Guest Anonymous Posted April 5, 2000 Share Posted April 5, 2000 Help, I have strange vibration in my shifter at 2200 to 2500 RPM, it seems worse under acceleration. I have had two different SBC in the car(a '71 240)and the problem has been the same with both, the current motor is a balanced 415ci stroker motor. The trans is a T-5 and LSD R-200 for rear end. The vibration is only in 4th and 5th gears. It used to happen in the lower gears, but it went away after I changing the transmission and differential mount to reduce the angle between them.(they all are under 4 degrees) I was thinking that it may be my half shalfs, since I have not done any thing with them. Also, it seem that I have no vibration when the car is cold, like first thing in the morning, but the rest of the day it is there. Any suggestions would be appreciated on this problem.... Al Peterson Quote Link to comment Share on other sites More sharing options...
John Scott Posted April 5, 2000 Share Posted April 5, 2000 Al, I don't know if this will help, but I had a similar problem in one of my cars, until a sharp mechanic friend of mine made a suggestion. I used to get the vibration under acceleration and sometimes braking. I found out that one of my u-joints was starting to seize. There was no play in it, but it had lost part of its range of rotation. Only under accel or braking did it reach that point transmitting the vibration. I had to pull the shaft and check the range of motion before I discovered the problem. Your diff. will want to pitch up under power changing the angles. You might also want to tie down your diff. mount, if you haven't already, as recommended in the JTR book. Hope you find the problem. John [This message has been edited by John Scott (edited April 05, 2000).] Quote Link to comment Share on other sites More sharing options...
John Scott Posted April 5, 2000 Share Posted April 5, 2000 Do you have the GTO body?? Like to hear more about your project. Must be a screamer! John [This message has been edited by John Scott (edited April 05, 2000).] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 6, 2000 Share Posted April 6, 2000 V8 GTO, I just noticed a bit of a vibration yesterday too...and it wasn't there before I swapped my R180 for an R200. But mine is not constant...it's like a come and go vibration...It will vibrate, stop, vibrate, stop. I can only feel it when I'm in 5th gear at 70-80MPH...and I feel it throughout the whole car, like in the gas pedal, shifter, rearend, etc. I can be driving at speed and watch the shifter knob, and it will shake and quit, shake and quit??? I changed the rear driveshaft flange when I put the R200 in, so I think that I need to get my driveshaft rebalanced or something. Does anyone have any other suggestions? Lee [This message has been edited by JuJu (edited April 06, 2000).] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 6, 2000 Share Posted April 6, 2000 If I didn't know better...which I dont...I'd say the input shaft bearings in the Diff for the half-shafts were bad. This would cause bad things to happen back there and the vibration would be picked up more at certain RPM's than others. Probably the best way to check would be to drain the oil in the diff and see if there are metal shavings floating around. This would mean the ring gear was floating and losing metal from misallignment with the pinion. I guess it could also be the pinion bearings too so check that out as well. SpencZ MonsterZ cont. http://members.xoom.com/SpencZ/index.htm Quote Link to comment Share on other sites More sharing options...
Guest Locutus Posted April 6, 2000 Share Posted April 6, 2000 What about the driveshaft angles, I have heard that causes vibration at certain speeds as well Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 6, 2000 Share Posted April 6, 2000 Everyone, Thanks, for the input...I think that I'm going to replace the half-shaft U-joints this weekend and I will look at the bearings in the rear-end. I have checked the driveshaft angles and got them down to less than 4 degrees. This did help the vibrations in the lower gears.... Thanks Al Peterson Quote Link to comment Share on other sites More sharing options...
Rob Posted April 11, 2000 Share Posted April 11, 2000 I had a temperature sensitive vibration problem, similar to what you describe, and I replaced the mushy stock Chevy tranny mount with a Energy Suspension brand mount from Summit. It's polyurethane with a feature that keeps the poly under a preload at all times. It did a great job on my vibration problem. It was $21. Worth a try, I would say. Also, I have my diff front mount tied down with cable, wrapped as tight as I could get it. Good luck! Rob Quote Link to comment Share on other sites More sharing options...
Mikelly Posted April 11, 2000 Share Posted April 11, 2000 I use the Aluminum Diff mount sold by MSA. The vibration issue went away for me whenI did the mustach bar mod. I'd do the Ujoints and then recheck yuour pinion angle. I'd also get that Trans mount someone recommended. Nice unit. Mike ------------------ "I will not be a spectator in the sport of life!" mjk Quote Link to comment Share on other sites More sharing options...
Sumo Posted April 11, 2000 Share Posted April 11, 2000 Not that this has anything to do with the Z but my brothers former Crown Victoria did that too. Vibrating only at certain speeds or RPMs. Turns out one of the bearings went bad in the rear end and caused the front U-joint to shake it self apart and disengage from the tranny. Good thing the Y-pipe was right underneath and prevented the drive shaft from planting. Ruined the pipe though and had to put new U-joints on it. Turns out after the rear end was taken apart, all kinds of metal filings fell out and one of the bearing caps was burned severely. Sold that car real quick. So check out the bearings on the rear end, hope it helps. Quote Link to comment Share on other sites More sharing options...
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