ok well a few things id like to mention is when im on the highway starting about 60-70mph and up it has a bad vibration only getting worse with rpm, even with it in neutral, i tried fliping the driveshaft 180 degreees but that didnt help, its a brand new slp flywheel, centerforce clutch, and sphon toruqe arm is it possible that the pinion angle is too much or too less i believe its set at around 3degrees negative..

and how do you properly check the angle

Fix known problem first. Your engine is running on 7 cylinders.

doesnt feel like 7 cylinders.... drove it all day and been pullin hard and doesnt sound like it either i think it decided to work...its not engine related heres some diagnosing i did

sitting in neutral can rev all the way up to redline, up to about top of 3rd is when it starts vibrating, on the highway seems really bad around 80+ it gets to a point where it sounds like somethings gonna brake and i have to slow down

so i would speed up than put the clutch in and engine would rev down to idle speed and would still vibrate, with it in neutral it vibrates the same, so i think we can clear out the pilot bearing/clutch/flywheel good job bennie and when it vibrates its not on the clutch pedal or shift **** its the WHOLE CAR, not the steering wheel but you can feel it underneath you ...

I know this sounds stupid, but check to see that you didn't loose a wheel wieght. You tires could just need to be balanced. The only reason that I say this is because you say that it is not in the pedals.

Chris

you pressure plate is not properly aligned with the flywheel. (out of balance)

I don't beleave it would be the pressure plate sounds like something to do with your driveshaft or pinion angle. Are you using a ES poly trans mount, I know some guys complain about that one. Maybe try changing the pinion angle to 0* and see if that makes a difference.

stock t-56's use a pressure plate that is "marked"(the flywheel as well) with a white dot. they are balanced a certain way. if the pressure plate and the flywheel marks are not aligned there will be vibrations. i had the same vibration that porky is having. feels ugly.


don't ask me how i know. i learned the hard way on my fourthgen.
don't take my word for it. look a centerforce clutch replacement guide.

only on gm flywheels does it have the dot, i have an slp flywheel,

and keep in mind it doesnt vibrate idle when i rev it up, its not at a certain rpm its at a certain speed, with even with the car idling and in neutral it will vibrate at that speed.

perhaps a broken motor mount?

well i called up spohn today and the guy figured out my problem in less than 5 minutes, he said its a common problem the transmission mount im using is energy suspension dont know if you guys are familiar with it, but they include a plate in the kit, he said just remove the plate and it will go away he said its happened to alot of their cars, and doenst know why they include that plate ill give that a try

Excellent--hope that works--I remember the guy you paid to help you who banged away on your components before you drove him off. Did he do something to your driveshaft, figure--sure it's straight? Does your vibration seem to be driveshaft speed or wheel speed?

hmm...yea it is drivetrain related, but i believe it has to do with pinon angle, yea the guy i was gonna pay to finish my swap ended up undoing eerything he did and redoing it my self he only dropped the tranny, everything ended up getting replaced anyway, cause after i finished everything up it wouldnt go into gear so i said screw it

than too it to tuffz's shop aka bennie, he figured out they gave me the wrong flywheel for a t5, ruined the clutch, so i got both a brand new flywheel/clutch.

Man, you are going to be the world's #1 T56 swap expert.

You don't need to remove the plate.

You need to remove the 2 bumps which are part of the polyurethane which ride against the plate.

<--- 700-R4 with E.S. mount
<--- T56 with E.S. mount
<--- TH350-C with rubber mount

He has to knock me off first.

Excellent--what a run of hard knocks, uncommon knowledge.
jmd--did you find tables on speedometer gears for T5's? I'm just gonna buy a 19 tooth and see if it's right--I'm slowly building a box full of this stuff.

Sorry, been busy working and stuff. Sending a PM now.

I don't use the plate that came with my energy suspension trans mount also, to many people on here complaining of vibration problems buy using it. I guess I should have been more clearer on my first post but it looks like spohn's got you straightened out, hopefully it works out for ya, seems like these t-56 transmissions are nothing but a pain for you and me both I think this is going to be my 6th or 7th time taking the bastard out, pops out of reverse

maybe the console is hitting the gear shifter i know i have to push mine alittle bit its not biggie for me, only thing i dont like is that when i get in my dialy driver after 2 days i keep wanting to go into 6th gear haha, i start to and than forget.....

well...expert somewhat right dumb enough to use a t5 flywheel...should hav eknown when the clutch wasnt going on and i had to force it which is what warped the clutch, doh.....but infact guys a write up is on the way i feel that every write up didnt include certain information that was essential ive got pictures too..

