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flex plate shield

3K views 20 replies 5 participants last post by  scotty57406 
#1 ·
pulling the trans. out this winter for a rebuild,it is a BW super t10 and as it is now i do not have a scatter shield, i see Quick time makes a flex plate shield that says for ALL chevy sbs and transmissions,the part # is RM-6098-4, i was under the impression that a flex plate is for automatics and a flywheel for standards or are they both fall under the same category, is this shield suitable for use with a manual or should i go with a real scatter shield, i was not really worried about it until last night when a guy asked me if i had one on my trans, then he proceeded to tell me about his experience when his let go shifting into third, he said it was like a buzz saw and did not stop ripping until it met the master cyl, he kept his feet but now would not run with out one, i do not race or go overly crazy very often but every now and then i tend to, i am not trying to cheap out but what do yous'e think of of the shield verse the scatter shield, thanks in advance, Scotty
 
#2 · (Edited)
That shield is strictly for automatic transmission flexplates. It is no where near stout enough, nor wide enough, to cover and contain a flywheel or clutch pressure plate explosion.

For a manual trans, you need a safety bellhousing/scattersheild due to the much heavier weight of a flywheel or pressure plate. When one of those cuts loose, it's sheer mass x rpm will saw through far more than just the pieces of a light flexplate are capable of.

If you've never seen what a flywheel or pressure plate explosion does without a steel bell, it's an eye opener. I've seen a car pretty much totaled out, close to $4000 worth of damage to the floor, Dash, windshield, cowl panel, inner cowl, roof skin at the front edge all torn to scrap in a 68 Camaro once, even got the corner of the hood and put a hole clean through the rear of the passengers front fender, it wasn't pretty. Driver lost about a 1 pound chunk of calf meat but was otherwise damn lucky to walk away.
 
#4 ·
thanks Eric and Tech, buying a full scatter shield, makes me shiver just thinking what could possibly happen without the proper safety parts installed, NOW what
brand should i buy? is there any preference or are they all equal in terms of fitment, installation etc.
 
#5 ·
i'd suggest you PM Autogear, he's the Muncie 4-speed guy here and deals with this stuff the most....last 4-speed I did was 25 years ago, ST-10 with a vintage Ansen scattershield, and then a Lakewood when the track said my Ansen was too old to re-certify.
I've heard the Quick Time are lighter, being a spun form bell rather than a pressed form like the Lakewood, and supposedly the QuickTime are more accurately dialed into crank centerline.
 
#6 ·
Hey there!

This question comes up a lot; and while a quality BILLET STEEL flywheel is less likely to come apart, the relative 'quality' of the avg clutch pressure plate is not conducive to super high RPM.

The stuff that was produced 'back in the day' like the Ansen scattershield Eric mentioned; were usually very accurate. However, we don't know what its life looked like. We also don't know where your engine block falls as far as core shift, line boring the mains, crankshaft forging/casting quality, etc.
The modern Lakewood bellhousing, while SAFE, is not very accurate and will absolutely eat 3+ hours of your life trying to argue it into place. Its also fairly cost effective.
The quicktime and mcleods are more money, easier to manage, just as safe. I prefer the quicktime BY FAR. I am not compensated in any way professionally or privately for my opinion. In fact I don't even sell them. Yes they're more money, but they're easier to get aligned, and they weigh half as much as the Lakewood.
Choose either based on your budget, and use a dial indicator to mock it up on your block.


If it needs to be adjusted; get the adjustable dowels from RobbMC AFTER you do your trial alignment.
RobbMc Performance Products - Bellhousing Alignment Dowels
Now, do you need the SFI cert? If you're not planning on drag racing; no. Also remember certs expire and they need to be re-certified technically.
 
