The DOs and DON’Ts When Installing Polyurethane Suspension Bushings 

I would be careful with using a bolt that has a shank that's the exact size of your tabs. Especially since the tabs will deform some when tightening. If you run out of threads your torque wrench will click off but the joint isn't necessary tight. The bolt sees a relatively low load because the bolt is tight(Joint stiffness ratio). If the bolt isn't able to provide enough preload to the inner sleeve then the bolt will see more load than it should. This is why you see bolt holes in tabs get egg shaped because the bolt wasn't tight enough. With that said if you use enough washers to make sure the nut has threads to grab on to then you are golden.

Thank you for never assuming that your audience knows what the heck they’re doing. And, more to the point, for never adopting a patronizing attitude when you set things straight. Your build videos have been and continue to be tremendously helpful. Thanks for keeping up the standards and the humanity.

Great information, thank you. The difference between these and OEM is on an OEM bushing the rubber is bonded to both the inner and outer barrel. The only movement is the flex of the rubber between the inner and outer metal barrels. That's why when changing things like control arms, you don't torque them up until they are on the ground (or ramps) under their own weight. That way, you are tightening them up in a position in the middle of the suspension's range of motion: In full compression they twist one way, in full droop, they twist the other way. If you tightened them up fully while unladen in the air at full droop, they would be much more likely to tear at full compression because now you are asking the rubber to twist in one direction to cover the full range of the suspension's motion. the take-away: Tighten them while on the ground or they will tear quickly.

What a fantastic video. No excess blabbering but straight to the point and everything presented in an easily understandable fashion. Subscribed immediately, just starting on the first project car where I have to rebuild the entire suspension and this kind of info is priceless. Thanks you!

Good video. I have fixed a few 'death wobble' trucks just by installing longer sleeves that lock down when the bolts are torqued. It's amazing how little movement in suspension will create such a large issue

I’ll classify this as one of the best YT vids out there. Actually very informative to people who don’t know, but also informs the people who THINK they know of proper techniques for safety and durability. Bravo bro

You never know everything my father use to tell me and try to learn something new every day and i just did!!! You are a really good teacher my hat off to you! Thank you for your education and my learning. Joe

FINALLY, a person who KNOWS how to measure a BOLT. Fat too many mechanics tend to think the HEAD size is the size of the bolt and they usually get all bent out of shape when they ask for a 1/2" bolt when they are really after a 5/16" one.

More than I ever expected to learn in my lifetime when it comes to bushings. Enjoyed it for sure.

A couple of additional comments - when a ZERK grease point is used, make sure the sleeve is welded in a position where the nipple is accessable with the suspension member fitted to the vehicle - sometimes you can correct this with a 90 or 135 fitting, but not always. If the fastener uses a castellated nut which takes a split pin, you can usually replace it with a stainless steel "R" clip - they won't rust in place and are easily removed, and they're re-useable. Depending on the specific application, it may be wise to use a longer bolt than actually required and drill the end, after the retaining nut, for an "R" clip - it doesn't often happen, but if for some reason the nut loosens, the clip will prevent it falling completely off and so prevent the bolt backing out. If you have access, you can do the same thing with bolts into captive nuts. Something I got from Justin* is to turn up some alloy spacers that are a close fit to the sleeves and use them instead of the 'plastic' insert when tacking parts together - ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-aIGTNU6hG2Q.html *He also has a lot of sound advice to compliment this gentleman's advice - www.youtube.com/@TheFabricatorSeries/featured

I just found your channel....Nice video! many years ago, someone said to me "never use anything less grade 8 on vehicles with stressed or weight bearing. Like the engine in my 1946 Harley knuckle-head. or my 1972 corvette. They are both old beaters, but the running gear is very tight.

Just stumbled across the channel. Finally, somebody is making videos of the small details everyone else's leaves out that are so important. Major companies instructional videos always leave this out. They just say insert and tighten to spec without going into How it's supposed to function with the part that was just installed

Best teacher on the web man!!

This probably only applies to the after-market polyurethane bushings. Most OEM bushings are basically melted rubber that is stuck to both the inner and outer sleeves. Then it becomes important to tighten these bushings with the control arm at rest or “normal ride height” or the bushing will be twisted when the vehicle is on the ground.

yuP^ I would trust this guy with my vehicle he personifies wisdom and intellect and professionalism and good character.

This is a spot on video! Everything he said is correct. I’m talking as a tool&die maker with 50+ years experience. Really well done! Thank you!

Dude! Fantastic video! I've replaced the suspension bushings on my whole truck myself, but I never before fully understood how the parts function as a set. I am so grateful for this video. You are an excellent teacher.

