Front end dive help
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Front end dive help
Hi,
I have a 95 Aerostar xlt with 199K. I have a pretty bad dive to the front end even under mild braking. I have replaced the front struts in the last 30K and never the back. I thought that the back pads may be shot allowing only the front brakes to grab but after checking they are low but not gone. They have about 3/16 of pad left at the lowest point and grab the drum pretty well with the tire removed and checking for any movement with brake depressed. I have not checked the front brakes yet but they too were done not that long ago so I dont believe they are grabbing and it feels smooth when braking except for the front end dive. I dont mind replacing the front struts again if needed but first I wanted to see if I could get another opinion on what else there could be that might cause this. I searched for these terms to avoid an unnecessary post but surprisingly I found no results for "front end dive"?
Thanks,
Jeff
I have a 95 Aerostar xlt with 199K. I have a pretty bad dive to the front end even under mild braking. I have replaced the front struts in the last 30K and never the back. I thought that the back pads may be shot allowing only the front brakes to grab but after checking they are low but not gone. They have about 3/16 of pad left at the lowest point and grab the drum pretty well with the tire removed and checking for any movement with brake depressed. I have not checked the front brakes yet but they too were done not that long ago so I dont believe they are grabbing and it feels smooth when braking except for the front end dive. I dont mind replacing the front struts again if needed but first I wanted to see if I could get another opinion on what else there could be that might cause this. I searched for these terms to avoid an unnecessary post but surprisingly I found no results for "front end dive"?
Thanks,
Jeff
Post Fiend
Joined: Apr 2005
Posts: 5,720
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From: Washington state
the nose heavy hog Aero has to have high pressure shocks on the front end such at top line Konis, Tokico, Biltstein or KYB. the low pressure Monroes or Gabriels are worthless especially in hard braking
put in new sway bar poly bushings and don't grease them. Energy Suspension makes top quality
have the rear drums turned to remove hard glaze. flush the brakes and put on new Rabestos PG Plus rear shoes with new return springs and new cylinders for best braking performance. look for FF rated shoes, will be inked on the side of the brake shoe material. the factory OEM FoMoCo rear shoe material on the Aero is much too hard and they glaze
seat in the new shoes and drum resurface with 10 hard maximum stops from 40 mph to 5 mph without complete stop. then park and let brakes cool off with brakes released.
check the operation of the RABS and proportioning valve to make sure they are working and have fresh new clean brake fluid in them
the Aero will never handle like a low slung stiff suspension ricer on roids and nitrous
put in new sway bar poly bushings and don't grease them. Energy Suspension makes top quality
have the rear drums turned to remove hard glaze. flush the brakes and put on new Rabestos PG Plus rear shoes with new return springs and new cylinders for best braking performance. look for FF rated shoes, will be inked on the side of the brake shoe material. the factory OEM FoMoCo rear shoe material on the Aero is much too hard and they glaze
seat in the new shoes and drum resurface with 10 hard maximum stops from 40 mph to 5 mph without complete stop. then park and let brakes cool off with brakes released.
check the operation of the RABS and proportioning valve to make sure they are working and have fresh new clean brake fluid in them
the Aero will never handle like a low slung stiff suspension ricer on roids and nitrous
Lead Driver
Joined: Sep 2003
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From: SoCal
How are the springs? Does the van look like it's always going downhill or uphill? Maybe you need new springs as well.
Also check to see if the bushings on the control arms are worn out.
Suspension dive on braking (and squat on acceleration) is strongly determined by their geometry. Often times, what appears to be front end dive is actually rear end lift. If the suspension geometry has been upset by things like worn springs, it can exacerbate things like dive and squat. The axes of the front control arms are fixed, so it's mostly the attitude of the rear control arms that affect the instant center, which has direct affect on the dive and squat characteristics. Certainly the high center of gravity of a van does not help this.
Also check to see if the bushings on the control arms are worn out.
Suspension dive on braking (and squat on acceleration) is strongly determined by their geometry. Often times, what appears to be front end dive is actually rear end lift. If the suspension geometry has been upset by things like worn springs, it can exacerbate things like dive and squat. The axes of the front control arms are fixed, so it's mostly the attitude of the rear control arms that affect the instant center, which has direct affect on the dive and squat characteristics. Certainly the high center of gravity of a van does not help this.
Posting Guru
Joined: Jul 2004
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From: Mitchell, SD
Originally Posted by copper_90680
Nighthawk,
I just have to ask, now that you are working at a Ford dealer
Do they still carry the front springs for an AWD?
Thanks.
I just have to ask, now that you are working at a Ford dealer
Do they still carry the front springs for an AWD?Thanks.
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Thanks for all the replys.
I have some checking to do. The rear end lift you speak of was one of the things I suspected but thought of it more of a situation where the rear breaks were not doing their share causing the weight to load up on the front end when stopping. If it is the rear struts would that problem necessarily show up by depressing the rear of the van as if I was testing for worn shocks/struts? I have tested both the front and rear by quickly pushing down and releasing the front and rear of the van. I do not get much if any bounce although I would say that if I had to pick one the front seems a little softer than the rear.
Again thanks for the help and I will check those other items mentioned.
Jeff
I have some checking to do. The rear end lift you speak of was one of the things I suspected but thought of it more of a situation where the rear breaks were not doing their share causing the weight to load up on the front end when stopping. If it is the rear struts would that problem necessarily show up by depressing the rear of the van as if I was testing for worn shocks/struts? I have tested both the front and rear by quickly pushing down and releasing the front and rear of the van. I do not get much if any bounce although I would say that if I had to pick one the front seems a little softer than the rear.
