TR2 conversion to front disc brakes

[Rod1883]

Hi everyone,

My 2 is currently being restored, after being off the road since '85, and I'm considering a number of improvements as it proceeds.

 

I've read in a post by Trevor S that converting to late TR4 front discs is the best way forward.

Has anyone any advice on how to do this, what parts are needed (e.g. do I need to obtain the whole vertical link/hub/disc/caliper assembly?), how to identify the late TR4 parts, etc, etc?

 

I have in fact recently picked up a pair of front vertical link/hub/disc assemblys amongst some spares for the rebuild. I was told that these assemblys are for a TR4, but the links look too short to me, and the discs are only ~9½" diameter, not nearly 11". I think that these could in fact be for a Vitesse/GT6, are there any other identification marks that I could look for?

 

Also, assuming the ones I have are not suitable, does anyone have, or know anyone who has, the parts I need for sale?

 

Thanks in anticipation,

 

Rod

[pfenlon]

Be careful here, if you fit kingpins from a tr6 for instance you then lower the ride height by 1 inch.

 

get 3 degree trunnions and 3A uprights, and it then becomes simple, TR suppliers will sell you all the bits you need

 

Stuart will probably be a mine of info.

 

bushes are another anomaly superpro are the ones I fitted and I drilled the rear of my bottom wishbones and fitted grease nipples.

 

I also greased the top wishbone bushes, but you can go on and on.

 

I cannot give you a recomendation of discs over drums for I havent driven a TR with drums.

[tr3timme]

Hi, Rod: a couple of years ago I converted my early 3 to disc brakes and used TR6 discs and callipers. The whole conversion actually entails you converting your 2 to a Girling back axle, but this, although a slight hassle involving extra expense, is a boon, because it means that you get an unburstable pair of half-shafts on the rear.

Compare this with the Lockheed axle which is weak and prone to breaking halfshafts arbitrarily. Breaking two in two years prior to 2005, converted me to the idea of going Girling and I have not regretted it, over 2.5 years on. Travelling down mountain passes is relatively worry-free with the new system; on Lockheed drums all round it was an ageing experience doing Wrynose and Hard Knott passes in the Lakes, I can tell you!

Revington supplied me with the entire kit; not particularly cheap, but great quality and they are generous with advice, should you hit snags.

Good luck,

Tim.

[Trevor S]

Rod, I believe from memory that the late TR4 calipers are referred to as "16P" and I understand these were used up to the TR6 so are easier to come by and cheaper to obtain on an exchange basis than the earlier calipers. The 16P caliper requires a 10 13/16" diameter disc so the discs you have are too small. Again the discs that fit the 16P caliper are more common and less than half the price of the 11" discs required for the earlier caliper.

I've got to dash off to work now but will try to reply more fully regarding the other components soon.

Trevor.

[stuart]

Rod the easiest way to convert to discs and the cheapest to maintain is to buy the complete front uprights, suspension arms and steering arms from a late TR4 or 4a. That gives you the three degree castor as well which gives better self centering and less bump steer. The girling rear axle helps as well if you can find one, try and get one with 9" drums rather than 10" as the parts for them are cheaper. You will also really need the twin master cylinder and tank mounting bracket, master cylinders, reservoir tank and pedal set from a Girling equipped late 3/3a as I dont believe the old combined master will cope with the disc setup.

Stuart.

[ianc]

My first TR2 (bought in 1963) had drums and scared the living daylights out of me - I could reduce speed from 100 to 30 mph, but then the brakes had faded so badly that there was nowt left! I determined that my next TR would have disc brakes (and overdrive).

Second TR2 (bought 1964) had overdrive, hard top, soft top, tonneau, new upholstery, TR3A apron and disc brakes fitted by the previous owner. It was a revelation! The master cylinder was the original Lockheed and caused no problems whatsoever. Only two things were missing:

(a) a Girling back axle - the Lockheed was for ever wetting its rear brakes and new bearing seals lasted no time at all. Also, the half shafts are not as strong - I broke one in the 60,000 miles which I covered.

( decent wheels - it had 48-spoke wires, on which the spokes do not cross (interleave) front to back and vice-versa, with the consequence that I spent a lot of money having wheels rebuilt. Wheels need to be steel or 60-spoke wires (or alloys, but they don't look "period").