That was a really good video! I watched all 6 minutes and 52 seconds, thank you for making everything all nice and concise :D

Thank you for pre-empting my "But of course I grease the bolts, because I want to be able to get them back out again some day" comment. :D You're the bomb, dude. :D

It may sound inappropriate for some but… you’re like a god for me when it comes to this area of expertise. Amen! …and thank you, yet again!

Yessss! Now that was a great and well articulated run down of suspension bushings and components. Even if you’re not fabricating and all you’re doing is installing bolt on components like mid or long travel kits this is something you should be aware of. Make sure the manufacturer is giving you quality parts

Yes, I am a through bolt rust prevention greaser. Thanks. Great video to help everyone understand bushings, and how important it is to have them correctly built, and installed.

Just found this video randomly, I automatically subscribed after watching.

Since terminology is important, the fitting where grease is introduced is called a hydraulic grease fitting😊. But everyone calls it a zero fitting. But this video is very well made, thank you.

What a nice job of describing the correct way to mount a bushing assembly! The bushings I’m using specify white lithium grease in case anyone didn’t get that information with their bushings. I use drum brake bearing grease(stringy stiff grease) on the bolts and, a bit of red loctite in the nuts to make sure they stay put.

Escellent video again. You keep addressing things that I am currently dealing with. Love it.

I'm not expecting to be fabricating suspension components any time soon but this is just excellent automotive general knowledge regardless, along with a tonne more posted by experienced and knowledgeable folks in the comments. Great stuff, instant sub!

Finally someone explains it. This topic has driven me crazy dealing with 4x4's, low riders, etc. It's always fooked.

Exactly why I follow and watch your content, I don't want to just know what works, BUT WHY IT WORKS. As always, super informative, intelligently simple and concise. A++

Absolutely enjoy it when the smart people are annoyed.🤣✌😁

Thanks for this information I have a old 85 cavalier with a rusted up subframe. A arm is alright. But had a buddy do some welding on it. I think I should take it back off and redo it. Thanks again

I've never really built a full suspension but I have converted several different types to poly. All this seems very obvious to me but I guess I was learning on things that were pre-engineered. Thanks for the tip on where to get ends.

Yes your mostly correct. Engineering standards generally ask for no more and no less than 3 threads protruding after the assembly. So if you need to trim, use that as a guide!

LOL, I've never been so insulted by a guy who doesn't know what mechanical parts are properly called, while telling me sh!t I already knew. Good stuff, big guy!

So nice to have a direct and to-the-point Instruction video. Great Editing Thank you

Best not to use polyurethane where you can avoid it, as it tends to transmit a lot more of the high frequency stuff, especially because sizing is usually not done well (ie; the intaller doesn't know what the forces are or the range of compliance needed). This is especially true of engine mounts, where lack of compliance can kill alternators etc. Compliance problems are usually worst around 4 bar linkages, with triangulated 4 bars needing lots of compliance to work... Normally it's better to go for parallel 4 bars plus a watts link, it gives better control, less compliance interference with suspension behaviours etc and is simpler to calculate loads. Similarly, the type of bushing you're demonstrating here has very little lateral bearing capacity, it only bears on the edges of the steel tubes, so lateral loads are a big no no and should be oriented purpendicular to the link tube (unlike the triangulated 4 bar demonstrated). Finally, bolted joints are considered to be failed when they slip, so the end of thread is (or should be) totally irrelevant, if it fails it's because it's slipped and failed under impact loads, resultant from the post failure movement. Size bolts so you've got at least one fully formed thread on the unloaded side of the bolted joint, but no other aspect is critical unless you're engaging onto the unformed threads of the shank, which WILL result in premature failure. The only parts involved in the joint behaviour should be the inner tube, clamped between the two flanges and the bolt it's self. The friction between the outer flanges and the tube are the only forces through which the joint should operate.

Some stock rubber bushings are fused to both sleeves and you can expect a short service life followed by a rear steering wobbling nightmare unless you make a provision for the bushing to pivot. A bronze sleeve between the bolt and slightly opened inner sleeve is a great mod when feasible. Early polyurethane bushings had a tendency on rare occasions to squeak but only while driving unless you ignored their instructions for no lubricant.

Grease and bushing compatibility is huge. We put new polyurethane bushings on my wife's car, and they lasted about 8,000 miles altogether.

This was an excellent video. Explaining not only what to do, but what not to do and why in an easy to understand manner without sounding patronizing. As others have said, that can be a tricky balance to find when teaching. Nicely done.

This right here, clear info with reasoning that's east to understand. Also the engagement and pinned comment make this a clear win. Followed, thumbed, keep this coming. It's nice to see someone care about the details especially enough to acknowledge when a comment has merit to reinforce their point.

