1998 LeSabre with 4T65E (RPO M15).

Have been reading on these forums about dropping pan and changing out ATF and filter. As far as parts, I know I need:
-Filter
-O-ring (seal)
-Pan gasket

From what I've read, I want to stick to the original pan gasket if possible, because its rubber/metal construction is better than cork. Is this correct?
Tranny has 90k miles; how likely is it that the original pan gasket is reuseable?
If original pan gasket is not reuseable, which of these is the right replacement?

ACDELCO Part # 24206182 GASKET,A/TRNS FLUID PAN 2ND DESIGN; W/TRANS UPDATE LEVEL 01 OR GREATER, FOR 1ST DES SEE 24204624; w/4-SPD A/TRANS(MN3) GASKET,A/TRNS FLUID PAN 2ND DESIGN; W/TRANS UPDATE LEVEL 01 OR GREATER, FOR 1ST DES SEE 24204624; w/4-SPD A/TRANS(M15)

ACDELCO Part # 24204624 GASKET,A/TRNS FLUID PAN 1ST DESIGN; W/TRANS UPDATE LEVEL 00 OR LESS, FOR 2ND DES SEE 24206182; w/4-SPD A/TRANS(MN3)
GASKET,A/TRNS FLUID PAN 1ST DESIGN; W/TRANS UPDATE LEVEL 00 OR LESS, FOR 2ND DES SEE 24206182; w/4-SPD A/TRANS(M15)

How likely is it that the o-ring seal on the filter will be reuseable? In other words, which of these kits should I order:

ACDELCO Part # TF304 {replaces TF248 #25313825} FILTER,TRANS FLUID

ACDELCO Part # 24227477 FILTER KIT,A/TRNS FLUID w/4-SPD A/TRANS(M15); W/SEAL,LESS GASKET FILTER KIT,A/TRNS FLUID w/4-SPD A/TRANS(MN3); W/SEAL,LESS GASKET

Other than 8 or 10 qts of ATF, what else will I need?

If the pan gasket is the factory one still, the probability is extremely high you can reuse it.
Unsure on which part is the correct one, if you had to order the factory gasket.

Typically when you remove the filter, the "gasket" or plastic thingee will stay up inside the transmission. It'* been my rule of thumb (learned from a GM Certified Mechanic) that if the new filter goes into the existing "gasket" snug, then don't change it. That gasket is actually a plastic sleeve and more damage can be done trying to remove it. Only change if the filter does not fit in it snug.

If you purchase an aftermarket filter kit, it will come with the filter, plastic sleeve aka gasket and either a rubber or cork gasket. Add 2 gallons of trans fluid (typically use about 6-7 quarts) you should be ready for the project.

BillBoost37,

Thanks for the info.

We have owned the car since 36k miles, and it hasn't leaked a drop of ATF. I can see at the seam of the pan-to-tranny that the current gasket is rubber. I will take the chance that the pan gasket is original and reuseable.

About the seal...yeah, I saw in one of the procedure pictorials where the guy mangled the seal trying to pry it out of its hole.
So, if I buy the OEM ACDelco TF304 filter, can I be reasonably certain it will, as you say, fit "snug" into the existing seal?

I agree with Bill, buy the complete kit. I want to add a couple comments.

Sometimes the filter seal will come out of it'* own volition. You will definitely want to replace it in that case.

My car had 164K on it in August when I last did the Trans Filter change. My original OEM gasket is still good and reusable, so chances are that yours will be too, unless someone else was in there before you and was sloppy.

I found, at least down here, that the kit from Advance had everything you need plus it supplies a rubber replacement pan seal, which is a better option than the cork, IMO. That is only if your OEM is not reusable.

Oh, and you'll want to go to Walmart or equivalent and purchase a large plastic storage pan. In Walmart, it'* a Sterlite pan that is big enough that it contains the considerable mess you would normally get.

Don't forget to wash out the pan and the magnet before replacement.

Don't assume anything. The GM Delco box should come with that sleeve.

When you get the old filter out.. try the new one. If it'* snug. You are good. If not....be gentle and take your time replacing the sleeve

The OEM gasket was not rubber, so you may already have a replacement gasket.

Like said, buy the whole kit. It'* not that expensive and you'll have everything you need in case...

When I did mine, (1997 SSEi) I had a cork gasket. I threw that away and used the rubber one that came with the kit. IMO, if you use the rubber gasket that comes with the kit, put a light film of trans oil on both sides of the gasket before you use it. Helps it to seal better. Again, IMO. The gearheads may say otherwise.

Use decent trans fluid; that means no Supertech Trans fluid from Wal Mart.

The biggest part of the job will be the 14 bolts coming out and going back in. You will have a sore arm if doing it by hand

Have fun!

Good info Cheetah, for sealing any gasket like this, it is recommended in the FSM to assemble dry w/o a layer of oil. Being a gasket that you want to seal, I would suggest the dry assembly as well.

I cheat while removing and replacing the bolts by using my DeWalt drill with the socket attachment. When using this to reinstall the bolts I only run them to the pan, then hand torque them for consistency and no leaks.