Real crank seal

[Mr. Pockets]

When I replace the transmission in my SVX this Spring, I figure it might be a good idea to also replace the rear main seal. The seal is cheap, but looks difficult to get out. To replace the front seal, I actually removed the oil pump from the engine and popped the seal out of the pump. It was hard to get out of there, so I can only imagine how hard the task is without removing the pump.

With the rear seal, I don't have that option. It's set in between the two halves of the block and around the crank, with nothing else to remove to make the task easier.

Any suggestions?

Thanks.

[svx_commuter]

Hi Nick

I have done the front seal on the crank. Left the oil pump in and pulled the old seal out using the "Beav" method.

When I took out my broken engine I thought I would look at the rear seal. The flex plate has to come off. Oh yeah the engine or the transmission has to come out to get in there.

There is a special tool that holds the flexplate to the engine block. This keeps the flexplate and crank from rotating. It goes in one hole of the flex plate and looks like a great way to break the flexplate. All the torque required to remove the flexplate bolts will go into that one hole the tool is in.

The flex plate bolts are burried in the crank shaft. There is no way to get any PB Blaster on them. The ones on my engine look rusty. I tried just to see if I could break them loose. Made up something to hold the flex plate, used a 3' pipe on a breaker bar and no budge at all. I think this definantly IMPACT wrench terratory. A BIG impact wrench at that.

The seal is rather large in size. A good special tool or big socket would be required to push the seal in place. I do not remember if the oil seperator plate has to come off before the seal. But it would be a good Idea to do that gasket as well as you are there.

[Mr. Pockets]

While I appreciate your detail on how to get to the rear seal, it doesn't really answer my question - how to get the seal out.

Getting a new one in I'm not worried about - I used a PVC fitting that was roughly the same size as the front seal to push that in. I imagine I can do the same with the rear seal.

So, how do you extract the rear seal without damaging the crank or the engine block?

[Beav]

I use a 1/8th inch drill and carefully drill a hole or two in the seal, making sure to not nick the shaft or the seal land. After the holes are made you can use 90° picks or small sheet metal screws in the holes and grab those with pliers to pry the seal out. Patience and care are the key words here.

Also check for an access plate or two on the rear of the block when you have the flexplate off. It seems to me I've read (maybe on other model Subies) that these plates have no gasket and are sealed with RTV only. Over time the RTV begins to leak and is confused as a rear main leak.

[Mr. Pockets]

Originally posted by Beav
I use a 1/8th inch drill and carefully drill a hole or two in the seal, making sure to not nick the shaft or the seal land. After the holes are made you can use 90° picks or small sheet metal screws in the holes and grab those with pliers to pry the seal out. Patience and care are the key words here.

Also check for an access plate or two on the rear of the block when you have the flexplate off. It seems to me I've read (maybe on other model Subies) that these plates have no gasket and are sealed with RTV only. Over time the RTV begins to leak and is confused as a rear main leak.

Thanks, Beav. I'll have to remember that method when it comes time to replace the seal. Do you think it's right to replace it while I'm in there, or should I just leave well enough alone?

As for the access plate, I think that's the problem my mom's Legacy had earlier this year. The car was gushing oil out of the back. There was a TSB and a replacement access plate. But, apparently, it took Subaru a couple of tries to get it right and there was a second replacement plate under a different part number. My mom's dealer ran through the entire gamut of solutions before settling on the final Subaru TSB on the issue.

Of course, they had to remove the tranny a good three times first...

So should I just remove that plate and re-seal it with RTV while I'm in there?

[Beav]

1) It's like replacing your water pump when changing the t-belt. If you don't do it now there's a good chance you'll be there again in the near future. Especially if you have my luck. And getting to it is so much fun...

2) If indeed there is an access plate back there I'd be inclined to cut a gasket, I'm not much of a believer in RTV. It's o.k. for corners, etc., but nothing beats a good gasket for longevity.

[Mr. Pockets]

Originally posted by Beav
2) If indeed there is an access plate back there I'd be inclined to cut a gasket, I'm not much of a believer in RTV. It's o.k. for corners, etc., but nothing beats a good gasket for longevity.

Ah...so now you tell me...now that my oil pump is sealed with RTV.

[svx_commuter]

Originally posted by Beav
I use a 1/8th inch drill and carefully drill a hole or two in the seal, making sure to not nick the shaft or the seal land. After the holes are made you can use 90° picks or small sheet metal screws in the holes and grab those with pliers to pry the seal out. Patience and care are the key words here.

Ah yes the "Beav" method works quite well.

I like to use the pliers as a lever.

[Beav]

Originally posted by Mr. Pockets


Ah...so now you tell me...now that my oil pump is sealed with RTV.

When I said that remember that there are certain things that are engineered for RTV specifically, i.e. for clearance purposes, etc.

However, cover plates, pan gaskets, water pumps, intake manifolds, thermostat housings, etc. aren't very good candidates. RTV might work for a while on them but it's ugly and soft. When used in conjunction with regular gaskets it acts as a lubricant and allows the gasket to slide around when torquing, sometimes causing tearing or total ejection.

Most modern gaskets require no additional sealants, and if they do they usually have precise instructions included in the box. Install on clean and dry surfaces. If there's difficulty installing due to the gasket falling off, moving, etc. use Hi-Tack, or similar (light duty contact cement) sparingly on one surface only, preferably the surface that will be removed if ever required in the future. That makes for much easier cleaning.

[svx_commuter]

When I took the original oil pump off the SVX it was hard permatex as far a I could tell. The surfaces there are so flat that the gasket material could not have been .001" thick,very thin stuff. I would not use RTV here.

[Beav]

I've not had one off, it's probably Hylomar (common stuff for split cases, etc.) or some form of Tri-Bond.

[Mr. Pockets]

The diagram on Subaruparts.com does not show a gasket for the oil pump, and I'm certain that there was none on my SVX. I'm pretty sure that there was no RTV there, either, but my Chilton's manual told me to.

Serves me right for following their instructions.

So, if I'm not supposed to use RTV, and there's no gasket made for it, you suggest I make one? Won't that mess with clearances?

[Beav]

"If it ain't broke, don't fix it." If it was going to be a problem it should have shown up by now. However the next time you're in there I'd consider checking it closely.

Per Alldata:

"Apply Three-Bond 1215B or equivalent sealant to oil pump to cylinder block mating surface. Align flat surface of inner rotor with crankshaft and install oil pump assembly with new seal and O-ring."

I'm assuming Three-Bond 1215B is similar to Hylomar.

[svx_commuter]

All I know is that the stuff is like glue and not RTV. The oil pump body was really stuck on the block because of this stuff.

[mattski]

I just did my Legacy timing belt, and while in there, I checked the oil pump screws and replaced the O-ring. Some literature in Motor magazine spoke to the oil pump sealing issue. It did recommend a very thin layer of RTV between the pump and block due to the very small tolerances. The articles were for the 2.2 l engine but would probably apply here as well. If you need it, I can find and post the link.

Matt