• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

General Tech Triumph spindles

Share this page

CJD

CJD

Yoda
Country flag
Offline
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 centered with the tapered hole for the upper ball joint. Of the 8, only one was close to centered...which means 7 had been bent in service. My best was only .025" off center. The worst was over an inch!

If you want your car to turn easily, then the spindle has to be in alignment, as depicted in the service manual. If one or both are not in alignment, then the spindle(s) will bind as they rotate, since the trunnions do not allow any for and aft movement. Since 9 out of 10 spindles I have dealt with were bent...this is definitely something to check before you throw your new bushings into a rebuild.

All is not lost, though. I took a few pics as I straightened the spindles. The key is to chuck the spindle in a drill press or lathe by the bolt. Then slowly turn it by hand while checking the runout at the ball joint hole. You can see in the pics that I used a dial indicator, but just eyeballing the hole is really enough.

Here is the setup using a drill press:



Once I rotate it and find the low spot, I mark it with a pen:



Next I unchuck and move over to the hydraulic press and set the spindle in V-blocks with the high spot up...and gently press the center of the spindle. This frequently takes a dozen or so tries to get it right. Pressing, chucking and rechecking...repeat and so-on. One spindle took an hour, so patience is important.



And here is the final product. I chased my tale so many times trying to get them perfect, that I settle for .005" tolerance (since the trunnion should be able to take up that much misalignment). This one reads .003" max.



Anyway...just info for anyone interested.

Cheers,
 
Oh...with 8 spindles I got to work with 8 stub axles. Just for anyone interested, these are the most common failures. This first stub had a bearing come apart. You can see the gouges from the parts that chewed up the axle. Also, the bluish color is from the resulting overheating as the race began to spin on the axlef.



But, by far normal wear is what you find. This is an axle that looked perfect on the top of the shaft. This is the bottom, though. The inner races are designed to slowly "walk" around the axle as the wheels turn. This results in a gradual wearing of the axle...only on the bottom, since that is where the weight of the car is pressing the race. This pic is a normal wear pattern. I replace the axle if it catches my fingernail on the ridge. The reason is that the ridge prevents the race from freely sliding on the shaft when you set your bearing play. You can try cleaning the ridge with emery paper, but if you can still feel it...it will cause trouble.



The take-away from this is to check under the axle when you repack your wheel bearings. The top of the axle will always look perfect!
 
A broken vertical link is right up there with the rear hub failure on the IRS cars as far as nightmare material goes. Like Dan mentioned in the previous post, I would be concerned about bending. OTOH, I wonder about the quality of the replacements available now. One of my winter projects will be rebuilding the front suspension and will check the upright for straightness and have it crack tested as there have a cases of breakage at the threaded portion.
Berry
 
John, Thank you for all your efforts. We can all get a better job, now that you have shown us how.

Wayne


PS Just goes to show, you are never to old to learn, 74 in 2 weeks.
 
Last edited:
John, after reading your thread, I think the spindles are not strong enough for these cars. I'm wondering if they will stay straight after you straighten them? You don't say what size of press you are using, but it appears the metal is kind of soft. I now know part of the problem as to why my car steers so hard. Thanks for the posting.
 
John, Very interesting article! I'm going out of the park for a moment, hope you fellas don't mind, but could this happen to a 54/55 MG TF spindle? I know a fella who's TF steers very hard and wondering if this could be his problem? Mine steers very easy. PJ
 
I have to believe the vertical links (thanks for the proper term), have to be strong enough for normal use. They used the same basic link on cars for over a decade. I think a couple things may be a problem, though. First is the enevitable curb clipping that happens over the life of a car. And the second...and maybe the biggest problem...is that there is no camber adjustment on these suspensions. I think alignment techs may have a habit of bending the vertical link to adjust the camber. The thing is, if the camber was off to begin with, something was damaged, so bending the link is just adding to the problems.

You will note I did not put any pressure on the machined trunnion bolt for the straightening. I figured putting any pressure on the threaded bolt portion would cause problems. I only push on the upper forged arm going to the upper ball joint. My press is just a cheapo Northern Tool Chinese one, that says it's rated at 12 tons. I have to put some muscle into the job, so these are far from butter to bend. I also only fix the links that are close to begin with...the ones that were over 1/4" off got scrapped. Since these parts look like forgings, I'm not worried about the small amount they are being bent. The fact I had one that was bent 1" without cracking tells me they must be forgings. But, if I find out they are castings, I'll change my mind about that! A casting doesn't like being bent at all.

