TR2/3/3A Wrapped around the [Stub] Axle

[CJD]

Again, I'm at a loss on the front suspension. I had 2 decent vertical links chosen out of a stack of 8. But then the new trunnions arrived. When the trunnion is screwed onto the bottom of the vertical link, there is a bit of play. I had one with no play...but later measured and discovered the vertical link bolt is bent, so it was "wedging" itself into the trunnion...it got trashed. Of the remaining vertical links, I measure betwen .005" of play on one (which I am happy with), and .011 to .013" on all the others.

I can find no references anywhere in the book for trunnion play tolerances. I did find the limits for the through bolt to suspension arm, which is totally different.

So, am I over thinking this, or is .013" play about right?

 

[TR3driver]

IMO, you're overthinking. You didn't mention what axis you are measuring play in (or else I missed it), but the weight of the car takes up any vertical play. In general, i think, overcoming rolling resistance will take up any fore/aft play. And the suspension is by no means so precise that even .015" of lateral movement is going to make any difference. Especially with those original rubber bushings, the entire lower A-arm and spring pan assembly can move by 0.1" or more at the trunnion.

BTW, TRF does have new vertical links listed for sale. If you really want one with no wear, that's probably the way to go.

 

[SteveBones]

Hi John,

My input here is not unfortunately going to answer your questions. I am very interested in hearing more about this. My TR3 is out of alignment and I will at some point in the future rebuild the front suspension including replacing the trunnions. I am not sure what I will need to be looking for to figure out what is correct regarding acceptable tolerances. The answers to your questions will also be helpful for me.

Good luck,

Steve

 

[CJD]

Thanks, Randall. I cannot measure play in the vertical, or "in and out" direction, as it seems imperceptibly small. The play I am measuring is in the side to side direction, perpendicular to the vertical link bolt. I did look at the TRF links, but they run $240 each. Thats a substantial investment. Last time I bought trunnions (from Moss), I had to exchange 4 times before I found a set that weren't more loose than the trunnions that were coming off. I finally got those to fit with no perceptible side play. But I learned that "new" is no guarantee of tight fitting.

My fear with dropping bucks on new vertical links is that I will only learn that .010" play is average. With the 8 links I have, it seems unlikely, but possible, that 7 of 8 are worn out. Anyway, from what you are saying, I think I'll live with the play I see.

 

[SteveBones]

Hi John,

I have a question based on your comments below regarding Trunnion side play. Are you saying that if the trunnion has excessive wear, the impact would be excessive left to right movement of the spindle? If the trunnion wear is excessive, would I be able to determine this by grabbing the front wheel at 3 and 6 o'clock and look for movement where the trunnion connects to the vertical link?

I am trying to figure out if there is excessive wear with the front wheels of my TR3A and potential cause. I am hopeful all is well so scheduling of the suspension rebuild can happen at a later date and I can still drive the car.

I need to go back and check this. I recall there was movement with the front wheel when the car was jacked up and I wiggled the front tire while holding at 3 and 6 o'clock. I want to go back and check again, and it would help to understand where to look for a potential cause.

Thanks,

Steve

Thanks, Randall. I cannot measure play in the vertical, or "in and out" direction, as it seems imperceptibly small. The play I am measuring is in the side to side direction, perpendicular to the vertical link bolt. I did look at the TRF links, but they run $240 each. Thats a substantial investment. Last time I bought trunnions (from Moss), I had to exchange 4 times before I found a set that weren't more loose than the trunnions that were coming off. I finally got those to fit with no perceptible side play. But I learned that "new" is no guarantee of tight fitting.

My fear with dropping bucks on new vertical links is that I will only learn that .010" play is average. With the 8 links I have, it seems unlikely, but possible, that 7 of 8 are worn out. Anyway, from what you are saying, I think I'll live with the play I see.

 

[titanic]

John-FWIW there is a dimensioned drawing of the vertical link in the "big red" factory service manual on page 25 of the front suspension&steering section. There is a note pertaining to the threaded portion that states: Clearance on the effective dia. when screwed into part 200438 (trunnion) to be .008"-.002".
Berry

 

[TR3driver]

I need to go back and check this. I recall there was movement with the front wheel when the car was jacked up and I wiggled the front tire while holding at 3 and 6 o'clock.

