Auto Tranny Oil Change

[dieseltrooper]

I don't know how many of us might run into this, but when I decided it was time for a fluid and filter change on my 1991 Isuzu Trooper w/ GM V6 and GM 4L30 slushbox, I discovered there was no drain plug.

After researching the issue via phone calls to local shops and reading the Isuzu msg boards, I find out that in order to drop the pans (yes,Two!) requires the skidplate,crossmember and exhaust be removed...

I did find an alternative method posted on an Isuzu board that I performed yesterday. I didn't want to wait any longer, since I've never done it in the 6mo I've had it and no telling when, if ever, it was done. The fluid was reddish-brown and didn't have the pure, aromatic fragrance of fresh ATF.
So, here's how it went: The manual calls for 6qts capacity. I bought 2gal at Wal-Mart for about $8.80. I disconnected the lower tranny cooling line near the radiator. (hose clamp) Then positioned the drain pan and had my son start the truck. Now you are simply pumping the trans out like you've cut the femoral artery. When the flow starts to sputter and foam, shut it down asap so you don't run dry. Then add a quart or so via the fill tube. We repeated this (lather,runse,repeat) maybe 6-8 times until what was pumping out was more the normal red color. After it was all done, I had 6qts of old ATF to recycle at Auto Zone and a higher degree of confidence that the tranny will survive the summer heat. Less than $10 spent and not a cussword expended.

Yeah, and when you refill and the dipstick shows it to be full, sit there and run it through the gears a few times then recheck and add more. I skipped that and when I went to leave later, the trans started to slip on acceleration, so I knew it was low. pulled back into the drive way and it took another 1.5 qts...

 

[DARKSTAR]

Cars are sure fun to work on now aren't they. The filter still needs to be replaced once and awhile (as long its on with some type of element in it, some vechicles the filter looks like bug screen), so the next time drop the pans and get a drain plug kit for trannys, i know B&M makes one, drill a hole in the pan and install the kit makes servicing easier.

 

[dieseltrooper]

Yep. There's always something to bite ya in the butt...

The 2.8 GM V6 is very common and was used across several lines. When Jeep used it in the mid-80's Cherokee, you couldn't change the oil filter without freeing the motor mounts and jacking the engine up.What were they thinking?

In the 89-91 Trooper, to drop both pans, (the main one and a little one for the overdrive section), a skidplate has to go, the crossmember must be removed and trans/transfer case supported, and the exhaust system must be disconnected at the manifolds. I guess every vehicle has it's issues...

 

[CTCStrela]

Yeesh!!! Damn Trooper, you should have asked me first...there is a MUCH easier way of doing this!!!

Stick a clear length of tubing down in the dipstick hole and pump the pan out...

 

[dieseltrooper]

Right, I think that's how the quickie lubes do it. But that leaves the converter unflushed. As it worked out, I flushed the full 6qt trans capacity out.

This method's downside is not changing the felt type filter.

 

[CTCStrela]

Right Trooper, so you do it, run the motor, and do it again

 

[dieseltrooper]

Yep. About a quart at a time....

I'm reminded of pulling the 390 and A/T out of my '69 Javelin. Once you remove the driveshaft, there's nothing containing the ATF. Once the motor/trans tilted enough as I was using the hoist, all the ATF ran out of the tail shaft and down the driveway. It looked like I'd slaughtered a cow!

 

[Bigbng]

Yep, the "two stage" tranny reservoir makes it look like you've topped up, but then you need to take a few corners to slosh it around (so my mechanic told me).

And the siphoning thing works, but leaves all the sludge in the filter. (It might be okay to do it in between tranny filter changes, but how often would that be? My current vehilce called for it at 60k, and I did it at 80k (filter and fluid), so maybe a siphoning change at every 40k inbetween?

On a side note, has anyone ever purchased the fuel injector cleaning deal at the oil change places? I had one done about 3 oil changes ago, and couldn't believe the difference. I am going to try just adding a bottle of FI cleaner to see if I can produce the same results.

 

[dieseltrooper]

I haven't tried that. I thought it was bogus. I've used the autozone stuff before, but no difference. I rebuilt my TBI and noticed no difference on that either. I was trying to cure a persisitent hot restart malf. It acts like it's a little flooded, and you have to floor it to start.

 

[Green Co.]

DT...try using 1/2 qt of Lucas Upper cylinder lube to 20 gallons gas. Works very well. My 3/4t Chevy, 350k miles, had a terrible low octane knock. Running a 1/2 quart thru two tanks of fuel cured it. Now runs regular gas again, no pinging.

Another hot-shotter I know, had a spin-on filter installed inline between tranny (4L80E) & radiator...sure simple to change.