rec.autos.simulators

by **Ed Benso** » Wed, 23 Apr 1997 04:00:00

> >>Except that most teams now use a Jehrico transmission, where a clutch is
> >>not necessary for shifting. The gears simply fall into place.

> Depends what model you purchased.. I bought one a couple of years ago
> for drag racing.. Costs 2500!! That's w/o the clutch assembly and
> bellhousing!!

> >The clutch is never *needed* for shifting the Jehrico or Richmond
> >transmissions, nor is it *needed* to shift your street car. (Except
> >shifting into first from a dead stop.)

> Again, depends what version of the transmission.. They are derived
> from the T-10 .. FORD

> >The only purpose the clutch serves is to take up slight mismatches in
> >RPM between the mainshaft and layshaft in the transmission. The reason
> >it's easier on the Jehrico is that the dog gears are more widely
> >spaced and are tolerant of a little more mismatch without rejecting
> >the gear change and/or breaking.

> Which you mean.. "sliders"..

> >If you do it right, you can shift a street car without the clutch...

> I have .. on a T-5 and T-56

I can shift w/o the clutch on my Honda Accord, 5-speed. Up or
downshifts, upshifts are easier in general, but downshifts "fall right
into place" if I match the revs right. Since I match revs when I
downshift anyway, whether I use the clutch or not, I can usually get 'em
right.

--
Ed

"A friend of mine suggested I try America Online, I said 'But I already
have
a computer...'"

by **John Mela** » Thu, 24 Apr 1997 04:00:00

When I actually spoke to Harry Gant (He made an appearance when I went
to the June Pocono race in '95) I asked him about shifting at Pocono,
and he implied that (at least he) only used 4th gear between the
start/finish line and turn 1.

--John Melair

They're not bugs! They're random features!
------------------------------------------------------
Sorry, but to try to get away from all the damn spammers, I had
to change my email information, like everyone else.
reply to johnm973 (at) voicenet.com, thanks

by **John Mela** » Thu, 24 Apr 1997 04:00:00

>>Except that most teams now use a Jehrico transmission, where a clutch is
>>not necessary for shifting. The gears simply fall into place.

>The clutch is never *needed* for shifting the Jehrico or Richmond
>transmissions, nor is it *needed* to shift your street car. (Except
>shifting into first from a dead stop.)

>The only purpose the clutch serves is to take up slight mismatches in
>RPM between the mainshaft and layshaft in the transmission. The reason
>it's easier on the Jehrico is that the dog gears are more widely
>spaced and are tolerant of a little more mismatch without rejecting
>the gear change and/or breaking.

>If you do it right, you can shift a street car without the clutch...

>---Jim

I had a 84 Pickup with a stick (it was a Nissan) and the dealer told
me it had a "syncromesh" transmission, which he told me it would be
extremely difficult to grind the gears. As I never drove a stick
before, It wasn't that ***ce in a while! :D

Never really tried to shift without clutching though...
--John Melair

They're not bugs! They're random features!
------------------------------------------------------
Sorry, but to try to get away from all the damn spammers, I had
to change my email information, like everyone else.
reply to johnm973 (at) voicenet.com, thanks

by **Pete** » Thu, 24 Apr 1997 04:00:00

Julian, I miss the days of the old crash boxes! Think I still have
a T-10 with some teeth missing from the sychro's(on purpose) out in the
garage. Nothing quite beats the rush of bang shifting a 4 gear!

Pete

> Again, depends what version of the transmission.. They are derived
> from the T-10 .. FORD

> >The only purpose the clutch serves is to take up slight mismatches in
> >RPM between the mainshaft and layshaft in the transmission. The reason
> >it's easier on the Jehrico is that the dog gears are more widely
> >spaced and are tolerant of a little more mismatch without rejecting
> >the gear change and/or breaking.

> Which you mean.. "sliders"..

> >If you do it right, you can shift a street car without the clutch...

