Rear Main Seal replacement? for 2000 Silverado, 5.3L, 4x4

mountaintodd

Original poster
Member
May 7, 2017
3
Boone
Hi, I have a 2000 Chevy Silverado, ext. cab, 4x4, Auto. Trans., with a 5.3L engine with 210,000 miles on it. I bought it in January (5 months ago) in Florida from the original owner, it's nearly rust free! It runs and drives pretty well for an older truck, most regular maintenance is up to date, but it does have a tapping valve, starts rough, some smoke coming out of the tail pipe, and now an oil leak (looks to be the rear main seal). I do have some experience turning a wrench, and prefer to do the work if I can, but the rear main seal looks like a job for the professionals.

MAIN QUESTION! Related to replacing the rear main seal on my 2000 Silverado, 4x4, Auto Trans., with 5.3L engine with 210,000 miles!

1. Rough estimate to replace the rear main seal (# of hours, costs involved, parts?)

2. Should I do/replace anything else at this time (while the Transmission is out)? To be proactive?

3. Any suggestions, links, or advice to make sure the job is done right?

Just trying to prepare myself and my truck for the long haul. Thanks for all your time and help!

Todd
Boone, NC
 

Nexus1155

Member
Jan 26, 2012
141
if you are good, it will be down a weekend. Two at max if thats the time you are working with. The tapping valve with smoke coming out worries me that you have a leaking valve seal or bad valve. Happens a lot and if it gets worse then there would be no sense in doing a rear main seal.

The rear main is a suck job, not going to lie, and to put the torque converter back in takes some skill so read up on some guides or moosemans manuals he is a god for those.

With 210,000 miles I do not know what you plan on doing with the vehicle. If it were me I would save up a little extra scratch and get a higher rated torque converter, maybe get some window silicone and refill that transmission mount, if you can do anything like a servo or if you don't have hptuners to change shift firmness up maybe look into some more mods, but first and foremost I would rip into those heads and see what is going on, especially on those motors its very easy. Worst case, while you are in there, get the V2 polluter cam and some valve springs etc $~400. so its not a waste of time :smile: and you don't just replace the rear main for it to blow.

Also if you don't care much about it maybe toss some rear main seal oil sealer in it for shits
 
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mountaintodd

Original poster
Member
May 7, 2017
3
Boone
Thanks Nexus1155! I like the way you are thinking, but I have a few problems......
1. That's past my knowledge/skill/tools/garage level.
2. I don't know who I can trust to do the job right locally. Anybody near Boone, NC.?
3. It's leaking pretty bad all of a sudden (since my oil change last weekend).

So, if my wife demands that I get the oil leak stopped immediately. It's roughly a two hour job to replace the rear main seal only?

Until I can find a good local mechanic, I'm kind of at the mercy of getting taking advantage of and I don't want to deal with that. Ya know, my truck ripped apart in some strangers garage and he's telling me it's going to be $3,000! I'm not rich by any means, and I knew I was going to be taking a chance buying an older truck with high miles, but I like older trucks and it's rust free! So, I'm willing to invest some money into it, but I need to learn more?

Thanks again for all your time and help!
 

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
Just to simplify things just a little, replace the whole rear main seal mount piece rather than just the seal itself. Price is just a little more and saves having to replace the seal.

There is a thread on here somewhere on this job on the 5.3. It's a bitch of a job on the Trailblazer but may be different on full size. The starter has to come out to get to the torque converter bolts.
 

Nexus1155

Member
Jan 26, 2012
141
It's still a bitch of a job, at least 8-9 hours book time.

Damn, if its that bad I would make extra sure it is coming from the rear main. Any way you can look into the access hole of the tranny with a scope and actually see if thats the leak. It is not a job you would want to do if its coming down from somewhere else and kick yourself later for it especially if it just started to leak all of a sudden like that, usually you would get a little more of a warning vs. sprung a leak.
 

mountaintodd

Original poster
Member
May 7, 2017
3
Boone
Thanks everyone for the replies, info., and help!

Here's a little update after talking to 4 of my local shops/mechanics.
These estimates are only to replace the rear main seal.
Two said $500
One said $400.
One said $75 for inspection, $650-$700 labor, and $100 for parts.

Additional comments from mechanics when asked about my tappy valve at start up, exhaust smoke, or getting anything else done while the transfer case and transmission are out.

The expensive guy said that he hasn't seen a lot of cyl. head problems with these motors (5.3L) and that the tapping valve at warm up is very, very common (from excessive piston clearance) and nothing to worry about. He said he'd also wait another 10k and ride out the exhaust smoke (from possible valve stem seals). But he recommended cleaning the oil pan (additional $100-200), and valve covers (additional $80-100).

One said that he would do "the head job"/valve stem seals for $800 extra. He also recommended replacing the pump seal in front of the transmission too because they usually leak.

The cheapest guy (for $400) was someone that a friend recommended, an old guy that works from home. We didn't talk about anything else but the rear main seal.

Mooseman, you recommended replacing the whole rear main mount piece instead of just the seal. I can't seem to find a part by that name? Could it be the crankshaft housing cover, part #12639250? The Chevy dealer quoted me a price of $24.78 for just the seal, and $73.42 for that crankshaft housing cover. However, I would prefer to do my part shopping from Rock Auto.

Thanks again for everyone's time and help!
 

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON

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