4T40E transmission tips and tricks

[cchase]

I am planning on changing the transmission fluid in our 2002 Malibu this spring. It has the 4T40E transmission. The car currently has about 110k miles on it. The fluid/filter has never been changed but I believe some of the fluid was exchanged at some point in the past (but am not confident one way or another).

The car is driven very easily (and has been since new) with mostly highway, low load driving.

I am planning on draining and filling with Castrol Dex VI fluid.

Is there anything I should be concerned with? Filter brands that stand out? Gasket brands? RTV on the pan bolts? Ordinarily I would not wait this long to drain the fluid but I haven't really had a big hand in maintenance on this car. The fluid is still bright red and smells like new fluid, for what that's worth. Admittedly I don't have much experience with automatic transmissions.

Thanks in advance.

 

[mechanicx]

Its a good transmission but the bad part is as you know no dipstick. I think the top cooler line is the trans out/cooler in and I would flush through that line before you drop the pan and also to do the flush. The pan gasket is reusable and I wouldn't use RTV on the gasket or the bolts.

I prefer the ACDelco filter but most of the filters seem decent especially since you won't need to use a replacement gasket. The filter oring has to be installed in the transmission before the filter if you choose to replace it. Good choice on ATF and I think you will need 12-13 qts for a full flush. That's about all I can think of.
But if you are going to just do a pan drop and refill I think it might still be worth unhooker the cooler line and running it low so the pan won't be full of fluid.

 

[cchase]

Is there any way on these to use a Mityvac or similar to draw the level down? I don't know what the innards look like to stick a tube down the check cap.

Is it going to be better to pick up a gasket in case the old one doesn't seal up well on the re-install? I was not aware that they are re-usable - that may explain the seeming shortage of options out there.

I noticed mention of RTV on the bolts in the Haynes manual - is there any reason not to use it or is it just unnecessary? I'd rather avoid having to get under there multiple times if it leaks after reassembly.

 

[mechanicx]

I don't know if a mightvac would work. I never tried it that I can remember. It won't hurt to try if you have a mightvac. I think it would be easier to open the cooler line and run the engine until the fluid starts to sputter. I don't believe this will harm the trans and then youll be able to flush out most all the fluid later.

The gasket is reusable and very sturdy and pricey. So if it loks good you should be able to reuse it. I'm thinking there is really only one bolt that it is suggested to use sealer. I'll try to look it up. I don't think it will leak if you tighten all the bolts evenly to spec.

 

[artificialist]

OE pan gaskets are the best pan gaskets by far. You can even re-use the gasket once or twice.

Given the age of this car, I would replace the gasket with a new OE one.

 

[cchase]

I'm thinking about buying a gasket and then playing it by ear based on what the OEM gasket looks like.

I just wish there was an easier way to figure out the part number for the gasket...

 

[mechanicx]

The GM OE gasket should be part number 24203590. I think Wix and ATP and may be others offer the OE style reusuable gasket with filter. But it is more than double the price of just the filter. It is probably cheaper than buying the OE gasket and filter separately though. The OE gasket probably cost more alone than the ATP and Wix filter with gasket kits.

 

[cchase]

Looking on Wix's site, the gasket that comes with their filter kit looks like it's cork. But I do see that it's only about $18 on Amazon. Gasket kit from GM looks to be about $28 on Amazon.

Just don't want to close it all up only to have it be leaking on the original gasket.

 

[mechanicx]

Yeah you don't want the WIX with a cork gasket maybe the ATP B171 should have the OE style gasket. I would just use the OE gasket. It won't leak if the pan bolts are torqued properly and to specs unless the gasket's sealing ribs are somehow damaged. You should be able to see if the gasket is sound. The OE gasket is so expensive because it is pretty solid. Many people successfully reuse them.

I would just take the small gamble and take off the pan and see how the gasket looks and then buy an OE gasket if necessary. You could go with the ATP kit which I believe has the OE stle gasket, don't know if it is as good the OE. Or you could buy the OE gasket and filter speretely have the gasket on hand.

 

[1990LTD]

the ATP filter has the cork gasket. bought a filter (either B161 or B171 can't remember) for my 4T60-E and it's cork