Rear Main Oil Seal

[Larryjb]

First 4 hours: got transmission pan unbolted.

You either have to remove the exhaust Y pipe completely, or remove the transmission selector cable bracket. They prevent removal of the pan. You'd think the cable bracket, which is held on by T-40 bolts, should be easy to remove. They're in a cramped area with enough torque that you need about 12" breaker to break it free. Otherwise, the torx bit pops out of the bolt. It would have been much better to have used a 10 mm bolt up there, but GM in their infinite wisdom decided torx was better.

So, after about 1/2 -1 hour of trying to remove the bracket, then just trying to remove the transmission pan (another hour at least, trying to wiggle it free without spilling transmission fluid all over my garage floor), than another 1/2 hour to disconnect the O2 sensors and disconnect the bolts to the exhaust manifold, I tried to remove the pan once again. No go. Either the Y pipe or the bracket has to come out completely, just for a pan drop.

So, I've got the PB blaster on the last 2 nuts for overnight, then I'll try to get the Y pipe off.

When I say I take a long time doing stuff, this is why.

I should have just removed the Y pipe first, but I was stubborn and believed I should be able to get the pan off without.

 

[Larryjb]

Today's 4 hours so far have been slow, but good. That's pretty normal for me. I've got all the electrical connectors off from the transfer case and the entire wire loom pushed aside. Vent hose is disconnected, and everything supported at the transmission on jack stands (with wood between the pan and jack stands). I'm about to remove the nuts and remove the transfer case. If I'm lucky, I might get to the rear mean seal tonight. If I'm lucky.

I found that, even with the exhaust removed, that shift cable bracket still prevents removal of the transmission pan. I managed to get out Torx bolt out, but my torx keeps slipping off the bolt for the second one. I wonder if I can replace it with a stainless hex bolt? Anyway, once I resigned to not removing the pan yet, everything else is going according to plan, just slowly.

Also, there does appear to be a drain plug, but the shoulders of the bolt are so shallow that my sockets slip off the nut. I know my sockets are not the most expensive, but they have served me well for 30 years already, and are still serving me well. But, what they call a "lead in bevel" is so big that it won't grab shallow bolts very well. I believe the more professional sets have less bevel there.

 

[Larryjb]

Alright, most sane people wouldn't do this job without a lift. I don't have a choice. Well, I do, and the other option is to pay probably 2 grand to have the job done. Sorry, not for an 18 year old truck.

I'm about to drop the transfer case. All 6 nuts are removed from the transfer case to transmission (okay, adapter), the transmission is supported, no weight is taken by the transfer case. I can wiggle it on the studs, and am allowing any fluids to drip out overnight.

The very next steps are to pull it off the studs and lower it to the ground. I'm not a strong guy. If I bench press, it's likely to be no more than 50 lbs. That's the weight when I stopped picking the kids up regulariy. Sure, I can lift more, but I don't care to. Even though the case is drained and made of lightweight magnesium, I don't care to try benchpressing the thing. I've heard of two options: 1) pull it off the studs where it sill still be held up by the spline. You can then rotate it towards the ground and work it out, and (2) support it by a tranny jack, move it back off the studs, then slowly lower it.

Personally, I prefer option 2, but without ever actually having removed a transfer case before, I could understand why option (1) might be better, and I could be convinced if that is the consensus here.

At issue, of course, is that the transfer case has no flat surface to rest on the transmission jack. Also at issue is the fact that the transfer case has to tip forwards as it lowers to get the back of the TC off the torsion bar rack.

Any ideas from the DIY who have done this before?

 

[wjburken]

Alright, most sane people wouldn't do this job without a lift. I don't have a choice. Well, I do, and the other option is to pay probably 2 grand to have the job done. Sorry, not for an 18 year old truck.

I'm about to drop the transfer case. All 6 nuts are removed from the transfer case to transmission (okay, adapter), the transmission is supported, no weight is taken by the transfer case. I can wiggle it on the studs, and am allowing any fluids to drip out overnight.

The very next steps are to pull it off the studs and lower it to the ground. I'm not a strong guy. If I bench press, it's likely to be no more than 50 lbs. That's the weight when I stopped picking the kids up regulariy. Sure, I can lift more, but I don't care to. Even though the case is drained and made of lightweight magnesium, I don't care to try benchpressing the thing. I've heard of two options: 1) pull it off the studs where it sill still be held up by the spline. You can then rotate it towards the ground and work it out, and (2) support it by a tranny jack, move it back off the studs, then slowly lower it.

Personally, I prefer option 2, but without ever actually having removed a transfer case before, I could understand why option (1) might be better, and I could be convinced if that is the consensus here.

At issue, of course, is that the transfer case has no flat surface to rest on the transmission jack. Also at issue is the fact that the transfer case has to tip forwards as it lowers to get the back of the TC off the torsion bar rack.

Any ideas from the DIY who have done this before?

Would it be possible to make a crude wooden tray that you can bolt/attach to your transmission jack and then drop the Transfer Case onto it and have a ratchet strap ready to secure it to the tray.

 

[Fless]

If the TC is the NP246 the dry weight is around 85 lbs.

 

[afpj]

I thought I read that several folks just bent that shift cable bracket out of the way to get the tranny pan off. I've never done that myself though. Is that a possibility for you? I don't live in the rust belt though, so bolts do come off for me in general with pb blaster.

 

[Larryjb]

Would it be possible to make a crude wooden tray that you can bolt/attach to your transmission jack and then drop the Transfer Case onto it and have a ratchet strap ready to secure it to the tray.

I'm sure this would be possible. However, I'd have to allow the TC to twist around as it lowers because the output shaft end rests on the torsion bar cross member. I have thought of making a wooden cradle just to keep the TC from sliding off the deck of the transmission jack.

Steve tells me the TC is about 85 lbs. That is probably a little on the heavy side for me to want to lift out and back in by hand.

 

[Larryjb]

I thought I read that several folks just bent that shift cable bracket out of the way to get the tranny pan off. I've never done that myself though. Is that a possibility for you? I don't live in the rust belt though, so bolts do come off for me in general with pb blaster.

The bolt I did manage to remove wasn't rusted. It wouldn't be that hard to remove if it were a regular hex bolt, or even a larger torx head. And even a little more room to get just a couple more inches of leverage would have helped.

 

[wjburken]

I'm sure this would be possible. However, I'd have to allow the TC to twist around as it lowers because the output shaft end rests on the torsion bar cross member. I have thought of making a wooden cradle just to keep the TC from sliding off the deck of the transmission jack.

Steve tells me the TC is about 85 lbs. That is probably a little on the heavy side for me to want to lift out and back in by hand.

Yeah, it can be a pain. When I replaced the TC on my 2007 Denali, I ended up having to just press it into position as I didn't have a transmission jack and I was using my floor jack to support my transmission.

 

[Larryjb]

Note to self: don't mess with Wade. He bench presses transfer cases.