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Spacers for Heim Jointed Front Wishbones

PostPosted: Tue Oct 26, 2021 9:30 pm
by EricB
I was talking in another topic about heim jointed wishbones but then as I began looking at fitting them to the pick up studs on the front of the chassis, it was pretty obvious that one also has to take into account that these rod ends are much narrower than the wider normal sleeved ends. So I presume that the standard procedure is make up tubular spacers for either side of the rod end to preserve the positioning of the wishbones (both sides) relative to the chassis upright.

Pretty obvious once you think about it but this is the first time for me. What are the experiences for those of you who have done this already?

Re: Spacers for Heim Jointed Front Wishbones

PostPosted: Wed Oct 27, 2021 1:55 am
by bitsobrits
You will need spacers, but start with stacks of washers first until you get your caster dialed in, then make up spacers to the required dimensions. You might want to have some 1/2" ID precision shims on hand if you really want to get the caster dead nuts exact left to right.

In the photo you can see I have a spacer on each side of the heim, the outer one just filling out the space to the threaded portion of the shaft.

extsw.com is a great source for stainless spacers, btw, very nicely made, quick turnaround, and very reasonable pricing. No affiliation, just a very satisfied customer.

Re: Spacers for Heim Jointed Front Wishbones

PostPosted: Wed Oct 27, 2021 1:07 pm
by TWebb
What a great resource for spacers!

Thanks

Re: Spacers for Heim Jointed Front Wishbones

PostPosted: Wed Oct 27, 2021 8:32 pm
by miked
Presume standard vertical links?
I never understand this caster adjustment without putting strain on the trunnion. I thought you had to go a bottom ball joint to allow for the twist. :?

Re: Spacers for Heim Jointed Front Wishbones

PostPosted: Wed Oct 27, 2021 11:45 pm
by bitsobrits
Yes, standard uprights (vertical links). And if you are going for significantly larger or smaller than standard amounts of caster you will indeed put some torque on the trunnions. But if you are setting caster to the nominal figure for the chassis (early Elans at 7 degrees and later ones at 3) you shouldn't be introducing enough trunnion torque to be concerned.

Re: Spacers for Heim Jointed Front Wishbones

PostPosted: Thu Oct 28, 2021 5:54 am
by Andy8421
miked wrote:Presume standard vertical links?
I never understand this caster adjustment without putting strain on the trunnion. I thought you had to go a bottom ball joint to allow for the twist. :?

Mike,

I have never seen a ball joint replacement for the trunnion that doesn't mess with the effective length of the bottom wishbone. The original Triumph part has the rotational swivel (the thread and brass bush) separated from the up and down pivot point (the bolt through the bottom wishbone) by about an inch. Using a ball joint to combine both of these functions moves the pivot point outboard, effectively making the lower wishbone an inch longer.

https://www.canleyclassics.com/?product=trunnionless-front-suspension-kit

There have been a number of threads on this, and while I would like to show the trunnion the door, I never got comfortable with the change in steering geometry. Have you seen a kit that keeps the geometry unchanged?

Re: Spacers for Heim Jointed Front Wishbones

PostPosted: Thu Oct 28, 2021 1:29 pm
by baileyman
I had set my castor with spacers till someone here mentioned trunnion stress, then I reverted to the angle of the uprights, and that seems fine. As for spacers, in my gigantic TTR order they supplied me with twice as many urethane bushings as needed, and the stainless tubes inside were perfect diameter. I did find I had to sand the studs to remove the paint or the spacers would not slip on! John

Re: Spacers for Heim Jointed Front Wishbones

PostPosted: Thu Oct 28, 2021 6:38 pm
by miked
Andy,

Thanks for reply. No, I don't know of a piece of kit that would do the job. Aware of the Canley item but never looked into it.
The reason i chipped was of the uncertain accuracy of some of the Chassis's.
:D

Re: Spacers for Heim Jointed Front Wishbones

PostPosted: Thu Oct 28, 2021 10:25 pm
by fotsyr
What you require is a Safety Retaining Washer for Rod End Bearings.

https://www.pegasusautoracing.com/produ ... oduct=3068

chris

Re: Spacers for Heim Jointed Front Wishbones

PostPosted: Fri Oct 29, 2021 3:28 pm
by EricB
Thanks guys, great response. That extsw looks like a great source for the spacers once I sort out their dimensions via the washers. I also wonder about using those special Pegasus washers.

I had originally only intended the heim joints for camber adjustment but hadn't yet thought out about caster. Easy to do on my Lotus Cortina via moving the front struts but similar thought process should apply here with the upper wishbones relative to the lower via the spacers.

Re: Spacers for Heim Jointed Front Wishbones

PostPosted: Sat Oct 30, 2021 12:29 am
by bitsobrits
fotsyr wrote:What you require is a Safety Retaining Washer for Rod End Bearings.

https://www.pegasusautoracing.com/produ ... oduct=3068

chris


I have those on my other Elan, which uses the same Spydersport adjustable upper arms and occasionally goes to the local track. But I would say on a street only car, the heims would have to crazy worn (as in never gonna happen) to have any possibility of the heim separating, even with very high mileage. My other Elan, btw, has 25k miles on those heims (precision, teflon lined) with NO discernible wear. No dust seals either.