• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

TR2/3/3A bottom out the trunnion

Share this page

S

sp53

Yoda
Country flag
Offline
Trunnion installation, the Haynes manual suggest bottom out the trunnion and giving it one turn up, but that did not look right on the ones I just installed, so what I did was turn the trunnion down so the radius stop was centered on the flat face of the vertical link. It turned freely in my hands back and forth and did not have a large gap on the seal, but the seal did seem to be a little smashed on the base, whereas the seal seem loose when turned out the one turn and again the seals are a little thicker than stock. I thought I was good to go, but now that I have the trionnion in the car, I feel a slight bind when I move it back and forth with my hands plus with the ball joint hooked up it is naturally a little stiffer.

My concern is when all the components are hook together in unison the stiffness will multiply and make the steering too stiff which brings me to another question when is the steering too stiff or too sloppy. I like the steering stiff, but I do not want the car to be too much work to drive. Part of me wants to undo the trunnions and back those off another turn regardless of how that sits on the radius adjustment, and part of me feels the car will loosen up over time as it is driven. Tr3s have stiff steering normally, I believe, but having never driving one new I just do not know.




 
You've already checked that you have free play betwen the stops - so I'd leave as is. I think you still would have that binding feeling even backing off a rotation - its normal with new components.
 
If you are using the original style "silent bloc" bushings on the center link, then it will always feel stiff. New ball joints are also stiff.

One thing to check, though, is for a straight spindle. Half of the spindles I have worked on are bent. When they bend, the thread for the trunion does not point to the absolute center of the tapered hole for the upper ball joint. The 2 joints must be absolutely lined up, or the spindle will bind when you turn it. I am convinced all it takes is one clip with a curb to bend a spindle. I also suspect that some body shops have intentionally bent the spindles to adjust the camber...but that puts the suspension in a bind.
 
CJD said:
One thing to check, though, is for a straight spindle.
Click to expand...

Doh! You are completely right there, excellent advice. When I bought my TR4 that was the problem I had on one side - all the suspension bits had worn down to accomodate the bent spindle so it wasn't obvious at first - but it was tight threading on to a new trunnion and you could see the top of the spindle rotate off center when the spindle was rotated in the trunnion.
 
CJD said:
One thing to check, though, is for a straight spindle.
Click to expand...
I agree, except I think you are talking about the vertical link (the piece that goes between the trunnion on the bottom and the ball joint on the top). Herman van den Akker once wrote for the club newsletter that he tested 5 vertical links before finding one that was straight.

The spindle is the part that sticks out horizontal and carries the wheel bearings. They can bend too, but only screw up the steering geometry.

Last time I installed new trunnions, it was quite obvious that they had to back off by almost a full turn. Otherwise, they bound before reaching the full lock position.
 
As usual, you are correct! I meant the vertical link. That was a case of my American-car-isms returning.

Just something to mention...I have had luck straightening the vertical links with a large drill press and a hydraulic press. I chuck up the link by the trunion threads and spin it by hand to see where it is off. I then unchuck and gently press it into shape on the hydraluic press. It often takes a dozen tries to get it perfect...and, of course, I would not recommend doing this if the bend is beyond about 3/8" at the tapered hole.
 
That was it; it is bent. I never would have figured that one out, but now that I know it is things are a little clearer because when I move the link with the ball joint hooked up the lower wishbone would flex also. I dug through my stuff and found another one that needs a good cleaning and popped that one in place and the lower wishbone stopped flexing. Again, now I can see how hitting a curb would knock that off being perpendicular to the base—Good call John.
 
Best to find it now! Let me know if you run short, as I think I can come up with another link, or I'd be happy to straighten that one for you...
 
Back
Top