When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Changing IRS fulcrum without taking apart, possible??
Long story short. When i had my IRS rebuilt, the guy must have lost one of the inner fulcrum, as he put it back together with a crusty old one that has the bolt rust seized to the fulcrum on one end and will not allow correct torque(seals/washers are loose and can be moved with my finger)
unfortunately I noticed only after receiving the unit.
i need to replace the fulcrum with a new one but I don't want the spacers/seals etc to fall out.
i am going to drop the IRS enough to access the rear facing nut(which does not appear seized) then my plan is to push the fulcrum out towards the front.
will have a coupler machined that will permit me to connect new and old fulcrums, the new one will push out the old one and I dont have to worry about spacers/seals falling out.
anyone see an issue with the above plan? Is this going to work?
side note, dont trust anyone else with your car…nobody cares as much as you do.
Maybe double nut (with thin jam nuts) the end you can get the OE nut off of; then tighten them against each other - use this to keep pin from turning. Then heat the nut on the seized end and remove it. Clean up threads with a die, and install a new nut to draw the pin fully in. Remove jam nuts, install a new nut and torque to spec. Probably longer to type this than to do it.
The pin is a tight fit in the cage; if the bottom plate is removed, the cage tends to spread and the bores go out of line- you may need to draw the bottom lips together to get the pin the locate in the bores. A bar clamp(woodworking) works for that.
I am going to try and get it out without taking it apart. Just need to drop the IRS enough to take off the good nut. Going to use a coupler to attach the new fulcrum to the old one and tap it out. Hopefully it will slide out as easy as I am thinking
What I am suggesting would not require lowering the cradle; nothing is supposed to rotate on the pin- so rusty or not won’t matter (of course as long as the washers/ races/ cups/ o rings are in decent condition and assembled correctly). The whole thing is kinda fiddly….
What you propose will probably work as long as the connector is slightly smaller in diameter than the pin. But be prepared, even when everything is in good shape, that pin will fight going through the bores in the cage. Not a clearance fit!
If it were me, what I would do is to Lower the Cage just enough to cut the end off that Fulcrum Shaft with a Grinder and Cutting Disc and then get another Fulcrum Shaft, either New or Secondhand and then use the New Shaft as a 'Drift' to knock the Old one out as you Knock the New one in
Knocking the Pin out of the Front, instead of out the Rear (also using plenty of 'Copper Grease')
Those Fulcrum Shafts can take a really good Bashing, with very little danger of messing up the Thread, as that is the way I do it when I use a Fulcrum Pin, to knock out the 'Dummy Shafts' when refurbing the Cage
I wouldn't remove the Bottom Plate, not unless you absolutely have to but just make sure to take the Weight off, when you Knock the New Shaft in to knock the Old Shaft Out
No real need to use a Copper Hammer, as a 2lb Club Hammer works just as well if you give it a Good Solid Clump!
Last edited by orangeblossom; Jan 10, 2025 at 02:13 AM.
They will come out either way, if that is your question, do not remove bottom plate to maintain alignment of the cradle bores. And hope they didn’t leave anything out….
Be very careful to check, before removing anything, that each of the two bearings has all the spacers and tubes it should have. If there is movement it is at least, if not more likely that something has been missed out, rather than the pin not being done up tight enough.
Parts 10 to 15 in this diagram are the ones to check. There should be a set of 11 to 15 each side of each arm, ie four per side. Only one bearing tube per eye (part 10), but two needle bearings (part 11) per eye.
It would be easier and safer to disconnect the shocks from the outer end of the wishbone before attempting any pin replacement, and essential to do this if a part is missing. The large washer (part number 15) is the most likely, if missed out, to create play.
Last edited by Greg in France; Jan 10, 2025 at 08:30 AM.
Be very careful to check, before removing anything, that each of the two bearings has all the spacers and tubes it should have. If there is movement it is at least, if not more likely that something has been missed out, rather than the pin not being done up tight enough.
Parts 10 to 15 in this diagram are the ones to check. There should be a set of 11 to 15 each side of each arm, ie four per side. Only one bearing tube per eye (part 10), but two needle bearings (part 11) per eye.
It would be easier and safer to disconnect the shocks from the outer end of the wishbone before attempting any pin replacement, and essential to do this if a part is missing. The large washer (part number 15) is the most likely, if missed out, to create play.
i dont believe any parts are missing. I am having a coupler machined that will allow connecting the new and old fulcrums, in theory…i should be able
to push the old one out without taking anything off. “Should” is the key word here haha.
Just in case your new fulcrum isn't OEM, try not to damage the original fulcrum while removing it just in case the new one is "not quite right". I was in a similar position and the brand new (aftermarket) part just wouldn't fit. When I checked the diameter it was very slightly larger than the original.
After an hour of polishing the new part I wasn't really getting anywhere. I threw it away and only use OEM parts now, sometimes good used - but I lost confidence in aftermarket after that.
What concerns me is that if the bearings are noticeably loose, and if the bottomplate is in the cage, I think something must be missing. For instance, if the bearing tube (part 10) is missing; that would create looseness as the washers (part 12) have nothing to be done up against. So do check carefully, a the tube cannot be seen easily, if at all.
I agree Greg, although if I was assembled without the bottom plate, the cage will spread (which is why the bores go out of line). Then the threaded end is all that enters the bore, but I don’t think enough would protrude to install a nut. Bet there is something missing….or really poor workmanship. A good tech would have noticed something wrong and never let it out that way.
Changing IRS fulcrum without taking apart, possible??
