knock in the floor board

stanger9219 · 03-23-2004, 07:09 PM

sometimes, but not always, when i let the clutch out in first, or change gears, there is a knock that i can feel in the floor board. And when i did a burnout for some friends a couple of days ago i felt it knock repeatedly until i let off the gas. Im hoping that at the most it is a clutch problem but want to find it before it grows into something worse. what do you guys think?

429mustang · 03-23-2004, 11:30 PM

I'd look at the trans crossmember bushings (could be trashed rubber or the actual crossmember, the metal around the bushings in my 86 GT rusted out pretty bad) and the engine mounts. We just installed a set of BBK equal lengths in my friends (my old car) 86, they fit tight and rub the steering shaft and hit the frame on the passenger side. His motor mounts are pretty smoked, anthough the headers could be made to fit slightly better

. I'd also go around and make sure any bolts/mounts are tight too.

stanger9219 · 03-24-2004, 02:25 PM

well as i drove the car more i noticed that it doesnt happen as i change gears but as i push and let off the gas. Could this still be the transmission bushings or loose bolts?

Fox Body · 03-25-2004, 03:58 PM

Quote:

Originally posted by 429mustang
I'd look at the trans crossmember bushings ...

That'd be the first place I'd check....

burn rubber · 03-25-2004, 07:51 PM

I had the same problem....my crossmember bolts were loose from the factory...check them.

stanger9219 · 05-15-2004, 01:44 AM

I just wanted to say that you guys were dead on about the problem being the crossmember....took me a while to get around to it but just bought a brand new one. I love this site!!

200k5oh · 05-15-2004, 05:15 PM

my 86 GT had the same problem, i just recently replaced the crossmember. seems to be common with these cars.

Red5Ltr · 05-17-2004, 01:08 PM

Do you have a h-pipe in your Mustang? If you do check to see if it's your h-pipe hitting the underside. I know I had the same issue and I put a piece of heat resistant rubber in between and problem solved.

03-23-2004, 07:09 PM	#1
stanger9219 Registered Member Join Date: Sep 2003 Location: st. louis, MO Posts: 197	knock in the floor board sometimes, but not always, when i let the clutch out in first, or change gears, there is a knock that i can feel in the floor board. And when i did a burnout for some friends a couple of days ago i felt it knock repeatedly until i let off the gas. Im hoping that at the most it is a clutch problem but want to find it before it grows into something worse. what do you guys think? __________________ 98 Cobra, CAI, Flowmasters, o/r h-pipe. 4.10s, Hurst shifter.

03-23-2004, 11:30 PM	#2
429mustang Registered Member Join Date: May 2001 Location: westerville, OH USA Posts: 618	I'd look at the trans crossmember bushings (could be trashed rubber or the actual crossmember, the metal around the bushings in my 86 GT rusted out pretty bad) and the engine mounts. We just installed a set of BBK equal lengths in my friends (my old car) 86, they fit tight and rub the steering shaft and hit the frame on the passenger side. His motor mounts are pretty smoked, anthough the headers could be made to fit slightly better . I'd also go around and make sure any bolts/mounts are tight too. __________________ 1990 Notchback: BBK Ceramic Coated Full length headers, Dr. Gas 3"- 2 1/2" x-pipe, Flowmaster 40's/turndowns.

03-24-2004, 02:25 PM	#3
stanger9219 Registered Member Join Date: Sep 2003 Location: st. louis, MO Posts: 197	well as i drove the car more i noticed that it doesnt happen as i change gears but as i push and let off the gas. Could this still be the transmission bushings or loose bolts? __________________ 98 Cobra, CAI, Flowmasters, o/r h-pipe. 4.10s, Hurst shifter.

03-25-2004, 07:51 PM	#5
burn rubber Registered Member Join Date: Sep 2002 Location: maryland Posts: 22	I had the same problem....my crossmember bolts were loose from the factory...check them. __________________ 01 GT 12.3 @ 112mph Steeda timing adjuster,Steeda underdrive pullies, ,steeda tri-ax 3650 shifter,24#fms injecters,bbk 70mm throttlebody,80mm maf,bassanni x pipe, Borla Side Exit exhaust, fms 4.10's, moser 31 spline axles, custom diablo chip.Steeda caster camber plates,g-trac bar,cobra r ground effects and hood,cobra r springs,ported upper intake.Comp cams #102600,fms jet hot coated shorty headers,mod max cam gears. msd 7020 Stacker 8

05-15-2004, 01:44 AM	#6
stanger9219 Registered Member Join Date: Sep 2003 Location: st. louis, MO Posts: 197	I just wanted to say that you guys were dead on about the problem being the crossmember....took me a while to get around to it but just bought a brand new one. I love this site!! __________________ 98 Cobra, CAI, Flowmasters, o/r h-pipe. 4.10s, Hurst shifter.

05-15-2004, 05:15 PM	#7
200k5oh Registered Member Join Date: Sep 2003 Location: Hometown, il Posts: 30	my 86 GT had the same problem, i just recently replaced the crossmember. seems to be common with these cars. __________________ 86 stang-sold

05-17-2004, 01:08 PM	#8
Red5Ltr Registered Member Join Date: Mar 2004 Location: Sandusky, Ohio Posts: 50	Do you have a h-pipe in your Mustang? If you do check to see if it's your h-pipe hitting the underside. I know I had the same issue and I put a piece of heat resistant rubber in between and problem solved. __________________ 93' Mustang w/ a stock 302 block, E303 cam, 3.73 gears, Pulleys, Edelbrock Performer upper and lower, Edlebrock 70mm throttle body, gt40 heads 1.94 intake, 1.60 exhaust, 1.6 roller rockers, American Thunder exhaust, BBK cold air intake, BBK off road H-pipe, BBK 1-5/8 shorties, AOD with shift kit and 15* timing.

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