Kael

Hey all. PO of my 2005 Express 2500 evidently did something with the tranny dipstick and put in one from a different tranny.

This is a 4L80-E, RPO code MT1. Can also tell by the bolt count in the tranny oil pan, 17 bolts.

My problem is the dipstick is clearly from a 4L60-E. I had to buy a new after the PO's broke and for some reason I thought I had an 4L60-E, likely because the length of the dipstick for that matched the broken one.

I know the 4L60-E dipstick is too long at 67". I pulled the tranny pan over the weekend and found that with the dipstick fully inserted, the tip hit the bottom of the pan with some to spare. Wondered why it wouldn't quite go all the way in (which is why I pulled the pan when it finally got warm). Pretty sure when running cold the pan should have more than 1/2" of fluid.

And as you probably guessed, I can't find a new dipstick. Well, the original style. I've found plenty for either a truck or some chrome, braided tube, $200 doo-dad (also likely for a truck).



So, long question, any one who has a 2003-2009ish with an 4L80-E (RPO code MT1) know how long the tranny dipstick is, say from the bottom of the plastic collar?

mountainmanjoe

https://www.dormanproducts.com/p-74540-917-308.aspx

Kael

Nope. That's for a 4L60-E. And, that's the new one I already bought which is too darn long.

Note in its long list of compatibility it does mention some 4L80-E's, but not for a 2005 Express 2500.
4L80-E on mine has to have been an option either ordered by the owner or it's a special fleet configuration, mine very likely was part of a fleet at one time.

Kael

Noted something useful, might chase if I can't find a stick length. $30 fluid + $10 gasket ain't expensive I suppose. Dumping tranny fluid all over my driveway AGAIN, hmmm.

Summary, correct GM transmission fluid level is at the level of the pan gasket when idling with hot fluid. So, pull pan and dump, insert dipstick. Mark at gasket surface level, cut about an inch lower for cold measurement.
https://www.chevytalk.org/fusionbb/s...hp?tid/322962/

I find the narrow "hot" good range on the stick silly, it's about 1/8". If you measure the fluid while the car is on a 3 degree slope (like most rain sheeting driveways), that can impact the measurement from the dipstick easily up to a 1/16" or more.

At least we have a dipstick instead of the "latest" method for cars WITHOUT tranny dipsticks.
Get this:
Lift the car.
Run the tranny fluid to hot.
Shift through all gears, etc. etc.
Leave in park and idling.
Remove the side plug on the tranny.
Watch the fluid leak out. If not, add more.

Guess I'll make sure any car I buy has a dipstick going forward!

Kael

Oh boy. Isn't it fun when you figure out how something really works after you've spent an hour or two (ahem) "correcting the problem"?

So, after trudging back and forth from the garage to Duck, checking how much the dipstick needed to shorten by chopping up the old stick, drilling some holes in the new stick to move the handle mounting to the right spot and various curses when the darn end just wouldn't stick out like it should, was getting to the red phase. Didn't matter how I wiggled the handle, tip wouldn't drop consistently. Gorram it!!

Then, lo', the eyes fell on the tranny pan and noted one corner looked like it had been bent in. What the heck did the PO hit to do that? Then I noted the corner was under the dipstick and the light bulb finally went on. Hey, it's like a little shelf in the pan. And the dipstick has this big plastic tip on it. Measured and yes, the stick matches the top of the pan when THE TIP IS SITTING ON THE SHELF. Ohhhh, I am a dumb dumb boy (I'm 50+, fyi).


So, the reason the tranny dipstick seems a bit long AND has a locking handle is simple, the long tube takes some pushing to get through there, so the extra stick helps push the tip down on the shelf, which it STOPS and one gets a good, consistent reading. 4L60-E dipstick works just fine in an 4L80-E for the same model year, etc.


DOH!!