leaking front main seal
Anyone have any clue WTH it's keeps leaking? Pulley warped/damaged perhaps? Does anyone have a pic of what the snout of the pulley looks like? Mine has a few ridges that almost look like threads on it... but they look factory machined. Could the seal eventually wear the pulley snout like that?
Anyone have an aftermarket underdrive pully for sale???
Thanks!
Shannon
Also, the pulley shaft can wear a groove where the front cover o-ring seal rides - yes, I know rubber and steel but this has happened to me before - and that can sometimes lead to a leak at high RPM's. The fix would be to replace the pulley and front o-ring seal in the engine cover.
Hi Guys,
When you replace the seal, look very closely at a few things.
First, look at the surface of the harmonic balancer where the seal rides. Any groove or imperfection in that area is a potential leak.
Second, immediately before installing the timing cover, place a small bead of non-hardening sealant ~in the CORNER~ where the timing cover / oil pan / engine block meet. This little area, if not sealed, has a big potential for leaking. Don't go crazy and smear the sealant on the gasket surfaces, though!
Third, when installing the timing cover, install all of the cover bolts, but leave them loose....until AFTER the balancer is fully installed. After the balancer is in, THEN torque down the cover bolts. This automatically aligns the front main seal to the balancer shaft.
IHTH!!
KoreaJon
When you replace the seal, look very closely at a few things.
First, look at the surface of the harmonic balancer where the seal rides. Any groove or imperfection in that area is a potential leak.
Second, immediately before installing the timing cover, place a small bead of non-hardening sealant ~in the CORNER~ where the timing cover / oil pan / engine block meet. This little area, if not sealed, has a big potential for leaking. Don't go crazy and smear the sealant on the gasket surfaces, though!
Third, when installing the timing cover, install all of the cover bolts, but leave them loose....until AFTER the balancer is fully installed. After the balancer is in, THEN torque down the cover bolts. This automatically aligns the front main seal to the balancer shaft.
IHTH!!
KoreaJon
It's a big job and I'd rather have a permanent solution to this harmonic balancer issue. What manufacturer of harmonic balancer would go the distance? My old 2002 Yukon with a gen-3 5.3 liter went 175,000 with no issues. The vette is street use only (sure I beat it like a pinata but no actual racing). While we're in there we'll replace everything that may be worn, what else is recommended? Recommended manufacturers?
It's a big job and I'd rather have a permanent solution to this harmonic balancer issue. What manufacturer of harmonic balancer would go the distance? My old 2002 Yukon with a gen-3 5.3 liter went 175,000 with no issues. The vette is street use only (sure I beat it like a pinata but no actual racing). While we're in there we'll replace everything that may be worn, what else is recommended? Recommended manufacturers?
The Best of Corvette for Corvette Enthusiasts


It's a big job and I'd rather have a permanent solution to this harmonic balancer issue. What manufacturer of harmonic balancer would go the distance? My old 2002 Yukon with a gen-3 5.3 liter went 175,000 with no issues. The vette is street use only (sure I beat it like a pinata but no actual racing). While we're in there we'll replace everything that may be worn, what else is recommended? Recommended manufacturers?
Powerbond, ftw. AFAIK, the SLP unit is actually a Powerbond. SLP is not a manufacturer, whereas Powerbond is. Powerbond was recently bought by Dayco (the engine belt company), but still make their balancers same as always. They used to use a clear-coat finish over steel, but now they anodize or powdercoat all their premium series black.
Shop around, for the Powerbond unit, prices vary. Note: if you see "Dayco" brand name it may be them, but I haven't checked in quite awhile since the buyout. It's the "Race Performance Series" you want.
Install an ARP crank bolt, not the TTY OE bolt. If you can borrow/rent one, get a crank pin kit and pin the crank.
IF you want stock diameter (none underdrive), order:
PB1117SS
The 10% underdrive unit is:
PBU1117SS10
The 25% underdrive init is:
PBU1117SS25 (this is the one I use)
I checked and found the Dayco online catalog and it has the Powerbond series listed. Remember, their "Race Performance" series is the premium unit that most everyone around here uses, as they also make an OE replacement as well. You'll notice in the link, I preselected a "generic" 2002 C5 Corvette, but that's really irrelevant as all Corvette LS engines use the same, with only a couple exceptions. The F-body LS motors use a different part number (different belt groove arrangement).
http://www.daycoproducts.com/parts?c...scription=1137
HTH
It's a big job and I'd rather have a permanent solution to this harmonic balancer issue. What manufacturer of harmonic balancer would go the distance? My old 2002 Yukon with a gen-3 5.3 liter went 175,000 with no issues. The vette is street use only (sure I beat it like a pinata but no actual racing). While we're in there we'll replace everything that may be worn, what else is recommended? Recommended manufacturers?
Also just buy an arp bolt and pin kit, that way you wont have to worry about it spinning off. That's what I am doing. The balancer i ordered was number 917278. Steel hub and ac pulley. 10% underdrive.
Last edited by Socko; Jul 21, 2015 at 11:10 AM.
My buddy broke a timing chain due to the less than desirable power bond pulley because it was balanced like a turd. He was so happy with it, he kept all the bent valves as souvenirs.
Katech, who builds a ton of road race cars said "we will only use ati"
Get your hands on a powerbond, then a ati. You will see the difference.









