Fulcrum pin

[mklotz70]

This should be the final info vid on the fulcrum pins.

 

[Charlie69]

Mike I really like how you check all the variables and when you build it for sale you know it will work.  Great R & D.

[wayno]

Mike don't have recalls, when he sells it, it is right.

[mklotz70]

Thanks guys!

[Charlie69]

Mike you only get what you have earned!

[jacimo98]

Hi Mike! got your uca bushing kit the other day! nice workmanship! I really want to thank you for posting this information, especially the videos.. I " I mean we" are in the middle of a senior project. and any info I find is a big help. we were supposed to be etching the frame today, and getting ready to spray por-15. that didn't happen, my kid got the flu..so I am tearing down the front suspension to send it out for media blast. and finding these videos today helped me to get a jist of how the teardown needs to go! as in careful with the cotter bolts! thanks man! all you guys are a huge help!

[Charlie69]

Mike your fulcrum pins worked great.  Used them when we installed the disc brake kit I purchased from you on Gene Knight's Grimace.

[mklotz70]

Hi Mike! got your uca bushing kit the other day! nice workmanship! I really want to thank you for posting this information, especially the videos.. I " I mean we" are in the middle of a senior project. and any info I find is a big help. we were supposed to be etching the frame today, and getting ready to spray por-15. that didn't happen, my kid got the flu..so I am tearing down the front suspension to send it out for media blast. and finding these videos today helped me to get a jist of how the teardown needs to go! as in careful with the cotter bolts! thanks man! all you guys are a huge help!

I still have more cotter bolts on hand......just haven't got them up o the site. 

[Drummerboy4as]

Reviving an old thread here, but I’m in the process of doing disc brakes on the front of my 620 and while I was in there I figured I’d replace whatever bushings and grease I could. The inner control arm bushings look pretty good, the upper dog bone bushing are shot so i ordered a set from mike. I wanted to take the dogbones completely off to clean them and whatnot but for the life of me I can’t get the cotter pins out of the lower fulcrum pins. They’re soaking in PB blaster right now but I’ve already damaged one of them *eyeroll.

I’ve been searching for a while now and haven’t come up with a source for these pins. I’ve found some for a Z but there’s no specs on size or anything. Does anyone have a good source or know if mike is still making them?

[mklotz70]

We've already talked about the cotter bolts.  As for removing them......you can try loosening up the fulcrum pin nuts on each side......you can tap on the nuts or remove them and tap on the fulcrum pin.....side to side.  Be careful not to damage them.  What you're trying to do is to get the pin to shift, which will break the corrosion free that's anchoring the cotter bolt to the pin.  You can do like wayno has described before....loosen up the lock nut on the cotter bolt about 1/16"...put a second nut on to protect the end of the threads.  They'll get damaged, but at least you'll still be able to pull the nuts off.  Anyway....hit the end with a hammer.  Once it pops loose, you can remove the nuts and drive the bolt out the rest of the way with a drift punch.  They're really soft bolts....so if you hammer on the threaded end without the nuts, there's a good chance you'll just mushroom them to the point they won't fit through the hole when the bolt does break loose.

 

***edit*** It just dawned on me that what I was trying to describe is directly above....posted by wayno.

[red13]

All this info is great and I rebuilt,my lingpins using mikes vidz. Recently there was a discussion of these pins. Some one informed me,about bycicle crank cotterz. https://www.amazon.com/SBS-Crank-Cotter-Pin-9-5mm/dp/B000WY8FOM

[2wheel-lee]

All this info is great and I rebuilt,my lingpins using mikes vidz. Recently there was a discussion of these pins. Some one informed me,about bycicle crank cotterz. https://www.amazon.com/SBS-Crank-Cotter-Pin-9-5mm/dp/B000WY8FOM

 

I don't remember too much, but I do remember from working in a bicycle shop in the 80s that there are different tapers for these crank cotters. I vaguely remember the French tapers being different than the Japanese tapers (we were a Peugeot dealer, if you remember their bikes). I vaguely remember having a few drawers dedicated to cotters. I was recalling this same thing when I was rebuilding my fulcrums. 

 

The term "cotterless cranks" stuck around decades after those old things were last used on bikes. 

[mklotz70]

The ones for the bicycles are typically the bigger size.  They might work for the kingpin, but the kingpin rebuild kit always comes with new cotter bolts.  The ones that are the real pain are the ones that hold the fulcrum pin at the bottom of the dogbone.  I made a bunch years ago and still have some.  I haven't put them on the site because I was afraid they'd sell out too quick and I wouldn't have time to make more. LOL  I've been hoping to get a bunch more made and then put them up.  Maybe I'll put them up....sell out.....then when more are needed, make more.  Maybe they won't sell out.  Hmm....I do need to hang onto enough for what I need!

[Drummerboy4as]

After fighting and fighting the lower cotter pin I finally beat it. 

 

Whats the worst that that could happen??

 

After drilling a hole through the pin, some gentle persuasion convinced it to break its bond

 

Carnage

 

Somehow by the grace of the gods of Datsun I managed to not damage the kingpin at all

[banzai510(hainz)]

I use lots of anti seize when putting this back together as I had to swap it out again.( I daily my 521truck)

[mklotz70]

Great work!

I hope you're keeping track of which is the front fulcrum pin nut and which is the back.....as well as which direction the pin goes.  It will make it much easier when going back together.

 

I find it interesting that it's a 620 spindle, but it has zerk fittings on the side of the top bushing......AND the cover bolt at the top.  Maybe that's a vent.  If I remember right, my 620 spindles have the zerk on the top and not on the side.

[Drummerboy4as]

I’m not, but I’m also installing new fulcrum pin/nuts, so hopefully it won’t make too much of a difference.

 

To my knowledge these parts have never been off the truck. I bought it from the original owner who bought it new in ‘73. It’s definitely never been cleaned in there lol

If you like I can snap a bunch of pics before I reassemble everything.

[mklotz70]

I'm not sure if it continued to the 620's, but the early trucks had different fulcrum pin nuts for the front and back of the arm.  I think the ones with the zerk fitting are the rear ones.  

 

Don't be surprised if the dogbones bind up when you tighten the nuts up on each side.  You may have to mix n match the nuts and pin positions.  The challenge is that the nut threads into the arm at the same time it's threading onto the pin.  If they don't "clock" just right with each other, the pin gets really tight and it will be really hard to swing the dogbone.

[Drummerboy4as]

It would appear that it did not, all 4 nuts have zerk fittings

 

I’ve watched your video on fitting the fulcrum pin so I’ll def mix and match and test fit till the dogbones move freely.

[mklotz70]

I never looked into it much, but there was definitely a time when only one side had them.