Whew--hope you're some kind of Shakespeare.

Well, to do a complete writeup of your experience, including all you've learned and how, complete so it helps others avoid the problems you found, wouldn't be any simple magazine article--that would take some real, professional technical writing. Try it--it would probably sell.

He's hoping your how-to writeup shall be well written.

for 10 bucks go get your local chevy high po. they have a t-56 swap guide for us third genner's

Are you running a spohn kit w/ the ds loop. I did with Jamex springs which led to the torque arm coming in contact with the loop. I had to bash the loop to make the clearance necessary.

What type of bushings are you running? I had a spherical originally, and control arms that were poly/spherical combo. All that resulted in vibrations that loosened everything from my crossmember to my dashpad.

I ended up switching the T/A bushing to a rubber one. Always run 0 degrees on the pinion, 3 degrees if you are breaking the tires out of the hole at the track ONLY. Spohn directions clearly said that 3 degrees puts extreme pressure on the driveline and you will be more susceptible to bind.

Get up to the critcal speed with the back tires off the ground. You might visually what is causing the vibration.

All that crap also loosened my accessories, eventually helping with the lock up of the A/C. I'm eventually going to get rid of the spohn T/A and go back to the stock setup. The link that he uses a solid link on the crossmember will always produce a vibration. I'll use it at the track only when I have enough HP to really need it.

well i got under it tonight....for a little bit...and the trans mount bolts on the side were completly loose...like finger loose so i tighend them up...and get on the road seemed to help...BUT still there ill try removing the plate tommorrow...ill take that inmind with the pinon angle ill take it down to -1 degrees....

Invest in a azzload of locktite...... RED and GREEN. Lockwashers and nylon threaded nuts help too.

Why -1 degree?

so under acceleration it wont go positive it equals more torque to the ground and better traction

Will it go positive..... if you are using a solid or poly link, it should not move at all. You compensate that by -1 when you have a "loose" suspension, or are running serious (450+ hp) and are using slicks or equiv.

Play with the settings when you are at the track so you can see the results of your launch. I drove mine at -1 & -2 on the hiway and it vibed worse. For street, I would assume that you will never hook up that tight to cause deflection of a poly bushing.

Did you find out how to set the pinion angle. I measure at the flat base of the T/A at the diff and then on the shaft itself. I can not remember which way the subtration goes, but mine always gave me a 0 at the diff and I adjusted the T/A to get 0 on the shaft.
REMEMBER to lossen the bushing at the trans cossmember mount or you will preload it and cause bind. Hit me back if you want me to scan Spohns directions.

In the future, I'm going to splurge on a digital angle finder (@ $100) cause my shakey hands can't keep still enough on my carbon fiber shaft to get an accurate reading I'm sure you know that there is not alot of difference between 1 degree and 0 on the angle finder scale.

Give us some feedback on what you are running bushing wise all around and if you have a driveshaft loop.

Peace,
Mike

When I pulled my clutch the last time, I measure the run out if the flywheel and it was way off. I know that you changed the flywheel, but did you do it with a fresh clutch and P. plate.

Get a dial indicator and set it up on the shaft to see if the vibe is pre or post shaft. Mine is still sleeping now, but I'll be on it again after the holidays.

Another idea that I though of is the alignment of the input shaft into the pilot bushing. I argueed this with others who say theirs does not vibrate and that you do not have to do that. I have a vib, so after I tighten up everything again, change out my clutch and PP, and put my new a/c back in, that would be my next step.

My mistake at one point was taking out the air pump and not placing the bolt back in the bracket. The bottom bolt I think goes into the block. I left it out, everything loosened up, and I actually snapped one of the support bracket bolts into the block. Fun stuff.

These cars esp when frame tied are such an amplifier for vibration. A long time ago my friends told me how much a solid bushing car sucks due to vibes and stuff loosening. For drag only ok, but a daily driver need some flex to absorb the vibes. I had solid links on the panhard, 1/2 the LCA's, on the T/A and on the strut mounts up front. Along with poly everywhere else leads to superior handling and a whole mess of vibe.

