Vibration

[JMRINS]

I know there has been a ton of talk about vibraiton, but I can't match mine. My FJ62 has a ton of vibration @ 45+ when decelarating. Once I step on the gas, vibration stops. Ujoints? Any ideas? Thanks again for the help on a worn out subject!

[mjed0708]

I had the same problem. Fxed it by replacing the rear end with used one with less miles from cruiserparts.net. I also changed the U jounts. I think my problem came from running too large of tires (35 inch BFGs) in a stock rear end. Now I have smalles gas saving tires and no problems.

[lehiguy]

Originally Posted by JMRINS

I know there has been a ton of talk about vibraiton, but I can't match mine. My FJ62 has a ton of vibration @ 45+ when decelarating. Once I step on the gas, vibration stops. Ujoints? Any ideas? Thanks again for the help on a worn out subject!

You didn't say what modifications you have done. It sounds like you might have an angle issue. Have you recently rebuilt the driveline and, perhaps, misaligned the slip yoke when you reassembled it? Are the U joints absolutely tight? After market U joints have let me down many times, they don't fit tightly.

[JMRINS]

Everything is stock. The trans has been rebuilt. I have a guy looking at it right now, but the driveshaft and U bolts are snug. I just don't get it. If we can't find anything, I'll rebuild the rear and go from there! Thanks for the help

[lehiguy]

Originally Posted by JMRINS

Everything is stock. The trans has been rebuilt. I have a guy looking at it right now, but the driveshaft and U bolts are snug. I just don't get it. If we can't find anything, I'll rebuild the rear and go from there! Thanks for the help

Don't go rebuilding an axle to try to eliminate a vibration unless the the axle shows signs of a problem. Have you had the driveline taken to a reputable shop for a balance? Never in my life have a traced a vibration to an axle problem.

[JMRINS]

I'll try that first then. They guy I bought it from said it's done it for years. W/O any mods, I just can't figure out why it would be out of line. Is this something that can happen over time through normal wear and tear? Thanks again for all the advise

[lehiguy]

Originally Posted by JMRINS

I'll try that first then. They guy I bought it from said it's done it for years. W/O any mods, I just can't figure out why it would be out of line. Is this something that can happen over time through normal wear and tear? Thanks again for all the advise

U joints wear as does the slip yoke. A good driveline shop can give it a clean bill of health. There is the possibility that it's something else like a bent wheel. Driveline vibes are very high frequency. They make coins in the console dance and your keys buzz like an electric razor. Things originating from a wheel (the wheel itself or a tire) are about 1/4 the frequency. I have had poor luck with after market U joints. They don't fit well and the trunion walks back and forth in the bearing caps. Ultimately, after almost 300,000 miles I had to replace the entire thing. I had a driveline shop make one out of Spicer parts so it would be easy to get replacement stuff as I needed it.