Silicone based brake lube is one of the most underrated tools by a lot of mechanics. It's rubber and plastic safe. Being brake lube, it won't run when the temperature goes up. AND it really takes the fight out of hoses, o rings, or intake ducts. A very light coat on both surfaces and things usually just click into place.

I like how at first you asked what's wrong. I didn't know what I was looking at, but as you went through it, I could start seeing what was wrong. It was so helpful!

Wow! So cool to hear you reference Max. He explained how an engine worked in the back of class when we were in high school. Awesome guy.

Very great video, TIP= Grade 8 is great for street vehicles but the off-road guys in Baja stepped back to grade 5, This is because grade 8 and 10 will break in the desert on impact but grade 5 will bend. A bent bolt can continue the race and a broken bolt takes you out. Just something for your audience to think about for the application they are building for,

Best bushings tutorial ever!

I'm actually helping a small manufacturer with R&D on replacement poly bushings for a car that has very little aftermarket or OEM support. Our goal is to offer owners with an alternative to the only existing poly supplier for these cars. We not only wanted to compete, but level it up by offering poly replacements for components not covered by the competition. This is definitely challenging as we're not making these parts for people building a car with custom links, we're making replacement parts for a car that was produced in limited numbers. So, preserving the foundation is key. Someday I hope to build custom subframes and control arms for performance restomodding these cars, but right now the goal is preservation. While doing our research we discovered a flaw in the competition's design. You touched upon this in your tab design comment. About how the tab needs to be wide enough to support the bushing flanges. We noticed this was not addressed in their design on many components and we've decided to address it in our design. A somewhat smaller flaw in their design was the minimal allowance for lubrication. They barely leave room for the grease. The designer building our parts has already addressed this in his prototypes. Another issue was the strict adherence to OEM inner sleeve dimensions on the part of our competition. The bolts used in the OEM design are much smaller than the inner sleeve diameter, especially for the subframe mounts. This is speculation on our part, but we believe the OEM believed that this gave wiggle room when attaching the SF to the unibody during assembly. Not all components were perfect and this compensated for that. We wanted to minimize that gap by bringing the tolerances closer together. When you have a 3,500lb car you're thinking about canyon carving or taking to the track, these components shouldn't be allowed to shift if someone didn't torque things down properly. This leads us to our next issue with the current maker. They don't supply installation instructions, not even a diagram. The only way customers know where things go is by referencing the part numbers on the bags to the online catalog where they bought them. Even then, there are no procedures or torque specs. Finally, the last bone of contention is with parts only being limited to suspension. We hope to bring more to the table, not by simply adding more suspension and subframe parts not previously offered, but by adding engine/trans mounts, radiator core suppprts, and muffler hangers. Long comment, I know, but the point I'm trying to make is you addressed a couple mistakes even professional manufacturers chose to ignore: lateral/torsional support and lubrication. What's worse is these guys corner the market on this car and they know it. So, they charge a premium for it. All while making an inferior product.

Very informative videos. I've done this for years and I know the tolerances need to be damn near perfect when dealing with rod ends and bushings. But, I like to see someone else out there that knows what they are doing also. Good videos man. Keep up the good teaching on all you do.

this is a vid every mini trucker needs to watch and some need to watch twice hahah . good work sir !

New sub, thanks for the content. I found your video interesting and informative. I like your straight forward factual approach, and look forward to seeing more from your channel.

This information was absolute gold. Thanks for another great video!!

Thank you. I was worried I was doing them wrong but I’ve been doing them exactly that way. Also just noticed the Keep Moving Forward sign very awesome.

Excellent and informative videos. Very exciting channel to find! Thanks for not making things longer than necessary to hit the 10 minute-mark!

Another of the most useful videos I've ever seen, and the other one was your u-joint video. AMAZINGLY GOOD content!!

This was so helpful and informative and your attitude was great. Definitely checking out more of your channel

Good to know. I've been working on/building vehicles for forty plus years and no one bothered to tell me this. Thanks.

I do alot of suspension "corrections" as well, on Scouts. One thing I do is ditch the sleeve and drill the hangers to 5/8"... then run a 5/8" bolt all the way through. I was told this bumps the strength by like 40x or whatever... but in practice it is just tighter and beefed! Got a real quick susp ? for you that is too complex for my buds, got time this week for a fast call? -Big. "GotScout"

Awsome clear and concise video. Thank you! I've never built a suspension, but I plan on building jeep wrangler just with a frame and a tub

Great simple terms to convey an understanding of this. One short video and you got yourself another subscriber.