> I have .. on a T-5 and T-56

> Julian "Mr. Turtle" Data
> IVGA Member 0004
> The N2 "SkunksWorks" is in progress
> Verite/3DFX owner

by **Bruce Kennewel** » Fri, 25 Apr 1997 04:00:00

This is a multi-part message in MIME format.

------=_NextPart_000_01BC504D.0F6655C0
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

The VW "Beetle" was/is one of the easiest cars in which to gear change =
without using the clutch....match the revs correctly after a bit of =
practice and the lever just shifts like a hot knife through butter! I =
once drove almost 200 miles like this (country highway at about =
4:00AM...so no need to stop!) after the clutch operating rod broke.
--
Bruce.

"....and unless I'm very much mistaken.....and I AM very much =
mistaken....."
(Murray Walker)
Vegemite Racing: =
http://www.netspeed.com.au/brucek/vegemiteracing/index.htm
Stunned Mullet: =
http://www.netspeed.com.au/brucek/stunnedmullet/index.htm=20

------=_NextPart_000_01BC504D.0F6655C0
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

<!DOCTYPE HTML PUBLIC "-//W3C//DTD W3 HTML 3.2//EN">
<HTML>
<HEAD>
<META content=3Dtext/html;charset=3Diso-8859-1 =
http-equiv=3DContent-Type>
<META content=3D'"Trident 4.71.0544.0"' name=3DGENERATOR>

</HEAD>
<BODY>The VW "Beetle" =
was/is one of=20
the easiest cars in which to gear change without using the =
clutch....match the=20
revs correctly after a bit of practice and the lever just shifts like a =
hot=20
knife through butter! I once drove almost 200 miles like this (country =
highway=20
at about 4:00AM...so no need to stop!) after the clutch operating rod =
broke. 
-- 
<HTML><BODY>Bruce. 
 
"....and unless I'm very much mistaken.....and I AM very much=20
mistaken....." 
(Murray Walker) 
Vegemite Racing: <A=20
href=3D"http://www.netspeed.com.au/brucek/vegemiteracing/index.htm">http:=//www.netspeed.com.au/brucek/vegemiteracing/index.htm</A> 
Stunned Mullet: <A=20
href=3D"http://www.netspeed.com.au/brucek/stunnedmullet/index.htm">http:/=/www.netspeed.com.au/brucek/stunnedmullet/index.htm</A>=20

</BODY></HTML>

------=_NextPart_000_01BC504D.0F6655C0--

by **Ed Benso** » Sun, 27 Apr 1997 04:00:00

> >>Except that most teams now use a Jehrico transmission, where a clutch is
> >>not necessary for shifting. The gears simply fall into place.

> >The clutch is never *needed* for shifting the Jehrico or Richmond
> >transmissions, nor is it *needed* to shift your street car. (Except
> >shifting into first from a dead stop.)

> >The only purpose the clutch serves is to take up slight mismatches in
> >RPM between the mainshaft and layshaft in the transmission. The reason
> >it's easier on the Jehrico is that the dog gears are more widely
> >spaced and are tolerant of a little more mismatch without rejecting
> >the gear change and/or breaking.

> >If you do it right, you can shift a street car without the clutch...

> >---Jim

btw- My Ford Asset class toured Mark Martin's shop about a year ago and
got to watch his transmission guy rebuild a Jericho transmission. The
gears are straightcut, with big, fat, rounded teeth, so it's easy to see
how you could just shove it into gear w/o the clutch.
Regular (street car) transmissions on the other hand, have helical cut,
smaller, sharper teeth (makes it unlikely to slip out of gear).

--
Ed

"A friend of mine suggested I try America Online, I said 'But I already
have
a computer...'"

by **Ed Benso** » Sun, 27 Apr 1997 04:00:00

> On Tue, 22 Apr 1997 23:22:19 -0400, Ed Benson

> >I can shift w/o the clutch on my Honda Accord, 5-speed. Up or
> >downshifts, upshifts are easier in general, but downshifts "fall right
> >into place" if I match the revs right. Since I match revs when I
> >downshift anyway, whether I use the clutch or not, I can usually get 'em
> >right.

