I have a spare xk 140 close raito 4 speed from 45 years in storage and I am rebuilding it. Does anyone have specs. for the rebuilding. The jag. book does not give anyting, such as shaft end play and other tec. things.
What book are you using? The WSM surely does!
The Mark VII / XK120 factory Service Manual covers the SH and JH models of the Moss box, but the JLxxxxCR will be the same repair specs.
Counter shaft and 2nd & 3rd gear end floats are .002-.004" or .05-.10mm and main shaft end float is .002-.006" or .05-.15mm.
Thanks Rob:
I have been rebuilding Corvette racing transmissions for many years.
I have 2 skids of XK parts that I just started going through. These skids
are from about 45 years ago untouched. I got them with my last XK 140 DHC C.
4 speed auto/CR trans. The car and parts came from a gentlemen that was a
Jag mechanic and part of a Jag. racing group in the 50’s. He kept them in
his back barn and never got around to working on them. This trans I am
rebuilding is not from the above car but a spare off the skid. I was told the
parts were off a car they raced. The building were the other car was kept
fell down and destroyed the car. They stripped all the running gear parts they
could off the car and put them on skids. I have no idea what type of Jag.
they raced.
The trans. I inquired about is untouched. It has a SH input shaft and
a JL counter gear set up. Stamped inside the top of the alum. case
is"11/50/1" ). Does that make any sense to you since the case was never opened.
#JL35935CR.
Also—This 140 I acquired I was told " was used for racing on the
beach in Datoyna, blown up and sat outside storage for 40+years. It is now
100% restored. I have been trying to find out about its racing history in
FLA. for about 10 years with no luck.
Also—I am very impressed with the machine work on the Jag. trans.
Very, Very Nice work.
THANKS for the info. ED D
In a message dated 12/9/2016 4:29:54 P.M. Central Standard Time,
noreply@jag-lovers.com writes:
_Rob_Reilly_ (http://forums.jag-lovers.com/users/rob_reilly)
December 9
The Mark VII / XK120 factory Service Manual covers the SH and JH models of
the Moss box, but the JLxxxxCR will be the same repair specs.
Counter shaft and 2nd & 3rd gear end floats are .002-.004" or .05-.10mm
and main shaft end float is .002-.006" or .05-.15mm.
Your gearbox serial no. JL35935CR probably dates from about 1955 or 56.
Any other numbers are production marks and we have not attempted to interpret those. We have enough trouble with dating heads and carbs. 
We call them Moss boxes because they were originally made by the Moss Gear Co. in Birmingham. The prefix SH meant Single Helical after they stopped making the double helical gears for their boxes. Then Jaguar acquired the license to make them about 1948 and those made by Jaguar had the JH prefix. JL is an improved version beginning about 1952.
They seem to be very strong and we rarely hear about broken gear teeth, although if the second gear synchro gets worn smooth due to a lot of speed shifting, they can get stuck in first gear, especially the early ones without the stop pin in the second synchro that prevents this.
Considering the racing history you describe, and the tendency of race shops to swap parts all around, if you are going to sell it, you might want to confirm that your box really does have close ratio gears before you advertise it as such.
THANKS AGAIN ROB:
Sorry to keep asking you questions. Do you know the number of gear teeth, on each gear, for the CR trans. I tried the internet but these gearboxs are hard to find info on. Your the expert on these transmissions. Do you know how common the 4 speed close raito with overdrive was. I was told years ago in 56 only 6-10 were found- and lastly- What do you think this trans fully rebuilt is worh completly rebuilt.
If it were not for the Jag lovers form I would have NEVER been able to rebuild or work on Jaguars. Great site.
THANKS AGAIN ED D
The parts catalogues do not give the numbers of teeth.
You would have to count them and calculate the ratios.
Here is a discussion of the ratios.
http://www.jag-lovers.org/xk-lovers/library/gear_ratios.html
The close ratio box was special order, more for people interested in racing, so is less common than the standard ratios.
You could go through www.xkdata.com and count them, then estimate as a percentage of the total reported there.
THANKS AGAIN ED
In a message dated 12/13/2016 8:21:24 A.M. Central Standard Time,
noreply@jag-lovers.com writes:
_Rob_Reilly_ (http://forums.jag-lovers.com/users/rob_reilly)
December 13
The parts catalogues do not give the numbers of teeth.
You would have to count them and calculate the ratios.
Here is a discussion of the ratios.
http://www.jag-lovers.org/xk-lovers/library/gear_ratios.html
The close ratio box was special order, more for people interested in
racing, so is less common than the standard ratios.
You could go through www.xkdata.com (http://www.xkdata.com/) and count
them, then estimate as a percentage of the total reported there.
Ed:
The close-ratio overdrive transmission was most commonly used on the XK150S (1958-1961). It was much less common on the 140s and non-S 150s.
Your gearbox JL35935CR is a non-overdrive close-ratio version. The prefix would be JLE for a XK140 with overdrive. My XK150S (May 1958) has the overdrive version (JLS40444CR).
Cheers,
Dave Q.
XK150S OTS 3.4
I have a 57 140 SE with a gearbox number of JL35444CR (Non overdrive). So it would have to be a very very late 140.
Gearbox JL35935CR would most definitely be a normal XK140 Gearbox, with no Overdrive fitted (thus JL prefix only) and with optional Close Ratio gears (thus CR suffix). The Serial Number ‘35935’ indicates, its not exact due to factory batching, and not necessarily maintaining numerical sequence in allocation to XK140, but still dates as being approximately third-quarter 1956, so July - September 1956, and we are talking about date-of-manufacture, and not common USA Model Year terminology. And every now and then you do get a factory glitch, that delays a gearbox being fitted a month or so later than normal, so not impossible a little later.
So Scapard - that would also apply to your ‘57 XK140 SE’ with gearbox JL35444CR. If you advise your Chassis Number that will tell us exactly when your XK140 was made, most likely according to gearbox number to be same third-quarter 1956, and definitely not 1957, albeit may well have been sold new as a 1957MY car given I presume you are in USA.
My JCNA cert says my Date of Manufacture is 4 June 1956, with a Date of Dispatch 4 July 1956. So I would have to agree its a third/fourth quarter 56 build date for the post owners 35935 gearbox.
Thanks Roger:
The CR gearbox is part of a skid of Jag. of parts I was given when I got the last 56 XK Drophead 140-C in boxs. The car I have and restored raced in Florida on the beach at Daytona until it was blown up. It was taken apart and put in boxs for 50+ years. I found this car and parts from a friend in Church. TRUE story. He was a old Jag. race car driver and I used to race in the trans-am series. We clicked. He never had the time to put it back together so I acquired it and after 7 years of total restoration its perfect. Back to the trans. It was from a 56 Jag. which got crushed when a roof fell in on it and was totaled by insc. co. in the 50’s. The car was stripped of all running rear and engine parts that were good and put on a skid. I still have most of the front suspension and engine parts. I am putting them up for sale on ebay with many other corvette L88 racing parts. This trans has 100% rebuilt and is to be soon for sale.
THANKS ED D
I am restoring an XK140DHC frorm June 1956. It had originally a close ratio gearbox with the number JL34954 CR. Unfortunately the previous owner swapped the gearbox for a standard JL one.
So if one you encounter the original gearbox, please let me know.
Michael