Where do I start I purchased a real kool 62 F-100 it has a SBC TH350 and the original rear I really lime it , But It is dangerous .both axles are on top of the leaf springs witch makes for a good look but not a good ride I know everyone will say I must undo that , I have seen a few threads here of others that have done the same.Does thier stuff ride as bad??? I can deal with it not so slammed but I gave up 4x4s a while back and would like to have it as low as I can and drive a bit better. I wish I knew more people around my area who could look at what I got and help me come with a reasonable solution I am in the Tarpon Springs area of Florida in case anyone reads this and wants a look I am open to all suggestions.I got new wheels and a disc brake kit today so I will keep busy with that for now.
have you; checked for worn front end parts? adjusted the steering box? had a front end alignment? tires in good shape? tires real wide? have any pictures?
1.Tarpon Springs is in the Tampa Bay area North Pinellas County 2. All tires are new I will be mounting new Rims in the next couple days so they will all be spun balanced 3. Not to big of a whell rear are 255/70 r15 frt is 215/75 r15 4.I have a sorta pulsating in the ass end I figure it is either a bad tire , unbalanced drive shaft or the rear end could be cashed I will be addressing all this and checking all front suspension components rear axle drive shaft and of course 4 balance wheels oh yea and I gues check the steering box as said by last post . 5.Thank you for you replies I will take them to heart and I really wanna work this out and make this truck live up to its potential and not just look the part but be the part......
Might also help to describe what is happening, i.e. is it following cracks in the road, bump steering, when braking, etc.
Bumpsteer but not real bad unless it starts to roller coaster it gets to bouncing up and down bad.I also have som sorta pulsating sound like something is outta balance or about to bust loose . Hope I can get it on a lift this week and give it a good look over and maybee watch it run with the ass end in the air so maybee I can eyeball something outta whack. Posted using the Full Custom H.A.M.B. App!
Out back - Ill bet the pinion angle is jacked up since the lowering as well as the castor off up front. You need level ground to park on and a $10.00 angle finder to check it out.
Aside from your list above,check the alignment. Mine was all over the until I set the toe to 1/8th inch in. A drastic pitman arm angle can be part of it too.
Shocks? Too short or El Cheap-os will factor in. Does it track straight on flat road or wanders regardless?
One thing it does track strait I think the reply about the pinion angle may help out alot can you tell me how to go about checing it and what angle does it need to be set at , it startin to make sense power on and power off is a big difference if I slide into nuetral and coast it is smooth and quiet when I accelerate man it sounds and feels nasty Posted using the Full Custom H.A.M.B. App!
You can't explain "pinion angle" to somebody in just one post. It's not just one angle fits all cars. Do a search here on the HAMB and see if those dozen threads give you the gist. If not, come back and ask again.
So rides bad like in like a lumber wagon or????? If your axles are bangin the chassis then notch the chassis. if you mean squirrely (sorry squirrel) you should check things like bolt tightness, and alignment before you decide to do major surgery. A lot of guys don't get the castor correct when they are moving a front axle to the top of the spring for example, and sometimes it is just a matter of toe in/toe out adjustment. Then it could be king pins bad or needs new shocks, the shocks should be the proper length while you are at it or tie rod ends or wheel bearings. or spring bushings. Moving the axle does not cure worn suspension but it does not cause it either.
Sure somebody can, its Just that everybody else going to want to argue. Bench marks - * Centerline of the transmission output shaft & center line of the pinion angle must be equal, * either parallel or opposite doesn't matter unless (see next bench mark) • the working angle of the ujoints must be within their range The non benchmark details don't really matter as long as those details don't violate the benchmarks.
Okay lets start at the back first and try and quiet up the noises I am hearing then I will move on too the next problem 33 and a third stated a bad bearing with bearing axle or in the third member/pumpkin now will the improper pinion angle make it noisy? Also like I stated at a coast it gets quiet but on acceleration pulsating noise , so this makes me think that axle bearings maybee good and the noise could be from pumpkin area , agin will a bad pinion angle be a noise maker ? What are sighns of bad pinion angle ? Is it like the trans shaft and pinion need to be parrellel to each other but on a different plane. I drew a diagram with what I think shoyld be what is right and wrong I am no artist as you all can see again thanks you guys are all I have to help sort this out
engine was not supposed to look sagging like it came out should be level but I hope I can get my thinking to you all
Now if the trans and rear are inline with each other pointing the front of pumpkin down will give me some pinion angle , correct?
