Whats the clunk you here from the rear of the car when downshifting, and sometimes upshifting.

 

I think it's the goofy two-piece drive shaft. I hate it.

 

I get the same thing but only when upshifting and not all the time either. Any one have this checked out and corrected???

 

It's just take-up slack in the drivetrain, you hear it on sloppy shifts.

 

is it bad for the car?

 

dunno if related...guy at work had a similar clunk in his new pickup- took it in, they just greased the slipyoke and it went away...guess sometimes the splines are a bit loose, grease helps keep the metallic klunk quiet- but probably not for long

never hear mine unless I'm eating a burger, drinkin a coke, talking on the phone and shifting at the same time
seriously, if shifting mine carelessly, it'll klunk a bit, but think its normal these days...atf for tranny lube dont give much 'cushion' to the splines and gears unlike the old 90 weight from decades past...I think most of the klunk in mine is gear/transmission shaft backlash, when i was undercoating, noticed if trying to rotate driveshaft in gear, most of the backlash klunk came from tranny...a little from the rear gears, but slipyoke seemed tight/quiet- my rearend has had a slight whir-whir-whir like sound in synch with 1 rev of the tires, but its not noticeable unless everythings off/light throttle...guessing maybe a little ring gear runout, thought maybe it would lap in as I drove it, but it still sounds like it did new...

one really odd thing- WHY did ford put 2 CV's and ONE ujoint in there???
single ujoint causes accel/decel twice a rev(unless straight- but heard if less than 12 degrees the needle rollers can fret the trunnion journals from lack of rolling)
Seems like with all the NVH R/D being done to improve new cars, this woulda been 2 Cv's and a slipyoke- cheaper/smoother/easier to balance...
the cheaper part is what really makes me wonder- that ujoint wasnt free- in these days when they get rid of things like the rear seatbelt trim to save money, WTF???

 

See, I was going to say the POS drivetrain components, but you had to go and take it to the personal level!

Seriously, i hear that clunk all the time, even when I am taking care to shift "properly," and especially if downshifting to accelerate.

The only way I have found to down shift to accelerate is to get much more into the go pedal before I release the clutch, but when I do this, I get a long clutch release unless I dump it....

ugh. I always thought I could drive a stick, I even owned one previously, but this tranny is giving me fits...

 

Its not a personal thing, when you load/unload the drivetrain with any kind of jerky motion it just slops. A lot of vehicles do this, you just hear it more when the components are big like on a V8 rwd car. Its just the nature of the beast. It doesn't hurt anything.

 

I notice the car clunks less when everything is cold.

 

One can decelerate by letting the revs drop a bit first prior to letting the clutch out. Of course, one must let the clutch out very slowly. Or, if desiring a speed up after, do a rev match first.

The clutch release will be a bit longer and require a bit more throttle to avoid the clunk. In my Roush, I had the cable tightened to have the clutch engage an inch off the floor and be a bit stiffer. This helps and makes shifting faster. Although, streeting a car with such a short clutch one needs to get used to it. My heavy foot requires it as a long release and I would be slipping it.

There is a thread in here called something to the effect of "How well do you think you shift ?" and it talks about some of these topics. Makes for an interesting read.

The T3650 is known to be a bit sloppy - lol - in the S197 Tremec attempted to improve on the design and it helps. The 99-04s are even worse than this and they are less forgiving in less than perfect shifting.

 

I feel the exact same way. Not long after I got my Mustang, I started this thread:
http://forums.bradbarnett.net/showthread.php?t=62215

I still love the car, but the sloppy drive train and clunky shifting constantly bug me.

I've been driving sticks for 40 years. When I drive my Miata, it makes me feel like a great driver...the Mustang makes me feel like a beginner.

 

Like Kevin said, a lot of rwd cars do this, in fact, some more expensive cars have the shift clunk:

• BMW M3
• BMW 528
• G35

So this isn't a Mustang only characteristic....

 

I described my 3650's noises to someone I work with that has a MR2 w/ a 5-speed (2nd gen) and that person gave me this look:

I mentioned the synchro whirr in 1st and 2nd gear at slow speeds when the throttle is closed (WHIRR WHIRR WHIRR WHIRR...), the shift clunking from the 2-piece driveshaft, and the notchy downshifting (that sometimes requires revmatching or double clutching to work properly).

If I do a WOT run up into 2nd gear/3rd gear and shift directly to 5th gear, I'll hear a series of 3-4 clunks back to back: CLUNK CLUNK CLUNK CLUNK.

 

Yes, because everybody knows MR2 5 speed drivers are the ultimate source of transmission/driveline knowledge in the world... What they say is pure gold!

 

I hear it at low speed, especially in a parking deck when I'm looking for a parking space, and I have to slow down or sometimes stop to allow for pedestrians to cross or another car to leave (these require a 1->2 or 2->1 shift--that is when i hear the clunk and feel what seems to be slack). I don't know if its really slack or not. Anyway, that is just my layman's view of it.

 

I've also got a second gen MR2 and the shifter/shifting is excellent - especially considering it's a mid-engine.

 

How does the engine connect to the drivetrain? Is it basically a "FWD" setup that is reversed, with CV joints for the rear axles? How is the shifter connected to the gearbox? I've never looked at the MR2 before until this person told me about their car. It looks pretty snazzy (mid-engine, rear-drive) and balanced.

 

http://www.mr2-tech.com/bgb/mechanic..._transaxle.htm

Looks just like a FWD transaxle...

 

I believe the engine in the MR2 was from the FWD Corolla.

What I have always found amazing was how well it shifts considering how far the shifter is from the transmission.

Granted, we're comparing apples to oranges, but, getting back to the topic, it's normal to compare shifting action when one owns, or routinely drives, several vehicles.

The Mustang is a great car, but the drivetrain slop has been a disappointment to me. And the rev sticking (revs not dropping when the clutch is depressed) drives me nuts.

FYI, I don't hear any "whir".

 

I used to clunk a lot first learning the stick on this car. After awhile, with more clutch slip & gas it went away. Every now and then when I do a sloppy shift at low RPM, I'll still get it. Looking to get a one piece driveshaft later this year to get rid of it for good.

As far as the synchro whir everywhere...I bought a used tranny blanket for 1/2 price, wrapped it around the gear box and it has reduced the cabin noise almost down to nothing. All I want to hear is engine and exhaust!

I'm also running Royal Purple synchromax (debatable w/ Max ATF - somebody should confirm with RP) and that quieted some of the gear/bearing rumble at low RPM (parking lot). Just be sure not to overfill it. I did and it made shifting into 2nd notchier until I drained it a little.