a strange front-high/rear-high appereance. My car has always had a trailer hitch so i guess someone has installed the heavy-duty rear springs into it. These springs were really stiff and as i'm going to change the original shocks to harder Ford truck shocks i thought the rear would be too hard with HD springs.
Here's a pic where you can see the difference between the normal and heavy-duty spring. HD on the left:
The HD springs has less coils and its taller. I forgot to measure the material thicknes but it seemed to be thinner in the HD springs.
Here's a pic where you can see the difference between the normal and heavy-duty spring. HD on the left:
The HD springs has less coils and its taller. I forgot to measure the material thicknes but it seemed to be thinner in the HD springs.
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herr_sparky
- Posts: 145
- Joined: Wed Oct 24, 2001 1:01 am
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Lahti411
- Posts: 128
- Joined: Sat Jan 29, 2005 2:23 pm
These might be original factory options M263; Heavy duty rear springs. Atleast they were a perfect fit. Ofcourse they might be from another car but as my car has always had the trailer hitch it might be possible that the rear springs were fitted from the factory. I have never seen another car with such springs so i have nothing to compare with, though.
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raygreenwood
- Posts: 11910
- Joined: Wed Jan 22, 2003 12:01 am
Stooooooop!
(sigh)
How many times do I have to wrirte this one ...
...but I will.
The front end is designed to sit that way. 98% of the time there is nothing at all wrong with the rear end.
Heed this well: I have rebuilt more 411/412 suspensions that probably anyone on this forum. I have done most every mod you can...and many you cannot and should not....and suffered an learned. The only ones who have done more than I have...are Wally...who has gone forward in a very engineering wise manner to heavily upgrade his suspension.
That being said.....this is the WHOLE purpose of my modification of using an Audi front strut cartridge with a custom stub. It lowers the front end to dead level (actually mine is just a hair lower)....and as a functional by-product...has about 200% stiffer damping and oscillation rate control.
The factory front end is artifically high....as a design defect...because they put extra agressive springs on the front end to counter what would happen if you filled the cavernous trunk with weight. Over the years they had two different spring designs with two seperate series of spring loading (blue and yellow) and progressivness and three different strut cartridge set-ups....for a grand total of seven permutations...trying to fix this. They quit making the car before they changed anything.
What you are seeing is that when the front is lifted...the body pivots around the rear axle....... get it?
That means that since the front and rear body are part of the same piece...it drives the rear downward. Have a person stand on teh front bumper to drive the front end down level...and you will discover this immediatly.
Putting truck shocks from a Ford pick-up on will be a disaster. I have done this. The rear suspension of the 411/412 will destroy truck shocks in about a month....literally blows the seals out of them.
Why?...because the truck....has very large rear leaf springs. The shocks have NOTHING to do with how the rear of either the truck...or the 411/412 sits. They are simply DAMPERS...to arrest velocity. Yes you get a SMALL amount of lift from gas shocks because they are loaded upward. You get about 1/2" at best.
The rear suspension of the 411/412 has a very long trailing arm. The shocks are situated toward the outboard...rearmost end of this long arm. The pivot point is at the other. This creates a very high leverage situation...with a long stroke...and high velocity.
The rear of teh trucks on te hother hand have very large leaf springs, short stroke and low velocity. They are valved totally different.
Our rear shocks were the same VALVING as those on the front end of 1/2 ton and 3/4 ton vans. They have medium length double A-arm deep draw suspension. yes there is an engine up there on the vans.....but there are massive coil springs as well.
I Have destroyed one set of rear Ford F-150 Bilsteins and a two sets or Rancho rs-9000 five way adjustable shocks for teh same vehciles (f-150 and F250). I did that simply because they have a lifetime warranty.
This is NOT just about the measurment of the stroke and the outer diameter. The valving MUST be correct.
A for instance...the audi front struts I seleted...were the result of cutting open over 50 different strut cartridges...measureing shims, calculating bypass and measuring valve spring tension. It took me over a year to come across strut cartridges that would fit with mods, have more capacity to damp than stock...but have the correct valving to not shatter the springs in the ball joints...or shred the strut bushings.
The shocks have little or nothing to do with the ride height of the rear of your 411/412. They are also extremely critical in valving.
Just buy gas shocks listed to fit the front end of teh ford econoline 1/2 ton or 3/4 ton truck. You will get a much better upgrade than stock just because of the use of modern gas shock....but it will have the correct valving for the spring rate.
If you have done the front audi strut mod and it does not sit level...then something has not been done correctly. Ray
(sigh)How many times do I have to wrirte this one ...
...but I will.The front end is designed to sit that way. 98% of the time there is nothing at all wrong with the rear end.
Heed this well: I have rebuilt more 411/412 suspensions that probably anyone on this forum. I have done most every mod you can...and many you cannot and should not....and suffered an learned. The only ones who have done more than I have...are Wally...who has gone forward in a very engineering wise manner to heavily upgrade his suspension.
That being said.....this is the WHOLE purpose of my modification of using an Audi front strut cartridge with a custom stub. It lowers the front end to dead level (actually mine is just a hair lower)....and as a functional by-product...has about 200% stiffer damping and oscillation rate control.
The factory front end is artifically high....as a design defect...because they put extra agressive springs on the front end to counter what would happen if you filled the cavernous trunk with weight. Over the years they had two different spring designs with two seperate series of spring loading (blue and yellow) and progressivness and three different strut cartridge set-ups....for a grand total of seven permutations...trying to fix this. They quit making the car before they changed anything.
What you are seeing is that when the front is lifted...the body pivots around the rear axle....... get it?
That means that since the front and rear body are part of the same piece...it drives the rear downward. Have a person stand on teh front bumper to drive the front end down level...and you will discover this immediatly.
