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Long time lurker and owner of a 2003 7.3. I love the beast, and I think it's in need of some TLC.
When driving slow or fast, when I hit bumps, I hear a very loud knock at the front of the truck. It almost sounds like it's hitting the firewall or just below the passenger seat. It is very pronounced at low speed and sometimes the knocking happens loudly when turning and pulling into my driveway.
I have had some work done recently at a reputable suspension place in Denver -
Replaced front say bar end links both driver and passenger side
replaced front hub assembly
inner wheel seal
Axle seal
What else could be causing this knocking? I have plans to take it in to a shop in the next 7-10 days and I'd like to have an idea of what the problem might be. I have a separate issue with my 4x4 and am going to post another thread about that
I would check the right front shock absorber which is far more likely to be the problem. Push down hard on the hood and see what happens. Shocks on my trucks have lasted from 30K to 70K miles before needing to be replaced.
When the front sway bar end links were replaced, were the sway bar bushings changed as well? I had a bump through the floorboards due to these being worn out. Does not take much slop to make a noise.
Possibly worn out leaf spring bushings, or cracked leaf spring. Check those out first just to see if that's the problem
Thanks, I will check for cracks tomorrow and get some pics.
Originally Posted by Winter2
I would check the right front shock absorber which is far more likely to be the problem. Push down hard on the hood and see what happens. Shocks on my trucks have lasted from 30K to 70K miles before needing to be replaced.
Yeah, I've considered that. Thanks for the tip about pushing on the hood. I may have to get a ladder to get good leverage
Originally Posted by BWST
When the front sway bar end links were replaced, were the sway bar bushings changed as well? I had a bump through the floorboards due to these being worn out. Does not take much slop to make a noise.
Not that I am aware of. Thanks for the pictures... I now know where to look so I'll get some pics of the bushings. I am guessing there would be some play in the bushings if they're blown? Would I be able to move that by hand?
Make sure you do not have a protester or animal wrapped around the front driveshaft... they tend to make a rhythmic thumping sound that speeds up with the truck. Just saying.
Lower shock mounts on front leaf spring retainer plates have been found to be loose many times causing an audible clunk and thud in floorboard. The bolts aren't loose but the mount bushing itself wears and allows the shock to flop around on the bolt.
I also say that the first thing, and one of the easiest too, is to remove the shocks and go drive it. Whenever there's a knock like you describe, the first thing I think of is shocks.
^^ Thanks for all the replies. Since I am not very savvy when it comes to vehicle maintenance, AND I recently had my tool boxes stolen out of the truck, I've taken it to a local reputable suspension shop. I expect to hear what they've found tomorrow and I'll see if I can get some pics of what is causing the issue. I did try to bounce the right side and didn't hear anything.. but then I don't think I got a lot of movement. I didn't get under the truck to try and move the sway bar, but a couple of the bushings looked like they might be worn down.
Update tomorrow!
Last edited by charlatan; Jan 9, 2023 at 09:51 PM.
Reason: typing is hard
Update: Turns out it's the front sway bar / bushings. I didn't get any pics but I expect it'll be a much quieter ride when I get it back. Well, as quite as a 7.3 can be anyway
Update: Turns out it's the front sway bar / bushings. I didn't get any pics but I expect it'll be a much quieter ride when I get it back. Well, as quite as a 7.3 can be anyway
Good to hear it may be fixed. BWST nailed it in post #4...
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