I found a happy medium with 1/2 rubber in the LCA, a rubber trans mount (you don't need the extra strength of poly now since the back of the trans is not hooked up to the T/A) and some mixing of poly & rubber on the sway bar links.

Hope all this helps. It is surely motivating me to get my stuff together again. Maybe what you find out also will help all of us.

Later,
Mike

PS
1 more thing.... can you tell I', at work.

Check to make sure that your harmonic balancer did not slide. Make sure TDC of #1 lines up with the timing mark at 0. My friend told me to check that too, but I have not yet. A fluidampre street damper is on my wish list. I want to make this car handle well, but I do want the flexibility of a soft ride for long trips.

I'm outta here!!

graebz28--outstanding--thanks for the education. I was wondering about my torque arm mount, to keep looking for a stock rubber one or go with a hard plastic aftermarket one--I've heard the hard ones transmit a lot of vibration and noise. I'll keep looking for a stock rubber one and go for the hard plastic sway arm bushings. You know, it seems you should either go all rubber or all hard plastic but the combination makes sense to me, too. Excellent--a lot of long distance driving in West Texas.

I had kenny brown LCA's on my 89. It was rubber and poly, but the rubber part was the adjustable end, so I bolted that to the front of the torque arm. I had to drill out the metal plate to one bolt size larger. The T/A , LCA's poly and shperical bushings are all the same size, as well as the pan hard bar. I know Summit Racing carries rubber bushings on that size thread.

I'll get back to ya with some after the holidays with some pics and how i did it. It did help in the overalll feel, but the other vibes coming from the a/c being lose made it far from perfection. I'll end up doing some exp. w/ all that later, but for now I think I',m going back to the stock deal. The solid bottom mount and that hinge set up on the front of the T/A is not too forgiving. I want to take my x-member and mod it so I can have a rubber bushing on the bottom also. I know it can be done, just who when and with what $.

Anthor alternative that I have not tried but read alot about is that Del-A-Lum stuff. I have some friends with that on their control arms and they rave about it. GLOBALWEST.NET NOT .COM has a lot of literture about all that. I will try to call them over the holidays to see if they make that T/A bushing. The stuff is supposed to be a fair medium between soft and hard. They say that a pure poly set up is best for the track and worst for the street. Although I argued this with happy poly car drivers, poly is said not to flex at all.... again why you do not need -1 degree. Check out their chart cause it says that a full spherical setup is the best for street. I would disagree there, maybe street but not high speed w/o tons of vibration.... but I could be wrong cause I have not tried it. My end goal is to probably have a Del/Rubber set up and have another set of pure poly or spherical to run at the track. I got good at swappin g the control arms out and setting the pinion down for the track .... less than 45 minutes alone.

If you have LCA adjustable brackets, keep them on the higher hole (lower than stock, but not the bottom hole) since that leads to more vibration and should be track only.

Thanks for the positive feedback, hope this stuff helps also.

Mike

well guys i forgot something...well major...i have HUDGE flatspots ont he front tires...tread is at about 90% flat spot goes down to 10% tread...so im going to try on diffrent tires tommorrow see how it goes...

Flatspots--bummer--tread seperation or hard on the brakes?
graebz28--my car will see SOLO II and long distance drives to the Texas hill country and mountains of New Mexico, so I need good handling, durability and moderately comfortable road manners. It already has those duralum bushings in boxed control arms--my brother set up the rear end when he lived in Indiana near the Moser factory, made trips there for parts and advice. I've gotten used to the hard LCA bushings on the street , all the clunking and road noise--especially now with the whole interior out 'cept for the driver's seat, putting in a roll bar and new custom naugahyde.
From what you wrote, I plan on hard bushings in the sway bar mounts and links front and rear but rubber on the front end of the torque arm for quiet and dependability. My brother also rebuilt the whole front end with Koni stuff, rubber parts but good and stiff--car handles great.
A few years ago a friend bought a TransAm TA to build for road racing because it came with all the good factory handling stuff, springs, harder bushings and all (it was an '85, as I remember) and he found out that all the suspension mounting points were stressed, crystalized and cracked because of that factory heavy-duty stuff. He bought a babied V6 car and transferred all the Firebird stuff into it to have a solid body with good suspension--the Firebird was really ragged out.

