Drivetrain How to fix driveshaft rubbing on the floor pan?

AnthonyA1234

5 Year Member
Aug 17, 2020
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Florida
How should I go about solving this? It makes no noise when driving the only way I know this happens is because of the marks on the DS. Can I just hammer the floor pan?
 

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Some more pics
 

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Under normal conditions it should not rub, you need to look at suspension travel for how to fix.
This car ever have a bad wreck?
As far as I know it hasn’t, the chassis looks straight to me.

Car has H&R springs, bilstein shocks/struts, poly spring isolators, and the MM pinion snubber for lowered cars. It also has energy suspension motor and trans mounts.
 
Same reply from your other thread:

So is it just me or does it look like there has been a piece of sheet metal added over where the DS is hitting? Almost like a DS blew up and they patched the floor.

I had H&R Super Sports on my Coupe with 245/40R17’s on all four corners with Tokico Illumina dampers and never bottomed out there.
 
Same reply from your other thread:

So is it just me or does it look like there has been a piece of sheet metal added over where the DS is hitting? Almost like a DS blew up and they patched the floor.

I had H&R Super Sports on my Coupe with 245/40R17’s on all four corners with Tokico Illumina dampers and never bottomed out there.
Agree.
 
You really need to pull the back seat and see what is going on.

Spring rate on the Super Sports is:
Front: 700-760 lb/in
Rear: 275-300 lb/in

You can see that to compress the rear one inch will take 275 to 300 lbs (progressive rate). I have the same non-adjustable MM LCA's on the car that I had with the Super Sports and by nonadjustable I mean they are the ones that you cannot jack the ride height up and down. I also have the I have same audio setup in the car that I had in it then which is two JL Audio 10W3's, the enclosure, three Fosgate amps, and my spare in the trunk of the Coupe. I have to really compress the suspension to get it to bump the DS. Something is way off on your car man.
 
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You really need to pull the back seat and see what is going on.

Spring rate on the Super Sports is:
Front: 700-760 lb/in
Rear: 275-300 lb/in

You can see that to compress the rear one inch will take 275 to 300 lbs (progressive rate). I have the same non-adjustable MM LCA's on the car that I had with the Super Sports and by nonadjustable I mean they are the ones that you cannot jack the ride height up and down. I also have the I have same audio setup in teh car that had then which is two JL Audio 10W3's, the enclosure, three Fosgate amps, and my spare in the trunk of the Coupe and I have to really compress the suspension to get it to bump the DS. Something is way off on your car man.
How do you pull out the rear seat?
 
Do a search on here. Easier than me explaining it.
Pulled out the rear seats. Couldn’t see anything that didn’t look factory. I did see some cracks on the floor pan above the driveshaft just before the rear seats but I guess that could just be normal stress cracks with age. Let me know if you see anything strange or if I should be taking pictures of anything else.

Thanks for the help by the way.
 

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Yup. The floor pan has been damaged and they just put some kind of plate under the car and my guess is they used an adhesive to bond it to the floor pan. You really need to remove that plate and weld it up or have it welded up properly or if it is bad enough replace that section of the floor pan.

I am not saying that this is the cause of all your DS to floor pan contact problems but it could be depending on how far down from the floor pan the "repair" plate is. It really needs to be fixed the right based soled on the fact the car is a unibody and the floor pan is part of the substructure on the car.
 
Yup. The floor pan has been damaged and they just put some kind of plate under the car and my guess is they used an adhesive to bond it to the floor pan. You really need to remove that plate and weld it up or have it welded up properly or if it is bad enough replace that section of the floor pan.

I am not saying that this is the cause of all your DS to floor pan contact problems but it could be depending on how far down from the floor pan the "repair" plate is. It really needs to be fixed the right based soled on the fact the car is a unibody and the floor pan is part of the substructure on the car.
Are you sure? I’m looking at the bottom of my car and comparing it to pictures online and it all looks factory to me. That metal piece goes throughout the entire underside of the car with all the unique shapes on it.

Also the cracks do not have any metal under them it’s just cracked there not sure why.
 

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It is really hard to tell without putting the car on a lift. Some of the pictures convince me one way and others don't. Regardless you need to weld up the rips in the floor pan.

What are the part numbers on the rear springs? Should be on the coils in white letters in several spots.
 
The part number is 51650 R. Which I believe is the correct spring. I got the Maximum Motorsports starter suspension kit which came with the bilstein shocks/struts, H&R sport springs, MM camber caster plates, poly spring isolators, and shorter pinion snubber.

I’m wondering if removing the shorter pinion snubber and putting the stock one back will help?

Also what if I remove that dog bone weight on the bottom of the diff could that help?

Another thing, someone in my other thread recommended the Stifflers tranny cross member. Can this cross member allow me to adjust the tranny up and down?