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TR4/4A How rare is the TR4A with a live axle

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Paulus

Paulus

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Recently I have seen and heard a few references to the effect that the TR4A with the live axle is rare. One of my Triumphs is a 4A with the live axle and I was wondering if anyone had the production numbers at hand or knew if this was more an opinion than fact?
Second question would be; If the live axle is far less common will I run into difficulty obtaining replacement parts?

/ubbthreads/images/graemlins/england.gifPaulus /ubbthreads/images/graemlins/england.gif
 
Re: How rare isTR4A with a live axle

Not really rare. The next level up is the TR4A Internal Revenue Service.

Bill
 
Re: How rare isTR4A with a live axle

Or a Dove. Now that is rare!


Bill
 
Re: How rare isTR4A with a live axle

Hi Paulus,

No one knows for certain, but it's been estimated that 25% of TR4A production was live axle cars (i.e., not IRS). One reason it's an unknown is that the chassis numbers continued to be consecutive with the IRS cars, only the prefix changed from IRS to non-IRS cars. So the only way to really pin it down would be to review each and every chassis record for TR4A by hand and add up the total. AFAIK, no one has done that.

TR4A IRS cars have a "CTC" chassis number prefix. TR4A live axle cars have a "CT" chassis number prefix ("CT" was also used on all TR4, starting with CT1 and ending with chassis CT40304). TR4A chassis numbers started with 50001 and ended with 78684, so there appear to have been 28,684 TR4A built. 25% of that would mean probably a bit over 7100 of those were live axle cars.

This would make it it one of the rarer Triumph models. To put that in perspective, of the TRs only TR3"B" and TR5 are scarcer than live axle TR4A. There were actually a few more TR2 and TR250 models built, than "CT" TR4As.

About the only externally obvious distinguishing feature I can think of would be the lack of an "IRS" badge on the live axle TR4A trunk lid (or boot lid, if you prefer). Underneath, it shares the bulk of it's frame with the IRS version (not with the TR4, which also has a live axle, but instead uses a "ladder" chassis frame). There is a sort of sub-frame added providing mounting for the live axle, instead of the swing arms of the IRS car. The axle itself is a little different than the earlier cars, too, most notably the big bump stop platform on top.

Overall, there aren't a lot of differences and most of the parts are available. I can't think of any specific parts that are hard to locate for the live axle TR4A (but I haven't really shopped for parts for that model, either).

There has been a lot of speculation over the years why Triumph built the live axle TR4A. Some say it was in response to U.S. dealer concerns that buyers wouldn't like the then-new IRS. (Same dealers reportedly asked for and got the TR3"B" built during the initial years of TR4 production, supposedly for the same reason.)

Another reason they chose to continue offering a live axle version might have been that the factory remained quite involved in racing and rallying, as a means of promoting the cars to the buying public. In England and Europe, the factory never even tried to rally an IRS car (having decided the chassis wasn't strong enough) after many years of running the earlier live axle TRs in all the major events. Plus, the earlier, live axle TRs were highly popular with both factory and private teams in the U.S. (This was near the end of an era in the U.S., when a private team could still field a car relatively affordably. Very soon the cost to be competitive at a pro level was overwhelming and it became a rich man's sport.)

If you look at Kastner's factory racing efforts in the U.S., it appears that there was a real effort to gain acceptance of the IRS cars in motorsports. This began with the '66 12-Hour Sebring team entries (TR4A), continued with "publicity" speed runs of TR4A at Daytona and Bonneville, and carried on through the TR250 and TR6 factory sponsored racing efforts. Even the special TR250K was developed on an IRS chassis, I believe.

It took a few years, but I think it fair to call it a successful promo effort. By the time of TR6 a lot of teams were regularly developing using IRS Triumphs, including some very high profile independents like Group 44 and Paul Newman Racing.

I think now it's fair to say that the live axle TRs are quite a bit easier/cheaper to set up with suspension performance improvements. The IRS cars take considerably more work and money to get the very best out of the suspension, but in the end offer a bit more performance potential.

/ubbthreads/images/graemlins/cheers.gif
 
Re: How rare isTR4A with a live axle

[ QUOTE ]
so there appear to have been 28,684 TR4A built. 25% of that would mean probably a bit over 7100 of those were live axle cars.

This would make it it one of the rarer Triumph models. To put that in perspective, of the TRs only TR3"B" and TR5 are scarcer than live axle TR4A. There were actually a few more TR2 and TR250 models built, than "CT" TR4As.


[/ QUOTE ]

Of course your right if your referring to 'body on frame' TR's. Otherwise... there were less than 2800 TR8's produced. /ubbthreads/images/graemlins/grin.gif


/ubbthreads/images/graemlins/cheers.gif
 
Re: How rare isTR4A with a live axle

Once again, Alan, very good and informative comments. If you use the number of TR4As imported to the US from Mike Cook's excellent book, 16,311, that 25% of production for live axle 4As gets even smaller. /ubbthreads/images/graemlins/wink.gif

As for parts, I recently had to find a replacement rear end for my live, or rigid, axle 4A, which is unique to that model, and had quite a bit of luck from several vendors and it was affordable.

When I started my search for a TR4A, I was specifically looking for an IRS car, but I was pleasantly surprised when I bought my car that the live axle cars hold a special place in the "American" history of Triumph. Cool stuff!!! /ubbthreads/images/graemlins/cool.gif
 
Re: How rare isTR4A with a live axle

Both of my TR4As were live axle cars, as a matter of fact I'm selling off the complete rear end from the parts car, springs and all. it's listed in the free british car parts classifieds here on the site.
I've found the easiest way to spot a "solid axle" TR4A is to look in the gap between the rear tire and the quarter panal just behind the tire. If it's a aolid axle, the leaf spring is easily visable.
Excellent editorial Alan!
I think you covered it all.
 
Re: How rare isTR4A with a live axle

[ QUOTE ]
[ QUOTE ]
....one of the rarer Triumph models. To put that in perspective, of the TRs only TR3"B" and TR5 are scarcer than live axle TR4A. There were actually a few more TR2 and TR250 models built, than "CT" TR4As.


[/ QUOTE ]Of course your right if your referring to 'body on frame' TR's. Otherwise... there were less than 2800 TR8's produced. /ubbthreads/images/graemlins/grin.gif

[/ QUOTE ]

Whoops! I plum forgot the TR8. How could I do that?

You're correct, TR8s are about the rarest of the bunch.

/ubbthreads/images/graemlins/cheers.gif
 
Re: How rare isTR4A with a live axle

Great post Alan!

I remember how it was for me at the time this was happening.

I was totally in love with my TR4 and knew it was the best car ever built. OK, I was maybe a little slanted in my opinion. The truth is that I had a lot of company. There were many of us that did not like the idea of anyone messing with the best car we had ever owned or driven.

And, as Alan said, the factory knew it because the dealers relayed the message that many owners were giving them. "Don't mess with our car."

BTW, Even though I drive a TR6 now, the TR4 is still my favorite car ever, because it was a great car and because of the great memories connected to it.
 
Re: How rare isTR4A with a live axle

I've always heard around 8100 leaf sprung TR4a's out of the run total of 28k. I've heard it was originally the added cost of the irs that caused the demand. There was also some concern about the complication of the system and maintenance. The irs went a long way towards eliminating the hop associated with earlier TRs. The overall ride comfort improved. I've owned my 66 TR4a irs since 1966 and I assure you it has handled itself quite well straight up with earlier TRs and later TRs.
 
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