Hmmm, I don't think oil is supposed to come from there

[Yukon Jack]

Blazerboy came over last night and helped get the carb and HEI installed on my 70 K5. It hasn't ran in about 7 years I'm guessing. Couldn't get it to fire last night due to a very dead battery.

Well, after getting the 10 gauge wire actually onto the blade on th HEI tonight the Blazer lives!!!! BUT, she's gushing oil at the back of the engine. Looking from the underside of the engine it is coming from I think the rear main seal. There is oil dripping out of the drip hole on the flywheel bottom dust cover and the majority of the oil that is gushing is coming between the flywheel dust cover and the engine.

Is that a good guess?

If so, I'm hoping that doesn't mean I have to pull the tranny/transfer case to fix or pull the engine. The oil coming out of the drip hole in the flywheel bottom dust cover scares me - does that mean I'm gonna have to pull the clutch and clean degrease the flywheel? Just got done installing the flywheel and clutch and don't look forward to dealing with the tranny/tc install again.

Being mechanically challenged sucks - I can rip em apart and lift'em in the air, but I don't know jack about engines. (Well, I am slowly learning though)

Dang, was really hoping I wasn't going to have any more problems.

[71Rat]

sounds like a rear main seal is bad.... i am guessing you have a stick.... if so and the oil gets on the friction material of the clutch you will get clutch chatter real quick...... i have heard of people doing the rear seal if it is a 2 piece and they didnt remove anything but the pan and that rear main cap.

[stickshift_or_walk]

I'm on the road, without access to my books, but trying to remember...aren't the oil galley plugs on the back of the SB, and if one of them was left out...?

But, if it was OK when parked, the main seal probably dried out and busted up.

SSOW

[Fred T]

Replacing the rear main seal is not that tough. You have to drop the oil pan, which usually involves pulling the distributor for clearance if it's HEI, unbolting the motor mounts and jacking the engine high enough for the pan to clear the crossmember.

Once inside you unbolt the rear main bearing cap and drive the old seal out of the block and the cap. Then drive in the new seal. There should be a tool for removal/installation with the new seal. Only problem is that if there is a serious groove worn into the crank, your fix will be short-lived and will require removing and regrinding the crank. Otherwise the new gasket will be ate up, too.

[Yukon Jack]

Fred, better just have you head over and get busy on the K5!

Have no knowledge of the last condition of the motor - bought it in February and the owner said it rain when he last drove it. He said that was 4 years ago, but I think it is 6-7 years based on the inspection stickers and old receipts and newspapers in the Blazer.

[Dean]

I replaced the rear seal on my 66 Vette in the car so it can be done with some patience.

[Tx Firefighter]

Is the oil pressure sending unit screwed into place and not broken off?

[sneakysnake]

Originally Posted by Tx Firefighter

Is the oil pressure sending unit screwed into place and not broken off?

Or the freeze plug looking cap on the back of the cam shaft. Put an engine together and forgot the cap, its a ***** to put in as an after thought.LOL

[Fred T]

Originally Posted by sneakysnake

Or the freeze plug looking cap on the back of the cam shaft. Put an engine together and forgot the cap, its a ***** to put in as an after thought.LOL

Good point!

[Bobalouie]

There is a tool called a Sneaky Pete, you can get them anywhere. They make the removal and install of the seals alot easier. They cost about $5-10 bucks. And getting that pan off is no big deal either. I have done it 3 times on my 72. Just pull the motor mount bolts, then the 4 bolts that hold the crossmember to the frame and the bolts that hold the uprights to the framerail, and jack the motor up after removing the dist cap. The crossmember wont come all the way out (at least it wouldnt on mine, hangs up on brake lines) but it will slide forward enough to allow the pan to pretty much drop straight down. Should take about an hour to pull the pan.

[Yukon Jack]

Getting oil pressure and no oil leaking at the area on the intake where the oil pressure line plugs into.

I'm pretty confident it is the rear main seal. The Blazer was out of service due to the prior owner breaking the transfer case so I have a feeling it was in running order before it sat for 7 years. A buddy is gonna come by tonight hopefully and help me pinpoint before I dig into the engine. Sure would be nice to have the funds to just pull the engine and rebuild it - I'm sure it needs that, but need to get running and let my project fund recover from the K20 project.

[XXL]

Originally Posted by Yukon Jack

I'm sure it needs that, but need to get running and let my project fund recover from the K20 project.

Yeah, running is right...

picture removed by mod.

[72C203503ONTHETREE]

Does the 4WD Blazers have a crossmember? My 76 3/4 4WD had non under the engine and I was able to just drop the pan striaght down to replace the bearings, cam, etc.. Havent looked under a pre 73 Bklazer or truck to know if they do.

[Yukon Jack]

The crossmember is right under the pan so will take a little work to get the pan off - oh well, just a little bump in the road, that is all.