TR2/3/3A TR3A front suspension rebuild

[Dr Evil]

Hey folks, I bought a 1960 TR3A a few weeks back and I've started to strip the front suspension to see what's what before it gets driven. on the right hand side here's what I found under mounds of dried grease:

1) trunnion pins badly scored, not sure if I should keep the original trunnions and press in new pins or spring for new trunnions. I hear that new trunnions are hit of miss, so at least I know the ones that were on there fit. with the trunnion screwed into the upright there is a bit of side-to-side play, not much up and down, but I don't really know how much play is ok.

2) one of the inner lower wishbone steel bushes is seized to the chassis; I may try to heat it up and use a vice-grip to see if I can free it, but that will definitely ruin it. Any tips welcome.

3) upper ball joint is really notchy so that will get replaced.

4) upper inner wishbone bushes seem to be nylatrons as used in the lower inner wishbones... except that the metal inner bushes are stuck solid inside the outer nylatron bush, so the wishbones pivot around the fulcrum pins on the inner steel bush, not on the nylatron. Anyone know for this setup, shouldn't the steel bush be clamped tight so that the wishbone pivots on the nylatron bush, rather than between the steel bush and the fulcrum pin itself? Needless to say the fulcrum pins are bone dry, rusty and pitted, so to be replaced.

5) the spring spacer was mounted under the spring instead of top of it as shown in the drawings. When I inspected the spacer, I found some eccentric wear on the inside of the spacer. The top of the spax damper also has some wear on one side, so I suspect someone swapped the spacer to the bottom to avoid interference with the damper. I'm thinking of replacing spring with a standard longer spring 11" spring and not using the spacer, even if the original spring length seems nominal.

that's it so far, building a shopping list which is looking extensive - bushes all round, trunnions, springs, ball joints and other bits and bobs.

 

[charleyf]

First Congratulations on your recent adoption of a classic motor car. I love my LBC's ( that is Little British Cars in our lingo). And I hope that you will also. As to your questiions I will answer some of them as best I can from my experience. You will find that others will also answer the same questions and the answers may well vary.
1.
The trunnions on these cars are one piece. The pins are manufactured as a integral to the part.
Once the trunnion is screwed up a small bit of looseness is expected. You will notice it at the assembly stage by not after that.
2. These steel bushes have caused owners a lot of grief over the years. I have had to resort to heat and pipe wrench on a number of them. On one I had to cut it with a dremel tool to get it free. Done carefully it causes no harm to the chassis pin. Even if you do nick the pin the new bush covers that , so no real harm done.
4. If you have Nylatron bushes it means that somebody has done some rebuilding of the suspension in the past. The originals were rubber. Originally there were no steel bushes in this location. The upper fulcrum pins are a replaceable part.
5. These cars ride rather rough, so be careful about any springs that give any rougher ride. Unless you are looking at stiffening up the roll of the car. And then I use a front sway bar on my cars.
The cars that I have restored have all been pretty much original. So I have changed out all easily replaceable components possible. That includes the suspension as well as bearings.
Charley

 

[mctriumph]

Dr E. IMHO cut to the chase and upgrade to Tr4a bits now. Cost is the same but safety and handling
are greatly improved. Also this job is best done with the body off the frame.....
Mad dog

 

[Dr Evil]

Dr E. IMHO cut to the chase and upgrade to Tr4a bits now. Cost is the same but safety and handling
are greatly improved. Also this job is best done with the body off the frame.....
Mad dog

 

[Dr Evil]

Thx. Ive had a hard look at that, tr4 suspension needs at least lower wishbones, uprights, 3deg trunnions and upper wishbones in addition to the service items like bushes and ball joints. The A-arms are not as cheap/available as they maybe once were unless im looking in the wrong places?

Also, not sure it is worth that without neg camber? Tr4 still runs 1deg positive? Is tr6 front end neg camber?