RB,

Sounds like a good setup. Are you runnning an aftermarket torque arm? I would run a poly ta bushing is you have the stock setup as well as a poly trans mount if stock setup put all that stress on the back of the tranny. New rubber mounts are good too, they just do not have a long lifespan. Once you feel mush, you need to replace them.

What rim size are you running. The only thing that keeps me from getting 17-18's is the ride quality of going to a low profile tire. I rode down to Tucson for a third gen gathering in a car that had 17's and poly everything, and I knew after that I did not at all care for the feel. You could run rubber sway bar link bushings to dampin the vibrations and not really notice a feel in the ride. The sway bar mounts should be greasable polys for control.... or del-a-lum are made for the car.

By the way, what is a naughahyde??

Mike

I am running the whole sophn mount and dual drive shaft loops. it has the poly ends and I had the poly mount before (took out the plate too because I thought the trans was too high)

the only thing I don't like is I had to dent up the floor some for the loops. and the arm likes to really tug on the car hard on the rare times when I grab hard traction. (I will have to dent the floor more and make sure the arm bolts are tight enough)

I get some vibes but, nothing big

What loop is hitting the floor? Once your x-member is bolted in, you can bend the bar the olds the front d/s loop. Mine was too low, which made the torque arm to d/s contact that lead to my ultimate shake down. I'm surprised to hear you say that yours it hiiting the floor. I guess spohns jig has some play or he reconstructed it after we started to complain.

Mine ran fine for a couiple months too.

All I can emphasize again is to use new nylon threaded lock nuts lock washers and locktite.

Also, remember not to tighten suspension parts unless the car is at ride height.

mostly the rear loop on the right hand side (it has a split part that has bolts)- that ear hits the car.



I would have fixed it over a year ago but, I have only driven it a hand full of times

graebz28--Naugahyde (sp?) is fake leather--there's an upholstery shop in town that's been in business since the 50's, used to cut front seats on shoebox Chevies for Corvette shifters--really know their stuff and don't charge too much--and they're doing a complete interior old hot rod style, like a black leather jacket tucked in around the roll bar, which brings me back to this thread.
The street roll bar presses in tight to the rear seat floor and the back fender wells and up against the T top spar--not even bolted in yet, it takes a lot of flex out of the chassis. Next are frame connectors which I'll weld to the roll bar backing plates--I imagine this'll give a solid platform to really judge the performance of the suspension bushings. It's amazing how much better this car drives with the chassis stiffened up.
I run 16" tires on IROC Z aluminum wheels--there's a big jump in prices from 16" to 17" tires that seems to be just a matter of style. Right now I have the original 14" wheels and street tires on it for the winter. In March (I hope) I'll get a new set of Kumhos for the IROC wheels. Those rubber band sidewall tires may be based in racing but they're nothing but appearance to me, and a waste, actually making the vehicle less road worthy.
Anyway, when I get the roll bar bolted in and the frame connectors in I'll go for a duralum torque arm/tranny mount and rear sway bar bushings. My brother put all that cash into building the rear end for drag racing and left the stock, worn out sway bar bushings--says he never looked at them--an old drag racer.

Yeah, and--the torque arm is stock--I don't know if an aftermarket one has any advantage but adjusting the pinion angle and I don't drag race (much, officially).
That's interesting about taking a trip in a 17" tire, solid bushing car--just what I was wondering about. I drove this car from Tallahassee out here to West Texas a year ago with the hard LCA bushings, 3.73's and no overdrive--railroad crossings hit really hard--but I took everything apart and tightened everything carefully when I took out the automatic and put in the T5 and now it's not so bad.

ok well...i removed the plate from the trans mount...and its better...i can go 90mph without vibrations but as soon as im over 100 its there and bad still... what next??

tires

post ***** we tried that...and it was better maybe ill steal your rims again tommorrow when i come over

i mean.,.. tires since the removal of the plate.

did you guys try the drive shaft

ya , it helped some as well.

do you remember to balance your shifter?

JK , I had to do that! it seems like you tried everything else so I thought I would make you think alittle

i have a zero balanced factory one and i cant find the dot. were is the dot usually?


sorry i know this is a old post