[ttm300]

1998 Cobra SVT with TREMEC TKO TRANS.
I bought the car with the TKO in it and it had a SPEC stage 1 clutch that I burned up after 20K miles. I replaced it with a ZOOM HP clutch and a new flywheel (remanufacutred) from AutoZone. Thought it was running ok til i replace the motor mounts with urethane ones and there is a bad vibration at 1000-1800 RPM with the car out of gear or in gear in motion. Also the clutch squeeks when not depressed. I have a Steeda quadrant, cable and adjuster, tightening it up some makes the squeeking go away but i feel like its pulling on the clutch. I thought maybe the flywheel was bad cuz its a crappy autozone one that costed only 57$ after core charge, so i swapped it for another autozone one and the vibration is the same. I have no idea how to tell if the flywheel is the 50oz or 28oz imbalance, I didnt see anything at all on the flywheel. I dont know even if its a 10", 10.5" or 11". ANYBODY WANNA HELP WITH SOME INFO, EVER USED A ZOOM CLUTCH ? Cuz i think they mite suck. I am considering getting the SPEC SF84S steel flywheel and SPEC SF482T Stage 2 clutch (the T is from the tremec trans with 26 spline shaft). That way it will be a matched set. Somebody tell me something.

Jayme "GLADIATOR" McKinney
Pro MMA & Kickboxing HeavyWt
98 Cobra

 

[PencilPro]

I NEVER buy anything from Autozone anymore, I got tired of getting crap!:nono:
I don't know anything about the brand, but I know that going with matched parts is a good idea!:bigthumbsup

 

[ttm300]

Only used autozone cuz they could get it next day and the price was insignificant. Dallasmustang.com was the model SPEC clutch and flywheel I need 80$ less than SPECCLUTCH>COM and free shipping.

 

[2Manystangs]

I think 50/28 oz is applicable to 302/351 engines not the mod motors...I used factory Ford when I replaced my clutch, the vibration could be the motor mounts(which I suspect), I'd put maximum motorsports units in, the u joints, bad waterpump, bad trans shaft or a host of other things...good luck

 

[ttm300]

I know the motor mounts intensified it, but they didnt cause it.

 

[rj8806]

You say the vibration is there whether your in gear or not, is it there when the car is sitting still, just idling? Vibration, out of gear, in motion is basically just free spinning the internals of the gear box (no load). If this is the case, I would suspect a driveline vibration. I see you said it has a TKO in it and that it was there when you bought the car..? It is highly possible that the drive line angles are off because of the transmission swap. Do you know what they used for the cross member? Did they lower it to fit the TKO in the tunnel? Getting some base line angle readings is probably a good starting point. When I set them up, I take readings from the bottom of the tail housing case (call this A), middle of the driveshaft tubing (call this B) and finally, with the pinion yoke turned vertical, place a socket that is slightly smaller in diameter than the u-joint cup, on the cup itself and get a reading from there (call this C).
Now with these 3 readings, take A- B = front u-joint working angle. Then take C-B = rear u-joint working angle. These 2 answers need to be equal but opposite and in the 2* or 3* range max. In other words, if the front working angle is a +2* then the rear needs to be a -2* etc...
Also, the 3 initial readings, none of them can exceed 5* and they should also be in the 2* - 3* range.

The throw out bearing, if not properly adjusted can cause squeaking. When it is properly adjusted, the bearing is not contacting the fingers, therefore, it cannot squeak. By tightening up the cable, you can be doing one of 2 things. Either you are causing the T/O to ride the fingers, which obviously causes it spin, which, if it is bad to begin with, could be quieting it down, or you are pre-loading the clutch, which is causing the pilot bearing to slow down, which would cause it (the pilot), to squeak.

As far as clutches, I swear by SPEC and have never had any problems with them. That goes back to properly adjusting the clutch. General rule of thumb is you need between 1/8" and 1/4" max, gap between the face of the bearing and the fingers of the pressure plate, when the pedal is all the way out at the rest position. When setup this way, the T/O is not contacting the fingers and cannot spin or make noise until you depress the clutch pedal.

