TR2/3/3A TR3 Front Suspension

I have read of so called Triumph specialist recommending the replacement of TR3 front suspension components with the TR6. I just want to know if anyone on the forum has done this and if so, what if any problems did they encounter.

My TR3 is not a concourse and I want to improve the handling , braking and steering because I use it to cruse around in . Presently it has drum brakes on the front that I am going to upgrade this is one reason I am seriously looking at this change

I installed a rack and pinion set up from Racetorations in the UK. Simple installation costing about $1350.00 Made a large difference.
Soom members want to keep the cars stock and rebuild them. Probably a good idea if you can find the parts and know how to set them up properly.
As for the TR6 set up in a TR3, ?????

Not sure about a TR6 suspension swap, but a swap from a later TR4 would work well. Vertical arms stay the same, but the trunnions, ball joints and upper a-arms would swap and be a direct fit and give you 3 degrees castor vs 0 degrees as you have now. Also you would have the parts for the front disks at that point.

I think this was covered a few months ago, you can probably pick up a few earlier notes that may help with a search of the forum.

TR4nut said:

Not sure about a TR6 suspension swap, but a swap from a later TR4 would work well. Vertical arms stay the same, but the trunnions, ball joints and upper a-arms would swap and be a direct fit and give you 3 degrees castor vs 0 degrees as you have now. Also you would have the parts for the front disks at that point.

I think this was covered a few months ago, you can probably pick up a few earlier notes that may help with a search of the forum.

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I think the vertical links also need changing if you want to use the TR4 trunnions because the TR4 trunnions are handed (left and right) and the TR3's are not. A-arms changed early on in the TR4s as well.

Swap to TR4-6 disc brakes in the front are a good idea too.

But this all depends on how original your 56 is and how much you'd like to keep it so. IIRC the rear end on the early 3's (56?) is a week point specifically the axles. But then you'd get into to swapping so much stuff that your car values drops significantly (if that's important to you.)

<span style="text-decoration: underline">But to answer your question:</span>
I rebuilt the entire front suspension on my 58 last winter. I used poly bushings and Koni shocks, new OEM style silent blocs (today I would buy the delrin SBs from A.R.E.), all new rod-ends and ball-joints, etc. Added an Addco front anti-sway bar. Otherwise, everything is stock. Mine has disc brakes on the front and 10" drum on the rear. It handles great, tracks true @90mph and also @normal highway speed. I also have HVDA 5-speed. I autocross my car.

I've though about changing over to 9" rear brakes from a TR4-6 but really don't see the benefit, other than the cost of brakes shoes being a lot le$$. . I am trying to keep it fairly stock with only reversable mods. Values on our cars are up so I want to keep it that way.

R&P conversion would be nice to have.

PeterK said:

But this all depends on how original your 56 is and how much you'd like to keep it so. IIRC the rear end on the early 3's (56?) is a week point specifically the axles. But then you'd get into to swapping so much stuff that your car values drops significantly (if that's important to you.)

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The change to disc brakes was at TS13046. It was the same time that they went to the beefed up rear axle. All the drum brakes cars had the Mayflower type rear axle. They are known to snap half shafts.

Personally, I wouldn't bother with the suspension upgrade. The front drum brakes were miserable, IMO, I never felt safe driving the freeways with them; so I would definitely upgrade to TR3 front discs (which are larger than TR6 discs). The extra caster of the TR6 will give you more centering force (for somewhat better tracking on heavily rutted roads); but at the expense of more steering effort (many of the R&P conversions also have slower turning ratios than the stock TR3 steering).

I drove my TR3A to work every day for many years (was on my way home from work when it got wrecked), and after a careful rebuild, the steering suited me just fine. I've actually got the components in the parts bin to add the caster but never felt the need for it. Actually, I got them because the later upper ball joint supposedly makes it easy to adjust the camber more negative; but I've since learned of a better method that I will try (if the occasion arises again).

Of course I did make a few other modifications, like solid brass silentblocs, Nylatron bushings, ADDCO sway bars front & rear, wide sticky tires, etc. Handled really well, I used to really enjoy passing more powerful cars on freeway on-ramps ... even had a Saturn spin out once trying to keep up with me. Also took 1st in class in the only autocross I entered with it. My next improvement was going to be a beefier front sway bar, because the rear suspension was once again hitting the stops in hard corners (due to increased cornering force).

