The Triumph TRs – The Triumph TR4A

The Triumph TR4 was built until January 1965 when it was replaced by the Triumph TR4A.  From the outside the Triumph TR4A appears very similar to the Triumph TR4.  Visually the differences are primarily a slightly revised front grille and side flashing indicators.

In order to see the differences between the TR4 grille and the TR4A grille, it is best to see them at the same time as the difference are quite subtle.  Below is a view of the grille on a TR4.

Note the Vertical Bars on this TR4 Grille

The car below is a Triumph TR4A.  Note the absence of the vertical bars in the grille.

View of the Grille on a Triumph TR4A

The differences beween the TR4 and the TR4A are mainly in the chassis.  I found some great images of these differences in a very informative book “The Triumph TRs – A Collector’s Guide” by Graham Robson.  Graham Robson is not only a very good author regarding a wide variety of cars, he was the Competition Manager at Standard-Triumph for a few years.

The image below shows the chassis of the Triumph TR4 which was essentially the same as the chassis for the TR2, TR3, and the TR3A.

The Triumph TR4 Chassis

The image below shows the chassis of the Triumph TR4A.  As you can see there are considerable differences between the two cars.  Not only does the Triumph TR4A have independent reat suspension, it appears that the chassis is a little more stout and stiffer.

Triumph TR4A Chassis

The details of the independent rear suspension are shown below.

Rear Suspension on a Triumph TR4A

The changes in the chassis added about $150 dollars to the cost of the cars.  The information that I have shows that the price of the TR4 in 1962-64 period was $2,849 at the port of entry.  Standard-Triumph’s distributors in the northeast, Bud Forman and Les Genser were concerned that car sales of the TR4A would suffer if the price was raised by $150.  They successfully lobbied Standard-Triumph to produce a lower price 1965 TR4A with a straight rear axle.  The price information that I have notes that the price of the TR4A cars in 1965-66 was $2,840, or virtually identical to the price of the older TR4.

Rear Suspension on US Triumph TR4A Models

It seems that some Triumph TR4A cars were available in the US with the true independent rear suspension.  I understand that it was listed as an “option”, but as you can see, it was a little more than just a traditional “option” that is added to a base car.  The Robson book indicates that TR4A cars with a Commission Number that starts with “CTC” have independent rear suspension, while those cars with a Commission Number that starts with “CT” have the straight axle.  That said, if you are thinking of buying a Triumph TR4A, I would take a look at the rear suspension, so that you know what you are buying.

Standard-Triumph built 28,465 Triumph TR4A cars from January 1965 to August 1967.

In past postings about the Triumph TR cars I have included some images of Triumphs participating in the major rallies of the day.  It seems that Triumph did not have works competion cars based on the Triumph TR4A.

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6 Responses to The Triumph TRs – The Triumph TR4A

  1. Tony Centore says:

    Hello Steve. I had a Tr-4 in my youth and loved the car. My dream is to rent one and take a driving vacation thru wine country in California. Hope you are doing well. Last I heard you left PB.
    I am doing fine in my tenth year of retirement. I hope you are not selling more motor bikes to Paul Moyer.

    Regards Tony Centore

    • Hi Tony,
      It’s great to hear from you! A TR-4 was/is a great car. I had a MGB, but I did admire the Triumphs.

      I can’t believe that you’ve been retired for 10 years! Time flys. I’m now with HDR Engineering, Inc. and have found it to be a great company. I still ride my motorcycle, a Triumph Bonneville, but I have not heard from Paul in years.

      Regards,
      Steve McKelvie

  2. Ian Thomson says:

    Hi Steve, I have a 1965 TR4A with a live axle and was wondering where you took the picture of the frame with the live axle as on restoring mine I find the actual axle sits on the frame and there is little or no movement when the frame is pushed down.
    What I need to find out is if there is a space between the frame and the axle, and if so how much?
    I do hope you can help as I have tried my usual sorces with no luck.
    It seems I have one of the few TR4A’s in Canada with a live axle all the others are IRS.
    Yours,
    Ian Thomson
    ianmwthomson@eastlink.ca

    • Hi Ian,
      As I understand it the live axle TR4As were mainly shipped to the USA as the USA dealers wanted to keep the costs down for the TR4A cars. So perhaps your car originally came from south of the border.
      The pictures of the TR4A frames came from Graham Robson’s book “The Triumph TRs, A Collector’s Guide” that was written in 1977. There is a good discussion on all of the TRs including comments about the axles on the TR4 cars and its derivatives. I would recommend it to you.
      Perhaps for specific information about your problem, you might consider contacting a Triumph specialty shop in the USA.
      Steve McKelvie

  3. Dick Evans says:

    I have a 64 Morgan with a TR4A engine and a friend has a TR4 engine in his Morgan.
    What is the difference between the tr4 and tr4a engines? I am having trouble finding out.

    • Hi Dick,
      There apparently are slight differences. Using Graham Robson’s book “The Triumph TRs” as a guide, I note the following numbers: TR4 – 100 horsepower at 4,600 rpm with 127 lb-ft torque at 3,350 rpm. TR4A – 104 horsepower at 4,700 rpm and 132 lb-ft torque at 3,000 rpm. The difference in the two engines might be the inlet manifold with the TR4A engine being a little more efficient. Better air flow might explain the slightly higher rpm with the TR4A engine. Some early TR4 cars still used the 2 liter engine that had been in the TR3A, so if this is the case then there are more differences.
      Regards,
      Steve

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