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Restore of my 1986 Bronco XLT

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ReneH

Restore of my 1986 Bronco XLT

This post was updated on .

I've decided to open a new threat for the upcoming work and the resulting questions. For all the people that helped me in the past, I want first to inform you, that by now everything seems to be good. I've driven 250 miles since the successful cam break-in about two weeks ago. Only trips with more than 20 miles driving whithout turning off the engine. So I'm quiet confident, that now everything will work regarding the cam and the lifters. So as the next holidays are coming closer and I need the truck to drive with the family, there is some work left. Sure, I'll not be able to do everything I want or that's planed, cause we'll start in five weeks, so I have four weeks left to do necessary things.

Following my list of things to do:

Technical necessary

Engine is running shakey while setting the C6 in position P.
Front break rotors have to be changed, cause they're shrunk and squiking.
There is a low frequency noise when driving faster than 60 mph. A rotating noise, very deep and slow. At about 60 mph not more than two times a second.
Getting rid of the rattle and squiking that my door-panels do.

Nice to have

Getting rid of the whistling sound of the intake
Getting my 360° cams installed.
Building my center console with integrated dual subwoofer and adding the center speaker in the dashboard.
Adding the central door-lock to my remotecontrol. Tailwindow is already remote-controlable.
Mounting the steps, that the kids can enter the truck more easy.

Technical necessary

I already have changed the plugs, without any change. Today I'll check the vacuum value while idling. I'll also re-check the basic-timing, It should be set to 12 degrees. Maybe someone has other ideas what can cause a raw idle? It's most pronounced when staying in parking position and gets less in neutral and more less in driving or rear position of the C6
I'm still not 100% sure what parts I need, but Gary is already on the hunt to find the right ones...
I have no idea where I should start to search here...It's a very slow rotating noise. I can't imagine any rotating parts that rotates so slow at about 60 mph. Maybe the tires, cause the truck was standing about 3/4 year? I really have no idea...
The former owner has replaced the door- and sidepanels with parts from a 90th truck. That have told me BigBlue from the FSB forum. So, not everything fits 100%. I see the biggest problem with the inside windo guide felt. It has other clips than the 80th version. I'm thinking about to buy the felts from the 90th trucks

By the way, can someone tell me where I can buy the trim-clips for the chrome-trims?

Thanks for all your help in advance!

René's Profile

Bronco 1986 Ford Bronco XLT 302/347 stroker with 351W EEC-IV and 351W factory cam C6 gearbox. Jeep 1986 Jeep CJ7 256 I6 with T5 gearbox. Buggy 1972 HAZ Buggy 122 Ford Cologne V6
Baron 1994 Chrysler LeBaron convertible 183 V6 4-speed automatic

ReneH

Re: Restore of my 1986 Bronco XLT

So, to find out which rotor will fit, I've removed the wheel on the driver's side...

I think as I have to remove the wheel bolts, I also should buy new ones. Also my wheel nuts are not very pretty anymore...

So in my opinion the rotor from raybestos I've chosen will fit.

But looking at the rotor, it doesn't looks so bad at all...maybe it's a problem of the caliper or the piston? Turning the rotor without the wheel, you can hear the pads dragging on the rotor.

Gary Lewis

Re: Restore of my 1986 Bronco XLT

Administrator

The Bullnose calipers do not center well and the pads almost always drag on the rotors. Ford later changed the calipers so they slide better, but you are pretty well stuck with the style you have.

On the rotor, measure them where they are worn. Then go to the page at Documentation/Driveline/Brakes and then the Front Brakes tab and then the Disk Brake R&R tab. There's a section of the factory shop manual there and at the very end of it should be specifications on how thin the rotor can be.

If you do decide to buy new ones the Raybestos ones are the ones I'd go for. And it won't hurt to have new lug nuts, although yours don't look bad.

But if you are doing that you might consider buying a whole new hub. This one from ACDelco says it comes with the wheel bearings, but I can't confirm that from the advert so it will take more research. And, that'll add a lot of weight to your shipment. Plus, it says the country of origin is China.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

ReneH

Re: Restore of my 1986 Bronco XLT

Ok, new hubs are something after the holidays.

The break power is good. I only want to get rid of the squiking noise the breaks a performing...it makes you mad...

But as no knowing if it comes from old rotors that became new pads or if the piston is maybe the problem, it makes hard for me to order...

The next thing are the gaskets. It seems that the former owner has replaced the vent windows or the whole doors with ones from a 90th truck:

Sorry for the content hopping...but I'll try to use the time as best as possible...

