warp9pnt9
10-23-07, 07:45 AM
Summary:
0) 1997 Chevy Blazer ZR2
1) 4WD does not (dis?)engage (2WD, 4-HI, 4-LO buttons on dash)
2) Leaking gear oil from shift cable housing assembly
3) Leaky intake manifold gasket
Sent the ZR2 to the shop for oil pan gasket change about 7 weeks ago. It came back and about a week later, Pressing either 4-HI or 4-LO would blink, click a few times, then nothing. No lights stayed on. No indication if it was engaged or not. Tried this on a level surface at a stop and at an idling roll < 5 m.p.h. Mostly do 2WD on city streets anyways.
Looking under the vehicle, the shift cable housing that attaches to the front differential was leaking lot of oil, indicated by the sizable slick spot on the pavement underneath. I topped off the front diff gear oil. It was down so low that when I tried to remove any old oil (with a 1 quart syringe) I couldn't even get a tube wet with oil. But I couldn't exactly get the tube to go down too far from the inspect/fill plug as there seemed to be some mechanical parts in the way no matter what way I tried to route the tube.
The 4WD buttons now do not even blink, and the leaking rate has increased; I can wait and see a drop each few seconds.
I've looked and followed lines (cables, hoses, wires, etc) by eye and checked my Haynes and Chilton's books and pieced together the parts involved and the nomenclature.
Given that I know I'm leaking coolant, and have a leaky intake manifold gasket, I'm aware that the vacuum actuator may simply not be getting enough vacuum to operate properly. So first I'm going to change the IM gaskets and see if that 4WD engage/disengage problem goes away.
About the leaking shift cable housing, it there a gasket or a seal inside there, or just some RTV? Is there possibly something mechanical wrong, like a partially engaged shift fork that maybe got banged and push back against the housing or something causing the gear oil leak from the diff? Regardless of vacuum actuator status, I think this is an independent problem to fix first. Correct assessment? So how to go about it?
0) 1997 Chevy Blazer ZR2
1) 4WD does not (dis?)engage (2WD, 4-HI, 4-LO buttons on dash)
2) Leaking gear oil from shift cable housing assembly
3) Leaky intake manifold gasket
Sent the ZR2 to the shop for oil pan gasket change about 7 weeks ago. It came back and about a week later, Pressing either 4-HI or 4-LO would blink, click a few times, then nothing. No lights stayed on. No indication if it was engaged or not. Tried this on a level surface at a stop and at an idling roll < 5 m.p.h. Mostly do 2WD on city streets anyways.
Looking under the vehicle, the shift cable housing that attaches to the front differential was leaking lot of oil, indicated by the sizable slick spot on the pavement underneath. I topped off the front diff gear oil. It was down so low that when I tried to remove any old oil (with a 1 quart syringe) I couldn't even get a tube wet with oil. But I couldn't exactly get the tube to go down too far from the inspect/fill plug as there seemed to be some mechanical parts in the way no matter what way I tried to route the tube.
The 4WD buttons now do not even blink, and the leaking rate has increased; I can wait and see a drop each few seconds.
I've looked and followed lines (cables, hoses, wires, etc) by eye and checked my Haynes and Chilton's books and pieced together the parts involved and the nomenclature.
Given that I know I'm leaking coolant, and have a leaky intake manifold gasket, I'm aware that the vacuum actuator may simply not be getting enough vacuum to operate properly. So first I'm going to change the IM gaskets and see if that 4WD engage/disengage problem goes away.
About the leaking shift cable housing, it there a gasket or a seal inside there, or just some RTV? Is there possibly something mechanical wrong, like a partially engaged shift fork that maybe got banged and push back against the housing or something causing the gear oil leak from the diff? Regardless of vacuum actuator status, I think this is an independent problem to fix first. Correct assessment? So how to go about it?