dancer52 Posted June 14, 2012 Report Share Posted June 14, 2012 I had a driveshaft built by fast shaft....(actually 3 of them) all the had a very bad vibration ...These are brand new...new u joints...all new....I have sent it back 2 times (once in pieces)....they have built me new ones....same problem.... I have an old driveshaft I cut down....not balanced....heck not even straight....no vibration. So....what the heck could make a new driveshaft vibrate so bad it makes my in car camera blurred? I have even tried replacing the new u joints....I am at a loss...and at this point...I just want to know why...I am having a new driveshaft made by another company....but...would like to learn the real problem....anyone? Link to comment Share on other sites More sharing options...
Wayne Walker Posted June 14, 2012 Report Share Posted June 14, 2012 Check the tail shaft to make sure it's far enough in the tranny. Also, do the rear u-joints fit the yoke correctly? If it is not in correctly then it will vibrate. Check the pinion for looseness. Link to comment Share on other sites More sharing options...
dancer52 Posted June 14, 2012 Author Report Share Posted June 14, 2012 its the right u joints....the driveshaft is the same length as my homemade one...I have ran 3 different trannys...and 2 different gears during this ordeal....nothing makes any difference Link to comment Share on other sites More sharing options...
4cylfordz Posted June 14, 2012 Report Share Posted June 14, 2012 try putting the rearend on jackstands and set a third stand next to the driveshaft ( just as a referance point) and roll the rearend by hand and watch the driveshaft and stand for runout.... redneck balancing:). also feel for any binding in the u-joints. Sounds like either it's welded off center (bent) or the welded yokes are out of phase. Link to comment Share on other sites More sharing options...
Ford27 Posted June 14, 2012 Report Share Posted June 14, 2012 Have you verified its not in the flywheel or clutch. Your bad out of balance driveshaft might be just right for your out of balance clutch/flywheel. Link to comment Share on other sites More sharing options...
abrungot Posted June 14, 2012 Report Share Posted June 14, 2012 I went thru this 3 yrs ago... 3 drive shafts, 4 or 5 Tail Shaft bushings, 2 broken tranny cases, 4 different places balancing them. Finally took the same driveshaft that had a vibration, and changed the Front Yoke to one of my old ones. didn't even rebalance it.. and the vibration was gone.. Don't ask me why.. but it was in the Yoke.. (all 3 of them New except the 1 old one.) Link to comment Share on other sites More sharing options...
dancer52 Posted June 14, 2012 Author Report Share Posted June 14, 2012 Aaron....I will try that....I have a feeling they did re-use the yoke... Link to comment Share on other sites More sharing options...
dancer52 Posted June 15, 2012 Author Report Share Posted June 15, 2012 well...I was going to try and re-create the problem on jack stands....so i could see if changing the yoke helped....well...been on vacation for two weeks...so car has not been started in a while....tried to start....it spun over once and made a bad grinding sound....found starter broke in half....changed starter....new starter would not even spin motor over...well...pulled the plugs....found water in two cylinders....guess a bad driveshaft is not my biggest problem now...lol But...thanks for everyones help....this vibration has been thru more than one motor...one clutch...different trannys....and like I said...is not there with a different driveshaft....I hope Aaron is right and its the yoke...I will sure feel better....now time to pull the heads and see what went wrong....dang it.... Link to comment Share on other sites More sharing options...
railer Posted June 19, 2012 Report Share Posted June 19, 2012 well...I was going to try and re-create the problem on jack stands....so i could see if changing the yoke helped....well...been on vacation for two weeks...so car has not been started in a while....tried to start....it spun over once and made a bad grinding sound....found starter broke in half....changed starter....new starter would not even spin motor over...well...pulled the plugs....found water in two cylinders....guess a bad driveshaft is not my biggest problem now...lol But...thanks for everyones help....this vibration has been thru more than one motor...one clutch...different trannys....and like I said...is not there with a different driveshaft....I hope Aaron is right and its the yoke...I will sure feel better....now time to pull the heads and see what went wrong....dang it.... check if its phase with each yoke, like a split drive shaft Link to comment Share on other sites More sharing options...
