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Discussion Starter · #1 ·
...bang, bang, bang, bang - sounded like it was coming from the right rear. After the corner it was fine. Acceleration down the ramp was incredible - and no banging. I suspected the three link traction bracket was to close to the rim. After the drive I got under and sure enough, the lower edge of the right side bracket and back edge of the rim look like old friends. It has about 3/16" room between the two.

Any others with this problem? Aside from never turning left again, what fixed it?

First driving impressions - Wow! Even in gel coat and seams there is a lot of attention. I will have to get used to that as I do not enjoy the attention thing too much.

I have 120 miles on a rebuilt 5.0L so have not been on it too hard. I was told by the machine shop that did my machine work and supplied rings/pistons etc that it is likely broken in already - and to drive it like I normally would. Thoughts on that?

I have a vibration at 2100 rpm I am trying to track down. It is consistent in any gear, any speed, as long as the engine is at 2100 rpm. My simple thought process rules out rear end and driveshaft. Transmission is rebuilt and the input/output shafts were within spec for runout. New clutch, new billet flywheel, new harmonic balancer, balanced internals. I am wondering if a front accessory pulley could do that? Other than that it runs fantastic. Suggestions?

Thanks,

Geoff
 

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I had a pretty bad vibration that started at about 2000 rpm. Turned out that I didn't put the dowel pins in the flywheel. Pete
 

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The rim and the axle and all associated brackets should stay in static relationship to each other. My 3 link bracket is close but has never touched.
Maybe you have a worn axle at the C-clip or pinion shaft that allows the axle to move in and out?

Modern engines break-in almost immediately. Change the oil at 50 miles and look for metal, then again at 500mi. Now you are ready for the 3,000-5,000 mile or once a year interval.

As for avoiding attention, do what I do avoid eye contact and don't start any conversations.

Michael S.

I had a thought on the bang bang noise, check the driveshaft for contact with the ebrake cable hanger mechanism. The ballance weight makes a horrible noise when hitting things and it does move up and down and slightly side to side.
 

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Discussion Starter · #4 ·
Thanks for the info.

I bought and installed new dowels so I think I am ok there.

The rear end was rebuilt with new c clips. The axles are used though. I thought the C clip was to hold the axle in. Help me think this through. If I corner to the left, the left axle c clip is under pressure to hold the axle in, and the right is forced into the rear end - the center pin would take the pressure from the right no?

As far as the engine, it sounds like I am right on track. Michael, it must be hard for you to avoid attention with that beautiful color.

Thanks,

Geoff
 

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I had 3-link interferenc in th esame location. I took a grinder and rounded the corner. Its fine now, even on the high speed sweepers!
 

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I had the same issue. There is enough flex in the 17" rim that it would touch. I talked with Jesper at FFR on a couple of occasions and he said that the offending bracked is about four times overbuilt for it's purpose and can lose a little meat.

I took a grinder to where it was rubbing, being careful to leave rounded corners to not setup any stress risers for a crack to start in, and then painted it black. That way, when it rubbed again, I would have witness marks to guide further grinding.

Two iterations later, I was done.

-R :D
 

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Geoff,

Sounds like you're on track with the accessory pulley. Run the engine up to 2100 in nuetral and put your hand on the alternator and try and feel where the vibration is coming from. Try remounting the crank pulley 180* and see if it makes any difference.
 

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Discussion Starter · #8 ·
That makes sense. I like the idea of grinding the bracket better than R&R the axles. I will definitely give the brake cable a look - never even thought of that.

My alternator is old and there is abit of play in it - maybe that is it.

Thanks for the great experience/advice.

Geoff
 

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Just a dumb thought, check your lugnuts and studs? The bracket and rim should be static to each other. Also check your panhard and upper link jam-nuts as well as pinion angle. I had a driveshaft bind make that same type of noise.

A
 

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Check to be sure you have the rear end centered in the frame. It can be moved side to side by turning the pan hard bar. If you have this alignment out it can cause part to contact each other. measure each wheel from the same place. I used the upper shock mount to get rear centered.
Could also be e brake cables slapping the u joint.
Drive shaft binding if pinion angle was'nt checked or set.
New wheel studs if installed could not be seated causeing basically a loose wheel. Worth checking.
Pinion angle set,rear centered,"should have no interfernce with wheel and bracket. I also needed to do a small bit of grinding but to clear shock,not wheel.
With car jacked up wheels off ground you should be able to grab each wheel and at most be able to move in or out about 1/8". More then this suspect c clip. Doupt the problem since you would have lost an axle if drum brakes or have a major grinding brake problem if useing disc brakes in rear.
 

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Discussion Starter · #13 ·
Thanks for the comments. I think I found it. It was a wheel weight on the inside of the rear wheel hitting the bracket under cornering. I little bit of rub on the rim after the wheel weight. I massaged the bracket a bit and no problems to speak of...yet. The weights on the back of the rim are the kind that clip on the the rim/bead area. I will have to change them to adhesive type.

Lazer alingment was completed prior to this. Rear was centered and pinion set. New Clips have been installed with the new bearings and friction plates. There is very little play in the axle side to side motion. Also, on that corner the axle the right would be pushing into the rear which I think should be the center pin under pressure.

New Ford dowel pins were installed on the flywheel.

Axles are Ranger/Aerostar with Cobra brakes.

Thanks again for the help and suggestions.

Geoff
 

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Geoff,
I'm not sure which disks the Cobra set up uses but with my T-Bird disks and Aerostar axles the hub on the axle was to big and had to be ground down to allow the hat of the disk to sit flush on the hub. All I had to do was put a 3/32" bevel on the edge of the axle hub for everything to seat properly. Easiest way was to leave the wheel on the opposite side and have a buddy turn it while you bevel it slowly (light pressure) with an angle grinder. Might be worth double checking.

Cheers, Rod
 

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Discussion Starter · #15 ·
I'll check Rod, thanks for the suggestion.

All this flywheel/dowel talk has me thinking. I know I bought a billet steel 157 tooth flywheel for an 89 5.0L. I never double checked it for 50 oz weight. The flywheel came with a scratch, so I had it ground then during my rebuild I had the rotating assembly balanced with the flywheel and harmonic balancer. Would the balancing have picked up if it was a 28 oz vs a 50 oz flywheel? Visually, is there a difference?

What are the symptoms? Aside from a vibration at 2050 rpm to 2100 rpm- the engine runs smooth and pulls hard all the way up to 5500. A wee bit paranoid now.

Thanks again,

Geoff

T
 
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