Again thanks for the help and I will check those other items mentioned.
Jeff
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Lead Driver
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From: SoCal
Jeff,
You can check the operation of the rear brakes by trying to stop using only the parking brakes. (Do this in a safe place of course.) Start at about 20 mph, and pull hard on the hand lever. See if the van dives as much as when applying the normal brakes.
In general, when you apply the brakes, there is "weight transfer" toward the front; the mass of the van pushes against the center of mass, levering about the instant center, and the net result is loss of weight on the rear wheels. In this case, brake pressure to the rear has to be reduced, or the rear wheels will lock up. On most cars, the front brake do about 80% of the braking. But on taller vehicles, like vans, it's more like 90%. So the rear brakes don't really contribute much to overall braking, and therefore have little affect on weight transfer. (Unless of course, you do the above experiment.)
You can check the operation of the rear brakes by trying to stop using only the parking brakes. (Do this in a safe place of course.) Start at about 20 mph, and pull hard on the hand lever. See if the van dives as much as when applying the normal brakes.
In general, when you apply the brakes, there is "weight transfer" toward the front; the mass of the van pushes against the center of mass, levering about the instant center, and the net result is loss of weight on the rear wheels. In this case, brake pressure to the rear has to be reduced, or the rear wheels will lock up. On most cars, the front brake do about 80% of the braking. But on taller vehicles, like vans, it's more like 90%. So the rear brakes don't really contribute much to overall braking, and therefore have little affect on weight transfer. (Unless of course, you do the above experiment.)
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Postmaster
Joined: Apr 2001
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Originally Posted by copper_90680
Nighthawk,
I just have to ask, now that you are working at a Ford dealer Do they still carry the front springs for an AWD?
Thanks.
I just have to ask, now that you are working at a Ford dealer
Do they still carry the front springs for an AWD?Thanks.
Posting Guru
Joined: Jul 2004
Posts: 2,416
Likes: 1
From: Mitchell, SD
Originally Posted by aerocolorado
He will need the spring code for the AWD. I can't remember but its on the driver's side door data plate.
It looks like Ford has discontinued all of them (F19Z-5310-A) except for W which superceedes to X. I am not sure that Ford is just using the X as the general replacement for all AWD or not, sometimes their descriptions of what is going on is lacking in communication.
Post Fiend
Joined: Apr 2005
Posts: 5,720
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From: Washington state
nighthawk
does that mean that dealer parts rooms drop them from their online inventory?
try these guys, if they don't have it or can't get it for a Ford from the Henry J days forward, it does not exist
http://www.greensalescompany.com/
does that mean that dealer parts rooms drop them from their online inventory?
try these guys, if they don't have it or can't get it for a Ford from the Henry J days forward, it does not exist
http://www.greensalescompany.com/
Postmaster
Joined: Apr 2001
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Originally Posted by 93nighthawk
True, so I checked all of them.
It looks like Ford has discontinued all of them (F19Z-5310-A) except for W which superceedes to X. I am not sure that Ford is just using the X as the general replacement for all AWD or not, sometimes their descriptions of what is going on is lacking in communication.
It looks like Ford has discontinued all of them (F19Z-5310-A) except for W which superceedes to X. I am not sure that Ford is just using the X as the general replacement for all AWD or not, sometimes their descriptions of what is going on is lacking in communication.
Posting Guru
Joined: Jul 2004
Posts: 2,416
Likes: 1
From: Mitchell, SD
Originally Posted by 96_4wdr
nighthawk
does that mean that dealer parts rooms drop them from their online inventory?
try these guys, if they don't have it or can't get it for a Ford from the Henry J days forward, it does not exist
http://www.greensalescompany.com/
does that mean that dealer parts rooms drop them from their online inventory?
try these guys, if they don't have it or can't get it for a Ford from the Henry J days forward, it does not exist
http://www.greensalescompany.com/
Actually today my Parts Manager (17 years) and I had discussed how to tell the difference between the springs (mainly how much weight they hold) He has no idea which one would be more firm/softer, load rating, ect. Ford does not tell us. (It is a common question on the pickup side of sales, lots of owners come in want beefier springs, and the computer doesn't say.)
Anyway, to the point, Yes you can still purchase OEM replacement springs. The question is, will there be a change in ride compared to your current spring code? And I don't have an answer to that.
I will check with one of the tech's monday and see if he has some more insight for you.
Freshman User
Joined: Dec 2001
Posts: 39
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From: South of Austin, TX
Originally Posted by 93nighthawk
no 96, front springs are still availible through your local FLM dealer. The issue is which springs that originally came with your Aero. As Areocolorado said, you need to match the spring code on the door with the new springs that you get. Ford has discontinued all the other ones except for the W/X spring codes.
I wonder if the dealer checked for code x springs?
Does anyone know who has code w or code x?
Posting Guru
Joined: Jul 2004
Posts: 2,416
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From: Mitchell, SD
Originally Posted by grostig
I also need code w springs for you 1995 AWD Aerostar. My ford dealer in TX today said they were not available anywhere in the country. I think he checked the Ford warehouse computer and other dealers. I need two.
I wonder if the dealer checked for code x springs?
Does anyone know who has code w or code x?
I wonder if the dealer checked for code x springs?
Does anyone know who has code w or code x?