ReneH

Re: Restore of my 1986 Bronco XLT

In reply to this post by ReneH

So, it's my next post...I've measured the vacuum and also the idle rpm when C6 ist set to parking. Here is the video:
Video

I have unplugged the vacuum line to the cruise control to measure...no real shaking anymore while measuring...interesting...

So I've connected the cruise control again.
Now it's shakey again...interesting...

So, as my cruise control is in good condition, in my opinion and the line from the plenum to it is new, I've disconnected the line to the breakpedal release and plugged the opening at the cruise control...
Not shakey anymore...
Video

I've done a test-drive with this setup...a bit more shakey again when standing at a traffic light, but better than with the relese hose connected...so where is the problem?

It's maybe a vacuum leak...a small one...or only the idel speed is too high...as you look at the video, you'll see it's at about 630 when c9ld, 820 rpm when warm.

What do you think about my vacuum value?

ReneH

Re: Restore of my 1986 Bronco XLT

In reply to this post by ReneH

This is what I've currently added to my basket:

Are these brands ok? What do you think?

Gary Lewis

Re: Restore of my 1986 Bronco XLT

Administrator

In reply to this post by ReneH

I'm confused. In the first video it was idling at about 630 and 16 inches of vacuum and then it jumped up to maybe 680 RPM and 18 inches of vacuum. What happened to cause that?

But in all cases the vacuum is very steady. VERY steady, which seems unusual. Where do you have your vacuum gauge connected?

When you "unplugged the vacuum line to the cruise control to measure" did you plug the line or leave it open to suck air? If you left it open then it leaned out the mix and brought the RPM up due to the extra air. That may be enough to get out of the RPM range where the engine is shaking.

As for the shaking, have you posted a video of that? I don't think I've seen it. But from the sound and the vacuum I'm not seeing any problems.

Gary, AKA "Gary fellow": Profile

ReneH

Re: Restore of my 1986 Bronco XLT

Hi Gary,

I have disconnected the vacuum line from the plenum to the cruise control and plugged my gauge into it, so no open vacuum lines.

First video the engine was cold, second it was warm...that's the only difference.

Can this steady vacuum caused by the small drills that I have made through the throttle plates? Or do you think that there may a vacuum leak somewhere?

I have this video posted in the former threat:
Video

But the shaking seems to stop when I disconnect the line from the cruise control to the break-pedal...I can test this again and measure the vacuum on the line for the vent flaps (don't know if you know where I mean...

)

Gary Lewis

Re: Restore of my 1986 Bronco XLT

Administrator

Ok, no open vacuum lines. Good!

And I have now watched the video of the shakes. That's quite of bit of shake.

But I'm not sure what you mean by "disconnect the line from the cruise control to the break-pedal". That should be a vacuum dump line that is closed until you depress the pedal. If that line isn't closed when the brakes are off then you may have a vacuum leak. So I would concentrate on checking that out.

That line is a safety to kill the vacuum to the speed control, and while it isn't a good idea to cap it off permanently you can cap it off for testing.

Gary, AKA "Gary fellow": Profile

ReneH

Re: Restore of my 1986 Bronco XLT

Yes, I've only disconnected it for testing.
But if this line is closed with open brakes, how could it have a leak?

The problem only occurs when the car is standing still and mostly when set in parking...

Is my idle not too low when cold? I've read the 347 stroker should have about 800 to 900 idle speed...

And about the vacuum value. Is it OK?
What could be the reason for the steadiness?

Gary Lewis

Re: Restore of my 1986 Bronco XLT

Administrator

I don't see why the idle needs to be higher than ~650 RPM. And the vacuum looks good.

But I'm not sure that we are saying the same thing regarding the brakes and vacuum. The vacuum valve connected to the brake pedal should be closed when the brake pedal is up and the brakes aren't applied. If it was me I'd try to pull a vacuum on the line going to that valve. If it is leaking it could cause problems with the idle.

You can cap that line and test drive the truck. I wouldn't use the speed control, although it would probably be fine. It is just that the vacuum dump is a safety in case the system doesn't kick off when the brake lights come on.

Gary, AKA "Gary fellow": Profile

ReneH

Re: Restore of my 1986 Bronco XLT

So, I've found the problem. Actually it were two...

1st: the rpm, when warm was about 860 to 950...this seems to high. If I reduce it to about 720 to 750 with IAC disconnected, it runs very smooth without shaking.

2nd: the cable of the cruise control wasn't set correctly. It stops the throttles to reach the idle screw and holds the idle rpm high.

