Urethane Bushes

[Underdog]

Another install question that may seem dumb. The sway bar bushes that go into the lower pivot arm have a flat end and a tapered end. Which way round do they go? Flat towards the arm or the washer? I think I have them backwards as I can't get the washer and nut on.[:(]
Getting this sway bar & arms together is such fun. I think I will be doing it over.[:(!]

72 MGB BRG
80 TR8 Persian Aqua
If women don't find you handsome, they should at least find you handy.

[Underdog]

Got an answer over on Woody's site. Flat towards the arm. Luckily that's the way I put them in. Now to get the dang nuts started.

72 MGB BRG
80 TR8 Persian Aqua
If women don't find you handsome, they should at least find you handy.

[busheytrader]

Hi Underdog,

I found fitting these polybushes to be one of those trial and error, grunt and sweat jobs. No exact science to it but this worked for me, eventually.

1) With the car up on jacks and the front wheels off the ground you can get both ends of the antiroll (sway) bar through the track control arms. Hopefully you placed the first set of bushes on the bar beforehand.

2) Fit the remaining polybush on the end of the bar and there should be a couple of threads poking through. Place a large diameter but thin washer over the end and thread on the original nut. Ratchet up the nut up about 12mm (1/2")and it'll compress the polybushes a bit. Remove the nut and washer and you should now have enough extra threads showing to fit the proper dished washer and nut. Tighten up the nuts a bit but not too much since you want some movement in the bushes. You'll need it for the next step.

3) Place a trolley jack under the centre of the antiroll bar and raise it towards the subframe. With the antidive kit fitted, I found that the bar was too far forward and the bolt holes in the antiroll bar clamps didn't line up with those in the subframe. Whilst lying on the garage floor I pushed the track control arms back with my legs and as the holes lined up I pushed through the bolts. An extra arm and leg would have helped. Fit the bolts and fit up the nuts about halfway.

4) Remove all the jacks and with the weight on the front wheels torque up the bolts to the subframe. I was told to torque the nuts on the ends of the bar up firm but not so tight that they crushed the polybushes.

With polybushes being far less compliant than the original ones, an awful lot of pushing and shoving is required to obtain any movement and flexibility. The lube supplied with the bushes definitely helps. The payback is better handling for all your efforts......

Have fun doing it!!


Adam

TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, Single Pipe Exh, 3.08 Rear, 200lb Spax & Solid Bushes, Anti- Dive, Granada Vented Discs & Calipers, Braided Hoses, Green Stuff, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 5 Spokes and Cruise Lights. No Door Stickers. Mine since July 1986, V8 from 1991

[Underdog]

Thanks Adam.
I have the bar mounted, pivot arm bolts installed. Just need to get the backside bushes, cup washers & nuts on. I'll have a go at useing a flat washer. I would have thought the nuts/cup washers would get drawn up to the shoulder? I'll keep a watch as I tighten. You are right...a struggle no mater how you do it. My neck & shoulder are a bit sore today. Hopefully, this rids me of the shakes under braking for good!

72 MGB BRG
80 TR8 Persian Aqua
If women don't find you handsome, they should at least find you handy.

[busheytrader]

No problem.

I still have a touch of the shakes under braking even after fitting new polybushes on the subframe and front suspension and adjusting the wheelbearings. I've got a feeling it may be down to the greenstuff pads I fitted recently so I'll be refitting the std pads to check.

Adam

[Hasbeen]

If you have the shakes under brakes, check your caster. High caster
will give you the shakes under brakes. At 3 degrees, our cars have
high caster as stock. Any higher is a problem. This castor will
augment any unbalance in the wheels, when you brake.

As a cheep test, putting a washer or 2, in front of the front
control anm bush, on the anti roll bar, will reduce your caster, to
some extent.

If that workes, a castor, camber kit, for the top of the strut,
would be a good investment.

Hasbeen

[Underdog]

Greenstuff pads here as well on the Rimmer brake kit. But it did it even with the stock brakes & pads. I'll see how it does with the new bushes.
Hasbeen, good thought on the castor. I'll have to look for the specs when I had it to the alignment shop. Less castor would also help with the steering effort since I went to the manual rack.

72 MGB BRG
80 TR8 Persian Aqua
If women don't find you handsome, they should at least find you handy.

[busheytrader]

Hi Hasbeen,

You've mentioned the castor angle before and I hadn't forgotten.

The "flat" end of the polybushes are profiled to mate to the track control arm so I reckon I'd have to fit the washers on the other side of the leading bush, ie up against the welded cup on the antiroll bar.

I first got the shakes at 60 mph after changing to alloy wheels, greenstuff pads, fitting polybushes to the subframe and replacing the front Spax and track rod ends, all at the same time. This disappeared after having the wheels balanced properly at the 3rd attempt. A shimmy appears under medium to heavy braking once the brakes have warmed up. I had suspected a warped disc but there's no pulsing in the pedal.

It's far easier to change the brake pads over than remove and refit a polybushed anti roll bar so I'll go with that first. What thickness washer is needed to reduce the castor angle by 1 degree?

