TR2/3/3A TR3A front suspension rebuild

[Dr Evil]

Fully appreciate both views! I've got some tr6 upper wishbones on the way, and if they turn out to be ok, I'll likely go that way - fully aware this is a slippery slope I'm getting on and not in keeping with its year of manufacture. I'll need the 3 degree trunnions, but probably best to get new trunnions anyway, and mine look to be aftermarket replacements from a previous owner. I'm figuring probably R&P steering as well sooner or later; I think I'd like that anyway. The play on steering is about 1.5 inches at the wheel now that i've adjusted it as far as I feel it will go without binding. Current steering wheel I think is a moto-lita type, turn signal switch has been moved to the dash. I have the original banjo type wheel sitting in a box. Decisions!

 

[CJD]

I am pretty sure will will have to get new trunnions if you are adding the 3 degree castor...

 

[mctriumph]

Nobody was ever happy with steering effort in a Tr3!!!! And, yes updates & project creep can easily turn the
wife against the car( a major concern). I was quite happy with this upgrade on my 59. It is my belief that modern traffic
moves somewhat faster than Tr3's were intended to be driven( 80 vs 60mph) so any improvement is a good thing.
Take the Wilwood brakes, just yesterday I had to stop my car.......
Mad dog

 

[CJD]

Well...I am one that has no problem with steering effort in my TR2. But I took the time to make sure every component is spot on. I grew up only able to afford manual steering, so got to drive some really ratty steering cars...Mavericks, Darts, VW's, IH Scout...and several others that were just as bad or worse. I fly Boeing 787's for a living, but am restoring an 84 year old Boeing Stearman for fun. I don't expect the Stearman fly like the 787...and I don't expect my 69 year old TR2 to drive like my 2017 Vette. But, I have no problem operating either of them. For me the fun is "living in the year" of the vehicle I am in. My Vette will pull 1 lateral "G". Why would I want to change my TR2 when it can never do 1/2 that performance?

 

[Dr Evil]

slow progress, spring tower de-rusted and repainted. One thing I'm not sure of, there was some sort of circular flange protruding about 1/2 inch from inside the top of the tower to locate the rubber spring collar on; there was little left so I just dremeled it out for now.

 

[CJD]

You are correct, Doc. There is a doubler with a locating flange that should be inside your tower. I do not have a great picture, but you should get the idea from these partial pics

 

[mctriumph]

If the metal is too thin the shock absorber will cause it to fail. welding may well be called for here.
Mad dog

 

[Dr Evil]

thanks - I don't have the tools or talent to fabricate that flange much less weld it in upside down, so will be for the future. I think with the damper bolted in place and the rubber collar seated it will all be good. will be interesting to see if the other side is the same

 

[Herk]

The 3 degree trunions are a significant improvement, and don't increase steering effort significantly, at least with 165 section tires on wire wheels. The next big improvement is converting the center tie rod pins with the nylon type. This reduces steering effort a bit and improves feel. Revington do an Ackerman correction kit which will reduce steering effort in sharp turns and make it steer even more like a later car. IIRC to fit these the inner splash shields behind the disks need to be modded or replaced with the later parts.

 

[Dr Evil]

Slow progress getting parts together but I got some TR6 upper wishbones, new fulcrums, trunnions etc and decided to have a go at making some trick brackets to bring in about 1.5 deg negative camber based on an idea in the TR Register. The brackets offset fulcrum back by 18mm, but then the fulcrum is reversed bringing the offset to 12mm to achieve the negative camber. Trial fitting and the assembly and clearance looks good.

 

[mctriumph]

You are overthinking camber. The control arms can be slotted to allow the BJ to be adjusted inboard.
A custom washer is then fabbed up to strengthen the arm and hold the setting. Then it can be tack welded
if desired. This 1/4 inch gets you 1.5 degrees neg camber. It is also a fix to remove a pull due to cross camber
Mad dog

 

[mastaphixa]

I hesitate to jump into this dialogue between CJD and Mad Dog as I appreciate your contributions to this site and respect the experience you bring to the table. I did the TR4 swap on my TR3 when I rebuilt the front suspension. I also carefully overhauled the steering box. I love the way my car drives and do not find the steering effort objectionable. It is high if the car is stationary but with slightest movement it is quite acceptable. Is it higher than R and P? Certainly. Mind you I just hoon about town and am not involved in any competitive endeavors. Just another data point.

 

[Dr Evil]

You are overthinking camber. The control arms can be slotted to allow the BJ to be adjusted inboard.
A custom washer is then fabbed up to strengthen the arm and hold the setting. Then it can be tack welded
if desired. This 1/4 inch gets you 1.5 degrees neg camber. It is also a fix to remove a pull due to cross camber
Mad dog

Overthinking is one of my vices unfortunately ;-P

According the the information available, it looks like the upper pivot point needs to be moved 1/2" or 12mm inwards to change the camber from +1.5 to -1.5 degrees at standard ride height. I'm not sure how to slot that much into the a-arms without a lot of modification to extend the inner shoulders of the a-arms where it meets the ball joint. I think the slotting could be used to fine-tune the adjustment a few mm but not make such a large change.

 

[mctriumph]

Imagine a heavy washer ,oblong with 2 holes ,just wide enough to set into the arm.
There are limits as to how far this can go, but it is a solid way to modify the arm. You need 4 of
these washers, and it is not too hard to do. Perhaps it wont be enough to make 1.5 deg but it is a step
in the desired direction. I have mainly done it to equalise a cross camber issue, on a car just a bit out of spec.
Mad dog

 

[Dr Evil]

allright, slow progress, I pressed in new bushes in the lower arms and reamed them to fit new trunnions. Ran into an issue though - the trunnions I bought are TR4 3 degree castor from Bastuck; the way they are machined is that the trunnion pin hole is bored at a 3 degree angle through the trunnion casting (which looks to be same casting used on the 0deg trunnion), with the result that the shoulder of the trunnion is at a 3deg angle vs the pin. This means that the wishbones can not rest flush to the trunnion shoulder. Anyone know if this is 'normal' for the 3 deg trunnions? Below diagram a bit exaggerated for effect.

 

[TR-3rg]

Hi, Did you get a RH and a LH trunnion? Try swapping them, they will fight tight to the control arm.

Good luck,
Roy

 

[CJD]

I have seen, but never used the 3 degree set-up. I was under the assumption that the bushing should be straight, as the 3 degrees is in the vertical link and upper arms. There is not enough meat in those bushings to ream them off-center.

 

[Dr Evil]

thanks - no that's not it, I probably did explain it well. The outer a-arms bushings are pressed in straight and reamed to .625"

the issue (I think) is that the shoulder of the casting is not 90deg to the trunnion pin, so the a-arm does not sit flush with the trunnion pin shoulder. This is the righthand side such that the upright leans back with the famous 3 degrees caster. I suspect, but I'm not sure, that the supplier bored early 0-deg caster castings for 3 deg caster. I think the casting for the 3 deg trunnion might be different. I cannot really tell from the photos I see online because none are shown head-on, and the camera lens distorts angles.

how it is

below, how I think it should be:

 

[CJD]

I'm afraid that is a case of poor repro parts. You can tell they simply used a TR3 trunnion and drilled it 3 degrees off. The faces should be parallel to the shaft.

If you have access to a lathe, you can face the trunnion to the shaft...otherwise I would contact the supplier.