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bad tranny or bad clutch

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Old 07-28-2009 | 08:47 PM
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Default bad tranny or bad clutch

my tranny is grinding going into third unless i hold the clutch in for 2 to 3 seconds. fourth is the same way and sometimes stick in gear but very rarely. i have new tranny fluid in it. it has a spec stage 3 clutch. my question is if my clutch is close to going out will this cause the issues above. my clutch is starting to slip a little. i was gonna take the tranny in for a rebuild but if its the clutch that would be much better...and cheaper. thanks for any help
Old 07-28-2009 | 08:50 PM
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could it be caused from the infamous sticky clutch?
Old 07-28-2009 | 09:05 PM
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when i push the clutch pedal in its not spongy at all. it feels good and the fluid level is good. sometimes when im in 3rd and i floor it it feels like its slipping, other times it fishtales a little. i noticed it on the way to work this morning in 5th when i tried to pass a diesel truck i gave it some gas and it revved, normal indicator of a clutch going south?? im just wanting to knwo if this can cause the grinding and sticking in 3rd and 4th
Old 07-29-2009 | 09:48 AM
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Originally Posted by Chesty for President
. i noticed it on the way to work this morning in 5th when i tried to pass a diesel truck i gave it some gas and it revved, normal indicator of a clutch going south??

That description is classic clutch slippage, yes, AND, a bad clutch can cause it to "grind" going into gears.....
Old 07-29-2009 | 12:34 PM
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Actually, having and issue with the the selection of a single gear generally evidences a problem with the transmission, not the clutch...the OP references an issue when shifting to 3rd gear and then mentions a potentil for this in 4th as well. It would just be unsual for the clutch to allow for issue when selecting one or two gears while leaving the other alone. When clutch release is to blame for grinding gears it typically affects the selection of 1st and reverse, as selecting 3rd and 4th occur while the vehicle is in motion.

That being said, it would be very unusual for clutch wear to lead to shifting problems. Clutch wear can however lead to slippage and this may be the cause of your secondary issue (slippage) listed above. At this point it seems you need to pull the clutch and examine it for wear or any other factors. Measure the disc thickness and let us know what you find. Check for any contaminant on the assembly while your at it too. And, feel free to contact me with any questions you may have. Thanks,
Old 07-29-2009 | 02:55 PM
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Originally Posted by SPEC-01
, it would be very unusual for clutch wear to lead to shifting problems.,

I don't agree with that. A clutch that is worn can and will lead to shifting issue's, and is not unusual at all for that to be symptons of a worn out clutch, ESPECIALLY one that is slipping.
Old 07-29-2009 | 06:12 PM
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i have this same problem. but stock clutch. would like to know what the problem is before i go get a new clutch even though i need one anyway.
Old 07-29-2009 | 06:26 PM
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As a clutch disc wears it thins. This means that when release occurs it will leave a larger clearance between the disc and its corresponding friction surfaces on the flywheel and pressure-plate. That being said suggesting that clutch wear would inherently lead to shifting issues is rather counter-intuitive and illogical.

A Clutch that slips relative to wear does so as a result of the thinning of the disc and or the removal of material from the flywheel or pressure-plate surface as a result of friction or as a result of reduced clamp-load in the pressure-plate. Relative to wear, this would allow for greater clearance for the disc when the clutch is release which is contrary to the point that you seem to assert. Relative to the pressure-plate, as long as it is functional, even with a reduced clamp-load, it would not affect release.

In regards to clutch function, there are two ways that it could affect the ease by which gears are selected is:

1) If release is not complete:This could occur if the disc was too thick or bent; or if the plate was mismachined...but not as a result of wear. I will be happy to discuss this further if you like.

2) Or if the disc has a significant increase in weight over the originally specified unit which in turn would impact the functionality of the synchros.

Neither of these instances are related to wear. Let me know if you have any further questions. Thanks,
Old 07-29-2009 | 11:12 PM
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Originally Posted by SPEC-01
As a clutch disc wears it thins. This means that when release occurs it will leave a larger clearance between the disc and its corresponding friction surfaces on the flywheel and pressure-plate. That being said suggesting that clutch wear would inherently lead to shifting issues is rather counter-intuitive and illogical.

,

I'll say it again. A clutch that is worn out (and one that is slipping at that) can cause difficulty in shifting. To say otherwise is illogical.

You keep refering to the clutch as just teh disc, but I am talking about it as a package.
Old 07-30-2009 | 09:11 AM
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"You keep refering to the clutch as just teh disc, but I am talking about it as a package."

Gen, I clearly reference the plate in my post and I have provided a copy of it below for you:

"A Clutch that slips relative to wear does so as a result of the thinning of the disc and or the removal of material from the flywheel or pressure-plate surface as a result of friction or as a result of reduced clamp-load in the pressure-plate. Relative to wear, this would allow for greater clearance for the disc when the clutch is release which is contrary to the point that you seem to assert. Relative to the pressure-plate, as long as it is functional, even with a reduced clamp-load, it would not affect release."

