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Discussion in '2005+ Mustang GT 4.6L Tech' started by 46addict, Jan 31, 2018.
you can't shim parts at the factory, that's expensive.
In our world, we do it.
I'm not saying you can't or shouldn't. I'm trying to understand why you would with a 13 MC. The engagement point is already high, if you shim the slave 3/8" further, that's going to raise the engagement point further and a full depression of the pedal is going to be really pushing the PP fingers. I would be curious to see how far the PP is being pushed via bore scope in both shimmed/non-shimmed instances. Wouldn't be the first time I've drilled a hole in the tranny bell to see WTF is going on. (For the record, if you do ever drill a hole in the trans bell for a view port, local auto stores have grommet plugs to seal the hole when done, I recommend a dab of black RTV when inserting the plug. Alternatively, I used my tap kit to thread the port and got a short threaded hex plug and red Loctite so it was flush. Helpful for those who don't want to pull the tranny for inspections, IMO.)
I was referring to shimming the slave and checking/cleaning the flywheel.
My stock clutch was making these strange noises that I later tied to a tsb, eventually the clutch grenaded itself and thats why I got my Exedy. I took the clutch to Ford and had them change it. I dont know exactly what they did so maybe they shimmed the clutch too much I dont know.
The engagement point will not be higher.
Shimming the clutch moves it closer to the floor?
I think I see what he's saying. And you aren't shimming the clutch, you're shimming the slave. Because there is only a specific amount of volume the MC can move, it's not possible for the MC to actuate the full length of travel for the slave. If you have an empty cup that measures 12 oz (the slave) and a full cup that measures 6 oz (master cylinder) you can only ever put 6 oz into the 12 oz cup no matter where you move (shim) the cup.
Because the slave can only travel so far, it's important that the base of the slave be pushed far enough forward to have uninterrupted travel when the MC is fully depressed. By moving the slave forward, it ensures the slave doesn't hit the end of it's travel length before the pedal is fully depressed.
The only way to know for sure how much to shim the slave, is to know the distance between the bolting surface of the engine block and the face of the PP fingers, and the distance between the face of the bell housing and the face of the slave bearing (+1/8" for the metal tranny gasket that goes between the engine/tranny that I can't remember wtf it's called). Subtract those, and the remainder is how much travel the slave will have available. From there, you add shims if you need more travel, as you don't want the salve to be fully run out.
Important constants to know would be what the length of travel is for the slave being pushed by a given MC. 13 GT500 MC will have more travel than a OEM GT MC. The difference shouldn't be much, you're just looking to make sure the slave doesn't hit the end of its travel before the pedal is fully depressed.
Excellent insight 86, wish you could have just spelled it out for us lol.
I think everything helps a little but but a lot of this stuff is just worn out or defective parts.
I should test stroke volume on gt vs 500 master. Wouldn't tell you much as I don't know slave piston area.
I was thinking more physical test. Put a slave and master on the bench and test. Either way, unless you're trying to thread a needle as far as accuracy goes, the difference between the two shouldn't be so substantial that you can't afford say, a 1/4" buffer between the end of the travel stroke and the end of the slave center shaft and be just fine on either MC. I still encourage the '13 GT500 MC over the OEM GT MC, if for no other reason than better design so you don't have pressure leak-by at the internal seals.
Been waiting to find a post like this. My issues are similar but different. Magnum xl swapped. Recently switched a McLeod rxt and new sc in the car and it feels so much sloppier for some reason. When the car gets hot, it’ll get “stuck” in whatever gear you’re in. And when you engage the clutch it doesn’t fully disengage and the car sill continue to roll. And it also HATES shifting at anything higher than 4.5k so I can’t hardly beat on the car without a missed shift. I never shimmed the sc when I put this new one in, so I’ll do that and 13-14 MC as well and see how that goes.
Also, I never shimmed my new Slavs I put in, and my clutch disengage is nearly to the floor, which an rxt is not supposed to do. Assembly and install was textbook, but I didn’t know to shim the slave so I’ll say that’s my fault.
Let us know how it goes
Yep, I bet the shim is the issue. Clutch not fully disengaging would cause all the symptoms you describe.
But why would it be inconsistent? That’s my only concern.
I didn’t pick up on the inconsistency thing. If the issue is not consistent, that would point more to the TOB, in my opinion.
Or, it is the shim, and syncro alignment on some shifts is such that it’s less of an issue sometimes. I’m spitballing ....
My issue is pretty inconsistent too. I can literally shift by pushing in the clutch about a quarter of the way to the floor no problems but other times I can push it to the floor and still get locked out.
I have some money saved up now and Im in the process of getting my 87 grand marquis ready to be my dd. Once I do that Ill get a new clutch for the 07.
Also recently I had a run in with a branch in the dead of night, a few dents and it took off my antenna. Ill have time to fix it now lol.