Hope this helps, if not let me know...... :bigthumbsup




Richard
Tech Support
Tremec TKO, T45, 3650, T5 & T56 Transmission Systems

 

[ttm300]

Thank you Richard,
The equations there are a bit over my head but I dont think the drive line is the issue. The car vibrates harshly between 1200 and 2000 RPM when it is just sitting there idleing. When the car is warm and idles at 800 RPM it as smooth as can be even tho it has the aftermarket hard urethane motor mounts ( got from AMERICANMUSCLE>COM ). The car drives smooth in gear long as its not in the 1200-2000 RPM range. Im no expert but this would indicate to me that it has to be the clutch pressure plate that is atttacthed to the flywheel or the fluwheel it self. Especially since there was vibration in it since I first replaced the SPEC 1 clutch and stock flywheel with the ZOOM clutch and autozone flywheel. It just wasnt nearly as notable til I put the hard motor mounts on a couple months later. Is it possible that the clutch has just been installed misaligned on to the flywheel because that is the only thing that keeps making sense to me.

 

[rj8806]

Thank you Richard,
The equations there are a bit over my head but I dont think the drive line is the issue. The car vibrates harshly between 1200 and 2000 RPM when it is just sitting there idleing. When the car is warm and idles at 800 RPM it as smooth as can be even tho it has the aftermarket hard urethane motor mounts ( got from AMERICANMUSCLE>COM ). The car drives smooth in gear long as its not in the 1200-2000 RPM range. Im no expert but this would indicate to me that it has to be the clutch pressure plate that is atttacthed to the flywheel or the fluwheel it self. Especially since there was vibration in it since I first replaced the SPEC 1 clutch and stock flywheel with the ZOOM clutch and autozone flywheel. It just wasnt nearly as notable til I put the hard motor mounts on a couple months later. Is it possible that the clutch has just been installed misaligned on to the flywheel because that is the only thing that keeps making sense to me.

A vibration that occurs while sitting still changes my answer. You're right, that leads me to believe it is a flywheel or clutch but it could also be a broken harmonic balancer on the front of the crank.

The 4.6 motors were a neutral balance motor meaning the flywheel must be a zero balance F/W in order to be smooth. Most clutches are built and balanced to a neutral balance so as not to throw off the engine balance. Most of the time, there is a weight tack welded to the face of the pressure plate. While I have not seen a SPEC clutch out of balance, anything is possible. The only way I know to eliminate it would be to tear it down, remove the clutch and start the engine and see if the vibration is gone.

You might want to check the parts descriptions of the pieces you got at Auto Zone and make sure they list it as neutral balance.

Let me know of you have any more questions.




Richard
Tech Support
Tremec TKO, T45, 3650, T5 & T56 Transmission Systems

 

[2Manystangs]

I gotta reiterate I had this same type of problem on my Cobra, it wasn't until one day the guy putting my headers on saw the OEM mounts were shot and replaced them that the unknown vibration finally went away...might be alot easier and cheaper to put some stock mounts on and make sure that is not the issue...those solid urethanes may be magnifying the vibration that seems to be built into the driveline...I've been smooth as glass since (I lived with it for two years before the new mounts finally cleared up the problem)

 

[ttm300]

Thanx again Richard,

Why would it be the mounts if it only does it at a very specific RPM. Talked a local guy today that has an 03 cobra and he had the same prob when he installed the SPEC 3 clutch. He called Lethalperformance and they asked if he torqued the bolts equally and had the pressure plate alignment even. He had done the job himself so he tore it back down and stuck it back together and turns out that was the problem, no more vibration. Said the SPEC 3 puck style disk engages rough tho. That is supposed to be normal with that high torque a cluth with no springs on the disk and puck style

 

[ttm300]

sorry wasnt finished, got interrupted.

The harmonic balance was replaced when the transmission was swapped i think cuz i had to replace it bout 9 months ago and it was an aftermarket one on there already. The harmonic balancer appears to be ok, running true by looking at it. How do you tell if the harmonic balancer is broken ?


