Propwash
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LOL...I tried that...doesn't work. Callused hands are like a cheese shredder man. :worry:
Rear bounces excessively over bumps at 20-30mph
- Thread starter 68 Sport Satellite
- Start date
LOL...I tried that...doesn't work. Callused hands are like a cheese shredder man. :worry:
RustyRatRod
Well-Known Member
Now that really sounds like the voice of experience. lol
Ron 73
Deceased, But not forgotton
:headbang::blob1::headbang:
Jim Bob The Dancing Bear
Well-Known Member
I vote shocks. If you are not worried about the price I would get the Bilstiens that Hotchkis offers.
I just got off the phone with Hotchkis and spoke with 2 of their reps. As you may know, I've ordered direct from them before and had lots of tech questions and they have always been very positive and helpful. This time was no exception. They answered all of my questions and they also seem to think that it's the shocks, specifically the rebound portion. They said that they have no experience with the IAS shocks in my vehicle, but in truck applications they've heard that they work great at stock height, but if the vehicle is lowered at all then the shock starts acting a little different. I have Hotchkis leafs which lower the car about 1-inch. Maybe there's the problem?
At any rate, I was thinking I may have to pull the trigger on a set of 4 just to find out. Not so! I talked to James and he said they don't advertise it on their site, but that I could let all of you know that if you call them direct they will sell sets of 2. Be sure to ask for the 10% off FBBO pricing. I'm pretty happy with that kind of service.
The only downside is the rear shocks are on backorder until end of september (I've heard of this being an issue with these...) I'll let you know how it goes after I get them on my car in a month or so.
Thanks all!
At any rate, I was thinking I may have to pull the trigger on a set of 4 just to find out. Not so! I talked to James and he said they don't advertise it on their site, but that I could let all of you know that if you call them direct they will sell sets of 2. Be sure to ask for the 10% off FBBO pricing. I'm pretty happy with that kind of service.
The only downside is the rear shocks are on backorder until end of september (I've heard of this being an issue with these...) I'll let you know how it goes after I get them on my car in a month or so.
Thanks all!
Jim Bob The Dancing Bear
Well-Known Member
Backorder for a new product may not be a bad thing. It does take longer to get them but hopefully it means that they work great and the word is getting around.
I have had no issues to speak of from anything I have gotten from Hotchkis.
I have had no issues to speak of from anything I have gotten from Hotchkis.
Just a thought. Why not remove the rear shocks, measure the length compressed and extended, then go to a local auto parts store that has competent counter help and have them search for shocks that are a couple of inches shorter. Buy a pair of their cheapest shocks and try them out. If the problem goes away, replace them with the high dollar shocks when they become available. If you still have the problem, you just saved yourself a bunch of money.
Ron 73
Deceased, But not forgotton
LOL... I remember those days!
Thanks for the Firm Feel tip. They had them in stock and should be at my house in a few days. I hope to get them installed in a week or two and will report back.
Ron 73
Deceased, But not forgotton
What ever happened, problem ever get fixed...
I ordered the RCD Bilstein Shocks from Firm Feel. They haven't arrive yet. After they do it will be a week or two before I can get them installed and test them out. I'll keep you guys posted...
Ron 73
Deceased, But not forgotton
Hope it works out good, i would like to hear about them (Bilstein).. Thanks...
Azure
Well-Known Member
Edelbrock IAS shocks are normally installed upside-down compared to most other shocks. (body up / piston rod down) Have you checked to be sure that they are installed in the correct orientation?
Yep, been there and asked that question when first installed. They were indeed installed correctly "upside-down" with dust covers at the bottom. Thanks for thinking of that though.
67 coronet
Well-Known Member
the idea of the lowering being the problem may be correct.ias shocks may be like monroe sensatracs.they are smooth within a short throw of stock and change to stiff when moved farther then normal movement.if the ias shocks are like those you would be using them in the stiff zone(because of lowered stance)and you would get a very strange feel since the smooth part of the travel would happen when they are overextended on your lowered car.you might call edelbrock and ask if there shocks are like this,with a varied stiffness pattern.
67 Coronet - yeah, the IAS stands for Inertia active system. On rough roads they're supposed to behave softer and on smooth roads an internal valve remains closed for a firmer feel and response.
They also say that the shocks "have been designed to deliver an improved ride by eliminating chassis bounce at high speed and to allow for height adjustability at time of installation."
I didn't specify at installation that the rear was 1-inch lower due to the Hotchkis leafs and I'm running 28" tall tires (1 inch taller than stock) so I didn't think it would matter. Maybe it did?
So here's the update! -
After driving Dennis' car, he was helpful enough to put me in touch with one of his go-to mopar mechanics so we could pick his brain and have him help me fine tune the handling of my car. He went through everything with me and over the course of 5 days has my car handling better than I thought possible. Here's what I found out and what was done:
One of the top contributors to my problem was my tire pressure! I couldn't believe it. You learn something new every day...I'm running 275/60/15 Mickey Thompson Sportsman S/T's out back and the same brand tire in a 215/70/15 in the front. Those tires say max pressure = 44psi. This is much higher than the typical 35 psi I'm used to seeing and I've been inflating all 4 tires to 40-42psi. First thing that was done was the rear tires were lowered to 28psi and the fronts to 30psi. This helped the handling and the ride quality tremendously.
Next thing that was discovered was my Moog idler arm which had seen only 1500 miles had a lot of play in it and was thought to have gone bad. When I ordered the rear RCD tuned bilsteins from Firm Feel, i also ordered their fast ratio idler arm and fast ratio pitman arm (both longer than stock and won't work on a big block with most headers. I'm running a small block 360 with headers and they fit fine. They will also fit when I get my 451 big block done since I'm going to be running manifolds). The improved steering response of the fast ratio arms is very noticeable. The feel is great and it's not overly responsive at all.