I need to recheck the parts manuals before I dig in my heels, but I think the links are the same. I replaced a bent late TR4 link with one from a TR3 with no problems. The trunnions being handed, as well as the different a-arms give the castor change - this was why they changed on the TR4.

Regards,
Randy

So i guess the consensus seems to be, to toss Roger Williams book How to Improve TR3 - TR4a, and keep it stock except for the steering rack.

The TR3 vertical links are the same as the TR4 vertical links. However, the 4A-6 vertical links are different (both side-to-side and from the TR2-4 VL). The (later) TR4 trunnions are handed only because the pin is not perpendicular to the bore for the vertical link (to allow the VL to tilt for the non-zero caster), the threads are the same on each side.

fad64b said:

and keep it stock except for the steering rack.

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I wouldn't even mess with the rack ! All that money, and you lose the original turn signal function ... my TR3A steered just as easy as any TR6 I've driven (which admittedly isn't many) and a whole lot easier than the Stag with the PS pump on the blink.

Of course it's your car, so do what pleases you. I'm not saying the conversion is "wrong" in any way, just a waste of money in my opinion.

TR3driver said:

The TR3 vertical links are the same as the TR4 vertical links. However, the 4A-6 vertical links are different (both side-to-side and from the TR2-4 VL). The (later) TR4 trunnions are handed only because the pin is not perpendicular to the bore for the vertical link (to allow the VL to tilt for the non-zero caster), the threads are the same on each side.

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My 4A is handed and one side has left-hand threads and the other had right-hand threads; at least when I assembled it one trunnion screwed on to the right and one left. The parts catalogs show TR4 trunnions as LH and RH, and TR3 as a single part for either side.

I agree that one side of the TR4 uses the same vertical link as the TR3 zero caster. But the other side needs reversed threads for the handed trunnions. So how can they be handed and still have the same threads on each side?

PeterK said:

So how can they be handed and still have the same threads on each side?

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Because what is "handed" about late TR4 trunnions is only which direction the angle between the pin & threaded hole tilts. They are totally different than the TR4<span style="font-weight: bold"><span style="text-decoration: underline">A</span></span> trunnions, which as you note, have opposite handed threads between the two sides.

Very interesting. Got to <span style="font-weight: bold">hand</span> it to you.

There may be other subtle differences, too. For example, I think the 4a link (like the TR6 link) has a zerk fitting on the link for lubrication - but the TR3-4 link has none and the zerk is on the trunnion.


Randy

I thought about doing the change when I did my front end. But I initially thought it was just a trunnion swap to get the castor. Then the chewing gum go bigger and bigger as there was more to change out. If Triumph did the change as a service bulletin upgrade, then I'd go ahead. But I try to keep things relatively intact.

And like I said before, my car really handles well with the setup I now have.

Frank,

PeterK's advice as to how to get the original front suspension to handle very well is spot on, and I speak from having worked on our LBC's for many, many years.

The rack conversion improves the steering feel and accuracy if you want to spend that kind of money, but you still need to do the suspension.

The 3 degree trunnions on the later TR4/6 only help if you instal the rack and pinion conversion, because they were designed to work with the TR4 rack. Consider if any roadworthy or insurance issues arise if you mix and match steering or suspensions.

Regarding a brake upgrade, the best option is to get the front discs, master cylinders (brake and clutch needed), and the stronger Girling diff with either 10" or 9 " rear brakes, from a later TR3 or 3A. It think it's wise to fit the complete disc brake setup so everything works as designed by the factory.

Regards,

Viv

I did my front suspension and steering on my 60 TR3 in the last year. What a great improvement at reasonable cost just by replacing whatever moves. Rebuilt the steering box, replaced idler bracket, silent blocks, ball joints, bushings, trunions, tie rod ends etc.
Steering is much better than it was. So much so, that I can't see spending $1300 to "improve" it.
Don't start this project without a good and safe spring compressor.

I recently drove a 1958 TR3 and the steering was great. My car, a 1960, was in such bad repair that I completely rebuilt the suspension. Since ths steering box was totally worn out I bought a steering rack and pinion from Racetorations in the UK.
After further learning about the cars and knowing about part availability,it might have been just as good and much less expensive to replace or rebuild the steering box.

Just in case you care, after installing the R&P my car drives well and is much more relaxing and enjoyable. I have no regrets. The turn signals are located just below the dash in a panel and are just as easy to access and use.