Diagnosing Driveline Problems

[grumpyvette]

http://www.differentials.com/diagnose.html

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Tech Information
Diagnosing Driveline Problems
Diagnosing Noise

Whirring noise only while decelerating at any or all speeds is most likely caused by bad pinion bearings or loose pinion bearing preload, and almost never by bad ring and pinion gears.

A howl or whine during acceleration over a small or large speed range is usually caused by worn ring and pinion gears or improper gear set up.

Rumbling or whirring at speeds over about 20 mph can be caused by worn carrier bearings. The noise may change while turning.

Regular clunking every few feet may indicate broken ring or pinion gears.

Banging or clunking only on corners can be caused by broken spider gears, lack of sufficient positraction lubrication, or worn positraction clutches.

Rumble while turning may indicate bad wheel bearings.

A steady vibration that increases with the vehicle’s speed can be caused by worn u-joints or an out of balance driveshaft.

Clunking only when starting to move or getting on and off the gas might be loose yokes, bad u-joints or worn transfer case or transmission parts "



does that info help?

viewtopic.php?f=45&t=273

http://www.iedls.com/Driveshafts/Measur ... shafts.asp

viewtopic.php?f=45&t=757

Ive busted, and seen other guys bust so many 10 bolt rear differentials over the years that I don,t even waste time thinking about them as a performance differential, simply because salvage yards commonly sell DANA 60 and FORD 9" rear differentials at reasonable prices, you might want to spend an afternoon in several of your local u-pull it salvage yards

if your engine has under about 400ft lbs of torque and don,t have a manual trans or slicks you may get by for years, but life expectancy on those 10 bolt axles and gears drops drastically if your get into slicks and hard launches, nothing like shearing an axle on a 3-4 shift to give you religion


http://www.youtube.com/watch?v=d_8SpUXn ... re=related

http://www.youtube.com/watch?v=_Ykg6YiXCpM
of course knowing how to weld helps

http://www.youtube.com/watch?v=vjE-wHsjZ_E&NR=1

 

[grumpyvette]

Enginerd OFFERED THESE TIPS

"Vibrations can be any number of things... so get ready for some hardcore diagnostics. Firstly, determine if it's engine related. Run the engine up past the RPM that this usually occurs at with the car in neutral. Vibration? It's in the engine itself or something related like the flywheel/flexplate, clutch/torque converter, harmonic balancer, etc. No Shakey? Determine if it's in the rest of the drivetrain by playing around with what gear you're in, verses your speed. Depending on what you find, could be driveshaft (very common), transmission (not so common), rear end, tires, etc. Is it strictly speed related, gear making no difference? That points to anything past the transmission. Experiment, look for patterns, take notes. If you find yourself still pulling your hair out, let us know what you found; with more info, we can help you narrow it down further.Could be detonation. If, when it was "repaired," the specs were changed, especially the compression ratio, you could be getting detonation, which most commonly occurs at higher RPM and under load. If the vibration seems to have a somewhat, or very, random frequency, and you hear a rattling, or metallic banging noises (you may not be able to though while accelerating), then that may be it. Throw in a bunch of octane booster and/or high octane gas, and see if it goes away. Your repair man may have put the wrong pistons or made some other change, by mistake, or on purpose (for performance), without you knowing.
Valve float won't usually cause vibrations. And, unless they are damaged, valves shouldn't be floating at so low an RPM. Also, when an engine goes into valve float, it loses power and will not gain much more RPM. And when they do go into float, it permanently damages the springs (which can cause float at a low RPM, but you would have to have this happen at a higher RPM first, then get worse and worse), and will have problems forever after. It can either be a coincidence that the problem manifested itself now (not too likely, but anything is possible), or that something related to it is causing it. Something has probably been damaged from the lack of lubrication; a failed bearing, wrist pin, or something like that. Only flushing the motor out after an introduction of something foreign (whether water, metal partials, etc.) is a gamble, and I hate say it, but it sounds like you got a bad hand. Water in the oil can do a lot of damage in a short amount of time. I think it's time to pull the motor and go for a rebuild, but do some more testing and checking to be sure, as it's hard to give definitive diagnostics through a forum. As I said, it may be just coincidence that it started now, so check things like the balancer. You say it's stock, so it shouldn't be externally balanced, but if the balancer separated, or one of the accessories or the flexplate (check the bolts) is damaged, that can do it too. Good luck, and update us."



Enginerd
has given you good advise,
taking it a step at a time makes sense, but ID also start with the basics here and have you do a compression test and ask you to post clear pictures of each of your spark plugs numbered as to the cylinder they came from as a ] great deal can be learned from the compression test and the plug condition ID also suggest a tune up and CAREFULLY verifying the firing order and timing advance curve, and checking the fuses , and use a noid light to check injectors


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http://forum.grumpysperformance.com/viewtopic.php?f=44&t=6669&p=21699&hilit=tracking+noise#p21699

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