TR4 racing axle upgrade help

[Mike Mehl]

I have recently purchased a 1962 Triumph TR4 race car that I will campaign at two historic events in the Northwestern US. It has history and was a SCCA championship car. My father in law had it restored and had done solo racing with it. I understand that the rear axles are a weak point and will fail. I understand there is a fix (called a southwick conversion). I have talked to some other racers who suggest I crack check the axles every few events.

 

What suggestions do you have? Is there a step by step online proceedure to upgrade the axles.

 

I could really use some help as I work to get the car track ready.

 

my email is mike.mehl@yahoo.com

 

Thanks!!!!!!

 

Mike

[MadMarx]

My axles have done about 120000 mls and they serve me well in racing since year 2004. But this year I'll inspect them closely.

I hope I don't find cracks.

I suppose that if you drive easy on the axles and avoid hitting curbs then they will last, even with racing tires.

Most broken axles I've heard from are from drivers who don't care much about the car and giving it a hard life.

 

Cheers

Chris

[Mike Mehl]

My axles have done about 120000 mls and they serve me well in racing since year 2004. But this year I'll inspect them closely.

I hope I don't find cracks.

I suppose that if you drive easy on the axles and avoid hitting curbs then they will last, even with racing tires.

Most broken axles I've heard from are from drivers who don't care much about the car and giving it a hard life.

 

Cheers

Chris

 

thanks Chris:

I have heard horror stories from a few racers here in the US. I have been talking to a racer in Seattle who suggested the crack check idea. That will fit my budget better. What type of connecting rods do you use in your engine?

 

Thanks Mike

[MadMarx]

I use SCAT conrods.

They are light though cheaper than Carrillo.

A set of 8 for $500.

 

Cheers

Chris

[Tr4Tony]

Apparently the USA NON IRS beam axle halfshafts are stronger than the TR4 beam axle type .... they have a notch in the end of them and thsts how you can tell the difference. Ive had the same set in BST82B since I started rallying and they seem fine.

 

The Southwick conversions are also highly though of by the guys in the USA, but as I understand it they do an axle upgrade on an exchange basis, so you need to get one over there to them and have it all shipped back. As far as I remember the cost works out similar , but you have bigger hubs on the Southwick set up and im sure it is stronger. Question is, do you need it ?

 

Regards Tony

[Mike Mehl]

Apparently the USA NON IRS beam axle halfshafts are stronger than the TR4 beam axle type .... they have a notch in the end of them and thsts how you can tell the difference. Ive had the same set in BST82B since I started rallying and they seem fine.

 

The Southwick conversions are also highly though of by the guys in the USA, but as I understand it they do an axle upgrade on an exchange basis, so you need to get one over there to them and have it all shipped back. As far as I remember the cost works out similar , but you have bigger hubs on the Southwick set up and im sure it is stronger. Question is, do you need it ?

 

Regards Tony

 

Thanks Tony;

Is the USA NON IRS beam axle you are referring to a special axle that was put on US cars? Or is it a special axle. I am planning on pulling the axle apart in the next few weekends. Will the notch be obvious? Do I need to even pull the axle apart to see the notches? Do you think it is wise to crack check them regardless. Thanks for any help you can give me.

 

Mike

[jellison]

Never heard this before. I had heard the 2's and 3's half shafts can fails (seen a few way back in the 90's when the "Twins used to drive to the races in their cars - do reall y well and drive home - sometime changing halftshafts!

 

As far as I can make out my 4 makes the most power of any Naturally asprated TR 4 pot lump and I have never had and issue (never broken halfshafts in 19yearsm with or without and LSD).

 

Don't worry about it.

[marvmul]

I have steel billet rear hubs on my TR3 race car since 5 years, but the shafts are original ones. I bought these hubs because of the stories about the rear axles. The root of the (rare?) failures : the hubs are mounted on the half shafts with a woodruff key : when this key is too high, and the hub is moving a little on the shaft(turning to and fro a fraction of a mm under braking and accelerating forces) , the much harder key will eat itself into the hub : then the key will put very high stresses on the hub, every time the hub is moving a little on its shaft, twisting the key in its grooves. Before the hub will crack, it will be loose. So you can check the hubs : when you remove the big nut, it should be impossible to remove the hub with a (light) puller or hammer blows. If you can remove the hub, it is suspect and will likely fail. When you are mounting hubs on the shafts, be sure that the keys are not too high and do not touch the bottom of the groove in the hubs.

