Biting point of clutch

UKPhilTR7 · Postby **UKPhilTR7** » 17 Mar 2008 07:29

I have a new clutch in my car and the biting point of the clutch is right at the top of the peddle, just before the point where you would usually take your foot of. I was hoping to have it more towards the middle rather than right at the top.
Does anyone know how I can change the position of my biting point so it is more towarss the middle[?]

tr8coupe · Postby **tr8coupe** » 17 Mar 2008 09:51

[:D]changing the rod to a shorter one might do or a different size master [:D]

BMW Z1 ( sold)
Westfield sport carbon (sold)
Eurosport x1/9 turbo (sold)
TR8 coupe
TR7 v8 monster on 245 tyres all round
TVR VIXEN

TR7_FHC · Postby **TR7_FHC** » 17 Mar 2008 16:26

might be an idea to see if there are too many shims between the clutch slave and the bellhousing.

jeffremj · Postby **jeffremj** » 17 Mar 2008 19:02

<blockquote id="quote">quote:<hr height="1" noshade id="quote">might be an idea to see if there are too many shims between the clutch slave and the bellhousing.
<hr height="1" noshade id="quote"></blockquote id="quote">The system is self adjusting, so the biting point should always be the same. My guess is that the system needs bleeding or the master cylinder seals are leaking (assumes the slave was checked for leaks when clutch changed).

UKPhilTR7 · Postby **UKPhilTR7** » 18 Mar 2008 07:02

Not so long ago I replaced the master and flushed the system. The slave when I took it of looked OK so I didn't replace it. Where is your biting points?

John Clancy · Postby **John Clancy** » 18 Mar 2008 08:51

Biting point is roughly in the middle of travel. Sounds like you could have a perished rubber seal somewhere in the master or slave cylinders.

I've just amended the previous sentence because I should not have put a definite 'you have a perished rubber seal' in without the possibility that it's something else. However, I had this very same problem sometime in the early 90's and it was caused by the clutch master cylinder.

<center>[url="http://www.triumphtr7.com/documents/sales/codenamebullet.asp"]Buy the story of the Triumph TR7/8 on DVD here[/url]</center>

Hasbeen · Postby **Hasbeen** » 18 Mar 2008 13:03

Am I having a gray moment here?

I Presume that the clutch disengages early in the pedal travel, as
well as the clutch biting late.

My thinking is that any air in the system would make the clutch
disengage later, & bite earlier, not later. Any problem with the
thrust race, or fork would have the same effect,

It seems to me that the only thing that can give your trouble is,

1/ The clutch plate is too thin & is only just clamped by the
pressure plate at the last bit of its travel.

2/ The Pressure plate is too far back from the fly wheel, [front of
the cover, which bolts to the fly wheel]

3/ The thrust race is too far forward on the fork, or the fork is
too far forward.

Phil, I hope I am having a gray moment, as if I'm right, only a
little wear will mean the pressure plate will no longer grip the
clutch plate tight enough, & the thing will slip.

Please someone, tell me I'M wrong, & why, otherwise I'm afraid the
thing has to come out to have the correct gear installed.

Hasbeen

jclay (RIP 2018) · Postby **jclay (RIP 2018)** » 18 Mar 2008 13:52

Hum? Apex_Kyle went through a problem like this last year. It seems that although his new clutch pressure plate was listed for TR7s, it was not correct. Forget the names of the manufactures, but here are the pressure plates.

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Apex-Kyle:
The stupid car is on biting point with the pedal fully pressed, even with brand new master and slave cylinder for extra oumph.
Ok rant over, i guess its better than setting the car on fire <hr height="1" noshade id="quote"></blockquote id="quote">

Have fun, drive fast & safe, be kewl,

jclay

terryjm1 · Postby **terryjm1** » 19 Mar 2008 01:58

I have used both types of clutches pictured. It really is not a problem for the biting point to be high. In fact the one listed as "incorrect" I originally purchased as an "uprated" higher spring pressure cover. It works, just bites higher and as advertised with more bite. As the plate ages a bit the biting point gets a little lower.

Terry Merrell
St. Louis, MO

TR Tony · Postby **TR Tony** » 19 Mar 2008 15:50

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Hasbeen

Am I having a gray moment here?

I Presume that the clutch disengages early in the pedal travel, as
well as the clutch biting late.

