Rear Main Oil Seal

[OR VietVet]

Ah, the joys of using new or louder curse words and having a neighbor hear them and then days later asking what "THAT" was all about. Then you ask them, "Do you have some time while I relate to you why all that came about". I am looking forward to you being done and hopefully sharing lots of pics along the way.

 

[Larryjb]

I'm probably not going to take many pictures for this job. There are plenty of videos and other pictures for the basics, but what there is not much of is a nice list of steps complete with socket sizes. It's really nice when I find some one who has taken the time to document what socket size he used.

I'll take a couple of pictures of anything interesting for sure. One thing that is not well pictured anywhere is the location of where to put the oil-resistant RTV.

 

[Rocket Man]

I'm probably not going to take many pictures for this job. There are plenty of videos and other pictures for the basics, but what there is not much of is a nice list of steps complete with socket sizes. It's really nice when I find some one who has taken the time to document what socket size he used.

I'll take a couple of pictures of anything interesting for sure. One thing that is not well pictured anywhere is the location of where to put the oil-resistant RTV.

It’s at the 2 spots in the front and 2 spots in the back where the front cover and rear main cover intersect the pan, there’s a gap there.

 

[OR VietVet]

I knew Rocket Man would be all over this answer. He posted the same file in another thread. Plus, it answers all questions concerning the sealer locations. Great call.

By the way, Larry, can you please record the audio during the work process for any new curse words with the Canadian accent?

 

[Larryjb]

Thanks Rocket Man,

I did manage to figure that out without pictures, but that is a nice drawing to confirm what is necessary.

I got the pan out very easily. Rickafix has a nice video which covers the basics. He said he struggled for a 1/2 hour or an hour to wrestle the pan out. 10 minutes of removing those axle-differential bolts and letting the differential sit on the center link and mount bracket gave me enough room to just about slide the whole thing out in about 2 minutes. Plus, there is no strain on the CV joints. Of all the unnecessary things I did, I would not consider separating the diff unnecessary. It helps a lot with space.

If you look back in my previous threads, you will see a thread about a cracked non-Castech head, and oil sludge. I've been using Valvoline synthetic for the last 2 years. Although my oil filter didn't get clogged up these last 2 years, and the oil drained easily, and I've had decent oil pressure, there was a good inch of sludge in the bottom of the pan. I'll be spending the better part of today cleaning that all up.

Of yesterday's 4 hours, probably a good 45 minutes was spent cleaning sludge from the cross member. It was so gross, and I really didn't like the idea of that sludge falling into my face while trying to reinstall the thing. As it was, I almost ate some sludge that fell off the front of the oil pan.

And yes, I am considering the possibility that the front timing cover may be leaking too, but I want to take care of oil pan leak first. If the timing cover seal needs replacing, there's a whole ton of stuff to come off for that one.

On a side note, while the transmission jack is working fine, and is very useful to lift and manage the differential, it came without enough hydraulic oil. I had to add quite a bit before it would lift up to the full height. Even after that, I had to bleed it several times as well. But so far, it is very nice to use. This one is by PowerFist,

 

[Larryjb]

Now that I'm working to clean the gasket surfaces, having the differential out completely would have been a big help. One more nut holding the center link to the pitman arm is all it would have taken. Alas, I've done most of the work now, so I'll leave it as it is.

I'll post a picture later, but the machining of the gasket surface on the pan is quite poor. There is a ridge crosswise alone the mating surface. When I install the pan I'll add a tiny smear of RTV in that location. The RTV from the rear main cover and the front cover bulged below the mating surface on the block. I used a razor to even it with the mating surface. That's where a new dab of RTV will go anywway.

So was my pan the only one machined so poorly? Or did no one else notice it on theirs? I'm close to putting things back together. I only have to install the new o-ring and finish cleaning the gasket surface of the block.