walt Posted July 3, 2012 Report Share Posted July 3, 2012 I had a driveshaft built by fast shaft....(actually 3 of them) all the had a very bad vibration ...These are brand new...new u joints...all new....I have sent it back 2 times (once in pieces)....they have built me new ones....same problem.... I have an old driveshaft I cut down....not balanced....heck not even straight....no vibration. So....what the heck could make a new driveshaft vibrate so bad it makes my in car camera blurred? I have even tried replacing the new u joints....I am at a loss...and at this point...I just want to know why...I am having a new driveshaft made by another company....but...would like to learn the real problem....anyone? I would guess they have a rookie building them or the balncer is out of sink. Link to comment Share on other sites More sharing options...
walt Posted July 3, 2012 Report Share Posted July 3, 2012 well...I was going to try and re-create the problem on jack stands....so i could see if changing the yoke helped....well...been on vacation for two weeks...so car has not been started in a while....tried to start....it spun over once and made a bad grinding sound....found starter broke in half....changed starter....new starter would not even spin motor over...well...pulled the plugs....found water in two cylinders....guess a bad driveshaft is not my biggest problem now...lol But...thanks for everyones help....this vibration has been thru more than one motor...one clutch...different trannys....and like I said...is not there with a different driveshaft....I hope Aaron is right and its the yoke...I will sure feel better....now time to pull the heads and see what went wrong....dang it.... AJ spend some money and buy some multi layer head gaskets ,, re useable and worth there wieght in gold they are about 135.00 bucks a set ,, Link to comment Share on other sites More sharing options...
dancer52 Posted July 3, 2012 Author Report Share Posted July 3, 2012 well...I was going to try and re-create the problem on jack stands....so i could see if changing the yoke helped....well...been on vacation for two weeks...so car has not been started in a while....tried to start....it spun over once and made a bad grinding sound....found starter broke in half....changed starter....new starter would not even spin motor over...well...pulled the plugs....found water in two cylinders....guess a bad driveshaft is not my biggest problem now...lol But...thanks for everyones help....this vibration has been thru more than one motor...one clutch...different trannys....and like I said...is not there with a different driveshaft....I hope Aaron is right and its the yoke...I will sure feel better....now time to pull the heads and see what went wrong....dang it.... AJ spend some money and buy some multi layer head gaskets ,, re useable and worth there wieght in gold they are about 135.00 bucks a set ,, I wish this was it...heads are cracked... I plan to test the driveshaft at practice in edna....hope replacing the yoke worked Link to comment Share on other sites More sharing options...
jwmbishop Posted July 3, 2012 Report Share Posted July 3, 2012 Keep in mind - the ONLY thing that cracks heads is heat. Too much heat overall, too fast a change in heat or heat too concentrated in one spot. Identify and solve that heat issue! Link to comment Share on other sites More sharing options...
JohnnyT66 Posted July 4, 2012 Report Share Posted July 4, 2012 Keep in mind - the ONLY thing that cracks heads is heat. Too much heat overall, too fast a change in heat or heat too concentrated in one spot. Identify and solve that heat issue! If heat is the only thing that will cracks heads, Why did mine crack in winter, while car was sitting out side....Dont really need the answer,just disagree with your answer.......frank t Link to comment Share on other sites More sharing options...
dancer52 Posted July 5, 2012 Author Report Share Posted July 5, 2012 These heads were cracked last year....got water in the cylinder last year...changed heads..no problem....sent the heads to machine shop (cause i didnt see anything wrong) he checked them out...said all is good, then charged me alot to rebuild them....put them back on...water in the cylinder... I am still just assuming their cracked...I see small lines in the chamber that look like cracks...but i can rub them off...so I am guessing there small cracks that open up under heat and pressure... Link to comment Share on other sites More sharing options...
jwmbishop Posted July 6, 2012 Report Share Posted July 6, 2012 Keep in mind - the ONLY thing that cracks heads - is heat. Too much heat overall, too fast a change in heat such as the negative change of freezing , or heat Or lack thereof due to freezing too concentrated in one spot. Identify and solve that heat issue! If heat is the only thing that will cracks heads, Why did mine crack in winter, while car was sitting out side....Dont really need the answer,just disagree with your answer.......frank t Good point. Fixed that. But still must be solved. lmao Link to comment Share on other sites More sharing options...
