GM 4L60E Transmission Service Tip

Good afternoon!

I took possession of my low mileage (48k) '96 Roadmaster Wagon just over two weeks ago and I'm going through my "service reset" routine of fluid changes. Since it came with what appears to be a fresh oil change (oil looks new on the dipstick), I hit the trans first with subsequent plans for the rear diff and a brake fluid flush.

The transmission shifts as it should and the fluid looks excellent on the dipstick but since I have no service records I figured I'd do a filter and fluid service. Based on the aformentioned observations I'm not going to worry about the fluid in the torque converter and just change the filter and fluid in the pan.

The first thing I did to minimize the hassle while dropping the pan was to remove a few quarts of oil with a Topsider oil extractor. I bought this a few years ago for the transmission fluid change on my Jeep and it draws a few quarts out of the pan via a hose and vacuum through the dipstick tube. It makes dropping the pan pretty simple since it only leave a quart or so in the pan, meaning when I drop the pan fluid isn't spilling out all over the place.

https://www.northerntool.com/shop/tools/product_390306_390306

I prefer Wix filters and went with the NAPA gold brand. I was told by the parts guy at NAPA that Wix makes the filters for NAPA and the filter itself has a steel backing plate (not plastic) like the Wix filter. I also used a Lubelocker gasket which is made with a steel core and has silicon beads on both sides of the gasket surface- no need for permatex or any gasket sealer which made installation a breeze.

After watching a bunch of videos on the filter seal removal and replacement, I didn't feel like trying to use the method of screwdrivers and pliers to pull the old seal. While it may work for some people, I didn't want to take the chance of marring the transmission valve body or driving myself nuts trying to pull the seal either. I also know that some people choose not to replace it at all but I figured if I already had everything apart I might as well do it right for peace of mind. I picked up a slide hammer and bearing puller set (Harbor Freight, $70) and it worked like a charm. It was as simple as illustrated in this youtube video (go to time stamp of 7:58)...

https://www.youtube.com/watch?v=brfev0N2iJc

Here is the link for the Harbor Freight tool kit...

https://www.harborfreight.com/slide-hammer-and-bearing-puller-set-5-piece-62601.html?_br_psugg_q=bearing+puller+set

I purchased it over president's day weekend and used a 20% off coupon so it dropped the price of the kit down to about $54.

Will I ever use the tool kit again? Unlikely, but you never know. Can you do the service for a few bucks less? Probably, especially if you use the pan gasket supplied in the filter kit. I chose the Lubeocker gasket because it's "beefy" compared to filter-kit gaskets and I wanted both simplicity and a sense of security knowing that it'll work the first time it's installed.

I hope someone finds this stuff useful...

-Carl

All good ideas for certain.

As long as you have the pan off you probably should consider using put a drain plug in it. That is what I did when I had ours off. Very easy to empty the pan before removing then and also allows for more frequent and quick fluid changes if you want to like I do with filter changes every two or three times.

I used a 1/4" bulkhead brass fitting and then silver soldered it in, removed the inside nut and cut off the extended thread that limits the draining. Silver solder distorts pans even less than tig welding does.

An excellent idea for sure and I was thinking of replacing the differential cover with one that has a drain plug when I service it. It's absolute ludicris that auto manufacturers don't add drain plugs to the rear ends and transmissions (although my Jeep has drain plugs for the differentials). It significantly simplifies fluid changes but the manufacturers are seeking every penny they can for profit and since recommended trans/differential service intervals are so few and far between, they skimp on drain plugs. It's just dumb!

I also added one to my rear axle when when I changed the oil to Motec after I got it. Even easier than the pan as you can tap in a 1/8" pipe thread in the bottom.

If you don't have the vacuum kit, you can just separate the cooler line right next to the battery, put a hose over the hard line, aim it into a milk jug, and start the car to pump it out. Shut it off once it sputters. Super fast and works like a charm. More info here.

You need 3 milk jugs.

In the GM service manual it says that unless the car is being driven under adverse conditions like city driving in high temperature or hilly roads and towing etc, that the transmission fluid should be changed every 100,000 miles.
How come here everyone is saying to change it much more often? I understand that more is better obviously, but if the manufacturer recommends every hundred thousand miles and you’re changing it every time you change your oil every 5000 miles or so, isn’t that a bit much? Sort of like changing your engine oil every 500 miles.
Just wondering……

roadsurfer wrote:

In the GM service manual it says that unless the car is being driven under adverse conditions like city driving in high temperature or hilly roads and towing etc, that the transmission fluid should be changed every 100,000 miles.
How come here everyone is saying to change it much more often? I understand that more is better obviously, but if the manufacturer recommends every hundred thousand miles and you’re changing it every time you change your oil every 5000 miles or so, isn’t that a bit much? Sort of like changing your engine oil every 500 miles.
Just wondering……

I have never really trusted the factory recommendations for service intervals because long intervals are a good selling point and all they really need to do is get through the warranty period. I would say that most us do at least some of the adverse driving like towing, in town, acceleration runs or hilly areas with lots of shifting.