 

[Rocket Man]

Separating that Pitman arm is way harder than removing the nut. If you’ve ever replaced one you would know. Pulling a differential so you can scrape a gasket better is crazy imo! I had no problem cleaning mine up. My pan surface wasn’t machined poorly at all. Maybe your pan has been replaced with an aftermarket? Did it have 2 pop rivets holding the gasket on? I reinstalled those on mine, some don’t but it sure helps hold the gasket in place when putting the pan in.
Edit: after reading again I see you weren’t talking about pulling the Pitman arm but still... good to see you’re making good progress though!

 

[Larryjb]

Pulling the differential completely out would not be much more work than what has already been done. Most pull the 4 bolts holding the differential in, disconnect the electrical connector, and vent hose. The two long bolts supporting the differential in the mounts are the most difficult by far. It was 10 more minutes to mark and separate both axles. After that it's just the center link.

There are more reasons than to scrape the gasket that pulling the differential makes sense for. Dropping the oil pan is dead easy with the differential completely out. It was easy enough when the differential resting on the center link already. Furthermore, aligning and torquing the oil pan bolts will be much easier and more accurate with the diff out. The use of swivel joints to get the pan bolts above the diff will change the torque. Hopefully not by much, but it will change it.

Here's a picture of my oil pan:

My pan is definitely original and the gasket was held in place with the rivets. This could have been the leak all along. This is not a score or gash. The two sides are actually different heights. I'll smear a thin coat about 2 inches on either side of this point.

 

[Larryjb]

I knew Rocket Man would be all over this answer. He posted the same file in another thread. Plus, it answers all questions concerning the sealer locations. Great call.

By the way, Larry, can you please record the audio during the work process for any new curse words with the Canadian accent?

Simple, no audio required:

%#^!@ sounds like %#^!@-eh
and
*$@&^* sounds like *$@&^*-eh

French Canadian accents just add tabernacle just before the "eh".

 

[Rocket Man]

Simple, no audio required:

%#^!@ sounds like %#^!@-eh
and
*$@&^* sounds like *$@&^*-eh

French Canadian accents just add tabernacle just before the "eh".

Lmao

 

[OR VietVet]

You could take some fine grit sandpaper and smooth out that spot on the oil pan.

 

[Larryjb]

Starting reassembly. All the bolts have been soaking in brake cleaner. I tried dry fitting the pan and it will be super easy to slide it in. If I rest it on the differential while sliding it forwards, I can watch it go into place and wiggle it beside the wiring harness, then pop it in place.

Interestingly, the oil baffle bolts in the pan didn't go in smoothly for the last 5-6 turns. I cleaned them out with brake cleaner, and they did go in. Torqued nicely to 106 lb-in. Now just cleaning the gasket surfaces. This part always takes me forever. I like to be able to eat off my oil pans. I could have done this even better if I had removed the differential... (Can I get Mark onto his high horse again?

Ron, I'll use the sandpaper to make sure there aren't any sharp ridges on that edge. The RTV should take care of anything else.

 

[Rocket Man]

I think at this point you should really just pull the differential, you’ll be able to clean the gasket surface better. Probably save you some time.

As far as that ridge on the pan, I’d use a block to sand it with just to make sure it stays perfectly flat. But I imagine you’re already on top of that. Good work.

 

[Larryjb]

I hate it when you count 14 bolts, set them aside in a box under the truck, install them, then find out you're one short. I spent an hour, while the RTV was doing its initial cure hunting for this bolt. I looked everywhere, including around all the steering and differential stuff. I finally installed an old exhaust bolt which fit.

I began the final torquing of the bolts. When I got to the last "exhaust" bolt, I saw a silvery bolt hanging on my differential. -eh

I'll check the torque once again tomorrow and get things put back together tomorrow.

 

[OR VietVet]

Larry, you try to plan for all contingencies and try to lay everything out just so and then "it is what it is" bites you in the ass. Remember, you are not really in control. Life is.

 

[Rocket Man]

I hate it when you count 14 bolts, set them aside in a box under the truck, install them, then find out you're one short. I spent an hour, while the RTV was doing its initial cure hunting for this bolt. I looked everywhere, including around all the steering and differential stuff. I finally installed an old exhaust bolt which fit.

I began the final torquing of the bolts. When I got to the last "exhaust" bolt, I saw a silvery bolt hanging on my differential. -eh

I'll check the torque once again tomorrow and get things put back together tomorrow.

