Vibration - could it be T5 tranny?

Mustang_289 · 11-04-2003, 10:27 AM

We've got a vibration in our 88GT 5-speed. Only vibrates when it's in gear at higher rpms. Recently started acting up, could it be the original T5 starting to munch out? Any ideas on what we can check to find the vib?

Here's a list of what we've installed in the car:

Drive Train:
King Cobra clutch - brand new
Pro-5 shifter
machined fly wheel
aluminium drive shaft
3.73s
Eaton Posi
31-spline axles

Engine:
ZEX 100shot gas
under drive pullies
MAC longtube headers
stewart high-flow water pump
Fluidyne radiator
140amp alt
X303 cam(recent install)
Typooon intake(recent install)

crazypete · 11-04-2003, 01:49 PM

On my T-5, it was caused by the driveshaft pinion flange bolts backing off just a bit. Check those. I see you already have the aluminum driveshaft cause the stock one is a big suspect.

Check the harmonic balancer if it also vibrates in neutral.

In general, when any transmission/gear related item is "going" then you will hear shrieks and whines. I love it! When my T-5 went, the input shaft retainer broke and the car sounded like it was in reverse through all gears and it built to a loud hiss. People thought I had a turbo!

Fox Body · 11-04-2003, 03:41 PM

crazypete, that's funny about people thinking you had a turbo.

Mustang_289, once again looking at the harmonic balance, what kind do you have on there. I would check that first as that would be my biggest (most important) concern. Make sure the rubber is in good condition and it spins true.

When you say "vibration in gear at higher rpms" what exactly do you mean? Do you mean something like "in 4rth at 5000 rpm"? When you say "vibration" do you mean like Major vibration or more than you expected would be there? Do you mean it's vibrating througout the whole car or just a vibration you're feeling through tthe shifter? I just like to mention and search the easy and perhaps overlooked (but obvious) things first. For example, you will feel more vibration with the race short throw shifter than the stock due to the lack of all the rubber bushings and sound deadeners that are in the stock shifters. A little to moderate vibration in the shifter at say, yellow line rpms isn't abnormal in many cases. Also, as mentioned b4 you already have a new Al drive shaft (and new rear diff??).

BTW, how are you liking the Typhoon intake???

Coupe50h · 11-04-2003, 04:35 PM

lol, crazy pete, my clustershaft broke some teeth in my old t-5, everyone thought i had a blower

i drove it around a long time like that.

Man, make sure all your bellhousing bolts and fasteners are tight, i cant stress that enough.
also like mentioned, the harmonic balancer and u-joints need to be checked.

Mustang_289 · 11-08-2003, 01:39 PM

the harmonic balancer is a ford oe replacement. it is about 4 or 5 months old. when i put it on it was working fine no vibrations or anything. the car only vibrates in gear. if i put it in neutral and rev there is no vibration. so it is something from the flywheel back. i know that for sure. the transmission does not whine or anything like that. vibration is bad 2k rpms and up.

11-04-2003, 10:27 AM	#1
Mustang_289 Registered Member Join Date: Sep 2001 Posts: 512	Vibration - could it be T5 tranny? We've got a vibration in our 88GT 5-speed. Only vibrates when it's in gear at higher rpms. Recently started acting up, could it be the original T5 starting to munch out? Any ideas on what we can check to find the vib? Here's a list of what we've installed in the car: Drive Train: King Cobra clutch - brand new Pro-5 shifter machined fly wheel aluminium drive shaft 3.73s Eaton Posi 31-spline axles Engine: ZEX 100shot gas under drive pullies MAC longtube headers stewart high-flow water pump Fluidyne radiator 140amp alt X303 cam(recent install) Typooon intake(recent install)