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Part No. HP48-1S Warranty ZOOM Performance Kevlar Clutch Set; Cover Type: Diaph.; 10 1/2x26Tx1 1/16; TKO Trans. - 26 Spline Disc


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ZOOM Performance Kevlar Clutch Set; Cover Type: Diaph.; 10 1/2x26Tx1 1/16; TKO Trans. - 26 Spline Disc
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[2Manystangs]

Thanx again Richard,

Why would it be the mounts if it only does it at a very specific RPM. Talked a local guy today that has an 03 cobra and he had the same prob when he installed the SPEC 3 clutch. He called Lethalperformance and they asked if he torqued the bolts equally and had the pressure plate alignment even. He had done the job himself so he tore it back down and stuck it back together and turns out that was the problem, no more vibration. Said the SPEC 3 puck style disk engages rough tho. That is supposed to be normal with that high torque a cluth with no springs on the disk and puck style

I'm not sure why it only occurs at a specific RPM, it just does...the factory mounts are much softer than the hard urethane and absorb the vibration...I know you want this to be the trans or driveline but I maintain it is not...remember I have a 96 so it will be more similar than the 03 to your car...I drove my car for two years with that same driveline vibration and no mechanic could figure it out(it was deep, it was noticeable and it did it moving or stationary)...I was like, "oh well I'll drive it until something fails and then I'll know what it is"...it was the mounts, nothing more.

 

[ttm300]

Im %100 its not the motor mounts.

Had a transmission specialist drive it last nite. Said it has to be flywheel/pressure plate misaligned or harmonic balancer or a random pulley on front of engine. Clutch still squeeks like hell.

 

[gdp2001]

If you pull the transmission again to try and fix it I'd replace the throwout bearing and piolt bearing while you are in there. the squeak is probably the thowout bearing.

 

[rj8806]

Im %100 its not the motor mounts.

Had a transmission specialist drive it last nite. Said it has to be flywheel/pressure plate misaligned or harmonic balancer or a random pulley on front of engine. Clutch still squeeks like hell.

I'm with you, but to be sure, have a friend help you and with the hood raised, car in neutral, e-brake applied, stab the gas a few times while having the friend watch the engine itself. With bad motor mounts, one side (or both) of the engine will raise and lower quite dramatically when a bad mount is present. You may even have to put it in gear and have your buddy stand to the side while you ease the clutch pedal out and apply gas a few times to load the engine and the brake applied. Same principal, with a bad motor mount, the motor will jump dramatically up and down when load is applied and taken away.

You can also check the transmission mount by using a floor jack and seeing how much the tail housing raises and lowers when jacking the up the transmission at the end of the tail housing.

Do a visual inspection of the harmonic balancer and look for the obvious signs of cracks etc.... You can even pull off the serpentine belt and run the engine at idle. Watch the harmonic balancer and make sure it goes round in a true circle and not egg-shaped.

As far as a mis-aligned flywheel/clutch, I don't think that's possible if the input shaft seated into the crank, but an out of balance PP or F/W will certainly cause your symptoms. Loose pressure plate or flywheel bolts will also cause a vibration and you have to be careful how you torque them. Generally, pressure plate bolts are 35ft/lbs and flywheel bolts are 55-65ft/lbs. They usually require tightening them in a star pattern, half the amount on all of them and then the final amount again in a star pattern. In other words, if it calls for 35ft/lbs, don't tighten each one up to 35ft/lbs individually. Tighten them up to 15-20 ft/lbs in the same pattern you would a wheel, then go back and tighten them again another 15-17ft/lbs in the same, repeating pattern until all 6 are equally tight.

Do yourself a favor and check the obvious things before pulling the transmission or worse yet, paying someone to do it for you, who knows, you may get lucky and find a bad balancer or mount.


When you say your clutch squeaks, can you elaborate more? What is squeaking and when? Is it in the pedal itself? The pedal bushings up under the dash are famous for dry cracking and causing squeaks. A bad throw out bearing or pilot bearing could also be the culprit. I have also seen many guys chase down a squeak to what they thought was a throw out and it turned out to the serpentine belt. :laugh: That is easily checked by using a bar of soap. With the engine running at idle, VERY CAREFULLY hold the bar of soap against the belt for a few seconds. If the squeak goes away, it is a bad belt, if not, you can rule out the belt. A spray can of white lithium grease works well too and is not as dangerous as the bar of soap trick but the soap works if you are in a pinch. :bigthumbsup





Keep us informed and let me know if I can be of help.




Richard
Tech Support
Tremec TKO, T45, 3650, T5 & T56 Transmission Systems

 

[95gts silver/bl]

I am having same problem with my 95 5.0 stec stage 2 .just put it in and have that same vibration.I have had this problem before.I have changed 2 ballancers and the one on there looks to be doing the wobble again.but since the new clutch and old flywheel(sorry had to do it)its really bad