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HELP QUICK! Pressure Plate & Flywheel bolts

Banditt007

NAXJA Forum User
Location
New York
1998 XJ
4.0
Ax-15 5 speed

I need to find a source...hopefully other than the dealer... that has both the flywheel to crankshaft bolts, as well as the pressure plate (clutch cover) to flywheel bolts. Or atleast someone has the part numbers for these two parts!?

Last guy that was in there 1)rounded off a few of the PP bolts and 2) AS PER THE MANUAL! you should replace the flywheel to crank bolts.

I cannot seem to find either of these ANYWHERE. And find it insane on how common the 4.0 and AX-15 is and that these parts are seemingly no where but the dealer? WTF!!!!

Please help, thanks.
 
Pressure plate screws I've replaced using 3/8"-16x3/4" socket head capscrews with good results (SHCS are routinely H&T to SAE8 specs, and they're easy to find. And, I prefer the internal wrenching approach. They're cheap enough that they get replaced every time I take them out.)

Flywheel screws are a bit more difficult - they're threaded 1/2"-20, but they're not a standard hex head. They're what is called a "place bolt" - and the head is designed to maintain clamping force under a lateral load. You can probably get something like that at a tractor supply outfit or a speed shop (ARP makes a kit that should be equivalent for a Pontiac engine, but I'm not sure about the length. I know they'll work on an AW4 flexplate - 1/2"-20x.590" 12-pt head, 6 pcs.) I'd think that the flywheel screws are a shade longer - perhaps not quite .750"
 
The local savage yards in your area should have them..

Good Luck
Nick
 
The local savage yards in your area should have them..

Good Luck
Nick

True - but those screws are under an awful lot of strain - and they're LocTited in place and torqued to something around 100 pound-feet. I'd not trust used ones (and you don't know what kind of I-D-10-T was driving before it got there.)

These screws are an example of something that it's better to buy new (and, if you're going to take them off in the boneyard, I advise a battery-powered impact wrench, and possibly a small torch.)
 
I think if the dimensions are right it should be fine, assuming the vendor is reliable.

While I was working on my clutch recently, I was very careful with the fasteners, putting them all in a neat little dish, but when I came to put the new pressure plate on, I found I was one bolt short. I have a multi-decade collection of bolts and nuts and bits and pieces - a barn full, a shop full, drawers and buckets full. Do you think I could find a grade 8 bolt of the right size. Of course not.... So I'm hunting and scrabbling around trying to find something when my wife comes out to say hi, and I explain that I've lost a bolt, and looked everywhere, etc. etc. She says "show me the bolt, maybe I can spot it." No way, I 've looked, blah blah blah. I show her one anyway. A minute later she points to the bolt still stuck in the old pressure plate and says innocently, "Does it look like that one?' :doh:
 
Well I have to take some measurements tomorrow, but so far I can tell you guys this. The bolt length is not ultra critical (thread section) for the PP to flywheel. I checked w/ what i believe to be the OEM bolts and they do not thread even 1/2 way through the thickness of the flywheel. So there is more than enough space for the bolt to be of different length. (longer in the case of the Mr. Gasket bolts)

I believe we are also in the same situation for the flywheel to crank bolts. Once that bolt is placed through the flywheel only about 7/16" of threads will be threading into the crank. I am very sure the crank is deeper than that but I will check tomorrow.

If what I see so far is correct assuming the other dimentions of the bolts are correct, we are good to go.

PS sorry for being so anal about this, but this is a job i do NOT want to do over again.
 
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Save your money on the pressure plate screws - a quality socket head will be cheaper, and they're just as good (I've been using them for a number of years. Make sure to use LocTite #242 or equivalent.)

The Mr.G 914 flywheel screws should work, as long as they're the right length. As I said, I'm not sure how long the flywheel screws are, so I can't say at the moment. But, they're the right thread, the right head, and you can always grind down the ends if they're overlong (just make sure to chamfer the ends after you grind them to length. Advise threading an SAE8 nut onto them before you grind - grind, chamfer, and run off the nut to dress the last thread back into shape.)
 
Only thing i worried about on the PP bolts, was how well the smooth shank portion fit in the hole of the PP, since I wanted that fitment to be very close tolerance, so they act more like pins than bolts w/ the torque just holding them from backing out, not so much clamping the PP to the flywheel. Hope that made sense. If the Mr. gasket ones don't work out, hardware store it is.

As for the Flywheel -> crank bolts if they are what they say they are... 1" long the stock bolts (used/stretched) measure at .870". If my replacement flywheel is the same thickness as stock, they will stick out of the back of the crank .130" (1/8 inch) I will take a better look tomorrow (started pouring rain) if that would work. I think there is a good bit of clearance behind the crank so i may not need to grind the bolts. Good idea BTW w/ using the nut first then grind, but i'll one up ya, i was gonna use a dye =) I think i'd be much better off grinding the bolts some if i need clearance, compared to using washers to space them out.

Anyway when the job is done i'll let everyone know if these two bolt packages work well w/ or w/o modification. If they work w/o modification i'd def suggest we put it in a sticky. Since otherwise, at least for the flywheel bolts you are the dealers slave for $8 or so a bolt. Hopefully all parts come in and job gets done this saturday.... blah blah blah :eeks1:
 
Only thing i worried about on the PP bolts, was how well the smooth shank portion fit in the hole of the PP, since I wanted that fitment to be very close tolerance, so they act more like pins than bolts w/ the torque just holding them from backing out, not so much clamping the PP to the flywheel. Hope that made sense. If the Mr. gasket ones don't work out, hardware store it is.

As for the Flywheel -> crank bolts if they are what they say they are... 1" long the stock bolts (used/stretched) measure at .870". If my replacement flywheel is the same thickness as stock, they will stick out of the back of the crank .130" (1/8 inch) I will take a better look tomorrow (started pouring rain) if that would work. I think there is a good bit of clearance behind the crank so i may not need to grind the bolts. Good idea BTW w/ using the nut first then grind, but i'll one up ya, i was gonna use a dye =) I think i'd be much better off grinding the bolts some if i need clearance, compared to using washers to space them out.

Anyway when the job is done i'll let everyone know if these two bolt packages work well w/ or w/o modification. If they work w/o modification i'd def suggest we put it in a sticky. Since otherwise, at least for the flywheel bolts you are the dealers slave for $8 or so a bolt. Hopefully all parts come in and job gets done this saturday.... blah blah blah :eeks1:

The dye will let you know when to stop (if you don't have something handy you can set as a "GO-NO GO" gage...) but I run the nut right up under the head. Gives me more to hold on to while grinding, and you're just using the nut to chase the threads after grinding anyhow.

That measurement should be pretty close to when they came out - so about 7/8" long for manuals (The auto screws are a shade over 1/2" long underhead - the .590" long Pontiac screws from ARP worked neatly.)

I've not had any trouble using SHCS to retain the clutch cover - I've done it on a number of vehicles. Those holes aren't really "close tolerance" anyhow - you'd have to use a shoulder screw and play around with machining the screw holes in the flywheel to make that idea work properly.

I find it mildly odd that they didn't use place screws on the clutch cover (like they did on the flywheel/flexplate - and even on the torque converter-to-flexplate screws...) but there ya go. Probably because they're bearing against spring pressure just as much as they are against shearing forces? Dunno.
 
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