Of course the pressure plate can affect release...we can agree on this. But, as far as wear is concerned (which is crux of this discussion), as the parts clearance themselves, release will be greater and shifting will be made easier. Again, as long as the plate is functioning properly: i.e. releasing when the bearing compresses the diaphragm fingers...then it would not affect shifting. If the pivot or the fulcrum were damaged then this would affect shifting...but again, I am referencing a properly functioning plate.

Heat generated from an excessively slipping clutch, could lead to aeration of the fluid, and this could affect release but this is actually a tertiary affect that is relative to the boiling fluid. Perhaps it is this that you are referencing in regards to the impact of wear on shifting. At any rate...let me know if you have any further questions.
Old 07-30-2009 | 09:23 AM
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Chesty, it is worth noting that your reference to needing to depress the clutch for "2 to 3 seconds" in order to select 3rd gear would most likely evidence synchro wear. Remember, as the clutch is depressed (unless you are revving the motor) the RPM's would drop allowing the gears to more easily mesh and reducing the stress on the synchronizers. Since you do not mention that this is required in any other gear (except occasionally 4th), and since the clutch performs the same job no matter what gear is selected, it is safe to assume that the plate is actuating and that the clutch is releasing.

Of course you can always send the unit in to us for assessment if you like. When and where was this unit purchased? But remember that if the unit is slipping (your secondary concern as discussed above) as a result of wear then it is likely time for a new clutch. I'd be happy to work with you an getting a new one. Just let me know how you would like to proceed and we can go from there. Thanks!
Old 07-30-2009 | 09:34 AM
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Originally Posted by SPEC-01
"You keep refering to the clutch as just teh disc, but I am talking about it as a package."

Gen, I clearly reference the plate in my post and I have provided a copy of it below for you:

"A Clutch that slips relative to wear does so as a result of the thinning of the disc and or the removal of material from the flywheel or pressure-plate surface as a result of friction or as a result of reduced clamp-load in the pressure-plate. Relative to wear, this would allow for greater clearance for the disc when the clutch is release which is contrary to the point that you seem to assert. Relative to the pressure-plate, as long as it is functional, even with a reduced clamp-load, it would not affect release."

Of course the pressure plate can affect release...we can agree on this. But, as far as wear is concerned (which is crux of this discussion), as the parts clearance themselves, release will be greater and shifting will be made easier. Again, as long as the plate is functioning properly: i.e. releasing when the bearing compresses the diaphragm fingers...then it would not affect shifting. If the pivot or the fulcrum were damaged then this would affect shifting...but again, I am referencing a properly functioning plate.

Heat generated from an excessively slipping clutch, could lead to aeration of the fluid, and this could affect release but this is actually a tertiary affect that is relative to the boiling fluid. Perhaps it is this that you are referencing in regards to the impact of wear on shifting. At any rate...let me know if you have any further questions.


Right, while I agree with MOST of what you are saying, I am trying to KISS it. And what I am saying is, we don't know how thick or thin or how worn the disc is, nor do we know the condition of teh PP (clamping).
So, what I am saying is that teh clutch is WORN as a whole, as we do not know the condition of the PP or disc, but we do know his clutch is slipping, agreed? So, for all we know, the disc is perfectly fine, and the PP is the culprit in this situation, agreed? And likewise, COULD be the disc, agreed? In these situations, I am talking about the "slipping" he has referred to in these examples, and NOT the grinding, OK?
So, now that we know we have a clutch that is slipping, and we are not positive on which of these parts is teh problem (could be both), we can then say that it can cause poor shifting. Why? Because if in fact it is the PP that is bad, THAT WILL affect shifting, agreed? AND the PP is part of the clutch (KISS) and that is what I am saying.

Sometimes we don't need to "overthink" something. Guy says his clutch is slipping (goes to pass someone, nails throttle, car goes nowhere, but motor revs). We can make a pretty educated guess that his "clutch" is bad (whichever part is irrelevant at this point), and a poorly performing clutch CAN have an adverse affect on shifting, agreed?
Old 07-30-2009 | 10:25 AM
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Your argument thus far has indicated that a worn clutch would have issues shifting. If it is merely worn, though still functional then your argument is incorrect. Secondarily you indicated that I never referenced the impact of the pressure-plate relative to the proper function of the clutch (which I did and reitterated in my last post) yet now you indicate " whichever part is irrelevant at this point". This seems a bit contradictory.

You are correct in saying that we do not "know" for sure what is happening within the bell and I agree with that. But whether the clutch slips as a result of wear, reduced clamp, or contamination...as long as the unit actuates/releases then it would not impact shifting.

"...if in fact it is the PP that is bad, THAT WILL affect shifting, agreed? AND the PP is part of the clutch (KISS) and that is what I am saying"

The above portion of your post takes a logical truth about clutches (a faulty or ill-functioning plate can affect release) and attempts to apply it to a situation, as listed by the OP, that affects a single gear which in and of itself isn't possible.