 

I would agree that rear drums should be 9" - the 10" drums are too big (even with 0.7" wheel cylinders - my brother tried it on his TR3!) and cause the back end to lock up before the front, which is hopeless. You'll note that the TR4, which is heavier than a TR2/3 had 9" drums. Another advantage is that parts for 9" drums are readily obtainable, as has been noted above.

 

Ian Cornish

[Herald948]

I have in fact recently picked up a pair of front vertical link/hub/disc assemblys amongst some spares for the rebuild. I was told that these assemblys are for a TR4, but the links look too short to me, and the discs are only ~9½" diameter, not nearly 11". I think that these could in fact be for a Vitesse/GT6, are there any other identification marks that I could look for?

You're likely correct. The later Vitesse and GT6 used a 9.7" diameter rotor. Of course, if the hubs are still present, the 3.75" PCD (bolt circle) of the small Triumph line would be the giveaway!

 

--Andy Mace

[Rod1883]

Thanks to everyone for the advice.

It is now clear to me that the link/hub/disc assemblys that I have are for the smaller triumphs.

 

Therefore I am in the market for the complete assembly, if possible, of vertical links, suspension arms and steering arms, hubs, discs and calipers from a late TR4 or 4a as suggested by Stuart.

 

Can anyone help?

 

Regards

 

Rod

[peter clarke]

Thanks to everyone for the advice.

It is now clear to me that the link/hub/disc assemblys that I have are for the smaller triumphs.

 

Therefore I am in the market for the complete assembly, if possible, of vertical links, suspension arms and steering arms, hubs, discs and calipers from a late TR4 or 4a as suggested by Stuart.

 

Can anyone help?

 

Regards

 

Rod

 

 

Consider fitting Toyota 4 pot calipers. They bolt straight on with the later bolts as fitted to TR6 caliper mounting and only require custom flex hose metric/unf. I have put these on my TR2 rebuild with TR6 vertical links but it is not yet ready for the road. Picked this idea up off the web and were much cheaper than TR6 calipers. Feedback from anybody who has experience of this appreciated.

[Rod1883]

Thanks to everyone for the advice.

It is now clear to me that the link/hub/disc assemblys that I have are for the smaller triumphs.

 

Therefore I am in the market for the complete assembly, if possible, of vertical links, suspension arms and steering arms, hubs, discs and calipers from a late TR4 or 4a as suggested by Stuart.

 

Can anyone help?

 

Regards

 

Rod

 

Apologies for bringing this back to the top, but I have now obtained a pair of front link/hub/disc assemblies from a 4A.

 

The question that I now have is - can this assembly just be bolted on to the earlier car chassis? Clearly, the 4A arrangement has small brackets on the inner ends of the lower wishbone arms - is it as simple as removing these brackets and then the arms go on the chassis mounted fulcrum pins on the earlier car?

 

Is there anything else that needs to be done/changed, or that I need to look out for?

 

Thanks

 

Rod

[stuart]

Apologies for bringing this back to the top, but I have now obtained a pair of front link/hub/disc assemblies from a 4A.

 

The question that I now have is - can this assembly just be bolted on to the earlier car chassis? Clearly, the 4A arrangement has small brackets on the inner ends of the lower wishbone arms - is it as simple as removing these brackets and then the arms go on the chassis mounted fulcrum pins on the earlier car?

 

Is there anything else that needs to be done/changed, or that I need to look out for?

 

Thanks

 

Rod

Rod thats pretty much it as the inner ends of the arms will fit the pins on your chassis. Obviously you will need to fit new bushes all round (Polys for preference) and dont get the top arms mixed up (they are marked on them L\R)

Stuart.

[ianc]

Stuart is correct, the Upper Fulcrum Pin for the TR4A has the same Part Number as for the TR2 (200659).

However, the lower wishbone arms and the spring pan differ (i.e. different Part Numbers from TR2 to TR4A and they look different in the Parts Books) and I think you will need to compare the items and decide which you should use - it may be that the differences are purely cosmetic.

 

For the sake of your own safety, please use a proper, internal, spring compressor - the external clamp types are very dangerous on a TR. If you haven't got a compressor, one can be made quite easily with some studding (about finger thickness), nuts and washers - you will find at least one thread on the Forum with helpful details.

 

Good luck,

Ian Cornish

[Nick Webster]

Stuart is correct, the Upper Fulcrum Pin for the TR4A has the same Part Number as for the TR2 (200659).