As far as the durability of the fix...I straightened the links on my TR3A 3 years ago. I have not hit anything with them, and this weekend I gave it a grease job. On jacks with the wheels removed, I can grab the brake rotor and turn the vertical links easily with one hand from stop to stop while I'm accessing the grease fittings. So far still straight. When I bought that car, the steering felt like an 18 wheeler with no power steering. With the bent spindles, when I turned the links while the car was on jacks, they always tried to return to same point when I released the pressure...almost like the steering was spring loaded. With straight links the steering stays where I put it.
 
I don't think that straightening would have much of an impact on the ones that showed the lower amounts of runout, but that one at an inch would definitely make me nervous without performing some sort of non-destructive inspection on it. Then again, I'd probably NDI all of them for that warm and fuzzy feeling. If you are nervous about the part after any straightening operation, you could always do some NDI yourself or take it to a local inspection house and have it done professionally.

Something we used when I was racing motorcycles was what we jokingly referred to as "flour fluxing." To do this on small parts we'd take a container of very dyed light weight oil and warm the part to about 150°F and then let the part sit in the oil for about ten minutes. After we'd pull out the part and wipe it down to remove excess oil and dust it with flour, shaking off the excess. If there was a crack the oil would wick out of the crack into the flour and show up. Kind of crude, but it was what was available to mere mortals at the time. Now you have more choices.

While I don't think it is worthwhile to set up a home magnufluxing facility, there are now penetrant inspection kits available to the public in both fluorescing (blacklight type) and conventional dye penetrant inspection kits (essentially a high zoot version of our "flour flux") available to the general public. You can find them at industrial supplies like MSC, Grainger, Mcmaster-Carr or places like Aircraft Spruce.
 
I like that flour method. No reason it wouldn't be just as telling as the professional dye penetrants. What concerned me as much as the bending on these links is that the upper ball joint tapered hole on a couple links had very thin walls...like 1/4" of metal from the side of the hole to the outside wall. They obviously worked for many years, but they sure look flimsy. The better links had 1/2" walls or more.
 
Just a wrap up to this thread...

I went through 8 trunnions, and all were too loose, so scrapped all the used ones and ordered a couple TRF new trunnions. Excellent quality, and they even have the hole drillings for the castle nuts, unlike the ones I got 3 years ago. I assumed that the brass of the trunnions would wear and the harder vertical link steel would not. It turns out that assumption is wrong! I'm sure the old heads knew this fact, but thought I should state it for the newbies like me.

I had selected the cream of the spindles I had. One fit the trunnion tightly...but the other had enough play to make a clicking sound. So, had to check the new trunnions on each of my stack of vertical links. That eliminated 2 of them. So...in the future I will check the trunnion bolt threads before spending the effort on cleaning and straightening...
 
Last edited:
Resurrecting an old thread to ask for some opinions on this.

I checked the runout on both my vertical links per John's method above. I have it chucked in a lathe rather than a drill press. Both read around 0.050 in.

One of them had bad threads so I'm scrapping it and bought a brand new one from Rimmer Brothers which arrived today. It also has around .050 runout out of the box.

Here's what it looked like: [video]https://drive.google.com/open?id=1N1yd5_z7ZyZZbOnSmqFMxRjmM0YXS28s[/video]

Both old links turned easily before I took them out. The new link is noticeably more snug in the trunnion threads than either of the old ones. (Snug in a good way, not too tight.) Slop in the threads would allow the steering to compensate for runout in the link, but the new link doesn't have any slop.

I'm reluctant to start pounding on a brand new link with the 20-ton hydraulic press that Santa is bringing me this year. I'll definitely try it out on the scrap one first, but what do you guys think?
 
Great information, so mush to learn. It is details like this that can only make our cars handle better and make them safer.
Frank
 
I think between trunnions and gauges, John has a cottage industry standing by, if it pays enough...

Great work and documentation!
 
I posted at more linkth on your thread, Snow...I think your links are fine to use. .050” is a very good runout number!
 
Back
Top