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View Full Version : TR2/3/3A TR3A upper fulcrum bushings



PeterK
05-05-2007, 09:40 PM
I am pre-assembling my TR3A front suspension. The new upper fulcrum bushings seem to be too long. When I fit them on the control arms and put the control arms on the fulcrum pins, there is just barely enough room to add the outside washer and a single thread for the nuts.

Same bushings are listed for TR2 - TR6.

Do I need to trim these to fit so that the outer lip of the bushings sit flush with the outside of the control arms?

These are the standard bushings, poly are on the way here.

mcguijo
05-06-2007, 09:41 AM
I've run into this same problem. . .but I don't have an answer. I tried to really tighten down the castle nut on the fulcrum and it greatly compressed the rubber bushings (they flaired outward well past the diameter of the washers). I don't think they way I did was the correct way to do this. . .

Twosheds
05-06-2007, 10:36 AM
The rubber bushings will squish when you tighten the castle nuts down. I think this is normal.

PeterK
05-06-2007, 11:01 AM
The reason I ask is that on my 4A, which uses the same replacement bushings, they fit "correctly," but which also has a wider control arm.

I would have to squish the rubber at least 3/8" on the 3A which seems like a lot of squish to me.

The red poly bushings I took out seemed to fit correctly but were ovaled on the ends so I am replacing them. I'm waiting to see how the new poly bushings from TRF fit.

Glad to hear others have had the same problem with replacement parts.

Twosheds
05-06-2007, 11:10 AM
Poly bushings have no squishabilty, so they must be the same dimension as the arms.

I don't know about a 4A, but the wider arm explains the difference.

Any news on the traction-bar-to-frame mounts?

martx-5
05-06-2007, 11:31 AM
I originally replaced those upper bushings that were supplied in TRF's front end rebuild kit. They fit fine. I decided to go with the poly bushings instead (from Moss) after I got it all together ('cept for the springs and shocks), and those also fit fine.

I think The Roadster factory pays more attention to some details much better then the other suppiers.

Tinkerman
05-06-2007, 12:20 PM
Hi Peter:
I had to trim my rubber bushings to get them to fit right. They came with the car but the PO bought them from TRF. Talked with TRF's tech guy and he said to trim them, so I did.
If I ever have to go through the front end again I will go with the poly bushings.
Regards, Tinkerman

PeterK
05-06-2007, 12:23 PM
Any news on the traction-bar-to-frame mounts?

Actually I have a lot more info on the traction bars. Originally made by Traction Master who is still doing business today, but not making TR bars. https://www.tractionmaster.com

I found that they still make bars for Sunbeams and Shelbys. The Tiger bars come in two formats LAT-5 which bolt or weld with a simple angle bracket to the chassis just to the side of the front leaf spring hanger. The TRs used the same angle bracket mount but I am fab'ing a U bracket from a trailer spring perch that will mount to the 4A front spring bracket (same as IRS trailing arm hanger.) The TR4 bracket attached to the inside of the chassis next to the spring tube. For Tiger specs and info, https://www.tigersunited.com/resources/parts_service/lat.asp

LAT-6 bars are a supposed improvement. The are a bit shorter and have an angle welded to the front of the bar which clamps around the front of the leaf. The improvement is because the original bar tended to rip out of the chassis and the newer bars also use an improved mount at the spring perch.

The original TR bars used a 5/8 bolt through a rubber hat bushing. I fitted my bars with energy suspension poly bushing with a steel inner sleeve and 9/16" bolts. I have detailed picture with measuements of the rear brackets on my site but don't have the link handy because I'm in my garage right now (will post later.) The bars themselves are 19-1/4" o.c.

https://mysite.verizon.net/kentech0822/triumph/trackbars/rear_bracket_side.jpg
https://mysite.verizon.net/kentech0822/triumph/trackbars/rear_bracket_back.jpg
https://mysite.verizon.net/kentech0822/triumph/trackbars/rear_bracket_top.jpg

I have seen a few other Traction Master bars on ebay lately but not TR bars. I think you could make you own set up pretty easily with rose 3/4" joints and have them adjustable.

Twosheds
05-06-2007, 04:43 PM
Thanks for the traction bar update. The spring side mounts are a little different from the ones illustrated in Technicalities. Why do the Traction Master ones only have three holes for the U-bolts? are they to be used in addition to, rather than instead of, the stock spring plates?

Mine look like they were made to the Technicalities drawings and have four U-bolt holes. They take the place of the stock spring plates.

I take it don't have the frame side mounts?

PeterK
05-06-2007, 06:06 PM
I think the later (improved) bars use four hole and replace the spring splates as you suggest. This one is meant in addition to the spring plate I think.

I don't have the front mounts but mine is a rigid axle 4A and I need to fab anyway because the bars are for the ladder chassis. I'll probably hang shackles from the front spring perch or use a U bracket welded to it.

Oh, and if yours are marked "M-1" on the bar end tees, they're Traction Master. Otherwise not.

Harry_Ward
05-06-2007, 09:33 PM
Peter,

For standard rubber bushings approx.,
The outer bushing compresses to the outside diameter of the outer washer and the inner bushing compresses to the outside diameter of the upper inner wishbone fulcrum casting. The nut is fastened to hold the bushings firmly in place but not fully tightened until the car is back on the ground. The seats either have to have people sitting in them or have at least 150 pounds of weight in each seat to assume a normal suspension level. Once the tires are on the ground and the car is laden with weight then the nut can be fully tightened and the cotter pin replaced. I did not not have to trim the bushings just compress them.

PeterK
05-06-2007, 09:48 PM
Hi Harry,

Thanks for the tip on the bushings. I see in the cross section of the upper fulcrum that the bushing hats are indeed squished to the diameter of the washers.

But I think the preload that you refer to is only valid on later cars (TR4 onwards) with positive caster trunnions. On my 0 deg. caster suspension, there is no mention of preloading the suspension in the Service Manual prior to tightening the castelated nuts and fitting the pins. So I really can't see any reason to not tighten down the suspension as long as the ball joint and lower wishbone alignment is true on axis. But I will keep your suggestion in mind as I continue getting things put together right, then tighten last.

I thought the timing chain was OK too but changed it today with a new one which is MUCH tighter.

Thanks Harry!

PeterK
05-07-2007, 10:43 AM
The poly bushings from TRF today and they fit perfectly.