My thinking is that any air in the system would make the clutch
disengage later, & bite earlier, not later. Any problem with the
thrust race, or fork would have the same effect,

It seems to me that the only thing that can give your trouble is,

1/ The clutch plate is too thin & is only just clamped by the
pressure plate at the last bit of its travel.

2/ The Pressure plate is too far back from the fly wheel, [front of
the cover, which bolts to the fly wheel]

3/ The thrust race is too far forward on the fork, or the fork is
too far forward.

Phil, I hope I am having a gray moment, as if I'm right, only a
little wear will mean the pressure plate will no longer grip the
clutch plate tight enough, & the thing will slip.

Please someone, tell me I'M wrong, & why, otherwise I'm afraid the
thing has to come out to have the correct gear installed.

Hasbeen
<hr height="1" noshade id="quote"></blockquote id="quote">

Yes with you on your line of thinking here, Hasbeen! If there was air in the system or a faulty seal allowing fluid seepage then surely the clutch would bite almost as soon as you start to let the pedal up, or conversly not disengage until the pedal was right down. Biting near the top of pedal travel suggests a fault such as you describe.

My FHC has it's original clutch, and it bites progressively from about half way pedal travel. Last year I had a master cylinder seal leak which caused the biting point to get closer & closer to the floor, as the system was loosing pressure when you depressed the pedal. I changed the master cylinder seals & it's back to normal. The point being that the fluid leak demonstated the opposite symptoms to yours, Phil.

Tony

1981 2L FHC Cavalry Blue - very original & not rusty!
1980 3.5L V8 DHC Regency Red - on the road again.

jeffremj · Postby **jeffremj** » 19 Mar 2008 20:58

<blockquote id="quote">quote:<hr height="1" noshade id="quote">I Presume that the clutch disengages early in the pedal travel, as well as the clutch biting late.

My thinking is that any air in the system would make the clutch
disengage later, & bite earlier, not later. Any problem with the
thrust race, or fork would have the same effect<hr height="1" noshade id="quote"></blockquote id="quote">A good point. It is 'erroring' the opposite around to 'normal'.

Steve @ SandS · Postby **Steve @ SandS** » 20 Mar 2008 11:36

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by UKPhilTR7

I have a new clutch in my car and the biting point of the clutch is right at the top of the peddle, just before the point where you would usually take your foot of. I was hoping to have it more towards the middle rather than right at the top.
Does anyone know how I can change the position of my biting point so it is more towarss the middle[?]
<hr height="1" noshade id="quote"></blockquote id="quote">

What make of clutch did you fit and did you chnage anything else at the same time, pin etc ??????

Steve @ S&S Preparations

Beans · Postby **Beans** » 20 Mar 2008 18:57

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by jclay

... Forget the names of the manufactures, but here are the pressure plates <hr height="1" noshade id="quote"></blockquote id="quote">
LHS is an uprated AP Racing cover (which I nearly cooked last weekend [:I])

On the RHS is a Borg & Beck unit which is (or maybe by now was) sold as a direct replacement for the original TR7 clutch cover. With everything in order the clutch would only disengage with the pedal on the floor, or not at all. I believe it is from a Saab, but not 100% sure.

After changing the cover the problem was gone, clutch engages now were it should, near the half way point of the pedal stroke.

<center>

1981 TR7 FHC Sprint (better known as 't Kreng)
1981 TR7 DHC (not very well known yet, but back on the road)
Also a 1980 TR7 DHC, 1980 TR7 DHC FI, 1981 TR7 FHC
http://tr7beans.blogspot.com/</center>

UKPhilTR7 · Postby **UKPhilTR7** » 24 Mar 2008 11:15

Hi there,
When I changed the clutch, I also put a stainless steel pipe on and changed the master. The only thing that I didn't change was the slave as it looked OK and like it could go for a few more miles.
I am not too sure what type of clutch it was as it has been in my garage for a year waiting for me to get it in. I got it from a Triumph show, from what I can remember it is a German make and everyone I spoke to said it was a really good make.

Beans · Postby **Beans** » 24 Mar 2008 11:54

If it was German, it'll probably be a LuK. They indeed are good.
Was it in a yellow box [?]

<center>

1981 TR7 FHC Sprint (better known as 't Kreng)
1981 TR7 DHC (not very well known yet, but back on the road)
Also a 1980 TR7 DHC, 1980 TR7 DHC FI, 1981 TR7 FHC
http://tr7beans.blogspot.com/</center>

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Biting point of clutch

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