 

[Dr Evil]

Ok further sleuthing, looks like later tr4a-Tr6 upper wishbones can be paired with tr3a uprights & early tr3a lower wishbones as long as early tr3a 3deg trunnions are used. That would be a lot more economical than replacing uprights and lower a-arms.

 

[mctriumph]

Yes the Tr4a trunnion and the upper arms/ball joint are the key .Then, if your rotors are shot,
use the later rotors too,This allows for Wilwood brakes to be installed at a later time if desired.
Mad dog

 

[Dr Evil]

Yes the Tr4a trunnion and the upper arms/ball joint are the key .Then, if your rotors are shot,
use the later rotors too,This allows for Wilwood brakes to be installed at a later time if desired.
Mad dog

Do you know if lower trunnions also need definitively to be changed? I assume the tr6 ball joint is offset backward to affect the 3deg caster, so trunnions need changing as well?

 

[sp53]

Well doctor have you separated the ball joint? You can either use a big hammer with the correct forked tool, or there is a special tool, a ball joint separator. I use a hammer, but I have wanted to buy and try one of the separating tools.

To collapse the spring I made a simple tool out of a very big bolt and 4 holed adapter to fit over the bottom studs of the lower bracket.

My advice is to take the suspension apart now and get a feel for the suspension and components before you make any decisions. I have kept my cars stock and the suspension works fine

 

[Dr Evil]

Yes, right side is completely off. Ball joint worn, trunnion pins scored, fulcrum pins pitted. Nothin bent as far as i can tell.

 

[TR-3rg]

Hi, I see the TR-4a spindle being mentioned here. A TR-4a spindle will lower the front of a TR-3 about 1.5". Its also a different thread going into the Trunnion. If you want to keep the car level, a TR-3 Spindle can be used with a late TR-4 , not TR-4a, Trunnion and Upper Control arm assembly. That's what I have on my TR-3a.

Good luck! Roy

 

[Dr Evil]

Hi, I see the TR-4a spindle being mentioned here. A TR-4a spindle will lower the front of a TR-3 about 1.5". Its also a different thread going into the Trunnion. If you want to keep the car level, a TR-3 Spindle can be used with a late TR-4 , not TR-4a, Trunnion and Upper Control arm assembly. That's what I have on my TR-3a.

Good luck! Roy

Will go that way…

 

[Dr Evil]

What does anyone know about slotting tr4a-tr6 upper wishbone balljoint holes to remove positive camber? (Thinking ahead…)

 

[mctriumph]

Can be done ,but you are paving over a problem. You must fab up an oblong washer to fit in
the arm(X 2).Check first that the upright(spindle) is not damaged.If it is good, you have some old
collision damage. Cheating the upper balljoint will net you 1.5 deg at best.......
On my 59 I reused the spindles and just added the Tr4a trunnion ,upper arms and the joint.
All done in an hour,fixed the castor issue(yea!). Only one lower arm had to come off to make this
swap(shock and spring stayed in place)
Mad dog

 

[Dr Evil]

Thx, not sure ithere is a problem as such. Unfortunately i didnt check the camber before putting the car on stands, but it was -1deg both sides on the bump stops which i think is consistent with the expected geometry where it would be +2 at ride height. Getting to around -1 at ride height would be fine for my intentions. I understand about 1/2” is needed.

 

[sp53]

I would not be concerned about the pits in upper control arm, either glass bead it or clean with a wire wheel. Do not throw anything away until you are very done. Many of the aftermarket parts do not have the quality of original parts. Even some of the small original washers are probably better than what you can purchase.

The Roadster Factory which was a Triumph parts supplier had a nice suspension kit. The problem is they had a fire and I am not sure they are going to reopen. You would have to call and see. Moss Motors is probably the Gold standard for Sport Car Parts. They have a nice catalogue if you do not have one, they send them out free.

There is also Rimmer bro’s in England

I do not know how to modify a tr3 suspension, so I will leave that to the more experienced people.

Steve

 

[TR-3rg]

Hi, If I remember correctly, the Upper Fulcrum Pin is not symmetrical. It can be installed backwards. Unfortunately, I do not remember the correct orientation. Check the other side, if it looks correct and has not been removed.