I got a few tips for the rear axles :

-painting a line over the nut, hub and shaft will warn you early for any looseness and impending failure of the hub.

-aside : the seals between axle house and shafts often leak, ruining the brake linings (and the brake performance during a race!): to check this without removing the brake drums, you can drill the grease nipples on the axle tubes (near the wheels) to remove the small balls and springs and then slide a small plastic tube of 15 cm over the grease nipples : when the seals are beginning to fail, you will find oil traces in these tubes before the oil is reaching the brake linings.

These plastic tubes and the painted lines will allow to check the rear axle in no time after every race and practice.

[Mike Mehl]

I have steel billet rear hubs on my TR3 race car since 5 years, but the shafts are original ones. I bought these hubs because of the stories about the rear axles. The root of the (rare?) failures : the hubs are mounted on the half shafts with a woodruff key : when this key is too high, and the hub is moving a little on the shaft(turning to and fro a fraction of a mm under braking and accelerating forces) , the much harder key will eat itself into the hub : then the key will put very high stresses on the hub, every time the hub is moving a little on its shaft, twisting the key in its grooves. Before the hub will crack, it will be loose. So you can check the hubs : when you remove the big nut, it should be impossible to remove the hub with a (light) puller or hammer blows. If you can remove the hub, it is suspect and will likely fail. When you are mounting hubs on the shafts, be sure that the keys are not too high and do not touch the bottom of the groove in the hubs.

I got a few tips for the rear axles :

-painting a line over the nut, hub and shaft will warn you early for any looseness and impending failure of the hub.

-aside : the seals between axle house and shafts often leak, ruining the brake linings (and the brake performance during a race!): to check this without removing the brake drums, you can drill the grease nipples on the axle tubes (near the wheels) to remove the small balls and springs and then slide a small plastic tube of 15 cm over the grease nipples : when the seals are beginning to fail, you will find oil traces in these tubes before the oil is reaching the brake linings.

These plastic tubes and the painted lines will allow to check the rear axle in no time after every race and practice.

 

 

Can you post a photo of the axle tubes you described in your post. It sounds like you have the axle issues figured out.

 

Mike

[JRCWeedon]

I got a few tips for the rear axles :

-painting a line over the nut, hub and shaft will warn you early for any looseness and impending failure of the hub.

-aside : the seals between axle house and shafts often leak, ruining the brake linings (and the brake performance during a race!): to check this without removing the brake drums, you can drill the grease nipples on the axle tubes (near the wheels) to remove the small balls and springs and then slide a small plastic tube of 15 cm over the grease nipples : when the seals are beginning to fail, you will find oil traces in these tubes before the oil is reaching the brake linings.

These plastic tubes and the painted lines will allow to check the rear axle in no time after every race and practice.

 

I thought Marvmul's tip was a really good idea so duly painted a line on the hub etc.

My first hillcimb arrived and whilst loading the TR back on the trailer noticed that the lines did not line up. There was an element of doubt in my mind since I thought I could have messed up the painting so did it again. One more hillclmb last weekend and the hub had definitely moved relative to the half shaft. So removed the shaft and a friend of mine got the hub off with a 10 ton press to discover that the woodruff key was split along it's length! It had been turning and in the process damaged the half shaft and the steel hub. I should perhaps explain that whilst it is a TR5 it has a live TR4 axle with steel hubs

Although there is a lot of stress with a powerful 6cyl engine and sticky hillcimb slicks I was more than surprised.

Any tips or recommendations gratefully received.

Regards

John

[Tr4Tony]

Thanks Tony;

Is the USA NON IRS beam axle you are referring to a special axle that was put on US cars? Or is it a special axle. I am planning on pulling the axle apart in the next few weekends. Will the notch be obvious? Do I need to even pull the axle apart to see the notches? Do you think it is wise to crack check them regardless. Thanks for any help you can give me.

 

Mike

The non IRS set up is standard, but see the posting above on the hub and woodruff key issue. This is one also worth noting and you'd be wise to check out / line paint etc. as per JRCW's post - its usually quite revealing! The non IRS shafts are slightly different as they are not quite as notched at the primary failure point, hence why Id say use these.

 

Regards

 

Tony