Ford Mustang Forum banner

Motor Mounts and now Driveshaft?

4K views 19 replies 5 participants last post by  PMDmustang13 
#1 ·
Approximately 3 weeks ago my car started making a clunking noise. It turned out that my top red polyurethane bushing for my steeda motor mounts had failed. I should have originally installed the black bushing on the top of the passenger side and bottom of the driver side because I used to occasionally race my car down the 1/8th mile in the previous couple years and I have attended about 3-4 road course events.

I replaced the top bushing with the black one and then a week ago I heard some clunking again. Had the car towed home and inspected the motor mounts and found there was damage to both the top and bottom driver side bushings. So I replaced both of those bushings with 2 new black ones that Steeda provided to me free of charge. The car seemed to be back to normal and I drove it for around 20 miles.

Then I was on the interstate going about 60 mph and I started experiences really strange vibrations and a noise. I hit a dip in the road and the noise and vibration went away for about a mile or so and then the vibration and noise redeveloped. If I gave the car more gas in 5th and 6th gear the vibration was so bad my rear view mirror started shaking violently. So I got of the interstate and limped the car to where I needed to get my daughter on time. I heard intermittent clunking similar to when the motor mount bushings were failing. I had my buddy bring my ramps, jacks, and tools and inspected the motor mount bushings and they appeared to be fine and I could not find the source of clunking. I disassembled the driver side once more to make sure all was well and found nothing. So I drove the car home and the clunking did not reappear. When I got home I took the passenger side mount out and put a new red bushing on the bottom and reinstalled. I thought all was well again and then I thought I heard my exhaust rattling and contacting the bottom of the car. I readjusted the passenger side overaxle pipe to get a little more clearance.

Again I thought I had solved my problem but when I left to go to work I am now hearing more of a clicking/pinging sound and occasional clunking. I put the car up in the air again and when I turn the rear wheels I hear the same pinging sound. I also started the car and put it in gear and was able to get the clunking noise again with the pinging sound also. When I get underneath the car and rotate the driveshaft back and forth it makes a pinging sound as if something is loose in the driveshaft near the end by the CV joint. This is an aftermarket 3.5" diameter one piece aluminum driveshaft rated for 900 hp. From day one I would experience a slight single ting sound when first movement in reverse. I believed that was normal. Has anybody else ran into a similar problem? Does anyone know how the CV joint is attached to the 3.5" diameter aluminum shaft? I am guessing there is a female spline welded to the AL shaft and the CV joint has a male shaft inserted within and held with split rings.

I am going to reinstall my OEM 2 piece shaft Friday night hoping that solves the problem. If not then I guess I better check the transmission mount. Am I correct to assume that I don't need to adjust my pinion angle after installing the two piece shaft. I have the pinion angle set at -1 degrees with the one piece shaft in accordance with BMR recommendations.
 
See less See more
#2 ·
No feedback yet. Probably too long of a story/post. Anyway just want to try and figure out what is wrong with my car and I am not trying to lay blame on any aftermarket parts or Ford. Just want it back on the road with minimal cost and all fairness.
 
#3 ·
I had the DSS shaft and it would ping and on turns and starting from a stop. Not sure if that's what your hearing. I replaced it with a dynotech shaft. All is good now.

do you have that whiteline transmission bushing still in place? Does it look like the motor is centered or if it has moved slightly with you hit that dip in the road.
 
#7 ·
Yes I have the whiteline bushing in place at the transmission mount. I did not notice if the motor is off center. Maybe you mean the transmission off center? I will check that tonight when I start checking the torque of the driveshaft fasteners to see if they have somehow loosened.
 
#4 ·
I had the DSS shaft and it would ping and on turns and starting from a stop. Not sure if that's what your hearing. I replaced it with a dynotech shaft. All is good now.

do you have that whiteline transmission bushing still in place? Does it look like the motor is centered or if it has moved slightly with you hit that dip in the road.
 
#5 ·
WAG...mayhap the mount/bushing/spacer isn't sitting properly? On mine (JHR) there was a spacer which you put in/out if you wanted to change motor height. IDK if it was you but I remember a conversation about lowering the motor and how close it would put the oil pan to the motor mount...I would also look at that.
 
#8 ·
WAG? Wives and Girlfriends? I have triple checked that the metal bushings, poly bushings, and the metal spacers are sitting properly. But I will look again tonight. I have all the metal spacers in and yes I believe I had posted something about being careful of clearances and as a result I never took the chance of removing any spacers.
 
