Front Crank Seal

ranger952 · October 22, 2011

Front crank seal behind the harmonic balancer is leaking. Years ago, I knew you developed a groove in the harmonic balancer and would have to replace or smooth out with emery cloth.

Is this still applicable? Should I replace the balancer along with the new seal? Has anyone done this on their 5.3? Special tools needed at all?

2006 GMC Sierra, 1.2 ton, 5.3, 4x4.

Thanks guys!

pm26 · October 23, 2011

I do not understand what groove you are talking about, but recently I replaced the front crank seal on my Mazda 626 and here are some tips:

1. Use an air impact wrench to loosen the center bolt holding the harmonic balancer to the crankshaft. Do not attempt to jam a bar in the spokes of the balancer and use a breaker bar, as you will shear the rubber ring that bonds two halves of the balancer.

2. Use harmonic balancer puller to pull the balancer off the shaft. Auto Zone rents these free with a deposit.

3. Removing the old seal may be tricky, depending whether it has an outer lip or not. The one on my Mazda does not have the lip and removing it is not easy. I typically use a small flat screwdriver and a hammer to distort the metal body of the seal. Then I will use an awl to punch a small hole in the metal body of the seal and then drive a drywall screw into the hole. After that I use a small sliding hammer to pull on the screw and this usually removes the seal without any trouble. I recommend not trying to use a power drill to drill the hole, as the drill bit can slip and score the seal housing. Using a seal removal tool to try to get a crank seal out can be risky and you can score the crankshaft rotating surface, which would be bad news!

4. To drive in a new seal, I had to fabricate my own tool from a piece of PVC pipe and PVC fitting. It was not possible to drive the seal in with a regular socket or a seal installation tool. I typically coat the inner seal rubber lip with some grease before the installation, and the outer part of the seal with a small amount of high temperature RTV for better sealing in the housing. Do not use RTV on the seal inner lip!

5. To reinstall and tighten the harmonic balancer bolt to proper torque spec, I typically use an air impact wrench with a properly rated torque extension. The torque extension will flex in synchrony with the beatings of the air wrench once the required torque is reached and will not allow overtorquing, regardless of the capacity of the air wrench. I also typically use blue Loktite on the threads of the bolt.

Some of the tips above may not apply to your truck, especially if the seal has an outer lip. In that case, it is simple to remove with a screwdriver. Also a new seal will be easy to drive in.

ranger952 · October 23, 2011

I do not understand what groove you are talking about, but recently I replaced the front crank seal on my Mazda 626 and here are some tips:

1. Use an air impact wrench to loosen the center bolt holding the harmonic balancer to the crankshaft. Do not attempt to jam a bar in the spokes of the balancer and use a breaker bar, as you will shear the rubber ring that bonds two halves of the balancer.

2. Use harmonic balancer puller to pull the balancer off the shaft. Auto Zone rents these free with a deposit.

3. Removing the old seal may be tricky, depending whether it has an outer lip or not. The one on my Mazda does not have the lip and removing it is not easy. I typically use a small flat screwdriver and a hammer to distort the metal body of the seal. Then I will use an awl to punch a small hole in the metal body of the seal and then drive a drywall screw into the hole. After that I use a small sliding hammer to pull on the screw and this usually removes the seal without any trouble. I recommend not trying to use a power drill to drill the hole, as the drill bit can slip and score the seal housing. Using a seal removal tool to try to get a crank seal out can be risky and you can score the crankshaft rotating surface, which would be bad news!

4. To drive in a new seal, I had to fabricate my own tool from a piece of PVC pipe and PVC fitting. It was not possible to drive the seal in with a regular socket or a seal installation tool. I typically coat the inner seal rubber lip with some grease before the installation, and the outer part of the seal with a small amount of high temperature RTV for better sealing in the housing. Do not use RTV on the seal inner lip!

5. To reinstall and tighten the harmonic balancer bolt to proper torque spec, I typically use an air impact wrench with a properly rated torque extension. The torque extension will flex in synchrony with the beatings of the air wrench once the required torque is reached and will not allow overtorquing, regardless of the capacity of the air wrench. I also typically use blue Loktite on the threads of the bolt.

Some of the tips above may not apply to your truck, especially if the seal has an outer lip. In that case, it is simple to remove with a screwdriver. Also a new seal will be easy to drive in.

THanks for the reply. SOunds like it is the same as when I did one beofre. That was a long time ago.

Got the parts ordered. Sounds like fun too!

2010LTZ4x4 · October 23, 2011

You missed one thing. You will need to put a sleeve on the crank nose.

They can be bought at any performance shop it comes with lock tite and a very thin sleeve that slides over the crank nose and gives the new seal a smooth flat surface to seal on.

Thats what I did when I did my small block chevy. Never leaked again.

ranger952 · October 23, 2011

You missed one thing. You will need to put a sleeve on the crank nose.
They can be bought at any performance shop it comes with lock tite and a very thin sleeve that slides over the crank nose and gives the new seal a smooth flat surface to seal on.

Thats what I did when I did my small block chevy. Never leaked again.

That's exactly the type of info I was looking for. Would NAPA or similar carry that?

ranger952 · October 23, 2011

You missed one thing. You will need to put a sleeve on the crank nose.
They can be bought at any performance shop it comes with lock tite and a very thin sleeve that slides over the crank nose and gives the new seal a smooth flat surface to seal on.

Thats what I did when I did my small block chevy. Never leaked again.

That's exactly the type of info I was looking for. Would NAPA or similar carry that?