Thanks,

Adam

[Underdog]

Adam, I just took the car for a test ride and no brake shakes apparent. I did tighten the bushes on the pivot arms until the washers were tight against the shoulder on the sway bar as you would do with the stock ones. I don't know if there are different bushes out there but mine came from Wedgeshop and are black in color. You said you left yours a bit loose as not to crush them. I'm wondering if you may have defeated the purpose of the urethane in the process? Just a thought that I hope may help.

BTW, Car definitely feels better with the bushes, uprated sway bar and the stuff I did to the rear. Only about 1/16 larger bar than the stock TR8 but I do notice less body roll. Hope to get to the track next month to really see what it will do. Runoff areas are much more forgiving than trees and oncoming trafic![;)]

72 MGB BRG
80 TR8 Persian Aqua
If women don't find you handsome, they should at least find you handy.

[busheytrader]

Underdog,

Good to hear that the polybushes worked for you. I torqued mine up firmly but heeded Robsport's advice not to "overtighten them". Maybe I erred on the side of caution a bit too much so I'll nip them up further to take out any potential front to back movement. I thought I had them torqued up fairly tight though. My antiroll bar polybushes are purple sourced from Robsport. The subframe bushes from them are orange so must be a different grade of material.

I did have uprated Triumphtune bushes from the late 80's on the antiroll bar. They weren't of a polyurethane material but something fairly close in compliance when fitted. When I removed them last year they were as hard as golf balls with no flexibility at all.

Tightening the antiroll bar nuts potentially moves the track control arm forward to increase the castor angle. As per Hasbeen this increases the likelihood of shakes under braking.............I'll see what happens.

Thanks,

Adam

[Mowog73]

Crap. I put the bushes on backwards.

Mark

<font size="1">1973 MGBGT Teal Blue
1976 TR7 Mimosa
1980 Spitfire 1500 Vermillion</font id="size1">

[Underdog]

Easy enough to do. Before I asked, I examined the pieces and thought they went tapered ends out. The socket in the pivot arm has flat shoulders which match the flat of the bush. The bushes I got have indentations in the tapered end that match the inner raised part of the cup washers. I was glad to learn my assumption was correct as I had already fought the pieces into place. I began to doubt myself when the washer & nut wouldn't go on. Drawing them in a bit without the cup washer worked great. My sympathy to you Mark. Not a fun job at best and worse to have to do something over.

Adam, those must be of different manufacture given the different colors. Guy selling them has the experiance so I won't dispute his advise. My car had the uprated rubber pieces as well. However, the ones that hold the bar to the frame were the originals. They didn't get replaced because the only ones available were for the smaller TR7 bar and I didn't think they would fit. The originals I took out were very soft.

72 MGB BRG
80 TR8 Persian Aqua
If women don't find you handsome, they should at least find you handy.

[busheytrader]

I had some time this morning so tightened up the nuts on the end of the antiroll (sway) bar and had a test drive. (I have the blue / purple polybushes on the bar ends and in the middle. Orange polybushes mounting the subframe to the chassis legs)

It didn't make much difference to the slight shake under heavy braking. I swapped over the Greenstuff pads to the original items I had before and tried again. There was no brake and shake even when they had bedded in and were running warm enough to smell. I also have the welcome return of some pedal feel and movement. The Greenstuff with my setup gave almost no pedal movement, a bit like driving a Citroen CX.

I'm tempted to replace the rack and inner steering ball joints as they are the only front suspension and steering items not replaced within the last 18 months.

Cheers,


Adam

TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, Single Pipe Exh, 3.08 Rear, 200lb Spax & Solid Bushes, Anti- Dive, Granada Vented Discs & Calipers, Braided Hoses, Green Stuff, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 5 Spokes and Cruise Lights. No Door Stickers. Mine since July 1986, V8 from 1991

[Hasbeen]

Adam, have you adjusted the rack? It would not take much free play,
between the pinion, & the rack to let a shake develop.

It's just a matter of changing the shims, under the big nut, infront
the of the thing. We are talking in thou, not fractions.

Remember to allow for any wear at the centre of the rack. If you
make it too tight in the much used centre, it may bind at the much
less worn full lock areas.

One other approach would be to fit a steering damper. Before power
steering insulated the steering wheel from road shocks, & wheel
wobbles, many cars of the 60s had them. Like a double acting shock
absorber, hooked to the drag link, or track rod, they absorbed the
movement that generated excess feed back, & wheel wobbles, before
they got to the box, or rack.

The ones from a 60s VW should be adaptable, & are probably still
available.

Hasbeen

[Underdog]

I'm getting brake squeel with my greenstuff pads at near stop. Must be something about the big brake kit since I've had them on the MGB with no problems. Thinking of trying some of the coating product sold to dampen them to the caliper pistons. The adhesive backing pieces supplied don't catch the whole piston contact area on the 4 pot calipers.

On my test drive I also noticed the right front grabing as the car would dive to the right on hard brake. I confirmed this in my gravel driveway as the right frt would lock. Another drive I hit the brakes hard several times and the condition went away. Don't know if the pads had something on them or they are temp sensitive. Everything in the system is new so I can't see a hydraulic problem.

72 MGB BRG
80 TR8 Persian Aqua
If women don't find you handsome, they should at least find you handy.