Leaking VSS

[Scooterwrench]

Has anybody ever seen the sensor itself leak? About six weeks ago I checked my fluid and it was 1/2qt low so I crawled under there and found a drop of fluid hanging below the VSS,dry everywhere else. Went to NAPA and got a new VSS o-ring and changed it. Yesterday I was under there again taking measurements for the muffler I have to make and there was that damn drip again.

 

[NickTransmissions]

Has anybody ever seen the sensor itself leak? About six weeks ago I checked my fluid and it was 1/2qt low so I crawled under there and found a drop of fluid hanging below the VSS,dry everywhere else. Went to NAPA and got a new VSS o-ring and changed it. Yesterday I was under there again taking measurements for the muffler I have to make and there was that damn drip again.

What transmission or are you referring to a VSS in a transfer case?

As an aside, I'd only buy AC Delco or Rostra brand VSS. If that's what NAPA sold you, it should be fine.

Are you sure it's leaking through the sensor and not the bore?

 

[Scooterwrench]

What transmission or are you referring to a VSS in a transfer case?

As an aside, I'd only buy AC Delco or Rostra brand VSS. If that's what NAPA sold you, it should be fine.

Are you sure it's leaking through the sensor and not the bore?

'91 700R4 2WD The large sensor. I suspected the O-ring and and bought just that. Cleaned the area around the sensor,removed it and replaced just the O-ring. The bore was smooth,no knicks or gouges. I didn't see any cracks in the sensor and the O-ring groove looked good. Lubed the new O-ring with Vaseline. I'm not sure where it's leaking. New O-ring,good bore,installed correctly. Only thing I can think of is it's leaking where the terminals exit the sensor body.
I saw those Rostra sensors listed,so they're OK?

 

[NickTransmissions]

'91 700R4 2WD The large sensor. I suspected the O-ring and and bought just that. Cleaned the area around the sensor,removed it and replaced just the O-ring. The bore was smooth,no knicks or gouges. I didn't see any cracks in the sensor and the O-ring groove looked good. Lubed the new O-ring with Vaseline. I'm not sure where it's leaking. New O-ring,good bore,installed correctly. Only thing I can think of is it's leaking where the terminals exit the sensor body.
I saw those Rostra sensors listed,so they're OK?

Rostra is fine, i use those all the time in my 700 and early 4L60E builds. If it continues to leak, replace the extension housing. Ive seen a few that were worn out for whatever reason. They look fine by eye but leak.

 

[Scooterwrench]

Rostra is fine, i use those all the time in my 700 and early 4L60E builds. If it continues to leak, replace the extension housing. Ive seen a few that were worn out for whatever reason. They look fine by eye but leak.

Kind'a like mid 70's Harleys. Castings have flaws and leaked like a sieve. I'll get under there tomorrow and thoroughly clean it and dry it. I've got 100 mile round trip Tues,hopfully the leak will show by the time I get back.

 

[Scooterwrench]

Think I found it. Apparently when this tranny was rebuilt the guy used a pick tool to get up under the O-ring and gouged the groove creating a trough for fluid to pass through. I missed it when I replaced the O-ring. I worked a little ultra black sillycone down in the groove,re-installed the O-ring and cleaned off the excess. Waiting the the sillycone to kick off now before I pop it back in.

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Moral to the story, don't use pick tools on plastic or if you do be damn careful.

 

[NickTransmissions]

Think I found it. Apparently when this tranny was rebuilt the guy used a pick tool to get up under the O-ring and gouged the groove creating a trough for fluid to pass through. I missed it when I replaced the O-ring. I worked a little ultra black sillycone down in the groove,re-installed the O-ring and cleaned off the excess. Waiting the the sillycone to kick off now before I pop it back in. Moral to the story, don't use pick tools on plastic or if you do be damn careful.

I always use a flat blade screw driver to gently pry them out but I'm not overly concerned about damage as I always replace them with new which is what the previous rebuilder should have done as well...Hope that indeed fixes it so you don't have to replace it or the housing.

 

[Scooterwrench]

Hope that indeed fixes it so you don't have to replace it or the housing.

Yeah, me too. The sensor doesn't cost that much but those housings pricey.

 

[Scooterwrench]

Well shnit, Just got back from my service call and I can see tranny fluid around the sensor. Hasn't formed a drip yet but it's still a leak.
Hey Nick, Are the tail housings on 700R4 and 4L60-E interchangeable?

 

[NickTransmissions]

Well shnit, Just got back from my service call and I can see tranny fluid around the sensor. Hasn't formed a drip yet but it's still a leak.
Hey Nick, Are the tail housings on 700R4 and 4L60-E interchangeable?

I just happened to see you posted = please quote or mention me otherwise I won't know you responded....Yes, the 700R4 and early 4L60E 2WD large hole ext housings are interchangeable.