Top Trunnion Bushing Fit

I've started assembling the front suspension on my BT7 and am planning on installing rubber bushings. I have two sets of top trunnion rubber bushings from two different vendors. One set fits perfectly (snugly) but is missing the flange that goes between the top trunnion and the shock wishbone arms. It seems like this will make the top trunnion susceptible to lateral movement and I am not planning on using it. The second set has the flange, but is much wider (~.22" total - trunnion and both bushings) than the space between the wishbone arms. The internal steel bushing bonded to this second set of rubber bushings extends all the way to the outside edge of the bushing. I don't see how it is going to compress to fit.

I also have a set of adjustable camber bushings that I had decided not to use. These fit perfectly.

I took a look at the old rubber bushings, which are in poor condition, and it looks to me like they were modified to fit. I can see what appears to be file marks on the steel bushing in the center and cut marks on the rubber.

Is there a vendor that has a rubber bushing with the flange that will fit, or is it normal to have to modify the bushings?

I appreciate any insight.

Attached photos show the two rubber bushings, and the rubber bushing with flange and adjustable camber bushing.

Thanks....joe

There is no telling what your camber will be after you get everything back together and on the road. Most likely it will be positive to one degree or another and different on both sides. Ideally, you would want neutral camber. So unless you use the adjustable bushings you will not be able to get the best front end alignment for your Healey.

The bush without the flange is used on some BMC saloons with similar trunnions. I can't speak for it's suitability for a Healey, but, usually it has a steel distance piece/spacer inside.
This spacer is not the full length of the bush so that when the nut/washer is tight to the distance piece the end of the bush forms the flange. These types (in their correct application) are less prone to tearing the flange in service than the flanged type.

Danny

I don't believe the upper trunnion bushings affect ride much at all. I'm running adjustable offset bronze ones from Cape - had to modify them to get them to fit - and they're expensive - so don't recommend them. However, they use an eccentric bolt so were easy for the alignment guy to adjust.

BCS sells offset poly bushings that should fit properly.

If your white ones are adjustable and fit properly, I'd just use those. A wheel alignment shop can adjust them for camber. You can get about a degree either way. Any of the offset bushings - the alignment guy will have to undo the pin bolts in order to rotate the bushings to the proper camber. Not that difficult.

It would be great if we could DIY the camber adjustment using laser levels - maybe some of the racers will address this.

Except for the Cape, any of these bushings are inexpensive and relatively easy to swap out.

Thanks for the input. I appreciate it.

I think I will give the offset bushings a try. I was worried about ride quality and squeaks, but maybe the tradeoff is worth it. Is there a particular type of grease that is used?

JoeCA said:

Thanks for the input. I appreciate it.

I think I will give the offset bushings a try. I was worried about ride quality and squeaks, but maybe the tradeoff is worth it. Is there a particular type of grease that is used?

Click to expand...

I like waterproof grease for miscellaneous stuff like this - but a light smear of any grease will do. If the bushes are Delrin, they probably don't need grease at all.

Joe,
Check out this comprehensive alignment thread - includes tools for doing camber yourself:

http://www.britishcarforum.com/bcf/showthread.php?116365-Camber-Adjustment-(again)

Since you're on the subject, and I didn't see it mentioned, DO FOLLOW the procedure in the (Bentley) manual about setting the clearances for the lower outer pivots. Likewise, do not tighten anything until the suspension it sitting at static ride height (this can be simulated with a 2" spacer...).



It is normal to have to undo the bolt between the two (2) shock arms in order to squeeze the upper trunion & NEW rubber bushes into position (for the record, I have only ever seen the the rubber bushes you show WITH the flange).

On the subject of eccentric upper bushes, I made a set for myself (two sets, actually, one in bronze and the other in UHMW polyurethane) I milled a 1-1/16" hex on one (1) end so that I could adjust them without disassembly, using an open-end wrench milled thin enough to slide in between the shock arm & trunion. These upper trunions were relieved of their tapered bore back in 1985 to accommodate one (1) piece concentric UHMW bushes, I didn't make the adjustable eccentric ones until late 2003.*



I figured I would fit the UHMW ones first, then put the bronze ones in when they wore out; nearly twenty (<20) years later, the poly ones are still as tight as when I first fitted them__I don't think UHMW wears out__and they have never made a peep, no squealing whatsoever! Consequently, the bronze eccentric bushes are still waiting to be finished to their final size.







The occasion of taking the suspension apart in 2018 was to fit these Nadella Bearing assemblies between the upper trunion and stub-axles. While it's not as though you added power steering, the effort required to turn the wheel is definitely reduced (particularly noticeable at parking speeds).







* From the WayBack Machine:
My eccentric bushing project (or perhaps more appropriately called my bushing project by the eccentric Healey owner?).

Steve - Thanks for the grease recommendation and the alignment thread link - a lot of good information in there.

Randy - That is some nice work with the adjustable camber bushings. Incredible that the UHMW set has lasted so long! Good to hear that they don't squeak. I have the Bentley manual and have studied the setup procedure. This is my first time working on this type of suspension though and I really appreciate the advice.

I talked to a technical representative from Moss today. Moss supplied the rubber bushing with the flange and I was surprised that they would follow up on my inquiry regarding the bushing fit....after all, it is an inexpensive part. The tech representative assured me that the bushing would compress and fit correctly by loosening the shock arms and squeezing the bushing as Randy described. It seems like a lot of compression to me, but I believe him and am going to give it a try. He was really helpful and we reviewed the other suspension setup work that I had done. I think I am in pretty good shape at this point. That said, with all this information, I am now interested in installing the adjustable camber bushings.

I really appreciate all the feedback.

joe

steveg said:

Joe,
Check out this comprehensive alignment thread - includes tools for doing camber yourself:

http://www.britishcarforum.com/bcf/showthread.php?116365-Camber-Adjustment-(again)

Click to expand...

Ha ... that's the thread I instigated. Well, I decided I didn't really need a military-grade assault rifle for home defense so I've got a few bucks burning a hole in my pocket, and I decided to spring for the alignment system. My BN2 has Kilmartin adjustable, and I got a set of Tom's plates (from someone on the email list IIRC). Anyway, this fall, after the harvest is in I should have the time to do the alignment/handling experiments I've wanted to do for a while, after I get the DWR steering box and the caster plates installed on the BJ8. Yeah, it's a chunk of change but with 2 Healeys with adjustable alignment I should be able to educate myself on the intricacies of alignment and handling. I've also got 2 tractors that could use front-end alignment; heck, maybe I can write the whole thing off as a farm expense! Got a set of turnplates for caster adjustment just today.