91blkvette

I don't feel so bad now. I've been chasing leaks on my 427 for 2 years now. Three oil pan gaskets, two flexible SS oil dipsticks (stock ones won't fit due to my AHR headers), and 5 or so Felpro 1206 gasket sets...I still have a small leak coming from the damper seal.

But..install an engine evac system (elec vacuum pump) to vent the block. It is also a proven HP adder. Simple to build, I made one using a German engineered EGR pump. Also have a breather attached to an PCV on one valve cover. My pump comes on above 1500 rpm.

1985 Corvette

Alright, hate to revive this sinking thread but my starter decided to chew itself up, leaving me stranded at a gas station for a bit. So with the car on jack stands, I better do this before the Florida summer hits. So, for the third new rear main seal going into this engine, what's a good grease to smear on the seal area that contacts the crank? I'm still going to take the seal housing off to open the bolt holes so I have some play to center the seal as best as possible on the crank.

Best angle to get the ZF trans to slide out? I forgot how much of a pain in the *** this part can be. Clutch pedal is held down with a broom stick while I'm under the car with a trans jack altering the angles. Only got the trans to pull out of the bell housing about an inch. Gave up after about 30 minutes of wrestling with it.

856SPEED

I would check the oil sending unit on the back side of the block as well while you are at it. I think mine is leaking from there as oil is in the same area as you described. They like to leak from there as well.

ToniJ1960

do you get a varying readout of the oil pressure due to it leaking?

mtwoolford

Total Seal could be...pick one...conventional with gapped first and second compression rings...gapless second ring...or...gapless top ring.

remove your oil filler cap from the valve cover,, place a light weight piece of paper flat over the hole, if it wants to suck in, the crankcase is under a vacumn and the pcv system is working properly, but if it shows any sign of lifting up, you've got positive crankcase pressure caused by blowby and it will only get worse as engine load and rpm increase.

1985 Corvette

May need to look at a vacuum pump if that will help my situation and if it's applicable. Before I get to that part I finally wrestled the ZF out again....the weight of this trans gets me everytime. I've had a leak on the rear seal even after replacing the seal not too long ago. I think I may need a new slip yoke. It's not pouring out but even the beam plates were wet with gear fluid and I had a droplet hanging on the bottom of the tailshaft.






So front of the trans is dry which is good news so far. ZF doc has informed me the seal is no longer produced for the front of the case, although it is rare a ZF develops a leak that pushes gear fluid out the front. I was wondering if my leak was the ZF but it doesn't seem to be the case. So a new slip yoke from Doc is $200.... probably going to bite in a few days but want to look at the back of the motor first.

mtwoolford

get a "heavy duty" rear bushing from ZFdoc and install it...easy...and new rear main seal. the Heavy duty bushing is longer and will stabilize the slip yoke better than the shorter oem bushing.

1985 Corvette

Working with The Doc on that as of last night. He's gonna send me an invoice for the bushing, a few shims and seals.

1985 Corvette

More pics of carnage before I get to the main reason for tearing everything out. What is going on? Part of the flywheel seems to have early signs of heat marks, but only in one spot. I spent more time than I care to say making sure the flywheel and clutch pack were all torqued down and everything flush. Everything clutch related including the hydraulics are new and bled. The marks match the pressure plate.








I'm beginning to regret this SPEC Stage 3+ for a street car as there's no modest roll out. Car tries to shake itself apart if you try to let the clutch even modestly: you're either at a stop or immediately going 20 mph in 1st gear when you let the clutch out without slipping it. I know it's gotta break in but you can tell from the short amount of time I've driven it I'm ******* it up. I might do a different clutch.

C409

..... Its a friction surface ... put it together and drive it ! .....

1985 Corvette

Not going back together yet. Pulled off the flywheel and there's a small groove cut into a small portion of the surface that my fingernail catches. Not sure how it happened as everything was cleaned over and over again before it all went together. Might take it be resurfaced as I've got a few light blue rings. 30 miles of driving......not sure this counts as normal wear. My fault for slipping the clutch too much.


Edit: Alright Moron Alert: I never dialed in this bellhousing. That might be contributing to the issues I've had, including the leaking rear main seal again. Additionally, I may have had excess grease on the TOB that got flung on the clutch pack causing some of these mark. I made the simplest thing on this car a cluster ****.