Hey guys I just lowered my 64 f100 looks great but now it is giving me a fit.Used mono leafs and flipped the rear axle and when I take it out it shudders in second gear and I hear a horrible grind/screach in 3rd gear.It gets worse the faster I go and when taking corners.I am assuming I set the pinion angle wrong.and its the drive shaft.Im going to cut the welds out and see if I can move the rear end around but im kinda at a loss about how to set it now.Do I set the rear end yoke straight?Or just concern over the angle of the drive shaft?Any help would be greatly appreciated!It is my daily driver and I need it back on the road.Thanks!
check to see if the driveshaft is bottoming out in the transmission/tailshaft. that much lowering may require a shorter driveshaft. you should have 3/4 to 1" between the seal and the yoke
i would say either the driveshaft is too long, like Tinman said, and its trying to push your rear end out, or your driveshaft is rubbing on your floorpan like what happened to me when i lowered my Chevelle.
I went out and checked the trans/driveshaft and there is over an inch between the yoke and driveshaft and it isnt close to hitting anything on the truck.I hope I wouldnt need the drive shaft shortened I read up on the drop on here and have never heard of anyone having to shorten there drive shaft to get it to work on these trucks.Then again I dont know.Thanks for the responces so far.Here is some pics of the rear end/driveshaft if it can help anyone.
I dont know if the pics are deceiving but it only looks like you have at most 2"-3" of suspension travel before your rearend hits the frame...
A "quick temporary fix" would be to use off-set mini-blocks under your axle to locate your axle farther back from the trans on your spring. They sell them for cheap at most 4x4 shops and such. Of course, that's assuming that's the problem. They look like these in the link below... http://www.google.com/imgres?q=offs...6&tbnw=148&start=0&ndsp=28&ved=1t:429,r:2,s:0 If your driveshaft angle is off, you want the pinion angled as close as possible to parallel with the trans output shaft. Maybe someone else that explains it better will chime in. P.S. Don't start cutting unless you're sure...
you should also check to see if the driveshaft is bottoming out internally, pull it out and look and the end of the yoke/splines to see if theres any signs of rubbing or metal shavings. the pinion doesnt look right but without knowing the angle of crankshaft centerline its impossible to guess. in any event pinion angle wont usually cause that kind of noises unless the bearings are in bad shape.
Like Tinman said though, incorrect pinion angle shouldn't cause grinding... However.... It seems from the picture (if the motor is mounted in the stock location on stock height mounts) that the pinion is pointed downward compared to the trans output shaft? Or is it just me? If that's so, then there would be a pretty steep angle on that driveshaft that would need to be corrected by either re-welding the spring perches or using quite large angled perch shims (I don't recommend shims). My brother and I have one of these (1961 F100) but I can't recall if the trans points down or not...
In the pictures it looks like the pinion is pointing kinda downwards. The pinion angle should match the transmisson yoke but pointing upwards not downward. In other words the pinion angle and tranny yoke angle should be parallel. If the trans is pointing 3 degrees down, then the rear yoke should point 3 degrees up. Hope that makes sense.
You need to redo your pinion angle judging from the pics its way off id check your driveshaft for rubbing under the truck jack it up from under the axle so the eight off the truck is on it still and always use jackstands. Also if its a mono leaf you prob get a ton of axle wrap under acceleration could cause the pinion angle to get even worse and driveshaft bind on the rear where the ujoint bolts on look for any signs of shinny metal I assume you think your trans is fine correct?
Pinion angle needs to be level or a few degrees up (up ideally) and the noise is most likely your universal joints have been pulverized.
notice that or it looks as if you didn't change/replace u- joints. that looks like a LOT OF angle on that pinion. could be u-joints makin noise. dried up grease. just a thought.let us know what you find and good luck. you sure the yoke on the drive shaft is not bottoming out on the tail shaft of the tranny? take the drive shaft loose and see if the yoke will slide in the tranny any more at all. i have seen yokes not splined all the way to the end. again good luck
I've got to agree with everyone here and say the pinion angle looks wrong. Pinion angle usually only causes a shudder, not a noise. Had one once that the ujoint grease zerk was rubbing but that noise was cyclical.
Everyone was absolutely correct.The pinion angle was severly wrong. I got under there and ground down my welds and put the rear end parallel.And that fixed it.Took it down the road and didnt miss a beat no grind or screach.Still im going to replace the u-joint bearings asap.Thank You everyone!!And black panther your right I have'nt cut the notchs in the frame yet for the suspension travel.Its my wife and I's anniverary today she isnt to happy im out working on the truck.
Do I see a dark ring inside your left rear tire? Tires rubbing at all on suspension or inner fender parts?
please, dont post any more rear pictures until you take the time to get rid of that plastic covered clothesline wire you have wrapped around what looks like your exhaust. Nothing worse than watching someone spend time getting a vehicle to sit the way they want while they let other things (cheap fixes) languish.
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