back fire and sway problems

[knechtj]

i have 2 problems. #1 once my 68 bronco is warmed up for it starts back firing a lot and was wondering if a cracked manifold could be one of the causes. #2 once i get up to about 45 mph i have a hard time keeping the bronco steady...does anyone have suggestions on fixing these issues...i'm new to the whole mechanics stuff but i really want to learn how to fix this up myself.

 

[Seabronc]

I doubt that a cracked manifold would make it backfire, that is usually due to timing problems. Depending on the size of the crack, a lot of noise could come from the area of the crack.

Apparently it doesn't backfire too bad since you can drive it. By not steady, I assume that you mean the steering feels loose? If that is the case, there could be several possible causes, steering box, steering linkage, ball joints, etc.

Good luck,

>-

 

[Bully Bob]

Put front up on stands & start checking all steer. components. Wiggle wheels side to side & up & down. Insp all linkage incl. the track bar for looseness. Insp. the radius arm bushings.

Better you find the problems THAN "they" find you .... in a ditch, or worse. @-)

Backfire could be timing, timing chain, bad points , bad valve, etc.

Welcome to board....could give a bit more info. ....lots of diff. yrs. & engines in these rigs. P/S or manual...? :huh:

 

[STLKIKN]

Copied from an older post... I hope this helps you out..

" sloppy " steering can be caused by a multitude of problems...

some are cheap fixes, some can become costly...

what condition are the radius arm bushings in

are all four "c" bushings in place

if you have a two or three piece steering shaft, what condition are the joints in

drag link end and tie rod end play

ball joint condition

wheel bearing adjustment

track bar bushing condition

toe in adjustment

tire pressures

tire condition

steering stabilizer condition

loose steering box to frame bolts ( quite common on EB's with larger tires)

is the sector shaft in the steering box "jumping" up and down...

These items will require two people to check,

the tie rod ,drag link,sector shaft,and all bushings can be checked by having a friend sit in the truck and "wiggle" the steering wheel back and forth about 1/2" each direction, carefully watch each joint or bushing and look for play at each piece, for the steering box to move on the frame, or for the sector shaft to "jump" up and down ( the sector is the piece of the steering box that the pitman arm bolts onto.)

The ball joints and wheel bearings can be checked by jacking under the diff until there is a couple of inches under the tire,( use a jack stand to support the truck) grab the tire at 12 and 6, feel for top to bottom movement ( in and out) at the places you've grabbed. If you can't feel movement, the wheel bearings are ok.

Have a friend do this so you can watch the ball joints... do the same top/bottom "wiggle":

movement in the ball joints indicates wear.

Get a two or three foot lever ( steel bar works well) put it under the tire ( make sure the truck is still secure on the jack stand) gently lift the bar while watching the ball joints for movement, allow the tire to drop all the way between lifts,

up/ down movement in the ball joints indicates wear.

Toe in can be checked by measuring the difference between the centre of the tread on the front and back of the tires across the truck. Measure the tires at the same level to get an accurate measurement. The difference is your "toe-in".

Depending on your tire size, this should be anywhere from 1/8 inch to 1/4 inch.

To check your steering stabilizer, simply unbolt one end of it, see if it extends and collapses using the same amount of force each way. It should have a steady resistance all the way through its travel in either direction, without being harder one way or the other.

One other item to check while your truck is in the air is the axle u-joint, lock the hub, turn the steering to full lock ( either direction) and turn the tire. If you feel a tight spot as the wheel turns, make note of where the grease zerk is, if during the next rotation, the same resistance is felt at the same point in rotation, you have a bad axle u-joint. If you change an axle u-joint DON'T forget to grease the spindle bearings!!!

 

[fbrown3]

I was always told if it backfires thru the carb, its timing and if its out the exhaust its a burnt valve. so ive been told

 

[mtkawboy]

I was always told if it backfires thru the carb, its timing  and if its out the exhaust its a burnt valve. so ive been told

22813[/snapback]

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A cracked manifold will cause a backfire when you let off the gas. All the above suspension stuff is correct except a 68 if its original has kingpin bearings, not ball joints. Jack it up and see if you can wobble it up & down holding the tire at the top and bottom. They are lubed from the factory with no way to **** again so if they are original they are probably bad. If they are its a real crappy job replacing them. First thing I would check would be track bar bushings. Have someone sit in it and steer it back and forth while you watch the bushings for slop. They are simple to change

 

[Broncoholics]

If you have a lift you might need a drop trac bar and drop pitman arm.

Tires could be out of ballance too. Trac bar bushings do not last long and need to be replaced every so often like stated above. If they are bad you will see the front end move back and worth while stopped and turning the steering wheel back and forth. Get under there and look at the bushings, tie-rods and ball joints. You will see what it is. Other wise check the wheel bearings.