HUH? Thanks I have been wanting to use that smiley. What you are saying is that your drive shaft runs in a straight line from the rear end to the transmission when the pinion angle is set correctly, as in no angle @ the U joint , right? Then yes you want to change the pinion angle ever so slightly just for u joint life. For reasons that I don't completely understand a U joint does not want to work without undulation, it must have some angle to it. At least I read an article a year or so back that explained it that way. Unless you are building a race car where ever ounce of torque is important pinion angle is not an exact science and you should always allow for suspension travel anyway. a degree or two in either direction won't hurt you enough to measure by the seat of the pants. Figure it this way if you want to get it to launch well figure for spring wrap and subtract what is necessary for the pinion angle to be correct when the springs are wrapped.
The centerline of the trans output needs to be parallel to the centerline of the pinion, in all planes. They can (and should) be offset from each other, but they MUST be parallel. The best amount for them to be offset is so the angle at the U-joint is about 3 degrees. Might be 3 up at the front and 3 down at the rear, or vise versa. U-joint scientists say the 3 degrees works the joint sufficiently to move the roller bearings and grease inside them. Too little angle means not enough movement to keep them lubed, and they may start to get brinelled (look that up). Too much more angle means the joint might start binding at some of it's tight spots. A degree or two between friends won't matter too much though. Maybe you need to replace the joints at 30,000 miles instead of 90,000. Use a magnetic angle finder on the yoke of the pinion and then on the end of the trans output shaft. They should both be the same angle, but one positive and one negative.
So just exactly how far closer to the ground did you move the Trans out put shaft by lowering the vehicle? _____ And just exactly how far closer to the ground did you move the pinion by lowering the car down over the rear wheels? __. Zero here . So with the above in mind, look at this & see if you can spot where your problem could be and why. Don't be deceived, Equal angles is a must but they can be parallel, opposite, or zero. On a lowered rig, the pinion is above the Trans yoke 9 out of 10 times and Throwing a kink in the drive line that violates the working angles
31Vick, your "corrected" drawing is wrong. The only correct way to coordinate the U-joints is the first drawing or the second. In both of those the trans and pinions are parallel. Your third drawing does not have parallel centerlines in all planes. If he has lowered the truck so drastically that the rear axle is now above the trans and causes a huge angle at the joints (they don't like that), he may have to raise the tail of the trans and lower the nose of the pinion. But you cannot just do one joint, you need to do equal to both ends of the driveshaft. See what I meant when I said it couldn't be explained in only one post?
I think I know what to look for understand I did none of this work I bought it like this I now need to correct it or DIE in it .....I have contacted a fried who is gonna have me up to his shop an are gonna put it on a alignment table and figure out all that needs to be done he agrees the pinion angle is not right and says that the noise when power on is bad but not on decelleration is a sign of a bad pinion angle and /or pinion bearing, s gone bad also how long will it take for a bad angle to burn up the bearings. Realativly quick or will it take some time I just hope that this has not tore up the rear end I have not even put a hundred miles on it yet since I have had it
I agree that caster is likely the issue with directional stability/wandering. The purpose of caster is to help it track straight and help return the wheels to straight ahead after you make a turn so your don't have to crank the wheel back to straight. Look at a bicycle fork, how it leans back at an angle. If it didn't, the bike would be nearly impossible to balance. Raising the rear or lowering the front has the effect of giving you less caster. If you do either one, you are going to need some wedge shims between the spring and axle to give you back the caster you lost. The same angle finder you use for pinion angle can be used on your beam axle to tell you whether you have enough caster. If the king pins are pretty much straight up and down instead of leaning back a few degrees, that's your problem.
whip out the driveshaft and check the uni joints. failed/seized u j will give you a variance of noise / vibration when on and off throttle
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