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Jerky driveline

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My Boss has developed a jerky driveline when coasting down then re-accelerating, as in turning a corner in second gear then applying power out of the corner still in second gear. My dealer had the transmission out for a rebuild and this condition has developed since. It's become pretty hard to drive the car smoothly around town. The worse instance was on a side street with my wife where I had to coast down in second gear while an oncoming car cleared the lane. When I hit the gas to go, both our heads nearly bounce off the head rests from the shock of the power hitting the driveline. That's very disconcerting. I find that I have to apply power very carefully until the slack in the driveline is taken up.

The car was very smooth driving before, no clunks or jerkiness at all. Are there any specific parts or tolerances related to removing the transmission that may have caused this? I expect that I will send the car back to the dealer to try and correct the problem but I'd like to get an idea of what to expect before I set that up.
 
401
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This is one thing I really hate about the car. Im at 26000 kms with stock driveline as it came from the factory and have this issue as well.
 

dmichaels

Papa Smurf
547
30
CT
Mine has a good amount of slop too, mostly notice at low rpms. It hasn't bothered me enough yet to bring it in, but sounds like yours is worse. I haven't tried to diagnose but it kind is feels to me like its more towards the rear end of the car
 
Justin said:
Every since the 05 mustang and the two piece shaft I have experienced this. once I put a one piece alum driveshaft in them it went away.

There are mods I'd like to do to the car but I want to make sure that the car is basically sound first. The transmission was rebuilt because it was grinding it's way through the synchros in second and third. The rebuild did not cure the problem so I have ordered an MGW shifter to see if that helps...not that I wanted to replace the shifter on a 100 percent street driven car. It's just a factory weakness that needs to be addressed before I can even drive it to work properly.

Now that this clunk has shown up following the rebuild, I may have to go the route of a new driveshaft...not that I need a fancy new driveshaft but this issue needs to be addressed before the car can be driven normally. As of right now, the car is bone stock. I did not want to have to spend a ton of money on it just to be able to drive it down the street but here we are....
 
For the grinding issue I would think going the way of a new clutch may fix that. More expensive than a shifter, but if it fixes it then who cares, and I guess if it doesn't then you at least have a new better clutch. Are you driving around with the stock key or Trackey?
 

Justin

Save the dawn for your dishes!!!
the clunk is normal and doesnt mean its broken or is going to break. thats just the nature of it with it having twice the joints as a one piece DS. going with a one piece you will get rid of the clunk but you might gain some rear gear noise. so pick your poison on what noise you can live with.

The grinding I would take it to a dealer and have them look at it might be able to get a new clutch from the dealer for free and see if that fixes it.

A new shifter is a nice thing to have IMO but it too will give you some more NVH from the drivetrain. thats why the factory put a big bubble gum bushing on the back of it so people wouldnt complain about noise.
 
Justin said:
A new shifter is a nice thing to have IMO but it too will give you some more NVH from the drivetrain. thats why the factory put a big bubble gum bushing on the back of it so people wouldnt complain about noise.

That's one thing that really ruins the Boss to me, compared to the new Z28, which I am sure will have some sort of compromise. Seems silly to make a performance car but try to make sure it doesn't make any noise that may bother people.
 

Justin

Save the dawn for your dishes!!!
Brandon302 said:
That's one thing that really ruins the Boss to me, compared to the new Z28, which I am sure will have some sort of compromise. Seems silly to make a performance car but try to make sure it doesn't make any noise that may bother people.
thats what we have the aftermarket for :) but the shifter on the boss was just carried over from the GT's. would have been nice for them to have that FR shifter installed on the cars from the factory. but they were trying to keep the costs down so I get that.
 
The transmission has already been out of the car to be rebuilt once. It wasn't/isn't so much an audible grinding noise but rather the feeling of pulling the shifter handle through a bag of marbles when it's cold. Shifting it gives me that heebie-jeebie feeling of expecting it to catch and grind at any time. I have stopped using second gear, shifting first-third, until the car is thoroughly warmed up so I don't cause any damage.

Prior to the tranny rebuild, the rest of the driveline was solid and tight...no slop or jerkiness at all. I have to believe that it is not a characteristic of the vehicle. The jerkiness of rotating masses slamming into each other is surely not something that would pass NVH standards.

I have an appointment tomorrow and the dealer will try to address both issues.
 
If it doesn't grind and only feels notchy then I wouldn't worry about it. If it does grind then I would start worrying about something not being right.
 

Justin

Save the dawn for your dishes!!!
Boss0960 said:
The transmission has already been out of the car to be rebuilt once. It wasn't/isn't so much an audible grinding noise but rather the feeling of pulling the shifter handle through a bag of marbles when it's cold. Shifting it gives me that heebie-jeebie feeling of expecting it to catch and grind at any time. I have stopped using second gear, shifting first-third, until the car is thoroughly warmed up so I don't cause any damage.

Prior to the tranny rebuild, the rest of the driveline was solid and tight...no slop or jerkiness at all. I have to believe that it is not a characteristic of the vehicle. The jerkiness of rotating masses slamming into each other is surely not something that would pass NVH standards.

I have an appointment tomorrow and the dealer will try to address both issues.
try running redline MTL in the trans its what I and many others run in their bosses and for me it helped with cold weather shifting.
 
I've noticed the same "jerking" at low speeds, low RPM's. It is annoying and makes you think something isn't right. But It is just a minor annoyance as of now. Only have 3200 miles on it so far.
 

Grant 302

basic and well known psychic
Some slop is normal in our drivelines. If the dealer made it bad/worse with the tranny work, you should take it in and have them look at it and record that this problem came up after they did the work.
 
After annoying me on and off for a while and most recently a whole day of driving, I could not replicate the jerkiness on my way to work this morning or on my way to the dealer after work. It drove perfectly all day today even when I tried to create the conditions in which it happened before. No chance of getting it fixed if I can't show them the problem. That's weird, frustrating and little embarrassing.

I still went to the dealer. Talked about the rough shifting synchro issue. This issue doesn't really present itself if I shift at or above 3500 rpm. The service adviser suggests I drive more aggressively and use more revs all the time. It still feels like there is something wrong with the synchros but he says they will fix it if I break it. In the meantime, I'm supposed to drive it like a rental...doctor's orders.

I know some people only shift above 3500 rpm but that seems a little high for my quiet side street at 6 AM.
 
That seems like bull, not to say it isn't fun to shift above 3500, more like 6000, but still. I am able to shift mine fine around 2k so it does sound like something is wrong, seems a little reckless to ask you beat on it.
 
My '13 Boss has two rolling inches of drive line slop. Jerky on the throttle at low speed and that wonderful clunk getting back on the power in 6th gear. With the number of complaints out there it sounds like it's the price of admission for driving this thing.
 
Sometimes I have to ride the clutch to keep mine from jerking around at low RPM, 1 to 1.2k especially with trackey. But this isn't the first car that I've driven that's done this. I think it's more noticeable because this one has a lot more HP to get it jumping. This just my take on it.
 

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