1995, 4 Wheel Drive, 4.3 L V6- Gaining just enough clearance to remove/install Flywheel.

This method is not ideal for everyone... but it's another option for high mileage cars where you may not feel too comfortable about breaking the Trans away from the 4WD Transfer Case. Mine has 210,000 miles and was far more concerned about causing new mechanical problems than the cosmetic damage I was about to inflict.

This article is intended to supplement this DIY article about transmission removal:

https://blazerforum.com/forum/tech-articles-diy-29/how-700r4-4l60-4l60e-tranny-removal-4531/

Purpose: To provide an alternate method of gaining access to top two transmission housing to motor bolts AND to only move transmission back far enough for access to remove/install Flywheel on a 4WD.

Normally one would drop rear end of transmission to gain enough clearance to see top two transmission housing bolts. You would use a very long ratchet extension & swivel to reach them. However in this case, the 4WD gearbox prevents this as there is a welded frame member blocking the rear drive-shaft cone from dropping more than 2 or 3 inches... still not enough to even see the top transmission bolts. There is also not enough clearance to even get your hand up there. There is zero top clearance from going in under the hood as well.

Actually, with a 36" extension you can maybe see & reach the top-right bolt head but still not the top-left. The recommended procedure is to remove the gearbox from the rear of the transmission. This gives you enough clearance to tilt the Transmission down just enough to see those top bolts.

My alternate procedure leaves the transmission & gearbox attached to each other. This method also does not require removal of exhaust crossover pipe as transmission is not being removed from car.

Procedure:

1. Remove any Skid Plates and disconnect Battery.

2. Remove front & rear drive-shafts after marking position for easier reassembly.

3. Remove Flywheel inspection cover. It's tricky but I got mine out by gently pushing the engine support rods around.

4. Optionally remove the Starter. I had to change mine anyway as the Starter Gear and Flywheel were all chewed up.

5. Mark Torque Convertor to Flywheel position with chalk or grease pencil. Then remove three bolts connecting Torque Convertor to Flywheel.

6. Disconnect the two transmission coolant lines from RH side of Radiator. A small amount of fluid will drip out. There is no access to swing a tubing wrench on Transmission side of lines but all brackets allow for tubing to slide back several inches along with the Transmission.

7. Support Transmission/Gearbox assembly with a Transmission Jack and remove the frame support bracket. On mine there are two metric bolts/nuts on each end. One end sits on top and bolts to the LH frame rail and the other end bolts to the side of the RH frame rail.

Now there are only six bolts (9/16" heads) holding the transmission housing to the engine... in 9, 10, 11, 1, 2, 3 o'clock positions.

8. You can easily remove four of these bolts with a long extension and 9/16" swivel socket. Only the top two bolts at 11:00 and 1:00 will not be easily accessible.

9. This is where I deviate from the norm by cutting two small access portholes in the drive-train tunnel using a 4" angle grinder. Shove a piece of thin plywood or sheet metal up over the Transmission housing to protect the gas lines & wiring harness while carefully cutting. Use the 4WD shift cable as a point of reference for proper cutting location. See photo...


Note: If you're opposed to hacking up the floor of your Blazer, you'll have little choice but to remove the 4WD gearbox in order to gain enough clearance to tilt/drop the Transmission.

10. Now that the top-right bolt is removed, the bracket holding the Transmission Filler Neck is free. Remove the Filler Neck by pulling straight up and save the rubber gasket. You will loose a quart or two from the filler hole so get a catch pan ready.

11. You are ready to slide back your Transmission. I had to use putty knives to separate the Trans Housing from the Engine but once separated use the Transmission Jack to move the Transmission back while slightly lowering it. You will gain just enough clearance to get the Flywheel changed**. See photos...


Disconnection Review: Only Coolant Lines (radiator side), Filler Neck, Support Bracket, and front/rear Drive-Shafts are disconnected from Transmission. Nothing else was disconnected as all wiring, tubes, cables should have enough slack.

12. After job was completed, floor was easily repaired using straps, rivets, silicone sealant, and butyl backed foil tape. See photo...


Notes: This method requires removal of Center Console, Front Seats, Carpet, some misc trim and the Under Carpet Heater Ducts. If your car is even more of a junker than mine, you may think cutting the carpet is a shortcut. No good... those flat plastic ducts are still in the way and they run over the Drive-Train Tunnel and under the front seats.