If I am planning on buyg a new balancer and seal, would I still need the sleeve? I looked around a little bit about those. Looks like they are for use with the old balancers in case there is a groove worn in it.

2010LTZ4x4 · October 23, 2011

You missed one thing. You will need to put a sleeve on the crank nose.
They can be bought at any performance shop it comes with lock tite and a very thin sleeve that slides over the crank nose and gives the new seal a smooth flat surface to seal on.

Thats what I did when I did my small block chevy. Never leaked again.

That's exactly the type of info I was looking for. Would NAPA or similar carry that?

If I am planning on buyg a new balancer and seal, would I still need the sleeve? I looked around a little bit about those. Looks like they are for use with the old balancers in case there is a groove worn in it.

Even if you use a new balancer the groove is in the shaft.

Maybe they don't make them for the newer GM motors.

I would still check with a performance shop and let them source one out.

pm26 · October 23, 2011

My car, which I changed the front crank seal on, has a timing belt. The timing belt lower sprocket and the balancer itself is held in place by a square key, so there is a square notch cut into the crank shaft front. However, the seal goes into the block beyond the notched area.

If I remember correctly, on many American V8 engines which have a timing chain, the front crank seal fits into the timing cover, and there is an oil slinger behind it. Is this what you call a sleeve?

babydeuce · October 23, 2011

You missed one thing. You will need to put a sleeve on the crank nose.
They can be bought at any performance shop it comes with lock tite and a very thin sleeve that slides over the crank nose and gives the new seal a smooth flat surface to seal on.

Thats what I did when I did my small block chevy. Never leaked again.

That's exactly the type of info I was looking for. Would NAPA or similar carry that?

If I am planning on buyg a new balancer and seal, would I still need the sleeve? I looked around a little bit about those. Looks like they are for use with the old balancers in case there is a groove worn in it.

Despite what has been previously said, if you install a new balancer, you will not need to sleeve anything. On SBC/LS series engines, the seal is made on the balancer not the crank. The balancer is pressed on and bolted to the crankshaft nose. If you tried to "sleeve" the nose of the crankshaft, you would NEVER get the balancer installed. Depending on the milage of vehicle, and the condition of the original balancer, you may not have developed a groove from the crank seal, in which case you can clean the balancer surface with fine emery cloth and install.

This is not a SBC, but same setup, notice how the crank nose does not touch the seal... http://telusplanet.net/public/cdkruchk/4.5...ld/IMG_1763.JPG The balancer would be pressed on the crank snout and make the seal to the timing cover.

Jack

jblakeney · October 23, 2011

You need a new balancer, or a Speede-Sleeve. I am a NAPA Jobber, Sometimes they are offered in with the timing cover gasket sets. Other times, you can look them up in SKF just by looking up the timing cover seal. Other times you must end up looking them up the old fashion way in the specs sheets in the catalog.

Call around and ask about a Timing Cover set with a Speede-Sleeve, if I was at work I would look it up for you. We have them in Fel-Pro in timing sets and in SKF with our seals.

Or you could buy a new balancer. But the speede-sleeve will fix this problem.

Jbo

Edit: Ok, I looked it up on SKF's website..... Its a 99215 Speede-Sleeve and a 21605 Seal. And you will need a Fel-Pro TCS-45993 (Fel-pro doesn't list this one with the sleeve in the box)

ranger952 · October 23, 2011

You need a new balancer, or a Speede-Sleeve. I am a NAPA Jobber, Sometimes they are offered in with the timing cover gasket sets. Other times, you can look them up in SKF just by looking up the timing cover seal. Other times you must end up looking them up the old fashion way in the specs sheets in the catalog.

Call around and ask about a Timing Cover set with a Speede-Sleeve, if I was at work I would look it up for you. We have them in Fel-Pro in timing sets and in SKF with our seals.

Or you could buy a new balancer. But the speede-sleeve will fix this problem.

Jbo

Edit: Ok, I looked it up on SKF's website..... Its a 99215 Speede-Sleeve and a 21605 Seal. And you will need a Fel-Pro TCS-45993 (Fel-pro doesn't list this one with the sleeve in the box)

Guys,

Thanks for all the info. I am going to just go with the new balancer and new seal. From what I am seeing, that should take care of it.

Just didnt want to see the leak back in 10k miles.

ranger952 · October 28, 2011

You need a new balancer, or a Speede-Sleeve. I am a NAPA Jobber, Sometimes they are offered in with the timing cover gasket sets. Other times, you can look them up in SKF just by looking up the timing cover seal. Other times you must end up looking them up the old fashion way in the specs sheets in the catalog.

Call around and ask about a Timing Cover set with a Speede-Sleeve, if I was at work I would look it up for you. We have them in Fel-Pro in timing sets and in SKF with our seals.

Or you could buy a new balancer. But the speede-sleeve will fix this problem.

Jbo

Edit: Ok, I looked it up on SKF's website..... Its a 99215 Speede-Sleeve and a 21605 Seal. And you will need a Fel-Pro TCS-45993 (Fel-pro doesn't list this one with the sleeve in the box)

Guys,

Thanks for all the info. I am going to just go with the new balancer and new seal. From what I am seeing, that should take care of it.

Just didnt want to see the leak back in 10k miles.

Got it done last night. The old balancer had a groove in it. Glad I replaced it. I have done harder ones on past vehicles, that's for sure.

If you have to do yours, the new balancer was $160.00 bucks. I probably could have rubbed that groove out with an emery cloth, like in the "old" days, but why risk it???????

Just my two cents............................