11-04-2003, 01:49 PM	#2
crazypete Registered Member Join Date: Sep 2002 Location: Boston Posts: 592	On my T-5, it was caused by the driveshaft pinion flange bolts backing off just a bit. Check those. I see you already have the aluminum driveshaft cause the stock one is a big suspect. Check the harmonic balancer if it also vibrates in neutral. In general, when any transmission/gear related item is "going" then you will hear shrieks and whines. I love it! When my T-5 went, the input shaft retainer broke and the car sounded like it was in reverse through all gears and it built to a loud hiss. People thought I had a turbo! __________________ 91 GT Carb conversion, holley 600 double pumper, edelbrock performer intake, FMS "C" drop springs, march 1000 underdrive pullies, crane 1.7 roller rockers, GT-40P headers, bassani x pipe, american thunder catback, FMS 4.56's, msd aL6, trunkmount battery, A/C eliminator kit, 3000 stall tci streetfighter, AOD with transgo kit, A+ servo, 300M hardened lockup shaft, kevlar bands and 28,000 gvw trans cooler, 3 core radiator, 300 lbs stripped with a full interior

11-04-2003, 03:41 PM	#3
Fox Body Mustang Maniac Join Date: Sep 2000 Location: GA, U.S.A Posts: 2,266	crazypete, that's funny about people thinking you had a turbo. Mustang_289, once again looking at the harmonic balance, what kind do you have on there. I would check that first as that would be my biggest (most important) concern. Make sure the rubber is in good condition and it spins true. When you say "vibration in gear at higher rpms" what exactly do you mean? Do you mean something like "in 4rth at 5000 rpm"? When you say "vibration" do you mean like Major vibration or more than you expected would be there? Do you mean it's vibrating througout the whole car or just a vibration you're feeling through tthe shifter? I just like to mention and search the easy and perhaps overlooked (but obvious) things first. For example, you will feel more vibration with the race short throw shifter than the stock due to the lack of all the rubber bushings and sound deadeners that are in the stock shifters. A little to moderate vibration in the shifter at say, yellow line rpms isn't abnormal in many cases. Also, as mentioned b4 you already have a new Al drive shaft (and new rear diff??). BTW, how are you liking the Typhoon intake??? __________________ 351W-powered 1979 Ford Mustang Ghia notchback '79 Video @ Idle Stock 5.8L under 4" cowl 'glass hood, C4 w/ Transgo shift kit, Holley 750 cfm, Edelbrock Performer RPM intake; Fluidyne Al radiator, Flexalite 175 electric fan, 1 5/8" MAC shorty headers, FRPP Al driveshaft; S&W 6-point cage; 2.5" Off road H-pipe, 2-chamber Flowmasters, 8.8" Rear w/ 3.55s; Weld wheels (15x6;15x8), Front: 225/60/15, Rear: 275/50/15 Nitto NT 555R Drag Radials; 14 x 4” K&N X-stream air filter. '92 GT (5-speed) Small In Car Video Stock 5.0L, 2-chamber Flowmasters, MAC CAI, Tri-Ax, Al pedals... "Red, thou art my companion. Hasten now your quickened metamorphosis to Green that I may conquer all who dare abide there beside me. May they be left thither behind burnt black." ---Fox Body Last edited by Fox Body; 11-04-2003 at 05:37 PM..

11-04-2003, 04:35 PM	#4
Coupe50h Registered Member Join Date: Aug 2002 Location: SanAntonio, Tx Posts: 957	lol, crazy pete, my clustershaft broke some teeth in my old t-5, everyone thought i had a blower i drove it around a long time like that. Man, make sure all your bellhousing bolts and fasteners are tight, i cant stress that enough. also like mentioned, the harmonic balancer and u-joints need to be checked. __________________ X-Texas highway patrol ssp 1990 coupe - exploder Gt-40 iron heads, Explorer intake, 19 lber's. E-cam. crane 1.7 rollers. 190fp. 75mm maf. 65mm tb, tubular subframe connectors, mac cai, Asp crank pulley, T-5, king cobra clutch, flowtech 1-5/8 unequals, mac X-pipe Frpp driveshaft, lakewood Lca's. race weight 3,160 12.69 @ 107.35, 1.71 60' 26x8.5 drag's 3.90 gear 13.20 @ 106.91 - 235/60/15 firestones 2.3 60' 3.27 gear

11-08-2003, 01:39 PM	#5
Mustang_289 Registered Member Join Date: Sep 2001 Posts: 512	reply the harmonic balancer is a ford oe replacement. it is about 4 or 5 months old. when i put it on it was working fine no vibrations or anything. the car only vibrates in gear. if i put it in neutral and rev there is no vibration. so it is something from the flywheel back. i know that for sure. the transmission does not whine or anything like that. vibration is bad 2k rpms and up.

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