My rear main increased oil leakage after my last 230-mile, 90mph sprint down the interstate. The car has always weeped a slight amount of oil (not enough to drip) around the hole in the inspection cover, but this time it pretty much coated the plastic cover and some of the inside of the tranny housing. Still not enough to drip, but enough to concern me as it changed.

I just put a Streetdampr on awhile back, but in around town driving didn't notice any increased leakage. Before my trip, I changed back to 10W-30 M1 from 15W-50, but I used to run 5W-30 Mobil 1 in it with no problems.

So my question is, is the Streetdampr LESS effective at controlling engine vibrations at low RPM (1800-2600) than the stock torsional damper, thereby causing increased distortion of the seal and leakage, or is this just an odd coincidence?

I did feel some vibration around 85mph or so, but it seemed to go away above it. Maybe it's the driveshaft (stock steel)?

------------------
1990 IROC 350
Mods: Too busy trying to make it run right to mod it.
Airfoil, Dynomax cat-back, MSD coil, 180 t-stat, Bald Eagle tires,
Hypertech fan switch, Accel 23# injectors, Holley module, ported plenum,
Ported Daytona Yellow stock base, Moroso valve covers, other stuff,
Streetdampr, Ruger P95DC, hot wife, new oil filter, !cats, !TBC, !AIR.
18.0 @ 85MPH since I'm one big-a$$ MF
"It's better to have and not need than to need and not have."

 

i think it is probably a coincidence. A fluid damper should reduce vibs at all speeds.

 

no, actually its better. going from 15-50 to 10-30 will be the difference you noticed, that and mobil one will make leaks more apparent than dino oil. time to replace that rear main! its not to hard, just time consuming.