Remember...if the clutch releases, allowing the user to shift without henderence into other gears then the plate isn't the issue (it can't selectively decide not to release when the OP is shifting into third gear and function fine when shifting into 1st, 2nd, 4th, 5th, 6th and reverse). It doesn't really get any more simple than that!
Old 07-30-2009 | 10:26 AM
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Thanks for the replies but my Marine Corps brain can barely keep up with the above posts LOL. I think I get it for the most part. I called Jason at TDP and when I get some extra cash im gonna take my tranny to him, it needs upgraded anyway. The grinding it ALOT more evident if i do not hold the clutch in for 2 to 3 seconds and thats in 3rd and 4th, also something i didnt mention was downshifting. if im down shiftin i have to go to second then to third to keep the grinding to a minimum, if i do not go into second you can forget about down shifting. I changed the fluid and since then it hasnt stuck in fourth but the grinding it still there. Gen414 ill be hitting you up for a clutch id like to put a new one in when i get the tranny rebuilt but im gonna have to sell my Jeep wrangler first.
Old 07-30-2009 | 03:52 PM
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Originally Posted by SPEC-01
Your argument thus far has indicated that a worn clutch would have issues shifting. If it is merely worn, though still functional then your argument is incorrect. Secondarily you indicated that I never referenced the impact of the pressure-plate relative to the proper function of the clutch (which I did and reitterated in my last post) yet now you indicate " whichever part is irrelevant at this point". This seems a bit contradictory.

You are correct in saying that we do not "know" for sure what is happening within the bell and I agree with that. But whether the clutch slips as a result of wear, reduced clamp, or contamination...as long as the unit actuates/releases then it would not impact shifting.

"...if in fact it is the PP that is bad, THAT WILL affect shifting, agreed? AND the PP is part of the clutch (KISS) and that is what I am saying"

The above portion of your post takes a logical truth about clutches (a faulty or ill-functioning plate can affect release) and attempts to apply it to a situation, as listed by the OP, that affects a single gear which in and of itself isn't possible.

Remember...if the clutch releases, allowing the user to shift without henderence into other gears then the plate isn't the issue (it can't selectively decide not to release when the OP is shifting into third gear and function fine when shifting into 1st, 2nd, 4th, 5th, 6th and reverse). It doesn't really get any more simple than that!


Well it seems you are not understanding me, again. You can throw all the information you want out there, as you obviously are more interested in something other than the whole simplistic nature of this thread....so I will say it again for the cheap seats...If a clutch is worn, it can affect shifting. Period.

Will a clutch allow just one gear to "grind"? Of course not. I know that a clutch is not affecting just 1 gear change, as it obviously is directly related to ALL of teh gears.
But what you keep overlooking is the fact that you are not there with him in his car, driving down the road, so you have no 100% positive proof of what his car is doing, so all you are doing is speculating as to what may or may not be the cause (as am I), and that is exaclty why I try to keep thigs simple. Trying to diagnose a problem over teh internet is difficult, as we don't have all the info, hear all the noise's, feel teh "grinding", etc...

Does he have more problems than just the clutch? Yeah, probaly so. It is not my point though. Point is, a worn clutch can affect shifting, a point you keep overlooking.
Old 07-30-2009 | 04:38 PM
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How does a worn clutch cause grinding shifts exactly?
Old 07-30-2009 | 04:53 PM
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It is clear that we are going to have to agree to disagree on this one...you have your opinions and I have mine. I am basing the info I provide on the info provided by the OP. It's his car and he's used to driving it, so if he says that is is grinding in 3rd, and ocassionally 4th, I take his word for it...since I am not there to drive it myself.

In regards to information, I don't mean to overload you (or the OP) or anyone else for that matter. I am not trying to randomly deposit info for no reason. The information I provide is relative to the discussion at hand. You don't have to agree with me...in truth I don't expect you too! Have a good one!
Old 07-30-2009 | 05:40 PM
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Originally Posted by SPEC-01
It is clear that we are going to have to agree to disagree on this one...you have your opinions and I have mine. I am basing the info I provide on the info provided by the OP. It's his car and he's used to driving it, so if he says that is is grinding in 3rd, and ocassionally 4th, I take his word for it...since I am not there to drive it myself.

In regards to information, I don't mean to overload you (or the OP) or anyone else for that matter. I am not trying to randomly deposit info for no reason. The information I provide is relative to the discussion at hand. You don't have to agree with me...in truth I don't expect you too! Have a good one!

fair enough, and we can leave it at that. Ya see, a nice civilized discussion is all it was...
Oh BTW, you didn't overload me, I understand what you are saying.
Old 07-30-2009 | 05:43 PM
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Originally Posted by cam
How does a worn clutch cause grinding shifts exactly?

PP not disengaging the disc.
Old 07-30-2009 | 06:11 PM
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Gen, I never thought of it as anything more than a debate with two oposing sides...its all good in my book...and I am sure that no one would consider the info I provided as anything more than an explanation of my point. If you have taken any of my posts negatively I sure am sorry...

However, I think that Cam was asking for more specifics. We clearly disagree on the matter so why don't you supply him with an answer. I've made and stood behind my argument...but it seems thus far you have simply indicated that:

"Point is, a worn clutch can affect shifting..."

Wouldn't it stand to argue that if the plate wouldn't release the disc that it was evidence of something more than simple wear? A broken pivot perhaps? A malfunction of the plate?

You are up...lets hear it!


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