I had a relatively new clutch kit in mine when bought it about a year ago. While the car shifted fine moving, it wouldn't go into gear sitting still. What's weird, once you got it into gear, it was fine. Even when you pulled it out of gear sitting still, if you still had the clutch pedal depressed, it would go back into gear like butter. But, if you released the pedal (while in neutral), then depressed it again and tried to grab first or reverse . . . forget about it. While trying to force it in, the car would actually roll forward like you didn't have the clutch depressed.
But, again, only under those conditions. During any other conditions, the car would go into gear fine, the release point was high in the pedal travel, it didn't roll while grabbing the gear at idle, and it never grinded.
So, I bought a new clutch kit and TOB and had the shop install. While it was easy to replicate the problem for them driving the car . . . when they pulled the old clutch out, they could see nothing out of the ordinary with it -- no signs of any problems. But, they installed the new clutch and TOB, and the problem was fixed.
Point here, the clutches on these cars are wacky. Doesn't seem to be a whole lot of rhyme or reason to them when trying to diagnose the clutch/tranny. Even now, I believe that my car still requires too much shifting effort to move into gear at idle, or from gear to gear when moving. But, it has literally never had a grind or lockout at any kind even at high RPMs, so perhaps its just the nature of this transmission. Feels like shifting a tank compared to my other manual cars. I also have a short shifter, so that makes it worse.
Thats spot on with my symptoms too. It seems like a lot of exedy clutch owners complain about these problems too. Since I have an exedy clutch and a worn out tob my symptoms are compounded.
The one thing I love about my 02 gt is the direct shifter. It still has a tr3650, and has a pro 5.0 shifter set to the lowest setting and its tight but feels great no sloppiness or missed shifts. That car Ive practiced no lift shifting a few times and its fantastic, yes yes I know its bad for the synchros, I doubt I could do that with my 07 gt.
I hate to bring this thing back from the dead but I noticed today if I double clutch 1-2 and 3-4 I have no issues with it falling into gear. What would that point to?
I just started a new job and have no time to get the clutch done just yet. Im about to take it off the road and put my 02 gt back on the road after I get it all back together. At least I can shift that one...
Double clutching just slows down the speed at which you shift. It's almost more of a timing technique than "mechanical magic." It also unloads the tranny. Even during normal shifting, some load is carried by the tranny (assuming "normal" is within a second or two).
In this instance, I think the advantage gained is in synchronization. Even then, double clutching is really for down shifting. Assuming the clutch is disengaging from the flywheel properly, for whatever reason the synchro's aren't keeping up with the next gear selection. The operation goes as follows; rolling in 1st gear at 3,000rpm clutch out > clutch in and move to neutral > clutch out in neutral, engine rpm and transmission re-synchronize > engine rpm falls to 2,000rpm, clutch in and select 2nd gear > clutch out, engine and transmission are in sync from the last engagement point of 2,000rpm (which should be fairly close to the appropriate engine rpm for that gear ratio at that speed).
Synchro's don't work as hard when you double clutch because you're pre-synchonizing the engine/transmission between gears. Modern transmissions shouldn't need this technique, unless there's a serious synchro problem. Most synchro issues show signs, such as shitty shifting when trans fluid is cold but improves after it warms up. Additionally, if you use the incorrect type of fluid or weight, it could be shitty all the time, or in the case of type, even reverse (be shitty warm and smooth when cool). And all kinds of funky if both wrong type AND weight (I should say viscousity).
If double clutching will get you down the road, more power to ya. But it's sounding more and more like it's time to service that tranny. Curious about fluid you're running. Fluid level should be verified as well, but probably just as easy to change it. Royal Purple is good stuff, I ran their 20w50 XRC (XCR? FUCK it was something fancy... maybe it was 0w50? Ah hell... it was awesome shit whatever it was, saved me $100's on ATI's crap propritary blower oil) in my procharger for a couple years, cured all kinds of issues. Synchromesh is a good one too. I ran Motorcraft ATF Mercon V in my 3650 the whole 70k/mi I had the car though. Once I fixed the clutch, it was smooth as glass (as a 3650 can be...). Did my clutch fix at 30k/mi, so I was shift-issue free for 50k/mi. Best 50k/mi of its life though.
It was a spur of the moment thing I thought Id try it to see how it affected shifting since I cant find any problems. Funny Ive checked synchros per Fords tsb (unrelated) and passed but it does seem like a synchro problem with the lockout issues at random rpms. Even today I was locked out of second in a parking lot and literally nothing helped it go into gear. I had to stop and put it back into first.
I dont remember what fluid I used but I do believe it was Mobile 1 and I do remember it was in a red bottle. I havent even messed with it since I drained it about 50k miles ago. I plan on a dump and fill here soon anyway and I was looking at either synchromesh or dex/merc. I figure the shifting cant get any worse than now...
Also what is a good stock replacement clutch? After running an Exedy Id rather go back to stock or something similar.