billscamaros

iTrader: (1)

quick question on '01 Suburban 1500 4WD ..... time for me to replace trans filter and fluid. seems like there could be two or three different trans models used in my truck ..... 4L60E or 4L80E. how do i tell the difference? can i tell from the trans bolt pattern, or is there a code somewhere on the truck that indicates installed trans? how about deep pan vs regular pan? how deep is a deep pan? trans is totally stock.

thanks

bill

Mort

I am sure you would have a 4L60E in a 1500 series. You can check the code in the glove box on the RPO sheet.

M30 = 4L60E
MT1 = 4L80E

Not sure on the pan depth but if it is deeper than 2.5" I would say it is the deep pan. Most likely you have the shallow pan. FWIW the pan on my 4L80E is about 2 3/4" deep and is the shallow pan AFAIK.

If you are going to flush it then do it through the top rad connection which is the return to the trans sump. Flush 15-16 qts through and you should be good. Flush it by running the truck and using the trans pump to pump it out. Flush for 30 seconds then shut it off and refill the trans. Each flush should flush out about 4 qts. You will need to make up a fitting with a piece of hose attached to run to a container to collect the used fluid. Flush until the fluid is a clear red again like the new fluid. Change the fluid and filter before you flush the trans.

If your trans fluid has not been flushed before and has high mileage then just change the fluid in the pan and let it go at that. I don't think you will hurt your trans flushing it this way but flushes using an external machine seem to stir up some gunk in older high mileage vehicles that has caused trans failures.

Be careful dropping the pan. On mine the exhaust is it the way and I damaged a shift solenoid on the valve body getting the pan out the first time.

Best of luck

billscamaros

iTrader: (1)

thanks jim. i have the M30 = 4L60E trans in my suburban, and it looks like i have room to drop the pan without much problem from the exhaust. i hope to work on this over the upcoming weekend. thanks again.

Mort

Welcome and good luck with it. It can be a messy job so have some rags or shop towels ready. Nothing like a big drop of trans fluid in your ear...LOL