TR6 Installing adjustable trailing arm brackets

[steveg]

I'll be installing these soon. Does anyone have any experience-based comments on the installation? Do I really have to remove the axle half-shafts? I'm not planning on replacing the rubber bushings at this point as they're sound.

 

[glemon]

Steve, has been a while, but I put brackets on and off quite a bit before I got adjustable ones, messing with bushings and camber. As I recall I jacked up the car, let the arm fully release or extend within normal range of motion, and loosened one mount to the point where I could remove the other and install new, then same for the second mount. I believe some support and leverage with a floor jack and pry bar were also involved, but I don't remember it being particularly hard.

 

[steveg]

Steve, has been a while, but I put brackets on and off quite a bit before I got adjustable ones, messing with bushings and camber. As I recall I jacked up the car, let the arm fully release or extend within normal range of motion, and loosened one mount to the point where I could remove the other and install new, then same for the second mount. I believe some support and leverage with a floor jack and pry bar were also involved, but I don't remember it being particularly hard.

Greg (right?),

Thank you. Exactly what I was looking for!

The instructions that come with them seem to include installation of their nylatron bushings which I gather would necessitate removal of the swing arm to the bench.

 

[glemon]

Getting the new nylatron bushings in shouldn't be too hard (assuming they are a two piece "halved" bushing) but getting the old rubber out may be the tricky part that requires removal of the arm and axle. You might want to remove the axles anyway (loosen the boot and separate the splines) as you want the splines to be clean and well greased so they don't bind on hard cornering.

Greg

 

[steveg]

Getting the new nylatron bushings in shouldn't be too hard (assuming they are a two piece "halved" bushing) but getting the old rubber out may be the tricky part that requires removal of the arm and axle. You might want to remove the axles anyway (loosen the boot and separate the splines) as you want the splines to be clean and well greased so they don't bind on hard cornering.

Greg

Greg,
Thankyou for the info. When I bought the car a few weeks ago, my mechanic fitted new u-joints and hubs so the axles are in good shape.

Will followup when I do the install of the brackets.

 

[Tybalt]

A couple of things I noted from my install of the adjustable trailing arm brackets. First, the bolts supplied with the kit were on the short side and did not allow for the toe adjustment shims. It's been several years so maybe Richard is putting longer bolts into the bracket kits. The other is that I hate the idea of having threads in shear loading so I replaced the pivot bolts with AN7-41A (7/16, 20tpi, grip length 3 9/16" ± 1/16", overall length 4 7/32" +1/32", - 1/64", undrilled shank and head) bolts which allowed greater control of the grip length over SAE bolts and I made final adjustments to the grip length using AN960-716 and AN960-716L (thinner) washers. Aircraft Spruce, Coast Fabrication, Pegasus Racing types of places can fix you with a wide variety of AN/AS/NAS/MIL type hardware.

As for the Nylatron bushings, they are split. They come a little oversized and they were sized to fit by a combination of turning down and hand sanding. I went with them as Richard recommends using those when fitting one of the Nissan/Infinity differential kits as opposed to the stock bushings.

 

[Madflyer]

Could be as simple as slip out slip in new. And yes change with full shoulder bolt keep same grade bolt good idea. Removing springs just as easy. As I did you may find your old ones are split at the bracket mount bolt holes. I added an extra plate on inside. These brackets take the load when you hit a pot hole. The frame has tubes inside that mount bolts go through so frame does not compress. As to removing old rubber mounts a used a long bolt or all thread and a under size washer and nut with over size pipe and washer on the other side of arm to pull rubber out. I did stay with rubber as shock of roads to car. As to alinement some shops may not touch it. Tires should sit square with normal load say two people and a tank of gas. Do this with a 2 foot level on side of tire if you can not get it right a shim under spring. Toe in can be done with a tape measure front and back center of tread with normal load. The reason this is close enough is it is ever moving. If your car is true now just right down and replace as was when you started.

NOTE Triumph made a number of tries to get rear end right starting with TR 4A IRS, 250, early TR6 to later TR6. The brackets came four ways if you look at each bracket they will have a zero to three notches on the sides depending on your year car . It could have a one notch on the inside and a zero or two on the outside or a one and three This was done to set arm as the adj bolt does on your new ones. Each of these mounts have the pivot hole at a different pitch. I only know one of the reason they played with this. My TR 250 would squat on starting off from a stop That changed the foot print of the tire and made the car feel like lifting off. Also there are three or four rear springs so that need different mounts. Madflyer

 

[glemon]

I started out (literally, first car I owned) driving Sprites, then moved on to MGBs, Four cylinder TRs, and one big Healey. They were all basically a scaled up Sprite, bigger motors, transmissions and axles, bigger carbs, but all awfully similar. Then I got my TR250. The Triumph IRS has it's own learning curve, and after years of not worrying much about the back end other than the occasional leaky seal, sort of seems like a royal PITA at first. They can work well with proper maintenance and or modification. But they usually need some attention to make right. Sounds like you are moving in the right direction. Have fun.

Also will add that like Madflyer, I fabricated a plate from 1/8" steel for the backside of the frame where the brackets bolt on, seems like cheap insurance.