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FE Power Forums => FE Technical Forum => Topic started by: lstanford on April 05, 2020, 07:17:54 PM

Title: Crossmember shims and driveline vibration.
Post by: lstanford on April 05, 2020, 07:17:54 PM

I have a 1966 Fairlane GT with a 482 FE and a toploader. I am installing a Gear Vendors Overdrive which will not clear the transmission hump at the rear. I am going to need about 1" to an 1 1/2" to clear the hump. How much trouble am I asking for by changing the drive line angle with shims under the transmission cross member? The car has Calvert Bars and I should be able to shim the 9" axle to get the drive shaft angle correct. Should I just get it over with and cut the floor? This is a pristine no rust ever car.  This project has been dragging on for about four years and I am running out of oxygen.  This is a street car not a drag car (well, maybe occasionally), so I don't want a lot of drive line vibration. Give me the benefit of your experience and it's hard to hurt my feelings. I don't like doing things half a**.

Title: Re: Crossmember shims and driveline vibration.
Post by: jayb on April 05, 2020, 08:51:37 PM

Before cutting the floor, why don't you try to what you are suggesting, drop the crossmember or make a thinner mount, use some angle shims to adjust the pinion angle to match and see what happens?  Easier than cutting the floor, and easier to undo.  I think you may be just fine doing it that way.  The driveline angles might not be perfect, but as long as the trans angle matches up to the pinion angle under load, you should be fine.  You can always cut the floor later if it doesn't work out.

Title: Re: Crossmember shims and driveline vibration.
Post by: 338Raptor on April 05, 2020, 09:42:31 PM

I agree with Jay.
Match the angles and you won’t have a vibration.

Title: Re: Crossmember shims and driveline vibration.
Post by: cjshaker on April 06, 2020, 12:17:20 AM

Changing the crossmember would be my first attempt, but it'll change other stuff as well. It might cause interference with a fan/shroud combo, valve cover/booster clearance, drag link/oil pan, Z bar angle, shifter/console or a number of other things, so make sure it's not just your driveline angle you keep an eye on.

Title: Re: Crossmember shims and driveline vibration.
Post by: 66FAIRLANE on April 06, 2020, 04:23:00 AM

I cut the floor on my Fairlane  :D. I wanted to get the angles as good as I could & mines been cut way harder than that anyway! Link to my install here if it helps.

http://fepower.net/simplemachinesforum/index.php?topic=169.0

Title: Re: Crossmember shims and driveline vibration.
Post by: lstanford on April 06, 2020, 08:53:01 PM

Thanks guys, I appreciate the info. The install article was great even though my car is not an automatic. I guess that I will play with shims and see what I can make work.