Tension rod mounts worn out - please help!

[Zed Head]

4 hours ago, camaro-guy said:

I do not mind welding in a new section. What size is the hole in the center? Is it just large enough for the end of the tension rod to pass through it?

There is a bushing that goes around the rod, and the nut compresses the two washers against it and the step in the rod.  The rubber bushings sit n between.  The hole in the cups needs to be the size of the bushing.

Do you not have the original rods?  Part #23...

http://www.carpartsmanual.com/datsuns30/Datsun-Z-Index/Axle/Front-Suspension

[Zed Head]

The bracket itself might be dissassemblable.

#15...

http://www.carpartsmanual.com/datsuns30/Datsun-Z-Index/Body-260Z-280Z/2-2/Floor-Panel-Spare-Tire-Cover

[camaro-guy]

1 hour ago, Zed Head said:

There is a bushing that goes around the rod, and the nut compresses the two washers against it and the step in the rod.  The rubber bushings sit n between.  The hole in the cups needs to be the size of the bushing.

Do you not have the original rods?  Part #23...

http://www.carpartsmanual.com/datsuns30/Datsun-Z-Index/Axle/Front-Suspension

I do have the original rods, and they appear to be in pretty decent condition...

 

 

Edited July 9, 2019 by camaro-guy

[camaro-guy]

 

1 hour ago, Zed Head said:

The bracket itself might be dissassemblable.

#15...

http://www.carpartsmanual.com/datsuns30/Datsun-Z-Index/Body-260Z-280Z/2-2/Floor-Panel-Spare-Tire-Cover

Ok, so if I understand what you are saying: I should look at disassembling the bracket, replace the center section, and reassemble it on the frame? 

[grannyknot]

27 minutes ago, camaro-guy said:

 

Ok, so if I understand what you are saying: I should look at disassembling the bracket, replace the center section, and reassemble it on the frame? 

If you are going to replace the T/C bracket with another from a donor then of course you need to remove it from the rail but if you are cutting out the rust and welding in new plate then it would be best to leave the bracket on the car, much less chance of screwing things up.

[Zed Head]

21 hours ago, camaro-guy said:

 

Ok, so if I understand what you are saying: I should look at disassembling the bracket, replace the center section, and reassemble it on the frame? 

I was just offering another way to look at the problem.  You'd have to grind some welds and then reweld.  It's not a high precision area, squishy rubber bushings fit in the pockets and there is not adjustability.  Polyurethane bushings are probably stiff enough that you don't really need a pocket for them to ride in.

Their purpose is to locate the wheel, fore and aft, and prevent it from moving under braking.  Compression when stopping from forward motion, tension when stopping from backward motion.  Opposite on the ZX's.

[jonathanrussell]

If I were trying to envision how to repair what you have, and I had never seen a proper T/C mount before live in 3 dimensions (not true with all of us), I think it would be really hard to figure this out. It might really help you to go see one on a junk yard car or donor / parts car on craig's list. 

[camaro-guy]

On 7/9/2019 at 12:06 PM, camaro-guy said:

I do not mind welding in a new section. What size is the hole in the center? Is it just large enough for the end of the tension rod to pass through it?

 

Camaro-guy

 

I have a friend who is a professional welder, so I have left him a message to see if he would be willing to help. I like the dies you made, and they should not be that difficult to replicate. Is it possible for you to give me the dimensions of your dies, the inner diameter of the cups, or anything of that nature? Are the cups the diameter of the bushing when compressed or straight out of the box? What is the thickness of the metal the cups are made out of? How deep are the cups? Otherwise I may just have to make some educated guesses and see how it goes. I'm in the middle of the boondocks and there are no Dstsun experts near me that I know of. 

[grannyknot]

So I think you are talking to me, please excuse the lousy cutting surface, I wasn't going for looks just trying to get it made as fast as possible. Outside of male and female 77mm OD, male half 51mm by 8mm tall, female half 54mm ID, 9mm deep. The round blank is 20 ga and should have an OD of 95mm.  Make sure you grease both sides, I just put the center threaded rod to keep the blank centered.   You use a press or a 4lb mallet to hammer it into shape.  The cup is just there to keep the bottom of the rubber bushing from squishing out.

The hole in the T/C mount has to be about 3mm wider than the metal sleeve that ZH is talking about here, the T/C rod has to toggle in the mount when the suspension goes to extremes up or down.

On 7/9/2019 at 4:16 PM, Zed Head said:

There is a bushing that goes around the rod, and the nut compresses the two washers against it and the step in the rod.  The rubber bushings sit n between.  The hole in the cups needs to be the size of the bushing.

Hope this helps,

 

[Patcon]

7 hours ago, camaro-guy said:

I have a friend who is a professional welder, so I have left him a message to see if he would be willing to help. I like the dies you made, and they should not be that difficult to replicate. Is it possible for you to give me the dimensions of your dies, the inner diameter of the cups, or anything of that nature? Are the cups the diameter of the bushing when compressed or straight out of the box? What is the thickness of the metal the cups are made out of? How deep are the cups? Otherwise I may just have to make some educated guesses and see how it goes. I'm in the middle of the boondocks and there are no Dstsun experts near me that I know of. 

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@camaro-guy

[TJC1969]

I have a similar issue and Oregonipa pointed me to this post.  Lots of good info here but I still have a question - Are the cupped metal pans grannyknot made welded on each side or just held in place by the pressure of the two bushings bolted in?  My tension rods were both stuck through the holes with no hardware on the back side and no remnants of metal pan, so I assume not welded.  Also I've seen it's advised not to use poly bushings in both positions or the rod can break because not enough flex, so one poly one rubber should be used.

[zKars]

The stock cups where indeed welded to the overall mount. you don’t want to trying to line up any more parts than you have to when installing these. 

The actual cases of broken TC rods with poly is extremely low, and I bet of those, it was caused by pitted or less than perfect TC rods that were compromised to start with. Inspect the TC very closely, especially right at the step where the washer sits. ANY pitting means get new(er) rods. I personally put rubber on the front, and poly on the rear, or just stick with fresh rubber on both sides.  Impact harshness when going over bumps is reduced with rubber on the compression side of the mount.

If you are racing and trying to maintain a set of fixed alignment specs then get a set of adjustable length solid mount TC rods from any of the half dozen suppliers of these parts. (Techo Toy etc).

Edited February 24, 2022 by zKars