We also raised the nose of the car by almost 2 inches so it now sits just a hair down from level.
Since I ordered it from Firm Feel, I had the steering sector support installed. This removes slop from the steering box itself moving on the outside and involved drilling two mounting holes in the k-frame.
I left the Edelbrock IAS front shocks on and don't plan on changing them at this time.
The mopar suspension guru also greased all of the heim joints and pivot points with some industrial type teflon oil he uses on his mopars.
Another factor that was fixed that contributed to my handling, although not to the original bouncing issue, was we took my car back to the local rear end shop where I had originally had the 742 case 8-3/4 sure grip rebuilt and I had them pull it all apart again since it was very tight and still hopping and squealing around corners after 1500 miles and the initial 500 mile grease change. They determined that the case was bad after trying to adjust it over 10 times. The spider gears were also now shot. They had a new Auburn sure grip on the shelf and I had them install that with the 3.55's that I had put 1500 miles on. The rear handles like a dream now with no tire chirp around corners, and it doesn't fight the steering of the car anymore.
Last but not least we took it to the alignment shop and had the toe dialed in. The caster was fine as-is at +4.5. Can't remember what the camber was, but I think that was fine too.
After all was said and done, the car now feels great. It steers responsively and predictably. The balance is better with the nose raised a bit. The rear bounce is virtually gone now and feels smooth, but firm. I drove over a bunch of bumpy roads and had no problem at all. I drove over the same road near my house where the problem was originally very noticeable - there is still a bit of rear bounce (there's like 4 or 5 little dips in a row on this one stretch of road), but I would say that the rear bounce and bounce of the whole car has improved by at least 80%.
The mopar mechanic said in his opinion just changing the shocks would not have solved my problem and if we had left them on I may not have been able to tell that much difference between how it turned out.
Thanks for all of your input. I love driving my car now! A few months ago it was stressful to drive and now I feel that it's dialed in nicely.
They also say that the shocks "have been designed to deliver an improved ride by eliminating chassis bounce at high speed and to allow for height adjustability at time of installation."
I didn't specify at installation that the rear was 1-inch lower due to the Hotchkis leafs and I'm running 28" tall tires (1 inch taller than stock) so I didn't think it would matter. Maybe it did?
So here's the update! -
After driving Dennis' car, he was helpful enough to put me in touch with one of his go-to mopar mechanics so we could pick his brain and have him help me fine tune the handling of my car. He went through everything with me and over the course of 5 days has my car handling better than I thought possible. Here's what I found out and what was done:
One of the top contributors to my problem was my tire pressure! I couldn't believe it. You learn something new every day...I'm running 275/60/15 Mickey Thompson Sportsman S/T's out back and the same brand tire in a 215/70/15 in the front. Those tires say max pressure = 44psi. This is much higher than the typical 35 psi I'm used to seeing and I've been inflating all 4 tires to 40-42psi. First thing that was done was the rear tires were lowered to 28psi and the fronts to 30psi. This helped the handling and the ride quality tremendously.
Next thing that was discovered was my Moog idler arm which had seen only 1500 miles had a lot of play in it and was thought to have gone bad. When I ordered the rear RCD tuned bilsteins from Firm Feel, i also ordered their fast ratio idler arm and fast ratio pitman arm (both longer than stock and won't work on a big block with most headers. I'm running a small block 360 with headers and they fit fine. They will also fit when I get my 451 big block done since I'm going to be running manifolds). The improved steering response of the fast ratio arms is very noticeable. The feel is great and it's not overly responsive at all.
We also raised the nose of the car by almost 2 inches so it now sits just a hair down from level.
Since I ordered it from Firm Feel, I had the steering sector support installed. This removes slop from the steering box itself moving on the outside and involved drilling two mounting holes in the k-frame.
I left the Edelbrock IAS front shocks on and don't plan on changing them at this time.
The mopar suspension guru also greased all of the heim joints and pivot points with some industrial type teflon oil he uses on his mopars.
Another factor that was fixed that contributed to my handling, although not to the original bouncing issue, was we took my car back to the local rear end shop where I had originally had the 742 case 8-3/4 sure grip rebuilt and I had them pull it all apart again since it was very tight and still hopping and squealing around corners after 1500 miles and the initial 500 mile grease change. They determined that the case was bad after trying to adjust it over 10 times. The spider gears were also now shot. They had a new Auburn sure grip on the shelf and I had them install that with the 3.55's that I had put 1500 miles on. The rear handles like a dream now with no tire chirp around corners, and it doesn't fight the steering of the car anymore.
Last but not least we took it to the alignment shop and had the toe dialed in. The caster was fine as-is at +4.5. Can't remember what the camber was, but I think that was fine too.
After all was said and done, the car now feels great. It steers responsively and predictably. The balance is better with the nose raised a bit. The rear bounce is virtually gone now and feels smooth, but firm. I drove over a bunch of bumpy roads and had no problem at all. I drove over the same road near my house where the problem was originally very noticeable - there is still a bit of rear bounce (there's like 4 or 5 little dips in a row on this one stretch of road), but I would say that the rear bounce and bounce of the whole car has improved by at least 80%.
The mopar mechanic said in his opinion just changing the shocks would not have solved my problem and if we had left them on I may not have been able to tell that much difference between how it turned out.
Thanks for all of your input. I love driving my car now! A few months ago it was stressful to drive and now I feel that it's dialed in nicely.
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