#6 ·
Wasn"t this one of the reasons Ford chose to use a (2) piece drive shaft in the Mustang,angle of drive shaft from engine/transmission to the rear diff,I have read so many threads on vibration problems and noise, when a one piece drive shaft was installed,and the benefits were pretty nil, other than a little weight and noise (clunk). I know the 6 banger had a different problem with there drive shaft breaking at higher than recommend speed, but the GT was not affected by the same problem.
 
#10 ·
I believe you are correct on why Ford went with 2 piece shaft. I am beginning to also believe the benefit of a 1 piece shaft is not much except for weight and less joints. I am going to put in the original shaft tonight and see if I can determine if the transmission mount has been damaged or broken.
 
  • Like
Reactions: 5.0 Coyote
#13 ·
Friday night I was able to get the clinking noise to occur by putting the car in 1st gear with rear end off the ground and supported by jack stands. If I applied the emergency brake the noise would occur and it sounds like at the rear of the driveshaft. But I also found out that sometimes when I would push the clutch in the rear tires were still being powered by the engine/transmission. So I still believe there might be something wrong with the driveshaft but now I also believe that the slave cylinder does not have the proper preload for the aftermarket clutch that the dealer installed for me this summer. This is likely the cause of not being able to get the car to shift into gears if I come to a stop and put the car in neutral. When I am locked out of gear I have to shut the car off to put the car in gear.

I started to check the torque of the bolts attaching the driveshaft to the pinion adapter and gave up because I was just too frustrated. The car is scheduled to go to the dealer on November 8th. In the mean time I might remove the driveshaft and put the OEM shaft back on. And send the driveshaft to the manufacturer for inspection and repair if needed. Or I might just wait and have the dealer remove the shaft and install the OEM shaft. I am a little undecided right now.
 
  • Like
Reactions: 5.0 Coyote
#14 ·
I feel for you,there is nothing more troubling than to have more than one problem at the same time with your Mustang.A friend of mine had the same type problem with his slave unit when he changed out his clutch, for the BETTER aftermarket clutch,upgraded his slave unit and the problem was solved.I have a 2011 GT but still have the 2 piece Ford drive shaft in my garage queen,23,000 miles still quiet, and no vibraitions (A/T), so I am happy there,I wish you the best of luck in solving your problems, and thanks for the update, and keep us posted:smile:
 
#15 ·
Update. I believe both my problems have been solved thanks to the service technician at my dealer. We were able to determine the clunking noise was the CV joint on my aftermarket driveshaft. I believe that I had caused the damage to my CV joint because there is a dimension from the end cap on the aluminum tube to a piece of the CV joint that is supposed to be between 3.25" and 3.75". I was also told by the driveshaft manufacturer that I could actually go a little over 4". Well I measured the distance on my shaft recently to be 4.125". That is likely more than a little over 4". I had ran that shaft with that dimension since this spring after I installed my Watts link. At that time I had adjusted my LCA's about 1/8" longer than stock because I had an interference with my stock sway bar. I did not think about the driveshaft dimension requirements at that time.

Anyway the service tech installed my OEM 2 piece shaft, shortened my LCA's, adjusted the thrust alignment to be 0.00 degrees, and cut off some steel on the watts link that I believe was interfering with the sway bar.

When we were getting ready to take it for a test drive the technician was able to duplicate my other issue with being locked out of gear if I put the car in neutral, let out the clutch, and then pushed in the clutch and try to put it in gear. He hooked up a tool to my brake fluid reservoir to apply vacuum to the reservoir and pump the clutch pedal to bleed the hydraulic system. It did not seem to work right away. However, during our last test drive the issue went away. We believe that there must have been an air bubble in the hydraulic system that was causing the clutch to not fully disengage.

The technician noted the issue on my service bill and let me know that if it happens again to bring the car back in and go from there. I still have until 4/19/17 and about 6000 miles left on my 12 month 12000 mile warranty associated with the installation of my centerforce clutch, OEM flywheel, OEM pilot bearing, and OEM slave cylinder.

I drove the car home and it was shifting 100% properly with no issues. However, I am crossing my fingers and I am going to try and take it easy on my car for as long as I possibly can so I don't break something else. I feel a little jinxed lately with breaking motor mount bushings and a driveshaft during the same period of time.
 
#17 ·
I thought the lock out problem had been solved. But this morning after posting in this forum it was acting up again on my way into work. There must still be some air in the hydraulic system. And possibly from air in the brake lines even though the brakes feel fine? I will drive it some more in the next few days and monitor it.
 
  • Like
Reactions: 5.0 Coyote
#20 ·
OK I will keep an eye on the fluid. I drove it during the lunch hour and it was not locking me out of gear. I will keep pumping the clutch to release any air bubbles.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top