I concur with Terry’s description. “Close Ratio”, or “CR”, is all about the
gear ratios of 1st, 2nd and 3rd gears being closer due to different number
of teeth on gears, compared to “Standard” or “Wide” ratio gearboxes.
Nothing at all to do with gearbox externals, such as, and including “throw”
of gear-lever.
I didnt realise that the CR box had shorter thows of the gear lever .The CR
box had a tall first gear then the remaining three gears were all closely
spaced rev wise and forth has a long range of speed I am sure soneone out
there can explain it a 100
times better terry
Close ratio was NOT standard. The designation CR after the number on the
gearbox is how you can see this very specially equipped car of yours is
so
equipped. This is a gearbox with shorter throws, for faster shifting for
one
and used frequently in race prepared Jaguars.
Kind regards and LOJ
doc
Hi Morris,
I recently got the details confirmed through the Jaguar archives:
Model:- Jaguar 3.4L XK 150
Body Style :- Open Two Seater
Specification:- Left Hand Drive
VIN/Chassis number:- S831542
Engine number:- V5611-8
Body number:- F16529
Gearbox number:- JL42104CR
Color, exterior:- Imperial Maroon
interior:- Grey
hood:- Black
Date Built :- 13 October 1958
Additional note:- Vehicle equipped with close ratio gearbox.
This gives me an opportunity to ask What does the additional note mean?
Is
a
close ratio gearbox not standard?, if it is then what is the purpose of
the
additional note?
It’s been a georgeous sunny day in the Seattle area, I start dreaming of
when my OTS might be finished, probably not this year. Sigh!
-Dave Massy
----- Original Message -----
From: Morris Barnett mbarnett@axion.net
To: XK Jag lovers xk@jag-lovers.org
Sent: Saturday, March 20, 1999 6:36 PM
Subject: [xk] Close numbers
To Dave Massey
Just wondering Dave what your Chassis # is on your 150 ots
Morris in Vancouver Is’nt spring great, pity those down under are
going
into fall,
te, he.
Do all non overdrive Moss boxes have the overdrive oil feed galley or is
that unusual ?
John
terry hilton wrote:>
I have a CR box stripped on the bench at present roger&terry are correct
.the forks, rods,and shift hubs are all same as every other box i,ve
done.this box has the overdrive oil feed gallery, although it is a 4speed.I
intend to build it a up as overdrive box does anyone know where ican get a
1st gear cluster? regards TERRY HILTON crystallake@bigpond.com.au
I concur with Terry’s description. “Close Ratio”, or “CR”, is all about
the
gear ratios of 1st, 2nd and 3rd gears being closer due to different number
of teeth on gears, compared to “Standard” or “Wide” ratio gearboxes.
Nothing at all to do with gearbox externals, such as, and including
“throw”
of gear-lever.
I didnt realise that the CR box had shorter thows of the gear lever .The
CR
box had a tall first gear then the remaining three gears were all closely
spaced rev wise and forth has a long range of speed I am sure soneone
out
there can explain it a 100
times better terry
Close ratio was NOT standard. The designation CR after the number on
the
gearbox is how you can see this very specially equipped car of yours is
so
equipped. This is a gearbox with shorter throws, for faster shifting
for
one
and used frequently in race prepared Jaguars.
Kind regards and LOJ
doc
Hi Morris,
I recently got the details confirmed through the Jaguar archives:
Model:- Jaguar 3.4L XK 150
Body Style :- Open Two Seater
Specification:- Left Hand Drive
VIN/Chassis number:- S831542
Engine number:- V5611-8
Body number:- F16529
Gearbox number:- JL42104CR
Color, exterior:- Imperial Maroon
interior:- Grey
hood:- Black
Date Built :- 13 October 1958
Additional note:- Vehicle equipped with close ratio gearbox.
This gives me an opportunity to ask What does the additional note
mean?
Is
a
close ratio gearbox not standard?, if it is then what is the purpose
of
the
additional note?
It’s been a georgeous sunny day in the Seattle area, I start dreaming
of
when my OTS might be finished, probably not this year. Sigh!
-Dave Massy
----- Original Message -----
From: Morris Barnett mbarnett@axion.net
To: XK Jag lovers xk@jag-lovers.org
Sent: Saturday, March 20, 1999 6:36 PM
Subject: [xk] Close numbers
To Dave Massey
Just wondering Dave what your Chassis # is on your 150 ots
Morris in Vancouver Is’nt spring great, pity those down under are
going
into fall,
te, he.
–
This mail is a natural product. The slight variations in spelling and
grammar enhance its individual character and beauty and in no way are to
be considered flaws or defects.
If anyone is interested, I have a Close Ratio gearbox for sale.
The number is JL 35578 CR
It is in excellent condition and was removed from a running and driving car
that I have owned for over 10 years.
Contact me off line if interested.
Since my 120 has a 140 engine, there is no telling if the gearbox is
original. I’m interested in determining if I have a CR box or not. I was
under the car the other day and couldn’t find any indication of the gearbox
number. I guess it’s on top, so I’ll have to go in through the tunnel.
Unfortunately I duct taped everything to cut down on the heat.
So, my question is, if one has the standard rear end in an XK120, what would
be the speeds in mph for 1st through 4th at say 2000 rpm, for the CR box and
the standard box? I should be able to tell from that, correct?
“Mark 1” Mark Stephenson
1952 XK120 Roadster #673129 (w/XK140 engine and C head)
1958 3.4 Litre Saloon / 1984 XJ6 4.2L / 1985 XJ6 VDP
Jaguar Club of Central Arizona (USA) – www.cableone.net/jcca
I probably should know the answer to this what would be the gearbox number be on an XK120 gearbox with close ratio gears?
as above would it be JL####CR are there any gearbox examples for an XK120?
Is the matter of Moss gear ratios not established on this forum?
If not heres my pennys worth. The Moss type boxes have three gear ratio sets. Jaguar shaved (JS) and Moss standard and CR. If memory serves, the Moss standard has a 26 tooth 1st motion shaft and the Moss CR has 28 teeth. Both Moss standard and CR boxes havebuilt up` layshafts ie separate
cogs. The intermediate cogs on the mainshaft and layshaft ie 1st 2nd and 3rd are the same on both Moss standard and CR… Due to the larger diameter of the 28 tooth CR 1st motion shaft, its companion cog on the layshaft has a smaller dia than its equivalent
in the standard ratio Moss, so for given RPMs on the 1st motion shaft, closer ratios are achieved by increased RPMs on the layshaft thereby bringing 1st 2nd and 3rd closer to
direct drive 4th.
The JS gear set has a 27 tooth 1st motion shaft and a one piece layshaft.
I have obtained many CR boxes from 56/7 MK1s, considerd a sporty saloon when anounced but the lower power 2.4 gave the gearbox less stress resulting in less wear
on the layshaft and mainshaft 1st gear, a good donor box to build a CR box for any model including 3.8 E, in the latter case as long as you have a short mainshaft.
Peter B