#8 ·
Well i finally got the trans. out to do a rebuild on it and found a few problems that i need to address, first of all when i took the bell housing off i noticed that the clutch assy was wet with oil from the front seal on the trans, then i noticed the pilot bearing was not even in the crank, it came out with the input shaft when i removed the trans.and was just resting against the throw bearing and fork, no wonder the front seal went, i have a new bronze pilot bushing that is 1/4 inch longer that is non magnetic that i am installing along with the scatter shield that i picked up,i am going to align the bell housing upon assembly, I have two questions, #1 the new pilot bearing does not fit tight into crank as i can push it in by hand pressure and can also remove it with little difficulty, HOW CAN I Fix It # 2 the clutch disc is covered in oil, CAN I CLEAN IT WITH BRAKE CLEAN since it is had very little mileage on it, it is a centerforce clutch assy. needless to say that if i had aligned the bell the first time i put it together i would not be going through this now other than the rebuild
 
#9 ·
If I'm not overstepping bounds on Auto gear here you'll need to something about the pilot bushing. If it's loose in the crank it's not going to serve it purpose.

Auto gear, does someone offer an over sized pilot? didn't GM have a some with different diameters?

Scotty, I have a lathe so I'd make one but but if you don't have access to one perhaps a local machine shop can make you one if you had the specs. I've heard of stories about Eagle cranks going out the door with the pilot bore too big but neither my engine guy or me have personally seen it. This wouldn't apply with a GM crank though.
 
#12 ·
i have a piece of bronze round stock that measures 1.200, it is non magnetic, i will take it along with the one i bought down to the machine shop and have him duplicate it, since the one i bought just fits in the crank about perfect how much should i have him add to the outer diam. for a interference fit, would .002 be to much, the one i bought has an outside diam of 1.093, thanks for the suggestion, now with that question answered what do you think about cleaning
the clutch disc with brake clean ?
 
#13 ·
while trying to measure the total depth from the trans. bell housing mounting surface to the pilot bushing end ( having bushing made, want it made to fit my app.a little more precise) i tried to put the block saver plate on, no way will this plate fit over the end of the crank , the hole in the plate is to small, this is going on a 400 sbc , the lakewood bell fits fine, the plate part # 15705 says it fits most chevy v8s, can i omit the plate or can i open it up to fit over the crank end, if i omit it then the factory inspection cover plate will not fit, will have to fab one,thanks
 
#14 ·
.002-.005 will provide sufficient press fit. .003 prolly ideal.

I don't really have much experiance with the block plates on those. All mine comes from the mid plate we use in circle track cars. We use Pilots that are the same thickness as the mid plates (1/4") and don't have any problems doing that. Hope that helps a little.
 
#18 ·
That does seem weird.

Sorry I forget your other question about cleaning. If the disk is organic it tends to absorb the oils and causes chatter that's pretty annoying to live with. Getting it out is near impossible without adversely affecting the material. If the disk has more race oriented materials made from mostly aluminum/bnroze fibers you might get away with it and these tend to have rough engagement anyway. You'll have to decide if it's worth pulling it apart if it doesn't work. Either way make sure the flywheel and pressure plate is cleaned and flat.
 
#19 ·
the flywheel and pressure plate are as new, no high spots or burnt spots, the disc is the dual friction centreforce that has the little copper pieces in it, other than the oil that was on it it looks barely used, buying any performance parts in Canada is always at a premium, especially if you get into the big name brand parts, i will try and clean it and go from there, thanks
 
#20 ·
Thats a lakewood 'plate

Heres a little info; a lot of the pics are missing but theres some good stuff in here
Vintage Lakewood Scattershield - Wanted | Parts/Memorabilia - Wanted | The Supercar Registry Bulletin Board

Our pilot bushings are usually 1.09x in OD, Johnson is correct .003 is a good number
No sir; you are not stepping on any toes. We are all in this together, and I haven't seen everything - Im still learning new stuff.
Most aftermarket crank mfg don't hold a super tight tolerance there, because its not as critical for an automatic.
 
#21 ·
that is the one i have except for the extra digit in the part number, going to have to open up the center hole to fit over the crank end, also picked up my custom made pilot bushing from shop today , did a beauty job on it, with the .003 o/s od he told me to put it in the freezer before installing to make it easier to install, things are really starting to come together, thanks guys:thumbup:
 
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