> >--
> >Ed

> >"A friend of mine suggested I try America Online, I said 'But I already
> >have
> >a computer...'"

> When I was first learning how to drive a manual transmission, I nearly
> stripped the gears by letting the clutch out to much before getting
> the gear shift lever completely into the gear slot. I couldn't
> imagine attempting to move the shifter around without depressing the
> clutch first.

> Kyle Langston

I'm not going to try to go into the details of why this is so, but once
you engage the clutch, if you then let it out before the gears are fully
meshed they will ALWAYS grind. However, if you haven't engaged the
clutch at all, the gears will either slip into place, or if the speeds
are off, you will have too much resistance to bring the gears together
at all. (Unless you REALLY jam 'em, in which case they will grind.)
--
Ed

"A friend of mine suggested I try America Online, I said 'But I already
have
a computer...'"

by **Jim Sokolo** » Wed, 30 Apr 1997 04:00:00

On Sat, 26 Apr 1997 00:33:17 -0400, Ed Benson

>btw- My Ford Asset class toured Mark Martin's shop about a year ago and
>got to watch his transmission guy rebuild a Jericho transmission. The
>gears are straightcut, with big, fat, rounded teeth, so it's easy to see
>how you could just shove it into gear w/o the clutch.
>Regular (street car) transmissions on the other hand, have helical cut,
>smaller, sharper teeth (makes it unlikely to slip out of gear).

The helical cut on the gears doesn't do much of anything but reduce
noise in a passenger car transmission. (Speaking of synchromesh
transmissions only here, which is probably 100% of the passenger car
transmissions since 1965 or so... :-) )

The gears, with the exception of reverse, are in constant mesh with
their counter-part gear, but the gears on one of the shafts are not
connected torsionally to the shaft until the shift fork engages the
synchros, locking that gear to the shaft, completing a "circuit"
through the gearbox.

The differences in shifting under load with mismatches of RPM is a
matter of what type of engagement mechanism is used, be it synchros
(in your street car), or wide spaced dog gears (in a WCup Jericho
transmission.) These bit are located on the inner face of the gear,
and are moved about by the shift forks in case you're looking for them
in a cross-section or cut-away in a textbook.

The "big fat rounded teeth" are for strength (due to reduced stress
concentrations), but not for ease of shifting...

---Jim Sokoloff

by **Steve Vandergrif** » Wed, 30 Apr 1997 04:00:00

> On Sat, 26 Apr 1997 00:33:17 -0400, Ed Benson

> >btw- My Ford Asset class toured Mark Martin's shop about a year ago and
> >got to watch his transmission guy rebuild a Jericho transmission. The
> >gears are straightcut, with big, fat, rounded teeth, so it's easy to see
> >how you could just shove it into gear w/o the clutch.
> >Regular (street car) transmissions on the other hand, have helical cut,
> >smaller, sharper teeth (makes it unlikely to slip out of gear).

> The helical cut on the gears doesn't do much of anything but reduce
> noise in a passenger car transmission. (Speaking of synchromesh
> transmissions only here, which is probably 100% of the passenger car
> transmissions since 1965 or so... :-) )

> The gears, with the exception of reverse, are in constant mesh with
> their counter-part gear, but the gears on one of the shafts are not
> connected torsionally to the shaft until the shift fork engages the
> synchros, locking that gear to the shaft, completing a "circuit"
> through the gearbox.

> The differences in shifting under load with mismatches of RPM is a
> matter of what type of engagement mechanism is used, be it synchros
> (in your street car), or wide spaced dog gears (in a WCup Jericho
> transmission.) These bit are located on the inner face of the gear,
> and are moved about by the shift forks in case you're looking for them
> in a cross-section or cut-away in a textbook.

> The "big fat rounded teeth" are for strength (due to reduced stress
> concentrations), but not for ease of shifting...

