5.3 engine

[DEMETRIUS PERRY]

Question.  It's worth changing the rear main seal on a 2004 Chevy Tahoe with 300000 plus miles

[Jsdirt]

Depends on who you ask. For me, no F#$*g way. While the '04 is MUCH easier to extract a transmission & transfer case from than the GMT-900 models of '07 and up, to go through all of that for an oil leak? NOPE and NOPE. With no lift, and outside on jacks and jackstands? HARD PASS. I'd just buy cheap oil and keep pouring it in, and check it often.

 

This engine was built by people with contempt for DIY'ers. Hell, mechanics in general! They couldn't even put locating pins in the rear cover, like EVERY manufacturer has done since the dawn of the automobile. NOPE! So you have to spend even more money on a special tool to center the rear cover, otherwise, you'll spend a week under your vehicle only to have it leak 1,000x worse than what you had. I call this "A$$hole engineering". I see it constantly these days. 

 

I've had a rear main leak in my '86 Mercury Grand Marquis for 18+ years now. Leaks a quart every 1k miles or so. Hasn't got any worse in that time. I always said I'd get to that when the AOD transmission fails, that way I can kill 2 birds with one stone. Well here we are at 280,000 miles, and the original transmission (and OE electric fuel pump) hasn't failed yet. Meanwhile, my '07 Silverado is already on it's 2nd transmission since last year! 103k miles it was smoked. At 97k, the spider gears let go, too, among a hundred other failures since literally day 1 ... but that's an entirely different topic for another day. I was going to change the rear main on mine since I had the transmission out ... then I found out there's no way to center the cover without some stupid tool I'll use twice a year, tops, until all these models rot away to nothing in a couple more years & disappear forever.

[JimCost2014]

A$$hole engineering

 

Surprised GM hasn't used that in a marketing campaign yet

[JimCost2014]

1 hour ago, DEMETRIUS PERRY said:

Question.  It's worth changing the rear main seal on a 2004 Chevy Tahoe with 300000 plus miles

Welcome to the site.

 

Is it your daily driver/only means of transportation? How much oil are you loosing? Do you have the time and skills to do it yourself?

Bottom line, you know the truck a lot better than we do.