DRIVE TRAIN VIBRATION

My 88TC auto tranny has a vibration, starts
at 75-80 mph. I've had tires/wheels balanced so I'm guessing it's between tranny and axle.
I've only driven this car about 3000 miles since I bought it in July.(currently has 61,000 miles) The tranny was jumping in and out of O.D. when climbing a hill or under a load which I now know is typical of these autos. I had new fluid/filter put in and that
has done away with the jumping I/O of O.D. I need suggestions how to trouble shoot this.
Hopefully one of you guys has had this problem. I can't push past 80 mph w/o
my butt getting a massage.( i can hear the jokes now) Could there be something else in the tranny that could cause this. It's got me worried. I'm seeing big dollar signs.

Driveshaft ?

Could be off 180* as they are balanced...

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Dan Eaves
88TC 5spd, Crower 5.5" Sportsman Rods, Short Wiseco Pistons bored .030" Over, Ported Head with Polished Combustion Chambers, Gutted & Polished Upper, Ported & Polished Lower, Polished T/B, Ported E6, SVO T3 .63AR Turbo, Bosch Bypass Valve, 3" DP w/No Cat, 2 1/2" DynoMax single cat back w/DynoMax Super Turbo Muffler, RR Cam, K&N in Fenderwell, Gillis Boost Valve, Centerforce I Clutch, Removed A/C, Polished Wheels, Polished Valve Cover, Polished Crank and W/P Pulleys, Walbro 255LPH HP Pump, Kirban Adj FPR, and the DAMN Heater Core is new too !

http://www.geocities.com/wot_turbo/WOT.html

NATO MEMBER (Vice Chairman...if it's a vice...I deal with it)

Had the same problem with mine when i purchased it. Spent some time trying to troubleshoot it and finally tracked it to the driveshaft. I couldnt see where any weights had fallen of but it smoothed out nice after it was balanced.

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oldone
88 Maroon TC 5 speed
K&N Filter
Gillis boost valve

I had this problem once, same thing as the other guys...it was the drive shaft, only it wasn't out of balance, the bolts had loosened on their own! I could turn them with my fingers, I just put some locktite on them and tightened them really good. No more vibration.

Kev

Originally posted by oldone:
Had the same problem with mine when i purchased it. Spent some time trying to troubleshoot it and finally tracked it to the driveshaft. I couldnt see where any weights had fallen of but it smoothed out nice after it was balanced.

Had the same problem after I did the 5 speed swap. Had gotten my DS from a jy. $45 balancing and it's like new.

Could be a bad bushing in the tailshaft of your tranny. That is my problem.

Originally posted by Kev:
I had this problem once, same thing as the other guys...it was the drive shaft, only it wasn't out of balance, the bolts had loosened on their own! I could turn them with my fingers, I just put some locktite on them and tightened them really good. No more vibration.

Kev

Yup, pretty common problem on RWD Fords with the 7.5 and 8.8 rears. For some reason the bolts that attach the DS to the companion flange on the dif like to loosen up on their own.



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Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 20 psi, forced air intercooler, water injection, bypass valve, Ranger roller cam, subframes, etc., etc.. // 86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP nitrous, ignition, gears, suspension, etc., etc.... // 91 Escort: Bone stock winter car // 00 Windstar (wifes vehicle)