ReneH

Re: Restore of my 1986 Bronco XLT

I have tested the 4WD today. It works so far.
But if I lock the hubs and let the car roll without giving gas, it makes not a good sound in my opinion:
Video

What could cause this sound? As I don't need the 4WD in the upcoming holidays it's not very important...but good to know as I want to order new rotors, I can add the part that causes this noise...front axle bearings or propeller shaft? Differential?

Gary Lewis

Re: Restore of my 1986 Bronco XLT

Administrator

Rene - Several things.

On the RPM, if you have to unhook the IAC to get the RPM down then the computer is trying to keep the RPM too high. Or maybe it is the speed control cable? I'm not sure I understood that bit.

As for the noise, that is the sound of the transfer case in 4LOW. I'll bet it doesn't sound like that in 4High. That sound is normal given the straight-cut gears in 4LOW, and it is especially loud through the opening in the floor.

You do know that you aren't supposed to be turning corners on pavement with the hubs locked and the transfer case in 4WD - right?

Gary, AKA "Gary fellow": Profile

ReneH

Re: Restore of my 1986 Bronco XLT

OK, so maybe I've not exactly described what I've done. I've found a procedure to set/change the idle speed for the 302 EFI end of last year as I have had this big problems. That's the procedure:
Link to ford-trucks.com

So as having a 302 not anymore, I've read that the idle should be a bit higher.
Disconnecting the IAC is only while setting the new idle rpm.

My speed control cable wasn't set correcly, so it stops the throttle-plates to reach the idle-stop screw. That fact has nothing to do with the procedure itself. It's another issue.

About the 4WD: I know that not to turn corners on pavement as having no central differential.

But the noise occurs in 4High and also 2WD, haven't tested 4LOW. As hearing the noise first time with hubs locked and 4High set driving on a wet meadow, letting the car roll, I've set back to 2WD and do the samt test.

That's on the video:
Accelerating straigt on pavement with hubs locked in 2WD mode. Letting the car roll out. While rolling, you hear this noise. It seems to com from the front axle or propeller shaft...not easy to locate...but sure, sounds like straight-cut gears. Similar noise as driving in rear-gear with my CJ7 and let the car roll with pressed clutch pedal.

When unlocking the hubs, the noise isn't there anymore.

Gary Lewis

Re: Restore of my 1986 Bronco XLT

Administrator

I think Gacknar's procedure should work well.

But I disagree about the idle speed for a non-302 being higher. I don't see any need for the idle speed on your engine to be above 650ish once the engine is warmed up since you have a fairly stock cam. I would set the RPM where the engine idles well and smoothly, with the IAC just picking the speed up a bit, like the 40 RPM suggested.

As for the sound, I don't hear anything that sounds like bearings or u-joints. It all sounds like gears. I don't think I've listened to the noises Big Blue makes in 4Hi as I rarely use it in that mode. If I'm going into 4wd I usually go into 4Lo. So it is possible it makes that noise in 4Hi as well. But it doesn't make that noise in 2wd, even with the hubs locked.

So I'm confused. Have you checked that your front differential has lube? Have you lubed the u-joints on the front driveshaft?

Gary, AKA "Gary fellow": Profile

ReneH

Re: Restore of my 1986 Bronco XLT

Ok, I've checked the idle rpm. As first written, 700-720 ist best without IAC connected. If I go too low about 600 and change from parking to drive, the engine is starving... so I've set it as written upon.

I've also adjusted my TPS sensor from .85 to 0.889. Can't get more without working on the screw holes...maximum is now 4.445 volts.

About the differential: I haven't checked...in my opinion this is a relative plausible cause...maybe the former owner never used the 4WD and hasn't serviced the differential and the u-joints.

Gary Lewis

Re: Restore of my 1986 Bronco XLT

Administrator

I'm confused. You should set the idle to something like 600 with the IAC disconnected and the transmission in Park or Neutral. Then when the IAC is connected it should bring it up to about 650. And then when the transmission goes in gear the EEC will bring the idle back to 650 via the IAC.

Is that not working?

Gary, AKA "Gary fellow": Profile

ReneH

Re: Restore of my 1986 Bronco XLT

No, when changing from parking to reverse or drive the rpm gets lower. Cause of the torque converter? It's normal, as far as I know...

Before lowering the idle, it was ok when the transmission goes into gear, but too high when in parking. Now both transmission positions are ok and the car isn't shaking anymore.

Gary Lewis

Re: Restore of my 1986 Bronco XLT

Administrator

The EEC should bring the idle back up to the set point when you put the vehicle in gear. And yes, the torque converter is loading the engine then. But the computer should compensate.

So, you are ok with what you have? It isn't shaking and you like the idle RPM? If so then I'd say that is success.

Gary, AKA "Gary fellow": Profile

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