Whats involved in changing out TH350 tranny filter

[Mountain Man]

I have never changed oil in a TH350 tranny. I here that there is a filter/gasket kit to buy , to replace after you drop the pan.

Can someone tell me is the filter readily accessable? And does it just pull out, or is it bolted in? How hard is the filter to change?

[1972chevy4x4]

It is a somewhat simple process, the kits are very accessable at any parts store. Just drain the pan, remove all bolts around the pan, drop the pan, and remove I believe to be two or three bolts from the filter and it will drop out. Replace the filter and bolt back in, tack gasket to pan with sealant, replace bolts, and fill with fluid. hope this helps.

[Longhorn Man]

It is VERY simple...but also messy.
Get a filter kit from NAPA that has the re-usable gasket. Even if you don't ever re-use it...it is 10 times better then that cork crap.
Depending on the year of your tranny, there are 2 or 3 styles of filters. All of them are real simple to remove and install.
Remember to clean out the tranny pan with some solvent or brake cleaner while it is off. Make sure it is 100@ dry when re-installing it though.
I normally install a drain plug kit first time my pan gets dropped...it's the best way to keep dextron out of your hair on future trans services.

[Mountain Man]

Thanks guys. What is the fluid capacity of the TH350? I imagine some will get hung up in the torque converter.

[Longhorn Man]

That's one I can never seem to remember. (Quite a bit stays in the verter)
I'm thinking its like 6 to 8 quarts?
Some one please confirm/correct this please?

[1972chevy4x4]

That is correct, you are looking at five for the trans and in the area of two and 1/2 in conv. Start off by putting in four and 1/2 quarts in, start truck let trans warm up, check fluid level and fill as needed.

[mikep]

I put a new converter in my truck when I installed the TH350 . I had changed the filter and put a shift kit in it so the trans was empty except for what was bound up in the drums. I used 10 and a half quarts of Type F fluid ( it shifts faster than dexron ) . .

[keenee]

Longhornmail understated messy. IMO if you only get oil in your hair, you are too good at this job. I think the first time I tried the dexron ran down my arm, then down my side and into my pants! lol

[COBALT]

My opinion differs a bit:

1. I usually take this opportunity to clean and inspect the valve body, and make sure the parking pawl and other stuff is in good shape (no broken or bent-to-hell pins and stuff).

2. I always use a cork gasket for the transmission. The rubber or reusable ones get hot and shrink sometimes and don't make a good seal. Once they're wet they're almost ruined. It's impossible to get a good seal. I clean the case and pan with brake cleaner and some scotch-brite, and the cork gasket seals right up.

3. When pulling the pan I leave two bolts in one side loose, but still in the case. This makes sort of a hinge that makes draining the pan when I first pop it loose easy. Position a wide pan near the front of the tranny, and leave two bolts in the back loose but still in. Let the tranny pan tip down and let the majority of the fluid run over the edge of the pan into the drain pan. Once it stops secure the pan with the palm of your hand and remove the last two bolts, then pour the rest of the fluid into the drain pan.

4. Make sure you use petroleum jelly on any o-rings you put back in or use when replacing the filter, especially if the filter kneck is new. I've had to grind a bevel onto some filter knecks to get them to fit into the case.

5. Make sure to get the gasket-and-filter kit that has a high flow filter vs. a stock flow one. They seem to be better.

6. Installing a drain plug is a must, but I went with an aftermarket deep pan that added another 2 qts. It's cast aluminum from Summit Racing, and has a milled pan edge that's 1/4" thick, and substantial as hell. It came with an extra-long filter kneck, and extra long mounting screws for the filter. I went from a leaky tranny to exactly ZERO leaks, and a cooler transmission overall. That + new pre-bent transmission lines from Inline Tube and I had a good, clean, leakless system.

[Long Knight]

Well, here is my .02. Why are you changing your fluid/filter. Having problems? Has it ever been changed? The reason I ask is because I thought I would give mine a change awhile back and might have made a bad choice. I drained the 30 year old fluid and changed the normal stuff, two days later my tranny went out. That's not to say it wouldn't have happened eventually, but I and my tranny guy think it was sped up when I took out the old gritty oil. New lube made it too loose. Anyway, if it has never been done, it may be like replacing the old man's decaf with expresso. May not hurt but you just never know.

[Longhorn Man]

long Knight does give a good point, that has happened to MANY ppl.