Do you mean 3 and 9 ? If so, then the problem is more likely to be in the steering, IMO. Not impossible it could be the VL loose in the trunnion casting, but unlikely IMO. There is actually a certain amount of deflection to be expected as the "Silentbloc" joints do deflect a bit under load.

Wheel bearings are another source, especially if the play is about the same when you grasp the wheel at 12 and 6. Again, there is supposed to be a small amount of play (to allow for the hub to expand when it gets hot). But many people adjust the bearing clearance according to the workshop manual, which gives a much looser setting than the (later) owner's manual does.

 

[CJD]

Excellent eye, Berry! That is exactly what I was looking for. I kept reading that chapter, but always stopped when it went into the steering gear section. I was stopping to soon. Thanks!

So, the answer is that the allowable trunnion clearance on the vertical link is .002 to .008".

The sad news for me is that 7 out of 8 of my used vertical links are worn out of tolerance. Bummer! I do have 2 in Marv's parts car to check. That will keep me busy tomorrow pulling the suspension apart, and I won't get my hopes up since I'm only batting .125 so far.

Steve, to check trunnion play with the suspension still together, I would think you need to jack the car under the spring pan to take all the tension off the trunnion. Then push and pull the bottom of the wheel in and out while looking at the point where the vertical link enters the trunnion. If you can see relative movement between the 2 parts, then the trunnions are worn. From everything I've studied the last couple days, the bronze trunnion wears much faster than the steel vertical link. But my little sample shows that the vertical link does, in fact, wear slowly too.

 

[sp53]

Yeh I believe the cars were never that perfect to begin with plus the whole aftermarket parts for all cars is so frustrating. Moreover, when the car’s suspension is viewed as a whole with tie rods and ball joints and bushings and gravity pulling everything down, I believe the parts start to lap together and find balance/ mean. You have a high standard and a good eye, so the assembly process you generate will have a high standard and be as good as it gets. The car will handle well and be safe. You can only do your best and you do that. Throwing more money at it by purchasing new vertical links will offer little if any improvement and could easy be more of a problem than an old quality tested part. I prefer to use older proven parts, but clearly there is a limit there also. I am still waiting for someone to sue Raybestos or one of these other now Chinese parts makers for selling unsafe products, but it would be suing a foreign government. You could buy a new BMW or new Austin Martin, but never mind too much coffee.

 

[SteveBones]

Thanks Randall,

Yes, I was referring to the wheel's 3 and 9 o'clock position. Thanks for the information and suggestions.

I do need to recheck the wheel bearing again by grasping the wheel at 12 and 6. I recall they the amount of play was OK the last time checking. Regardless I will plan remove the wheels and re grease the front wheel bearings. It is something I need to do.

Steve

Do you mean 3 and 9 ? If so, then the problem is more likely to be in the steering, IMO. Not impossible it could be the VL loose in the trunnion casting, but unlikely IMO. There is actually a certain amount of deflection to be expected as the "Silentbloc" joints do deflect a bit under load.

Wheel bearings are another source, especially if the play is about the same when you grasp the wheel at 12 and 6. Again, there is supposed to be a small amount of play (to allow for the hub to expand when it gets hot). But many people adjust the bearing clearance according to the workshop manual, which gives a much looser setting than the (later) owner's manual does.

 

[CJD]

Spent the morning pulling my last two vertical links out of Marv's old car. I can now pull a link out in less than 10 minutes...a skill in low demand! Anyway, one link was just barely within tolerance...if...I sorta look at the dial indicator at the right angle!?! So, out of 10 spindles, 9 were bent and 8 were worn on the trunnion bolt. I hope those stats help others understand the problems with these links. It is important to check them for alignment, and just replacing the trunnion may not restore the suspension to like-new tolerances.

I wonder if there would be a demand for undersized trunnions to go on those worn vertical links? And the real question...why trunnions at all? A ball joint lasts so much longer, since it takes up its own wear.

Last serious question...has anyone actually tried running oil in their trunnions? I see from my research that many think oil is the trunnion lube of choice.