I really appreciate your information and explanation, thanks for this video help a lot was braking my head on where to purchase this for my hardbody on bags

I learn a lot watching your videos. Your editing dept. gets an A+ thank you

Good Stuff! I watched it twice to make sure I got it. Thanks for sharing your expertise MC! Cheers from Motown.

Great information! I'm making lower shock mounts that can twist for an old Dodge truck. Essentially, you just confirmed my design. Thanks!

Excellent educational vid. After seeing your video I immediately can see what is wrong with the installation before your vid. Great job!

Dude! You are killing it! Clear, concise, all excelent info, no bs fluff. More RU-vidrs should take note. Thank you for all your hard work. Keep it up! A+. Subbed

One upgrade i do on every car suspension or offroad jeep that i know i will take apart because or repairs or maintenance is i will mark the bolt about center and drill a small hole thru the side about halfway thru. Then drill a small hole from the bolt head to the hole u just drilled. Then tap for a 1/4-28 for thw fitting i use. And i keep a wide assortment and stlyes to choose from so i dont have to go to the parts store. Also wipe any grease off after ur done because it what u should do. Also use the plastic caps to cover them. That way they are clean the next time u go to service ur ride. This will help the rust belt and offroad guys....

Full of good info. Just found your channel yesterday and instantly subbed. Keep it up!

I keep coming back to this video. It's super helpful. I'm thinking of making a swing arm tire carrier that bolts to the back wall of my trailer in 2 places and was debating going this route instead of a spindle on the bumper. I like this idea of using these bushings as a hinge instead but not sure if it would be too tight or hard to move. Obviously it would be stiffer than a spindle but maybe a gas strut would help with that.

Man, this episode was a tight and a joy to watch and learn. Thanks for all the details 👍👍😎👍👍

This video is so expertly done I am jealous

Excellent description and detail. I’ve never even worked on a cars suspension, and I liked this.

Great video. Anytime you can give some knowledge about fabrication I am always interested. Your presentation style and ability to explain concepts in the simplest way make for great content. I don't feel talked down to or requiring my own shop to accomplish any task you present.

Thanks for sharing. for explaining every detail . I like the way those tab's can be maid.

Good on you thanks , working with suspension specialist yrs ago ,he would soak bolts in diesal before installing,and every one had hole after nut for split pin ,a fair amount of the work end up on race track ,when I asked about pins he said,it's the 2 dollar piece of mind factor

Toyota mechanics were the best in town during the 1980's when I was a young fella. I worked at a Toyota dealership after a Ford dealership and 2 years of mechanic Tech School. Before all that was a Navy Engineer for 6 years.

Thank you once again Aaron. Well explained. Best channel I follow by far.

Thanks for sharing your veteran experience. That was some great info 😎👍

Thank you for sharing your years of experience for free

This kind of teaching is super valuable. Awesome work.

All Great advice . Well presented. Thanks

Your 100% correct!! I've done this enough to know your spot on!

I love learning new stuff!

Good info vid, thanks. My first rebush failed within a month. The body men asked "Didja lube 'em?" Crimson me said "Oh." That was an easy fix. Two 1990 F-150 rear leafs quiet once again. Dick Cepek parts had no installation tips sheet with them.

Wow! Good stuff, thanks!! I actually learned something without getting confused.

Great video, very direct and to the point. Lots of knowledge here 👍🏻

Wonderful, simple, concise information. Thanks!

Yup thats exactly how i been doing them i use grade 8 black bolt with crimp nuts like factory nuts notice the lock washer will spread every once an awhile this is a great video for guys doing at home this video can save lives cuz suspension failure is critical

Outstanding video as always. Very good information and easy to understand. Thank you.

You are the Dr. House of Suspension Fabrication

Good information, great non patronizing way of laying it. Earned one sub. Thanks!

All necessary information in a short video. Great stuff 👍

Thank you! This is exactly what i needed to find tonight as im trying to fix a super duty traction bar that isnt available from the manufacturer anymore and the aftermarket isnt built correctly... 👍

thank you, learned to do bushings perfectly now!!!!

Excellent Advice! Keep up the wonderful work!

thanks for sharing the knowledge

Fun and informative video. I have picked up so much knowledge of of you channel highly recommend and love how you don't drown on and make thing fun. Keep up the good work and can't wait for the next one. Ps I love how it when you say the sizes you use on your materials as it hard for me to picture with out this.

I am constantly trying to learn. I may never use this but, excellent information and video!

Working on this kinda stuff I always wondered about these questions. Thanks for making a video answering them! Professional help is hard to find on the internet haha

Another nice quick hitter. Good info for all.

This guy is the man. Wow. Earned a subscriber

Now this is a great way to start a sunday!!!