Changing Rear Main Seal In Driveway? - 2003 Suburban

CleanSump

Site Donor 2022
Joined
Dec 13, 2019
Messages
956
'In my youth I changed clutches and auto transmissions on Pontiacs, Chevys, a Dodge Dart, and a Mercury in my mother's driveway. Changed 3 engines there too.
It is doable if you are strong and patient.
 
Joined
Mar 15, 2012
Messages
1,648
Location
PEARL River la
Short answer is NO
Exhaust bolts love to break off, transmission bolts at top are a pain and more than likely you will need a transmission mount. When you drop transmission be prepared for a fight as transmission will want to slide off floor jack. These are a few I remember from doing it.
 

CleanSump

Site Donor 2022
Joined
Dec 13, 2019
Messages
956
Short answer is NO
Exhaust bolts love to break off, transmission bolts at top are a pain and more than likely you will need a transmission mount. When you drop transmission be prepared for a fight as transmission will want to slide off floor jack. These are a few I remember from doing it.
Oh yeah. I forgot. But when we were younger it didn't hurt as bad for as long.
 
Joined
Sep 8, 2020
Messages
167
For 98% of people, even on this forum, no, not in your driveway.

My late dad's '92 Silverado has the same problem with the rear main seal. Did this become a problem for Chevrolet small-blocks? I'm not touching it myself, and the truck isn't worth even $1,000, so the expense makes no sense. I just keep an eye on the oil level...
My 03 z71 has the same leaks and they won't be getting fixed even with access to lift etc to fix. If I had the time I might but why on a 20 year old truck
 
Joined
Dec 19, 2013
Messages
6,995
Location
Fort Worth, Texas
Skill level is plenty of common sense, good with hands, plenty of tools, but don't do mechanics for a living, but done my fair share. Reasonable...I want to make sure that I will be able to have enough space to lower tranny and move out of the way for access to work on seal areas, and reassemble off my back under the car, don't want to make a huge mess in my driveway during disassembly, and should I anticipate any problems...potentially broken bolts, connectors, etc.. I don't want this to turn into a multi-week project which would cost me money in the end with down-time. In the end, I could save myself a grand doing myself, but if there are known problems with this project, I would probably use some credit to pay my mechanic to do the project.

I highly recommend having a Slip Yoke to plug the tail housing once you remove the driveshaft, It's the same common GM 27 Spline yoke used on TH350, Powerglide, 200-4R, 700R4 as well as most light duty manual transmissions.
You have to tilt the trans down to get the top bellhousing bolts & ATF will pour out like a waterfall without a yoke stabbed!

Go to a local Trans shop & get 2 Cooler Line Clips before you even start as you're going to lose at least one, There is a tool to release the clips without removing them.....Good luck getting it to work on the ground!
Install the clips on the cooler fittings before stabbing the unit....The lines have a ramp to allow simply pushing the lines back in.

You have to remove the starter to access the Torque Converter Bolts, They have threadlocker applied to them at the factory & can the be a bear to remove.
*Mark the Torque Converter in relation to the Flexplate & the Flexplate to Crankshaft!
*There's one Torque Converter Bolt Hole in the Flexplate that's different than the other 2....Smaller, Oval Shaped. Once the Flexplate is installed on the engine....Rotate it to where it's the FIRST Converter Bolt you install that way you can tighten them all in one rotation instead of starting all 3 first, Then having to go back around to tighten them. This alone will save you an hour on your back!

2003 was the last year for the SORRY (expletive) Lucas made Neutral Safety Switch, DO NOT attempt to remove the Electrical Connectors!!!!!!
The potting adhesive used in construction melts from Catalytic Converter heat & flows into the Connectors.
*Yes you can remove the Connectors by using a heat gun....But the odds of having Terminal Pin Connection issues afterwards is VERY high!
*Start out by removing the Shift cable, Then remove the Shift Lever, Using a small file.....Deburr the Shift Shaft all the way round.
*Remove the front NSS Bolt (Easy). The rear one is a pain because the Connectors are in the way.....Using a open end 13mm wrench, Slip it behind the Connectors & loosen the bolt, You'll have to keep sliding the NSS out as you loosen the bolt.
*Most R&R guys don't reinstall this bolt, But I do....It's a little tough but can be done.
*Use the imprint from the front bolt to align/adjust the NSS.

You will need a new Dipstick Tube "Boot" Seal....Especially if it's original!
*Speaking of the the Dipstick Tube, Take a picture of how the Tube comes up into the engine compartment, That way there's no confusion when installing the unit as they like to fall out on the ground.

These transmissions like to get VERY stuck on the Dowel Pins, Don't be surprised if this is the most challenging part of the entire job. Spray some penetrant in both dowel openings at the Bellhousing. Work the trans off with a pry bar.
*If one of the Dowels comes out in the Bellhousing....Remove it & install it back in the Engine Block!!

The Flexplate to Crank Bolts require Anaerobic Thread Sealant on the threads as they are drilled all the way through & will leak oil if not sealed.

The Exhaust Nuts don't give me many problems, But definitely spray them down with penetrant & use an Impact! Quickest way to snap the studs off is with hand tools.
*If they don't break loose right away....Heat the offending nut 'til "Cherry"....Hit it again with the impact.
*Use Anti-Seize during reassembly.
*The right donut gasket might fall off, Slightly bend the locking tabs out on the "Fire Ring" so it stays in the manifold if needed.
*Make sure the left ring flange gasket is in place.
*Tighten the left flange first....Then the right.
*Do Not tighten the rear Y-Pipe Flange until the Crossmember is it place (everything relaxed)
 
Joined
Nov 22, 2004
Messages
9,054
Location
Texas
Your shop is overcharging for sure. I've done several and the transmission and transfer case if 4wd can be removed in about 1hr to 1.5hr. Then another hour on the seal so you're looking at no more than 2-3hrs and even stretching to 4hrs that would be about 400-500 labor and the seal is only about 20 so where is the other 700-800 coming from?
 
Joined
Oct 7, 2012
Messages
4,086
Location
Northern Ontario, Canada
Your shop is overcharging for sure. I've done several and the transmission and transfer case if 4wd can be removed in about 1hr to 1.5hr. Then another hour on the seal so you're looking at no more than 2-3hrs and even stretching to 4hrs that would be about 400-500 labor and the seal is only about 20 so where is the other 700-800 coming from?
What's the book say for hours for the job, and what is his shop's $/hr rate.
 

4WD

$50 site donor 2023
Joined
Sep 21, 2010
Messages
20,106
Location
Texas via IAH
Based on that other thread - spend the money on a beefed up 4L60e for towing - seal gets changed then.
 
Joined
Sep 25, 2004
Messages
9,483
Location
Marshfield , MA
Lots of good advice here. Mostly to park it over a drip pan, and use the dip stick once in a while.
I changed the clutch on the Rat. A miserable driveway job on a rusty 4x4. So miserable that I replaced every part fr the O-ring RMS to the clutch pedal. To ensure that I never would have to do the job again. That was 10 yrs ago, and the clutch still works like butter. I had the truck jacked up and cribbed 2' in the air to get the trans out. It can be done in the drive way, but it wont be fast or easy. :cool:
 
  • Like
Reactions: GON
Joined
Mar 31, 2010
Messages
6,014
Location
Iowa
I second everything clinebarger said - especially heating the nuts on the exhaust. In fact I always go straight to that step...
 
Top