> ---Jim Sokoloff

Hey Jim,

My transmission kablammed this week...wanna drop by for a couple of
hours on Saturday? :)

God Bless,
Steve

by **Edwin Solhei** » Thu, 01 May 1997 04:00:00

> The helical cut on the gears doesn't do much of anything but reduce
> noise in a passenger car transmission. (Speaking of synchromesh
> transmissions only here, which is probably 100% of the passenger car
> transmissions since 1965 or so... :-) )

Hate to dissapoint you here Jim but helical-cut gears DO reduce noise.
In-fact they were invented for that purpose along with reduced wear.

I've driven the same passenger car with both a syncromeshed helical cut
gearbox and straight cut / close-ratio syncromeshed 'box. The noise-level's
are totally difference. The h/c 'box sounds "normal", while the s/c 'box
"whines" like and open-wheel racecar.
Ever watched the BTCC or NATCC on TV ? Well if you get a chance to see some
in-board camera shot - pay close attention. Most of the noise you'll hear
Is the "whineing" (sound) from the transmission.
Helical cut gears do also "steal" more hp than a straight cut layout. On my
racecar a switch to a helical cut 'box would mean a 5-7% loss in
power-output. This however do vary depending upon whilch 'box you use, what
type of engine and drive you got (FWD,RWD,4WD) etc.
A "dog-box" would reduce the power loss even more.

--
Ed_ - Norway

"Early on, the cars were getting faster and faster. And with
good reason: everybody was cheating." - Richard Petty

by **Jim Sokolo** » Fri, 02 May 1997 04:00:00

On 30 Apr 1997 17:12:08 GMT, "Edwin Solheim"

>> The helical cut on the gears doesn't do much of anything but reduce
>> noise in a passenger car transmission.

>Hate to dissapoint you here Jim but helical-cut gears DO reduce noise.
>In-fact they were invented for that purpose along with reduced wear.

I'm not disappointed at all... I see that you agree with me. :-)

My statement is that helical-cut gears don't do anything EXCEPT reduce
noise. In fact the helical cut reduces efficiency due to thrust
loading and slightly increases bearing complexity. I agree
whole-heartedly that it does reduce noise though...

---Jim

by **EDDI** » Fri, 02 May 1997 04:00:00

Also, a lot of the noise is also caused by timing "gear drive" rather that
a timing chain system. It really makes noise. I have a gear drive in my old
63 ford unibody pickup, converted to Chevy small-block. Noisy sucker. Need
help in gearing Jim. Swap you a great bass fishing outing on Table Rock
Lake if you want to help. <g>..............Thanks for your help here in the
ng........Later.
--

Regards,
Ed Medlin

> On 30 Apr 1997 17:12:08 GMT, "Edwin Solheim"

> >> The helical cut on the gears doesn't do much of anything but reduce
> >> noise in a passenger car transmission.

> >Hate to dissapoint you here Jim but helical-cut gears DO reduce noise.
> >In-fact they were invented for that purpose along with reduced wear.

> I'm not disappointed at all... I see that you agree with me. :-)

> My statement is that helical-cut gears don't do anything EXCEPT reduce
> noise. In fact the helical cut reduces efficiency due to thrust
> loading and slightly increases bearing complexity. I agree
> whole-heartedly that it does reduce noise though...

> ---Jim

by **Edwin Solhei** » Sat, 03 May 1997 04:00:00

> I'm not disappointed at all... I see that you agree with me. :-)

> My statement is that helical-cut gears don't do anything EXCEPT reduce
> noise. In fact the helical cut reduces efficiency due to thrust
> loading and slightly increases bearing complexity. I agree
> whole-heartedly that it does reduce noise though...

> ---Jim

Then, please accept my deepest appologies for misunderstanding your post!!

--
Ed_ - Norway

"Early on, the cars were getting faster and faster. And with
good reason: everybody was cheating." - Richard Petty

rec.autos.simulators

Change down to third at Martinsville

Change down to third at Martinsville

Change down to third at Martinsville

Change down to third at Martinsville

Change down to third at Martinsville

Change down to third at Martinsville

Change down to third at Martinsville

Change down to third at Martinsville

Change down to third at Martinsville

Change down to third at Martinsville

Change down to third at Martinsville

Change down to third at Martinsville

Change down to third at Martinsville

Change down to third at Martinsville