dmopar74
Well-Known Member
Where the hell can you order rubber strut rod bushings for a 73 duster? I found some at O'Reilly but they want $100, ridiculous.
Rubber strut rod bushings?
- Thread starter dmopar74
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The part number for the later ones from Moog was K7068, but they've been discontinued for about 5 years now.
I'd be surprised if you can order those from O'Reilly and actually receive them. If you actually found a set at a store you can lay hands on you should buy them.
The 73-76 cars use a different strut rod bushing than the 67-72 cars, they were thicker and the strut rods for the later cars were slightly different, the shoulder to retain the bushing was moved to allow for the larger bushing. Effectively with everything installed it was the same length as the earlier ones as far as the K frame to LCA distance goes.
I'd be surprised if you can order those from O'Reilly and actually receive them. If you actually found a set at a store you can lay hands on you should buy them.
The 73-76 cars use a different strut rod bushing than the 67-72 cars, they were thicker and the strut rods for the later cars were slightly different, the shoulder to retain the bushing was moved to allow for the larger bushing. Effectively with everything installed it was the same length as the earlier ones as far as the K frame to LCA distance goes.
dmopar74
Well-Known Member
Can I use poly strut bushings? I'm using rubber lca bushings
yeah, it'll be fine.
Locomotion
Well-Known Member
Shop around, I've used Energy Suspension or Prothane on my race car. Search "strut rod bushings at Summit & Jegs.
Do they still have free shipping over $100?
Might not hurt to check your front end alignment after install.
Do they still have free shipping over $100?
Might not hurt to check your front end alignment after install.
The poly bushings will work. Absolutely check the alignment after you install them, they’re not always the right size and if they’re not they can change the alignment and that’s not what you want.
Your other options are getting a set of 67-72 strut rods so you can use the earlier strut rod bushings that are available, or going to adjustable strut rods. Personally I’m not a fan of poly strut rod bushings (poly is fine/great in other spots), but there aren’t a lot of options at the moment for 73+ factory strut rods.
Your other options are getting a set of 67-72 strut rods so you can use the earlier strut rod bushings that are available, or going to adjustable strut rods. Personally I’m not a fan of poly strut rod bushings (poly is fine/great in other spots), but there aren’t a lot of options at the moment for 73+ factory strut rods.
Just a heads-up, I didn't like the way the poly bushings fit, so I went back to rubber.
I don’t disagree, but the rubber bushings are unobtainium for the 73+ struts.
dmopar74
Well-Known Member
I'm rebuilding the front end so yes an alignment will be done. Eventually I will get adjustable strut rods but it's not in the cards right now.
Kendog 170
Let the boy go !
The most important is the shear sleeve A metal sleeve built into the bushing itself . The poly style strut bushings don't have this and the sharp edge of the K-member shears the nipple off. this cannot be seen until you remove them. The original rubber without the sleeve built in also wears as seen in the 3rd picture of a factory 50 year old but it does not shear like the poly style does. I found several 7068 sets left over at NAPA stores and ordered in all the sets in our local area.
The 7040 is 2 piece for the early cars do not come with the inner bushing and have different cup washers . But the bushings have the sleeves in the rubber and can be used on the 73's with the original hardware from your 73 car. So you can also look for them. I bought most in north east Pa. But check your area.
The 7040 is 2 piece for the early cars do not come with the inner bushing and have different cup washers . But the bushings have the sleeves in the rubber and can be used on the 73's with the original hardware from your 73 car. So you can also look for them. I bought most in north east Pa. But check your area.
The K7040 strut rod bushings aren't suitable for the 73+ strut rods, certainly not without modifications. The inner diameter of the K7040's is 5/8", where the K7068's for the 73+ struts is 3/4" because of the inner sleeve that was used. The overall thickness of the bushing is also different, the K7040's aren't nearly as thick as the K7068's. So, they wouldn't slide over the 73+ struts using the later 73+ sleeve the way they're supposed to, and even if you left out the sleeve to get them on there you'd have to figure out a way to take up the leftover space (the K7040's do have an internally molded sleeve). If you just slapped the K7040's on there without the later inner sleeve and tightened the nuts down you would probably end up running out of threads before the bushings were properly compressed, leaving the strut rod loose. If you managed to get the bushings compressed, you would have pulled the LCA forward.
