At the risk of a foodfight it's probable you can be 1500 lbs below your chassis GVWR and still be overweight. Those chassis's are purchased as blanks and then any of number of different floorplan configurations are built on them. You could very well be overweight on one side or the other without being over the GAWR, and/or if you have one or both leaf springs which have lost temper you could very well could be overweight while under the vehicles RRGAWR. The GVW's handed down by some chassis manufacturers are considered by some and admittedly arguably overrated.
Is it normal for the rear suspension to "crash" over every bump in a Class C?
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If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
WME
Well-known member
The leaf spring bushings are likely shot. The spring moves and slams into the shackle bolts, instead of the spring flexing
CharlesinGA
Well-known member
I'm not sure what I am looking at in the pic in post #38. I see the spring, the parking brake cable the exhaust pipe, part of the U bolts for the axle attachment but not sure what the black thing with the label on it is. Its not a bump stop. I also see a place in the upper LH corner where the paint has been worn away.
Bump stop should look like this, its laying sideways, the stud goes up thru a frame bracket and the axle rises up and hits the bottom of the rubber part.
Charles
Bump stop should look like this, its laying sideways, the stud goes up thru a frame bracket and the axle rises up and hits the bottom of the rubber part.
Charles
The photo was of a rubber block mounted to the frame directly above the axle. I assumed that was the bump stop. I'll look again tomorrow.
WME
Well-known member
The front of the spring has a loop forged into it. There is a rubber bushing that goes inside and a large bolt goes through the bushing and brackets on the frame. This isolates vibrations from the tire to the frame.
The rear of the spring has a pair of shackles. They are steel plates say 2"X10". The shackle has a rubber bushing at the top and is bolted like the front. The rear of the spring has a loop forged into it. A bushing goes through the spring "eye". Again a large bolt goes through one shackle, then the bushing and through the other shackle. The spring is curved and as it travels up and down it's length changes the shackle lets the spring flex. If the bushings are shot the spring moves instead of flexing. When it moves it will slam in to the bolts and results in a very harsh ride.
In the photo in post 38 you can just barely see the shackles, they are all discombobulated. They should be parallel.
Each spring has 3 bushings and each bushing is 2 or 3 pieces. Front, rear upper, rear lower
The rear of the spring has a pair of shackles. They are steel plates say 2"X10". The shackle has a rubber bushing at the top and is bolted like the front. The rear of the spring has a loop forged into it. A bushing goes through the spring "eye". Again a large bolt goes through one shackle, then the bushing and through the other shackle. The spring is curved and as it travels up and down it's length changes the shackle lets the spring flex. If the bushings are shot the spring moves instead of flexing. When it moves it will slam in to the bolts and results in a very harsh ride.
In the photo in post 38 you can just barely see the shackles, they are all discombobulated. They should be parallel.
Each spring has 3 bushings and each bushing is 2 or 3 pieces. Front, rear upper, rear lower
PerroSucio
Well-known member
In your photo, the leaf springs look fairly flat and level…..are they not supposed to have some curvature to them ?
Ok I should get the bushings replaced then. I am thinking about trying these polyurathane shackles also.
Sulastic Rear Rubber Springs / Shackles 1980-2020 Ford
Check out the deal on Sulastic Rear Rubber Springs / Shackles 1980-2020 Ford at Diesel Power Products
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WME
Well-known member
Before you just start throwing $$ at the problem get your rig inspected. Starting with the rear spring bushings. The Sulastic bushings work good, so do replacement poly bushings for the stock suspensions
Trying to evaluate a problem over the net is problematic. We all are just guessing based on one photo and our own experience.
Trying to evaluate a problem over the net is problematic. We all are just guessing based on one photo and our own experience.
stripit
Well-known member
I met a fellow once who was saying his class C road worst than a cement truck. We spent some time trying all kinds of things, and what it ended up being the cause was his air rear shocks. Sometime in the past he or someone added air to the shocks, only the compressor must have been filled with water. As each shock was rock hard, filled with no air but a solid water. Replaced the shocks and blew out the air lines, back to being a smooth ride again.
Reinigm
Well-known member
I used to drive a concrete truck. They actually rode pretty good.
Here's an update - I swapped out my nearly-new Bilstein shocks in the rear for Koni FSDs. This has made a huge difference. The Koni FSDs are supposed to "move more" on small bumps and only resist movement on larger bumps. And they seem to be doing that. I don't plan on doing any other suspension upgrades at this point.