See? Should have pulled that damn differential, eh?

 

[Larryjb]

Mark, let's just say we have a difference of opinions. Next time this aughta speed things up


I took the day off yesterday. Not much to do for the next while anyway. I got things back together, almost. I pretty much just have to add fluids.

One thing that concerned me was the torque specifications for the oil pan bolts is 18 ft-lbs. That's just fine, except for the two long rear bolts. They seemed to not want to get up to 18 lb-ft. I got them up there, but I'm worried that I may have stretched the bolts like Rickafix did. As long as it doesn't leak, I'll be happy and leave it alone. If I do have to do this again, it'll go twice as fast easily, but I hope I don't. I am also concerned about the ridge on the back. I did use some sandpaper to make sure it was smooth. I added a strip of RTV in that location as well. When I got the pan up (it went up really easily with the diff simply resting on the centre link, no prying, no strain on the CV joints), and I hand tightened all the bolts as required by the RTV instructions. I then left it for an hour and went to torque them up. They seem much looser than hand tight this time. I can only assume that they loosened slightly as the RTV squished into seams over the hour. I hope I didn't mess up on something there. We'll see.

 

[Patrick0329]

Well, with the whole Coronavirus shelter at home going on, looking at doing the oil pan gasket myself as the car won't be needed anytime soon. Reading through this thread has been really helpful but I did have a couple questions. When folks have done the oil pan, what did you use to clean up the surface where the new gasket will sit? I've seen some videos where people use a rubber, kind of nobby looking "scratch pad" type thing because it won't break down and gives you less of a chance of some residue breaking off the cleaning tool and ending up in your pan. Is there a specific tool at Oreilly or something I should look for. The other question was on the adhesive you apply to the corners, would you apply it to both sides of the gasket? I may be overthinking this but I'm basically a do my brakes and change my oil level of mechanic. Any idea on how long this type of job should take me? I'll probably just assume double what you all tell me

It's a 2007 Suburban so if there's any other gremlins I should look out for, I'm all ears. I think the rear seal is leaking too but I'm going to leave that one to my mechanic.

 

[Rocket Man]

Well, with the whole Coronavirus shelter at home going on, looking at doing the oil pan gasket myself as the car won't be needed anytime soon. Reading through this thread has been really helpful but I did have a couple questions. When folks have done the oil pan, what did you use to clean up the surface where the new gasket will sit? I've seen some videos where people use a rubber, kind of nobby looking "scratch pad" type thing because it won't break down and gives you less of a chance of some residue breaking off the cleaning tool and ending up in your pan. Is there a specific tool at Oreilly or something I should look for. The other question was on the adhesive you apply to the corners, would you apply it to both sides of the gasket? I may be overthinking this but I'm basically a do my brakes and change my oil level of mechanic. Any idea on how long this type of job should take me? I'll probably just assume double what you all tell me

It's a 2007 Suburban so if there's any other gremlins I should look out for, I'm all ears. I think the rear seal is leaking too but I'm going to leave that one to my mechanic.

I used a gasket scraper tool ( you can get one at an auto Pratt’s store or Amazon) and Scotchbrite. You don’t need to worry about stuff falling into the pan since you’ll have it off and will clean it out anyway. The RTV just goes on the engine block side at the places in the diagram I posted earlier. I would figure on 4 hours so probably most of a day working at an “at home gonna take a few breaks” pace. Harbor a Freight sells this scraper kit for about $5.

 

[Larryjb]

Patrick,

I'll post my list of steps. Videos, such as the one made by Rickafix are great to see what it's like, but the outline I will post shortly will have bolt sizes, torques etc. Also, it provides a nice checklist to follow to make sure you are installing everything and not skipping a step.

I use CRC Gasket Kleen, then Brake Clean, and then I use a single edge razor to remove any remaining gasket material. Gasket Kleen is great stuff! As long as you keep the razor angle low and work slowly, there is no danger of damaging the mating surface. I used this method to clean the block surface for my head gaskets and they've sealed up just fine.