However, the lower wishbone arms and the spring pan differ (i.e. different Part Numbers from TR2 to TR4A and they look different in the Parts Books) and I think you will need to compare the items and decide which you should use - it may be that the differences are purely cosmetic.

 

Ian Cornish

 

In the parts books I have, the lower arm numbers are the same for Tr2 through TR4A- which rather surprises me but there we are.

 

I wonder if the change in spring pan is something to do with the change in spring lengths at CT29984?

 

I was never keen on taking the TR2 away from 0deg. castor, mostly because I believe it imposes a greater strain on the steering box and idler, which suffer enough as it is. It is worth bearing in mind that the TR4A caliper assy will fit straight on to a TR2 vertical link, if all you want is the disc brakes and do not want to mess about with the suspension. Also a good idea to fit TR4A master cylinders complete with pedal box which has the bonus of getting your pedals properly lined up.

[ianc]

TR2 brakes were Lockheed and the disc brakes for TR3 onwards are Girling. I have this feeling that the threads on the connections differ. It is vital that the correct mating connections are used, else the hydraulic fluid will be forced out of any connection where there is a mismatch. Consult one of the reputable suppliers to ensure you get this sorted. You may require bundy tubes with a Lockheed connector at one end and a Girling connector at the other (for the flexible to the disc caliper).

Ian Cornish

[ianc]

I have been reading Section M1 of the Technicalities CD, as I was pretty certain I had written and/or edited articles on this subject back in the 1970s. Irving price, like me, a founder member of the Thames Valley Group in 1970, whom I met at this year's International, recommended Lockheed flexible hose KL56506 to effect a connection between the Lockheed bundy and the Girling disc caliper. A word of caution - make sure that the flexible is of sufficient length to reach without kinking under all conditions of lock (left/right) and bump/rebound of the suspension; it may be necessary to re-locate the position of the end of the bundy on the chassis - there's discussion of this in Section M1 and the following Sections on the CD.

I think it is worth fitting the modern, steel-braided flexible hoses, as they are thinner yet stronger and provide a firmer feel to the brakes.

Ian Cornish

[peter clarke]

I have been reading Section M1 of the Technicalities CD, as I was pretty certain I had written and/or edited articles on this subject back in the 1970s. Irving price, like me, a founder member of the Thames Valley Group in 1970, whom I met at this year's International, recommended Lockheed flexible hose KL56506 to effect a connection between the Lockheed bundy and the Girling disc caliper. A word of caution - make sure that the flexible is of sufficient length to reach without kinking under all conditions of lock (left/right) and bump/rebound of the suspension; it may be necessary to re-locate the position of the end of the bundy on the chassis - there's discussion of this in Section M1 and the following Sections on the CD.

I think it is worth fitting the modern, steel-braided flexible hoses, as they are thinner yet stronger and provide a firmer feel to the brakes.

Ian Cornish

 

 

 

 

Early cars used BSF threads on the brake lines.

[Rod1883]

Hi everyone and apologies for dragging this thread all the way back up, but....

 

I've brought it back as I'm now really confused about the ride height and steering geometry issues discussed in other threads on the same topic. In this older thread the consensus was that the 4A set up could just be bolted onto an early car and off you go with the benefit of disc brakes and better geometry. Other much more recent threads that I've read and contributed to talk about ride height and other issues with the steering arms.

I'm a bit confused - can anyone give, in as simple language as possible, definitive guidance on this please as I and my restorer are struggling.

 

Thanks in anticipation.

 

Rod

[roy53]

Rod my TR2 with the later TR disc brake set up is sitting in my garage if you want to have a look for details as i am not to far from you.

ROY

[Rod1883]

Rod my TR2 with the later TR disc brake set up is sitting in my garage if you want to have a look for details as i am not to far from you.

ROY

 

Roy - Many thanks. I may well be in touch when the weather improves.

Regards,Rod

[Rod1883]

Apologies yet again to everyone for bringing this back up again, but.....

 

Ian, the restorer, now has the 4A vertical links, arms, etc fitted and the ride height looks fine, however he reports that we have significant positive camber.

Can anyone shed any light on what might be causing this?

I can't speak to Ian today, but I wonder if it could be due to spring length? If he has used the TR2 length spring/spacer rather than a later spring could it be as simple as this?

 

As before any advice gratefully received

 

Rod