**Flywheel Removal Tips: I found the best way to pop the Flywheel bolts loose was with a 9/16" closed-end 6-point box-wrench and a 24" cheater pipe. Once the initial force was released, they were loose enough to spin out by hand. I tried a 6-point socket but the force required caused it to slip off, jam, and booger-up the bolt head. I also tried a 12-point closed-end box-wrench but it only rounded the head. One bolt head was so messed up, I had to grind all six bolt-head faces flat with a Dremel Tool disk on a flex-shaft (all this with only 3 inches of clearance between Flywheel and Torque Converter!). From the clean-up grinding, the head was then slightly smaller so I used a 14-mm closed-end 6-point box-wrench... this worked and it popped loose.

Please let me know if I forgot any critical steps.

 

Oh my...

 

Yeah... 1995 with 210,000 miles though... I would never consider doing such a thing otherwise. The standard method of removing the gearbox was a can of worms that I did not want to open. That being said, my cosmetic alteration is invisible from inside/out and does nothing to impede mechanical stability or performance.

I talked with two transmission experts and both had no other suggestions/ideas for getting to those top bolts.

 

Kyle.......you said it all.

are you serious?!? they're a bunch of amateurs.

and how is it gonna cause any problem by removing the transfer case? (gear box is an old term used in reference to a manual trans.) it's 5 bolts, a few electrical/vacuum connections, and it's sitting on your chest.

i throw this type of "access panel suggestion" in with the one that stirred up a fuss last Fall, about cutting the floor over the gas tank, 'cause he didn't want to go through the hassel of dropping the tank.

the suggestion about using a box wrench is one method, but i've always just used 2 12" extensions, another 6" and a universal joint on the socket, to get @ the top 2 bolts. even if you don't drop the t-case, it'll still drop down far enough to gain access to the top bolts this way.

even though you think you've sealed the floor up well, what happens if you develope an exhaust leak?

i know it's "to each their own", but sometimes..................i don't know. i'm gonna end it here before i go to far.

 

They're amateurs for telling me the same thing as you? Without looking at my truck, they simply said I'd have to remove the transfer-case if I needed more tilt angle. Cutting holes was not their suggestion.

I have no idea other than the fact that this truck has over 200,000 miles and it's still running fine... I just wanted to keep it that way by not tearing apart the drive-train any further than necessary.


I'd like to see a photo of that (for this specific model). On this 1995, there is barely enough clearance between engine and firewall for the dip tube and the wiring harness. Certainly nowhere near enough room to get a hand or a box wrench on it. Not even enough room to get an open hand even part-way behind the engine. Also not even room to just see the bolts from the top... they are too far back behind the vertical plane of the firewall.

The box wrench method is how I removed the T350 trans from my 1978 1/2 ton pickup... that method is NO GOOD on this '95 S-10 Blazer.

Even the Chilton's manual #8139 (page 7-23) states that lifting the body off the frame for clearance is the factory recommended method specifically for the top-left bolt. There was no mention of removing the transfer-case separately.

I got 5 out of 6 bolts out with a 32" extension and a swivel. I wouldn't have given up if the 6th bolt (top-left) was even partly visible. Nobody wants to tear out half of their interior and hack holes into the floor just to see one bolt.

No... it absolutely did not!... if it did, we wouldn't be having this discussion. The rear of the transfer-case only drops about 2 or 3 inches and then hits a welded frame member.

The top-left bolt head was not visible from any angle. As recommended to me, removal of the transfer case was the only way to achieve sufficient tilt angle.

As per Chevrolet, lifting the body off the frame is the proper way to get to the top-left bolt.


I don't know. But I do know my patch is water-proof. After 15 years, is the rubber grommet GM uses to seal the 4WD shifter cable through the floor still water-proof?

I appreciate your opinions but my old truck was driven 200,000 miles through 15 salty Chicagoland winters. There are rust bubbles, rust spots, soft spots, and holes developing in the floor within 12 inches of my patch....

I wasn't thrilled about cutting into the floor but I really believed I was playing it safe by avoiding transfer-case removal. If dropping the transfer-case is as easy as you describe, maybe I should have felt more comfortable about doing it that way.