Ironically, these pictures are from @Oldmanmopar , showing the significant differences in the 73+ struts. The notations are mine to make things more clear
It should be obvious from the top picture that using the bushings intended for the 67-72 on the 73+ struts is a bad idea. Here's the original post where OMM basically said using the 7040 strut rod bushings on the later 73+ bushings is a bad idea. And for once regarding strut rods, he's actually right about that. Not sure why he changed his mind, he was right the first time. If you wanted to use the K7040 rubber bushings, you'd have to get a set of 67-72 strut rods. The 73+ strut rod set up is the better one, which is why it was redesigned from 67-72. And they made a lot more 73+ cars, so, I'm not sure why Moog has decided to discontinue that later bushing. It was better all the way around.
Some strut bushing info
As for the poly bushings, @autoxcuda ran them successfully for years. You can see what he did to modify his poly strut rod bushings so that they fit his car correctly. These were poly bushing he cut down in a lathe to fit the strut rods properly, he eventually replaced them with adjustable strut rods. I don't know what year strut rod he used originally, although there's more information in this thread. The issue is that the poly strut rods are all advertised as 67-76, and as you can see from the strut rod differences they can't accurately fit that entire range of original strut rods. They'd either have to be wrong for the 67-72 struts or the 73-76 struts, or, possibly the entire range. The ones I have seen looked like they were intended for the later 73+ strut rods, so they would have to be cut down for 67-72.
Here's that thread Cutting strut rod bushings for correct geometry?
Ironically, these pictures are from @Oldmanmopar , showing the significant differences in the 73+ struts. The notations are mine to make things more clear
It should be obvious from the top picture that using the bushings intended for the 67-72 on the 73+ struts is a bad idea. Here's the original post where OMM basically said using the 7040 strut rod bushings on the later 73+ bushings is a bad idea. And for once regarding strut rods, he's actually right about that. Not sure why he changed his mind, he was right the first time. If you wanted to use the K7040 rubber bushings, you'd have to get a set of 67-72 strut rods. The 73+ strut rod set up is the better one, which is why it was redesigned from 67-72. And they made a lot more 73+ cars, so, I'm not sure why Moog has decided to discontinue that later bushing. It was better all the way around.
Some strut bushing info
One thing you have to do when using this #PN is get 67-72 strut rods. These bushings #PN k7040 are for 67-72. The fine thread strut rods are much better then the coarse thread and will be the correct length, Don't ruin them drilling them for the longer 73 rods. You'll be buying new bushings. these are the best you can get
As for the poly bushings, @autoxcuda ran them successfully for years. You can see what he did to modify his poly strut rod bushings so that they fit his car correctly. These were poly bushing he cut down in a lathe to fit the strut rods properly, he eventually replaced them with adjustable strut rods. I don't know what year strut rod he used originally, although there's more information in this thread. The issue is that the poly strut rods are all advertised as 67-76, and as you can see from the strut rod differences they can't accurately fit that entire range of original strut rods. They'd either have to be wrong for the 67-72 struts or the 73-76 struts, or, possibly the entire range. The ones I have seen looked like they were intended for the later 73+ strut rods, so they would have to be cut down for 67-72.
Here's that thread Cutting strut rod bushings for correct geometry?
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dmopar74
Well-Known Member
Well I ordered some prothane 4-1202-BL bushings, well see if they are correct when they arrive.
The issue most folks have had is that the poly bushings end up being too thick, which pushes the LCA backward and therefore reduces the amount of positive caster you can get, which is already an issue unless you're running tubular UCA's with additional caster built in. This should be less of an issue with the 73+ struts, but that doesn't mean it can't happen.
The other thing to check is for any binding, if the bushing thickness isn't correct the effective length of the strut rod will also be incorrect, and that can cause binding on the LCA. So you'd want to install all of the suspension, leave the shocks and the torsion bar adjusters out, and then cycle the suspension through its entire range of travel to see if you have any significant resistance or binding of the LCA. It can be an issue even with the factory strut rods because they were really a "one size fits most" kind of operation with big, soft rubber bushings to deal with the wide factory tolerances. But the stiffer poly bushings can exacerbate that, even when they're the right size, and obviously can introduce even more binding if they're not the right thickness.
Kendog 170
Let the boy go !
Also isn't there a 3/8" difference in length between the 67-72 and 73-76?
IIRC no, the overall length of the strut rods is the same. The difference you can see above, the shoulder and cotter pin location is changed to allow for the thicker 73+ bushings.
Ultimately the effective length of the struts remains the same, when used with the matching year range bushings.
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