comission number and gear box number

[Piejun]

Hello

I am writing from Luxembourg and have following questions:

The TR4 I bought built 30/06/1964 has commission number CT14457L and gearbox number TS 1875. The car is now on positive earth.

I have some concerns but are not sure if I am right

• Looking at the restoration photos I noticed the car had US number plates and, correct me if I am wrong, normally US cars had neg earth (?) (minor problem)
• The gear box number seems to indicate it is a TR3 box (It has a straight gear lever). However the starter motor is a late one and bolt on tooth ring.

Following are my questions

• am I partly right concerning my assumptions?
• Does it matter if it has a TR3 gear box?
• Can I replace the straight gear lever with the TR4 one?

Would somebody be so kind and give me some help?

Thank you so much.

Pierre Jungblut

 

[Fireman049]

Hi Pierre ~

My 3A is fitted with a four synchro. gearbox and a straight lever. I think the box came from a 4A and fitted by the previous owner.

I think that you can easily fit the TR4 cranked gearlever (Moss part No. 131507 (TR4) or 143624 (TR4A).

Both these levers are listed as 'Not Currently Available' by Moss but contact them to see is they are now in stock.

Also try TR Bitz and TR Shop who may have good second-hand levers.

Best regards ~

Tom.

Edited November 17, 2018 by Fireman049

[NickKerfoot]

Hi!

CT 14457 would suggest a late 1962 built car.  The box will be a 3 synchro version as well...  has the area where the starter motor protrudes into the gearbox been modified? (A hole cut for the starter bendix to poke through...). Does it have  an overdrive fitted?

The car would most likely be +ve earth from new...( I’ll stand corrected here lol).  I suggest wire it up to your preference.... there’s no difference in the looms, just the polarity of the dynamo, and the orientation of the ammeter connections...  and any radio or aftermarket accessories that maybe polarity sensitive of course!

regards

Nick

 

[TR 2100]

CT 14457 would be a 1962 TR4, approx build date September.

TS 1875 on the gearbox would be from an early 1954 TR2 with
syncro on 2, 3 and 4 only.

TR4s have all syncro gearboxes from the start of production,
also +ve earth. Not sure when that was changed - may well
have been for the TR4A.

To explain the "cut hole", TR2/3/3A (up to TS 50,000)  starter
motors engaged from the front of the gearbox and did not
project far into the gearbox casing.
The later TR3As (post 50,001) and TR4 engaged from the rear,
therefore projected further into the gearbox.
Back in the day, if you wanted to fit a later started motor to
an earlier box, you could hacksaw off part of the gearbox
casing to allow the starter motor to fit, then probably fix a
shaped metal can with self tappers to cover the hole.
Messy, but it worked.

AlanR

[iain]

TS 1875 would be Tr2.....its a very early box

Edited November 17, 2018 by iain
Mine and Alans reply's crossed!

[Piejun]

Dear all

Many thanks for your comments which arrived so quickly.

Happy to be part of your Register.

Thanks again

Pierre.

[ianc]

Easy to tell whether it is a TR4 gearbox (synchromesh on all forward gears) or TR2/3 gearbox (no synchro on 1st gear). Try to engage 1st gear whilst travelling at about 15 mph (23 kph) - if there's some resistance as the lever is pushed forward, but the gears engage silently, it's a TR4 box.  If there's clanging from the gearbox, then don't use 1st gear when the car is in motion unless you know how to double de-clutch.  Pete Cox told me some years ago that replacements for 1st gear are expensive, so one should use 1st gear on a TR2/3 box only when moving from stationary.

Ian Cornish

[Willie]

Hi Piejun,  As with other replies, the serial numbers don't look right. My TR4 was built on 10th July  with gearbox serial No CT365** and Commission No CT352**.  Commission number is correct by Heritage Certificate.

Best wishes    Willie

[TR 2100]

7 minutes ago, Willie said:

Hi Piejun,  As with other replies, the serial numbers don't look right.
My TR4 was built on 10th July  with gearbox serial No CT365** and Commission No CT352**. 
Commission number is correct by Heritage Certificate.

Best wishes    Willie

Willie,

Those numbers are very interesting, in that they are consistent
with each other yet out of sync with typical numbers/build dates.

So, out of interest, does your car have any of the earlier TR4 features
(pre-4229 I think) like short bulge bonnet?

Looks to me as if it's an early 1962 build that was delayed being
recorded until July for some reason.

AlanR

[Willie]

Thanks for your response Alan.  I keep reading about how some blocks of numbers get used away from TR production. I see people advertising cars as "matching numbers" buuut I suspect they mean "original numbers", perhaps?  If of interest, my full suite of numbers is as follows - with last 2 digits shown as x. Car is original RHD non-overdrive.

Commission  CT 352xx;  Body in trim  CT 355xx;  Gbx  CT 365xx;   Diff  BT 351xx [3.7:1]  Engine CT 355xx E; and the one no-one seems to understand - "Body in white" 470xx. I haven't exposed the full plate in the NSR wheel arch, but there doesn't seem to be any letter pre-or suffix. I have no reason to believe any of them are not original. The BMIHT Cert gives the Comm & Body Trim numbers and they are 349 numbers apart! I feell sure diff is also original as it doesn't have a drain plug. After corresp on the Forum way back my theory is that as the car is only 6 months from TR4A production, the casings for live axle 4A's were used - this is backed up by the fact the diff number is stamped on the casing not on the top of the cover flange. The joys and mysteries of owning TRs!!

Best wishes    John

[Willie]

Forgot to mention - 10/7/1964 is the build date

[Steven Newell]

Specifically to positive/negative ground and early TR4 features from an American perspective:

While American cars were generally negative ground in the 60's, U.S.-bound TR4's were positive ground. My early TR4 (CT5018LO) delivered new to Houston was positive ground. The official change-over to negative ground came a few years ago when my old positive-ground Pertronix gadget failed and I ordered a negative-ground one without thinking. Conversion is very easy: disconnect and lift the battery, push the car out of the garage and turn it around, push the car back into the garage, lower the battery, repolarize the generator.

To TR 2100, the early TR4's had a performance bonnet with a shorter bubble which added 5-10 hp and a higher top speed. Revington says the short bubble lasted till CT6429. Although the longer bubble was likely introduced to slow TR's to MG speeds, some have argued that Americans like to slam their hoods (bonnets) and the shorter bubbles tended to bend or distort at the corner. Other extra special features of early TR4's like the long neck TR3 radiator were officially upgraded following a policy of "using up all the leftover TR3 parts".

Steven / Littleton, Colorado USA

[TR 2100]

Willie,

My mistake.  I read your CT 352xx as CT 352x so ignore my comments.

Steven,

That's the first time I have heard the early short bulge bonnet described as a
"performance bonnet" or seen any claim that it either enhanced performance
or was later modified to reduce performance to MG speeds.
Someone making up stories, methinks.

Although my reference to "early features" is not relevant to Willie's car, I was
not thinking of the radiator. I was thinking of the boot stay rod, chromed rear
cockpit capping and lack of rear boot lid badge.

AlanR

[stillp]

27 minutes ago, Steven Newell said:

disconnect and lift the battery, push the car out of the garage and turn it around, push the car back into the garage, lower the battery,

I'm sure there must be an easier way... 

Pete