The Roadmaster does not seem to dirty the trans oil quickly like some vehicles I have had and with the change to DexVI I think that 30-50K probably would be where I would be unless it was a lot of years besides. I am retired and this is my summer daily driver, so it historically had gotten only 2-3000 miles per year. But now that it has been nearly completely rebuilt in every area the reliability should be more of given (it hasn't had many issues at all in 10 years anyway) and my wife likes it so much we always use it for roadtrips now. Last year it got about 5K because of that.

Remember, in the mid 90s, having a 100,000 mile service interval was a BIG DEAL to new car buyers. So automakers were under tremendous pressure to advertise this. But remember, many new car buyers sell their vehicles after 5 years, so most of these cars would only make it to 60k on the first owner. So GM never really had to account for a fib in this case.

Over on ISSF, I have discussed in detail how transmissions with suction side filters MUST utilize detergent additives to keep the transmission clean, and the only way to then remove what the detergents pickup is to flush the fluid. Use my cooler line method over on ISSF to do it super fast.

One other note on the trasnmission filter - I don't think it's necessary to replace filter seal every time. It's plenty tight. And if you do, leave the replacement one sticking out enough that you can get a flat blade screwdriver onto the side of it and easily pry it out the next time.

sherlock9c1 wrote:

Remember, in the mid 90s, having a 100,000 mile service interval was a BIG DEAL to new car buyers. So automakers were under tremendous pressure to advertise this. But remember, many new car buyers sell their vehicles after 5 years, so most of these cars would only make it to 60k on the first owner.  So GM never really had to account for a fib in this case.

Over on ISSF, I have discussed in detail how transmissions with suction side filters MUST utilize detergent additives to keep the transmission clean, and the only way to then remove what the detergents pickup is to flush the fluid. Use my cooler line method over on ISSF to do it super fast.

One other note on the trasnmission filter - I don't think it's necessary to replace filter seal every time. It's plenty tight. And if you do, leave the replacement one sticking out enough that you can get a flat blade screwdriver onto the side of it and easily pry it out the next time.  

Yep they play the game all the way through in any way they can, deceptive or not.

I don't ever recall a spec or claim of detergent or not for transmission fluids, but I do recall back in the day it was very common to put a quart of trans fluid in the engine oil to clean sludge.

What fluids do or don't have detergent.

roadsurfer wrote:

In the GM service manual it says that unless the car is being driven under adverse conditions like city driving in high temperature or hilly roads and towing etc, that the transmission fluid should be changed every 100,000 miles.
How come here everyone is saying to change it much more often? I understand that more is better obviously, but if the manufacturer recommends every hundred thousand miles and you’re changing it every time you change your oil every 5000 miles or so, isn’t that a bit much? Sort of like changing your engine oil every 500 miles.
Just wondering……

look at the severe conditions as those are usually the most realistic for daily drivers, unless you drive slow and always take it easy. You need to remember that ALL manufactures want vehicles to wear out quicker than they should but not quick enough to become a legal issue, as if cars lasted too long the only way a manufacture could get people to buy a new car is through new features, and not because their old car is wearing out, so they want people to think that your usually driving in non severe or adverse driving when the majority of people actually are. was told that by one of the auto tech instructors when I was in tech school.

Sherlock, thank you for mentioning the issue with the filter seal. I didn’t see why I needed to replace it because it was plenty snug and when I did pull it out I gouged The inside wall of the housing by being too aggressive with the removal process. And what a brilliant idea to leave the new one hanging out just enough so you can grab it next time when it’s time to remove it. Too late now for me though, I already pounded the new one all the way in, thinking that’s how I should do it to do the job right.

That’s a good example of a problem I have working on this car. I’m not a mechanic but I have good common sense, mechanical aptitude, tools, shop manual, YouTube, and this forum for information. But I often run into some complication or question about a procedure and I don’t know what will go wrong if I don’t get it “exactly right “ and sometimes getting it exactly right it’s not possible or I’m not sure how to do it, but if I had a whole lot more experience like you guys do, I would know that some things are OK even if it’s not “exactly right“ like leaving the replacement seal exposed just enough to grab it next time.
When I was putting in the new seal I was being very concerned that I pound it all the way in because that’s how it’s supposed to be. I wouldn’t dreamed of leaving it out even a little bit. But now with your simple comment and my understanding of how it fits in there and what it does, I see that yes you can leave it out a bit and make the removal process so much easier next time.

By the way nobody in THIS thread was suggesting changing it as often as 5000 miles, I was referring to comments from a side thread link in the original posting about when or how to change the fluid. I did use your method of releasing the cooler line and of course it’s quite simple and now I will do it more often.

Thanks again