Maybe someone with a better memory can help out.

Good Luck, Roy

 

[CJD]

Sorry, I am late to the conversation...

Doc, just realize that if you switch to the 3 degree trunnion and vertical links, your car will track straight marginally better, but your steering force will be increased. The weakest link in the TR3 steering is, by far, the steering gear. If you go to TR4 suspension parts, then you will be unhappy with the steering until you also install a rack and pinion, to relieve some of the steering force.

The TR3 system works just fine, so long as you build it correctly and in accordance with the manual. The TR3 steering gear also works fine, so long as it is not worn out with a lot of play.

By far the most common problem in the TR3 suspension is bent vertical links. There is no camber adjustment in the TR3. So, if your car has been in an accident or severe curb bounce, then the camber is thrown off. If not repaired properly to fix the bent parts, then many shops unknowingly bend the vertical link to bring the camber back to 0. This results in a bind in the steering, and drivers who swear the TR3 steering is horrible.

Make sure your vertical links are straight. Rebuild the suspension and steering gear to spec. You will be happy with the result. If you decide to go TR4, you will have a lot of project creep (steady increase in parts and labor as you go along) that is unnecessary. I finished my TR2 7 years ago, and it still drives like a dream. I just want to make sure you understand what you are getting into if you start mixing and matching TR3/4 parts.

Here is a link to vertical link measurement:

General Tech - Triumph spindles

I just had the pleasure of disassembling, cleaning and inspecting 8 Triumph spindles, ranging from TR2-4. I have mentioned before how these are not the strongest of spindles...and my inspections proved it. In order to turn freely, the lower "bolt" that threads into the trunnion must be...

www.britishcarforum.com

This is a complete guide to TR2 front suspension rebuild, which is the same as the TR3 with the exception of the drum brakes:

TR2/3/3A - Recipe for a TR2

So, since the body thread is indefinitely on hold...here comes the chassis build thread I promised! Follow along as I build a TR2 from scratch... Start with one part TR2 frame, freshly blasted, welded, and painted. Well, not so fresh, since I did that 3-1/2 years ago?!? During a walk...

www.britishcarforum.com

Good luck and have fun!

 

[mctriumph]

I must disagree CJD, there was a reason Triumph made improvements to the Tr over the years.
Part of the charm of the beasts is that upgrades are easily fitted to older cars. Take for instance
the all syncro gearbox. Nobody misses broken gears.
The improvements made with the 4a steering helped make the Tr6 faster/safer/better.
IMHO there is no reason not to improve the zero castor steering on a tr3 by fitting the latter bits.
There are a lot of reasons for castor angles and every carmaker in the last 70 years has had from 3degrees
to 5 or 6. Better engineering makes better cars.I say rejoice, in that it is an easy retro fit ,done in a few hours.
I was thrilled with the change in my 59 when I changed it up.
Mad dog

 

[CJD]

No doubt. I never said the TR4 suspension and steering are not better. What I said is if you just add the TR4 suspension to a TR3, you will not be happy with the steering effort, and parking lot maneuvering turns into a real bear. So, if you do the change you will also want the rack and pinion steering to go with it, which adds a problem with the turn indicators and horn activation/cancelling. In the end you have a car that is marginally better to steer...but without a cancelling turn signal and patched in horn and signal buttons. If you want to argue that the improvement is more than "marginal", then I would argue that your '59 had some problems before the upgrade, AND it is all the marginal improvements over the years that got us to today's vastly better steering vehicles. It is not a revolutionary improvement between the TR2/3/4. The modern improvements, which also increased castor, came with power steering...That would be a substantial improvement.

The above is called project creep...and I merely wanted Doc to understand what changing to TR4 castor involves. I am not telling anyone what to do with their car, just making sure they understand what it involves! Not everyone has an unlimited budget, and upgrades are not always an improvement if you enjoy living in the year the car was built.