65 LUK throwout bearing

[John M.]

Re: 65 LUK throwout bearing

DSC01459.JPGJoe, Heres a photo. Wouldn't it be more effective to put a smaller weight out further. Note the three different bolts.

[Joe L.]

Re: 65 LUK throwout bearing

[ATTACH=CONFIG]41036[/ATTACH]Joe, Heres a photo. Wouldn't it be more effective to put a smaller weight out further. Note the three different bolts.

John------


That's exactly like some of the ones I've seen in the past. As far as the different bolts go, it's possible that this is a rebuilt pressure plate assembly that's been through a commercial rebuilder's facility.

[John M.]

Re: 65 LUK throwout bearing

Sorry to bug you guys, but I have one more question. Can anyone give me the length of the rod from the clutch fork to Zbar for a 65 SB? I can then compare that to what's in the car to see if it's correct.
Thanks,
John

[John H.]

Re: 65 LUK throwout bearing

Sorry to bug you guys, but I have one more question. Can anyone give me the length of the rod from the clutch fork to Zbar for a 65 SB? I can then compare that to what's in the car to see if it's correct.
Thanks,
John

John -

A '65 SB used P/N 3844209 fork pushrod, which was 10-9/16" long. That changed in mid-'66 to P/N 3872960, which was 8-9/16" long, in conjunction with P/N 3888213 new pedal pushrod, which was 1-1/4" longer, at 19-1/4".

[John M.]

Re: 65 LUK throwout bearing

Thanks John,
I'll check that out when I get the car back; it's at the body shop to correct a couple little errors and for a new top. Are the Zbars the same? lots of possible combos.
I'll measure everything and post the numbers.
John

[John H.]

Re: 65 LUK throwout bearing

Thanks John,
I'll check that out when I get the car back; it's at the body shop to correct a couple little errors and for a new top. Are the Zbars the same? lots of possible combos.
I'll measure everything and post the numbers.
John

John -

No, they're not. My notes show that the '63-E66 Z-bar was #3832857, which had 135* arm separation, and the mid-'66-'67 Z-bar was #3888279, which had 155* arm separation.

[James W.]

Re: 65 LUK throwout bearing

John -

A '65 SB used P/N 3844209 fork pushrod, which was 10-9/16" long. That changed in mid-'66 to P/N 3872960, which was 8-9/16" long, in conjunction with P/N 3888213 new pedal pushrod, which was 1-1/4" longer, at 19-1/4".

John,

What is the correct length of a '65 BB fork pushrod?

Is the correct LUK clutch kit for a '65 BB #04-049 and the throwout bearing different than the 1-1/4" length described above?

Thanks,

James West

[Joe L.]

Re: 65 LUK throwout bearing

John,

What is the correct length of a '65 BB fork pushrod?

Is the correct LUK clutch kit for a '65 BB #04-049 and the throwout bearing different than the 1-1/4" length described above?


Thanks,

James West

James-----


The 1965 L-78 clutch fork pushrod is GM #3872960 and is 8-37/64" OL.

1965 L-78 used a HD 10.4" clutch. I believe the closest LUK part is #04-021. Their 04-049 is an 11" clutch.

Release bearing, which comes with the kit, is 1-1/4".

[John M.]

Re: 65 LUK throwout bearing

John, Joe, Joe, and all. I just got a fiberoptic borescope, and after struggling a bit found that the throwout bearing is in there correctly and the pressure plate is a "bent finger" one. I was thinking, aha, here's the problem but John's post says that's what it's supposed to be. The one that was in the car seems to be more like the flat finger type. So I'm still in the same position with the nuts close to the top end of the travel on the rod from the pedal. The other rods and Zbar are correct for this year also. I'm afraid that Im going to have to take the transmission out just to try to "solve" this mystery. Myabe the ball stud is wrong??John

[Joe C.]

Re: 65 LUK throwout bearing

John, Joe, Joe, and all. I just got a fiberoptic borescope, and after struggling a bit found that the throwout bearing is in there correctly and the pressure plate is a "bent finger" one. I was thinking, aha, here's the problem but John's post says that's what it's supposed to be. The one that was in the car seems to be more like the flat finger type. So I'm still in the same position with the nuts close to the top end of the travel on the rod from the pedal. The other rods and Zbar are correct for this year also. I'm afraid that Im going to have to take the transmission out just to try to "solve" this mystery. Myabe the ball stud is wrong??John

John,

Note the position of the clutch fork in these photos. This is the position that it should be in with a brand new clutch disc when the TO bearing is contacting the PP fingers (zero freeplay). In this installation, the adjusting jam nuts are about 1" from the forward end of the adjustment rod with brand new equipment. If this is how your clutch fork is positioned, then you either have an improper bellcrank or improper link (lower clutch rod) between the bellcrank and the fork.

If the clutch fork is correctly located in this position with the release bearing contacting the diaphragm spring, then that implies that you have the design geometry correct as relates to ball stud length, clutch fork shape and size, flywheel friction surface location, release bearing height, and pressure plate diaphragm spring thrust location. If one or more of these dimensions is different from original design, then it must be compensated for as was done in the pictured application.

IMG_0108.jpgIMG_0109.jpgIMG_0110.jpg

[Joe L.]

Re: 65 LUK throwout bearing

John, Joe, Joe, and all. I just got a fiberoptic borescope, and after struggling a bit found that the throwout bearing is in there correctly and the pressure plate is a "bent finger" one. I was thinking, aha, here's the problem but John's post says that's what it's supposed to be. The one that was in the car seems to be more like the flat finger type. So I'm still in the same position with the nuts close to the top end of the travel on the rod from the pedal. The other rods and Zbar are correct for this year also. I'm afraid that Im going to have to take the transmission out just to try to "solve" this mystery. Myabe the ball stud is wrong??John

John------


The ball stud should be 1-1/2" in overall length.

[John M.]

Re: 65 LUK throwout bearing

1965 327/"365", 529 BHP @ 7000 RPM..........all motor

Holy Mackeral Joe!!!

Thanks for the replies guys, Ill check this out.
John

[Joe C.]

Re: 65 LUK throwout bearing

1965 327/"365", 529 BHP @ 7000 RPM..........all motor

Holy Mackeral Joe!!!

Thanks for the replies guys, Ill check this out.
John

Actually, it's: "Holaamagilandy !"

http://www.youtube.com/watch?v=Co_DKnPi3Yw

It may not be easy for you to ascertain whether or not your clutch fork is positioned properly within the bell housing. After removing the rubber boot, the straight part of the fork (the part that comes out of the bell before it bends forward) must be approximately perpendicular to the fore-aft axis of the engine/trans assembly. You should take pictures and post them here for us to scrutinize, which is what we NCRS nerds do best.

[John M.]

Re: 65 LUK throwout bearing

DSC01677.jpgDSC01680.JPGDSC01679.JPG


Joe, Ed, John,

Thanks to you guys I finally figured out what was wrong and, yes, I am a dope. The fiber optic scope showed that all the parts in the bell housing were correct and appeared to be installed correctly. So, I took the Zbar and the linkage out and made careful measurements. It was the wrong Zbar; a 66-67 155 degree one rather than the correct 135 degree 65. Thanks John H. It appears that a previous owner used a flat finger clutch with the corvette throwout bearing which would then require a different throw position on the Z bar and the 155 degree provided it and it worked fine. So when I put the correct clutch back in the combo did not work right. It worked but was way off position. So thanks guys, you've saved me again. I was thinking of taking the trans out of there..... The photos show where the fork is when in contact with the throwout bearing, where the adjusting nuts ended up and the two Zbars, 135 degree in the foreground.