Putting truck shocks from a Ford pick-up on will be a disaster. I have done this. The rear suspension of the 411/412 will destroy truck shocks in about a month....literally blows the seals out of them.
Why?...because the truck....has very large rear leaf springs. The shocks have NOTHING to do with how the rear of either the truck...or the 411/412 sits. They are simply DAMPERS...to arrest velocity. Yes you get a SMALL amount of lift from gas shocks because they are loaded upward. You get about 1/2" at best.
The rear suspension of the 411/412 has a very long trailing arm. The shocks are situated toward the outboard...rearmost end of this long arm. The pivot point is at the other. This creates a very high leverage situation...with a long stroke...and high velocity.
The rear of teh trucks on te hother hand have very large leaf springs, short stroke and low velocity. They are valved totally different.
Our rear shocks were the same VALVING as those on the front end of 1/2 ton and 3/4 ton vans. They have medium length double A-arm deep draw suspension. yes there is an engine up there on the vans.....but there are massive coil springs as well.
I Have destroyed one set of rear Ford F-150 Bilsteins and a two sets or Rancho rs-9000 five way adjustable shocks for teh same vehciles (f-150 and F250). I did that simply because they have a lifetime warranty.
This is NOT just about the measurment of the stroke and the outer diameter. The valving MUST be correct.
A for instance...the audi front struts I seleted...were the result of cutting open over 50 different strut cartridges...measureing shims, calculating bypass and measuring valve spring tension. It took me over a year to come across strut cartridges that would fit with mods, have more capacity to damp than stock...but have the correct valving to not shatter the springs in the ball joints...or shred the strut bushings.
The shocks have little or nothing to do with the ride height of the rear of your 411/412. They are also extremely critical in valving.
Just buy gas shocks listed to fit the front end of teh ford econoline 1/2 ton or 3/4 ton truck. You will get a much better upgrade than stock just because of the use of modern gas shock....but it will have the correct valving for the spring rate.
If you have done the front audi strut mod and it does not sit level...then something has not been done correctly. Ray
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Lahti411
- Posts: 128
- Joined: Sat Jan 29, 2005 2:23 pm
I think you got it all wrong Ray...
I'm going to replace my cars rear shocks with Ford 1/2 tonne truck FRONT shocks. Just the way you have described several times here.
My car had HD rear springs and i replaced those with original 411 Variant rear springs. The HD springs were very stiff and they lifted the cars tail so that with KYB cartridges (for 411/412, NOT Audi) in front, the car seemed to be on tip-toes: nose-high, tail-high.
At this point my car has the Audi cartridges in front and sachs 411/412 gas shocks in the rear with original, unmodified springs on all corners and it sits LEVEL.
I had bought already Gabriel-brand rear shocks that were originally ment for the FRONT of 3/4 tonne ford truck, but they were too thick in diameter (wouldn't fit into the trailing arm cavity) and i couldn't use those. So, i'm going to order some other brand and install those to my cars rear.
I'm going to replace my cars rear shocks with Ford 1/2 tonne truck FRONT shocks. Just the way you have described several times here.
My car had HD rear springs and i replaced those with original 411 Variant rear springs. The HD springs were very stiff and they lifted the cars tail so that with KYB cartridges (for 411/412, NOT Audi) in front, the car seemed to be on tip-toes: nose-high, tail-high.
At this point my car has the Audi cartridges in front and sachs 411/412 gas shocks in the rear with original, unmodified springs on all corners and it sits LEVEL.
I had bought already Gabriel-brand rear shocks that were originally ment for the FRONT of 3/4 tonne ford truck, but they were too thick in diameter (wouldn't fit into the trailing arm cavity) and i couldn't use those. So, i'm going to order some other brand and install those to my cars rear.
Last edited by Lahti411 on Sun Feb 22, 2009 2:02 pm, edited 1 time in total.
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raygreenwood
- Posts: 11910
- Joined: Wed Jan 22, 2003 12:01 am
Truck or van? There were are a few Ford trucks that also use the same parts # front shock as the Econoline 150 and 250 van....and those are identical to the rear of teh 411/412. But please be sure you have the correct part number. There are also some F-150, F-250 and F-350 trucks that have different valved shocks. Those are what you got the first time.
There are quiet a few different permutations. The shocks you want...have to be specific to certain years of Van or truck. They are not generic across the entire van and truck line because of difference in front A-arm and spring diameter. The ones you got that were too fat...are for a larger truck with a heavier coil spring and will have thw wrong diameter. Wait a day and I will pull up a list of dates and years of Ford Vans and trucks that all use the same correct front shock for you.
I think this is also all in here in the archives somewhere...the list I mean. Ray
There are quiet a few different permutations. The shocks you want...have to be specific to certain years of Van or truck. They are not generic across the entire van and truck line because of difference in front A-arm and spring diameter. The ones you got that were too fat...are for a larger truck with a heavier coil spring and will have thw wrong diameter. Wait a day and I will pull up a list of dates and years of Ford Vans and trucks that all use the same correct front shock for you.
I think this is also all in here in the archives somewhere...the list I mean. Ray
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Lahti411
- Posts: 128
- Joined: Sat Jan 29, 2005 2:23 pm
Yeah i got the list, but the retailer sold me infact 3/4 tonne van HD front shocks. So i guess the HD specification was too much. US cars have always been quite rare here so the retailers don't have that many options to choose from. But i'll take the list with me when i go shopping next time and make sure that the shocks will be ordinary 1/2 tonne van shocks not HD.
Here's the topic i got the part numbers from in case somebody else needs it:
http://www.shoptalkforums.com/viewtopic.php?t=120870
Here's the topic i got the part numbers from in case somebody else needs it:
http://www.shoptalkforums.com/viewtopic.php?t=120870