TR4/4A Rear axles on live axle car

[KansasWhirl]

Hi, after purchasing a lovely TR4 which will need a complete going over to make road worthy I've come across the youtube about something I didn't know existed- the axle breaking problem. It has me a bit freaked out now. I don't plan on racing it but did plan on spirited driving on backroads and racking up a lot of miles doing this. How much of concern should this be to me? Does the problem only happen under racetrack conditions at constant 80+ mph speeds or is it something that just could happen due to age and miles? I've been waiting 30+ years to buy a TR4 and my research over those years I never came across this being a problem so I'm surprised to find out now how big a concern it is to people racing them. Should I be concerned?

 

[Geo Hahn]

I've abused - err I mean driven -- solid axle TRs for 40+ years w/o giving a thought to a rear axle breaking. Nor have I heard of such a concern on the TR4s or TR3As. Early cars (e.g. TR2s) did have weaker axles.

What is not unknown, yet far from common, is breaking the front stub axles. Stronger alternatives are available but for non-track use might be more than is really needed.

BTW - congratulations on finally getting your long-awaited TR4. Enjoy the ride.

 

[TR3driver]

In my opinion, no. They do break on the race track sometimes, but almost never on the street. I've put down hundreds of thousands of miles on a TR3A (with the same rear axle & hubs as your TR4, just about 4" narrower), including some stints at over 100 mph and a couple of autocross trophies and never broken an axle. (Wish I could say the same for ring gears )

Of course you are driving a 50 year old car, and stuff does sometimes break. There are no guarantees.

 

[TR3driver]

Nor have I heard of such a concern on the TR4s or TR3As.

Oh, the problem is real. Tony Drews made an awful mess of his old race TR4 when he snapped a rear axle shaft a few years back. The in-car video was most impressive, especially the long pause before you can hear him say "Well, that sucked." He and his Dad worked to design a replacement using one piece forged hubs and axles fit into a modified TR4 housing. IIRC they're also the ones that came up with both the spacer kit and the uprated stub axles for the front.

PS, had to hunt a bit, but here is the video
https://www.youtube.com/watch?feature=player_embedded&v=PX82xKLZ2JE

 

[KansasWhirl]

Oh, the problem is real. Tony Drews made an awful mess of his old race TR4 when he snapped a rear axle shaft a few years back. The in-car video was most impressive, especially the long pause before you can hear him say "Well, that sucked." He and his Dad worked to design a replacement using one piece forged hubs and axles fit into a modified TR4 housing. IIRC they're also the ones that came up with both the spacer kit and the uprated stub axles for the front.

PS, had to hunt a bit, but here is the video
https://www.youtube.com/watch?feature=player_embedded&v=PX82xKLZ2JE

Yep, that's the one that got my attention! But that being said, it is really the only example I've heard about. I understand Mad Marx inspects his every year but he also pushes his car very hard now for years and nothing has happened so is it a real concern?

 

[KansasWhirl]

BTW - congratulations on finally getting your long-awaited TR4. Enjoy the ride.

Can't wait!

 

[TR3driver]

Well, let me put it this way. If I had that kind of money invested in a race car, with that kind of power, and was flogging it as hard as those guys do, I'd probably pony up the money for the Southwick conversion.

But my daily driver doesn't have it, and likely never will. Unless I manage to break one, of course

The other idiots around me are a much bigger risk than the car breaking, in my experience. And there's really no way to solve that except not to drive a TR3 on the street.

 

[JerryVV]

Mad Marx did just break an axle too. It's a real concern if you are racing, not so much if just street driving. The vintage race cars are much faster with corner speeds incresed as well due to suspension mods, wider wheels and sticky tires. That lead to a rash of broken axles with not so good results, usually ending upside down after a roll as shown in Tony's video. That lead Jack (May he rest in peace) to develop the Southwick conversion that almost all the solid axle TR guys are using.
I'd not worry about street applications however.
JVV

 

[glemon]

If you want to break axles buy a Sprite (they do break quite often), beat the heck out of my solid axle 4A for years, no problems, my brother drove his 3A for 35 years, no problems, have seen many other club members with 3s and 4s, autocross, tour cross country, no problems. Anything can happen, but the drivetrains of the 4 cylinder TRs can take a lot of abuse, like the old Timex commercials, "takes a licking, and keeps on ticking"