jwmbishop Posted July 6, 2012 Report Share Posted July 6, 2012 These heads were cracked last year....got water in the cylinder last year...changed heads..no problem....sent the heads to machine shop (cause i didnt see anything wrong) he checked them out...said all is good, then charged me alot to rebuild them....put them back on...water in the cylinder... I am still just assuming their cracked...I see small lines in the chamber that look like cracks...but i can rub them off...so I am guessing there small cracks that open up under heat and pressure... they are either cracked or not. Have them magnafluxed AND pressure tested. If they have seat inserts its possible the cut for the insert was too deep or too big a diameter insert - the exhaust seats are real close to the water jacket! Link to comment Share on other sites More sharing options...
HiTech Posted July 6, 2012 Report Share Posted July 6, 2012 Had a head crack in the intake valve guild ..took for ever to find it ...found when i pressured it up and let it set over night /that is how long it took to bleed down ..went ahead and ran the motor up to temp .pressured tested again ...took less that one hour to bleed off ....looked at all the intake valves and found some rust lines on the stem of one valve ...this motor never got hot . a motor does not have to run hot to crack a head ..my 01 jeep cracked and never ran hot .but filled the pan up with water ...seemed a problem with that year casting . Link to comment Share on other sites More sharing options...
4cylfordz Posted July 7, 2012 Report Share Posted July 7, 2012 the 4.0 is a head cracker, one of the few I've ever seen crack on the rocker side. always mag both sides of them. on your heads make sure they havent been milled so much that the water passages next to the spark plugs haven't been uncovered, it's common practice to plug them before resurfacing anymore than .020 as they can extend past the fire ring and cause leaks. casting #624 cracks everywhere. # 882 and 993 will crack across the exhaust though often cracks in the #2 or 5 cylinder hole around the outside of the exhaust valve towards the middle of the head, it's usually a large crack and can be overlooked because its nowhere near the valves and looks like casting error though usually ya can see it by eye. as others said when in doubt pressure test it (with the valves removed) as that will answer all your questions. a sunk valve usually a good sign of an angry crack. Link to comment Share on other sites More sharing options...
HiTech Posted July 9, 2012 Report Share Posted July 9, 2012 dancer you get it fixed Link to comment Share on other sites More sharing options...
dancer52 Posted July 9, 2012 Author Report Share Posted July 9, 2012 motor yes (went with different heads)....will find out on fastshaft driveshaft friday.... but...my new driveshaft (scottys) worked perfect....now i hope my 500$ anchor works.... Link to comment Share on other sites More sharing options...
HiTech Posted July 9, 2012 Report Share Posted July 9, 2012 motor yes (went with different heads)....will find out on fastshaft driveshaft friday.... but...my new driveshaft (scottys) worked perfect....now i hope my 500$ anchor works.... good deal good luck.......if your $500 anchor wont work ..send it back and give me the money .it wont go to waste . though that wont fix your problem .it will make me happy . Link to comment Share on other sites More sharing options...
flyingaces Posted July 12, 2012 Report Share Posted July 12, 2012 I had the same problem, chased it for awhile. changed the rear yoke on the rear end and it solved the problem. I blew a engine that wiped out the tranny, bent the scatter shield, and driveshaft. didn't realize the energy traved that far back to bend the yoke. Link to comment Share on other sites More sharing options...
dancer52 Posted July 12, 2012 Author Report Share Posted July 12, 2012 I had the same problem, chased it for awhile. changed the rear yoke on the rear end and it solved the problem. I blew a engine that wiped out the tranny, bent the scatter shield, and driveshaft. didn't realize the energy traved that far back to bend the yoke. have had this on 3 different gears (all with their own yoke) hope it was just the driveshaft yoke...but with practice rained out....I probably wont chance it this weekend... Link to comment Share on other sites More sharing options...
dancer52 Posted July 29, 2012 Author Report Share Posted July 29, 2012 OK....Aaron was right...thanks alot.....changed the yoke...driveshaft worked perfect....you are now offically more qualified than anyone at fast shafts..... Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.