Thread: Crank position sensor

Originally Posted by dbextreme

The front main seal is what the balancer slides into. It seals so oil doesn't leak. I was suggesting it because you will be right there, you'll just have to remove the old one and tap in a new one before you put things back together. (I'd get a GM one, they are like $16 at most I believe.) You can leave it alone, but if you have high mileage and start fooling with it by sliding the balancer on and off it might not seal back up properly... I just always have preventative maintenance on my mind..

This. When I did my cam install I neglected to change the seal and what do you know had to replace the leaking seal last week >_<

I hardly do case learns on cars. Only time is when the person has performance work done and is looking for all out power. The 3x and 18x rings plus cam sensor do a pretty good job of telling the pcm where the crank is ..

I just did it last Friday on 3.8. Bottom line, I did not have to do a case learn and it worked fine.
As far as the puller, bought the harbor freight cheap puller, went to ace bought the bolts. 1/4" - 28 (fine thread). I used 3", but I have seen post where they used 3 1/2" long. Definitely used grade 8 for the bolts and washers and screw them in far.

Bill has a good "How to" here:
http://www.grandprixforums.net/how-r...tml#post771701

Here is a blurb I posted of my experience:
http://www.grandprixforums.net/97-gp...ml#post1083872

Yup most of the time they don't.

I'm not sure what the seal number is. I just called my local Buick dealer (or you can call your local GM dealer either or) and had them look up a front main seal for a 3800. All the GM series 2 and 3 use the same seal IIRC.

I just did it last Friday on 3.8. Bottom line, I did not have to do a case learn and it worked fine.
As far as the puller, bought the harbor freight cheap puller, went to ace bought the bolts. 1/4" - 28 (fine thread). I used 3", but I have seen post where they used 3 1/2" long. Definitely used grade 8 for the bolts and washers and screw them in far.

^^^ If you are going to take the time to go to Ace and get the bolts, get the right ones.. LOL that way you don't booger up your threads.. The 1/4' will work in a pinch if that's all you have.

And I am not a big fan of the Felpro front crank seal. The actual GM seal seems to be a lot better quality. But that's my $.02. If you local parts store does not have just the seal alone, you can get the timing cover gasket set if you go felpro...

It is, if you go Felpro... The timing kit is like what $9? lol But like I said, if you want to spend a couple extra bucks, the GM seal will be better off. I believe it's more of a double seal then a single lip.. Others can elaborate on it, it's just my opinion.

No that is a transmission seal.

Have you used RockAuto much? It's a great site.

Here's the national front seal number.



The second pic is the cross referenced number you posted from amazon. It looks like it's a transmission seal and where amazon has it for $6.38 RockAuto.com has it for under $2...

Originally Posted by 94grandprix

Ok I'm ordering it tonight,thanks

check out this article on trouble shooting a crank position sensor.

Part 1 -GM 3.8L Ignition Module Test and Crank Sensor Test (3X, 18X)