68RFE Transmission Fluid Level

[RamVenture]

I have a couple 68RFE questions. I changed my oil this weekend and while confirming oil level this morning I also checked my transmission level. The engine was cold (80deg here in AZ), and oil level was at the "HOT" level mark. Sadly, I think it's been at that level for a couple years. The oil looked ruby red. I remember checking it some time back when the engine was warm, and it was a bit high, but it didn't seem overly high. I'm going to check again when the engine is warm and compare. Probably need to suck some oil out the dipstick. Does anyone know about how much fluid fit between the COLD and HOT marks? Also, I noticed by dipstick doesn't seem to seat snuggly in the tube, no resistance when pulled. Is this normal, need new O-rings?

 

[Topzide]

Did you have the truck running when you checked it? I replaced the dip stick handle with an aluminum end that I turned. Yes, o-ring may need replacing for a better fit. When I turned my end, I was able to use a thicker o-ring, in width and smaller diameter. I think it's just around a quart between the two marks. Color sounds right on. When mine starts to darken, I set up the time to change it. (get all the stuff together)

 

[RamVenture]

No, the truck was off, it had sat overnight.

I inspected the dipstick more closely and there is no o-ring (on mine). The plastic molding has a ridge and two vent hole notches at 12 and 6 o'clock. I'm guessing from the factory it's not setup to be a super snug fit like the oil dipstick.

This morning, I pumped out 2qts of AFT to bring level down from above the HOT mark to about 1/2in above COLD top dot. I thought about taking more out, but didn't want to overdo it before. The temp outside was about 90F (AZ) when I was done. I took the truck out for a drive and got the transmission up to 160F. Got back home, let the truck sit for a few minutes then checked again. The oil level was just below the lower "HOT" mark. I expected the oil level to read higher since I didn't initially pump enough to get it down to the COLD mark. The dipstick has marking stating 170F is hot. I didn't get the temp this hot so I'll check again when I'm pulling my trailer.

I went back and reviewed my notes from when I had to transmission serviced last. I have a note that it took 8qts. Reviewing the Cummins service procedures, it states total 68RFE capacity is 17.5qts with service refill to be 5.5qts to 6.5qts. With the 2qts removed this put me at 6qts.

 

[Ozymandias]

I wouldn't worry to much if you have driven for years at the level stated.
If the level is seriously to high the fluid will foam and you loose the traction.

The fluid level in a modern automatic transmission isn't so crucial anymore as it was in the past.
The pickup tube is all the way at the bottom of the pan like in an engine.

 

[NIsaacs]

No, the truck was off, it had sat overnight.

You need to check the transmission oil level with the temp warm, engine at an idle and in park.

 

[Hoefler]

Must check with the engine running, in park!!!

 

[Cummins12V98]

I concur with two above posts and will add be sure truck is on level ground.

 

[CoastyAV8R]

I changed the fluid in my transmission a few months ago and wonderful world of youtube a guy did his and said it would hold 7 quarts. I let mine drain all day and when I added the 7 quarts it barely registered on the dipstick so I wound up adding 11 quarts to get it up to the full line when it was warm. Don't shortcut getting the transmission warm when you check it, drive it for 20 minutes, put it in park on level ground with the engine running and check it.

 

[RamVenture]

Thanks for the information. I didn't realize it was checked with the engine on. I pulled the dipstick when cold and thought it was way overfilled. I have been checking when warm and the level isn't at the full mark. I will be adding more back in.

 

[Cummins12V98]

Thanks for the information. I didn't realize it was checked with the engine on. I pulled the dipstick when cold and thought it was way overfilled. I have been checking when warm and the level isn't at the full mark. I will be adding more back in.

Another "HAPPY ENDING" on the TDR

 

[ProLean]

Wait! I thought we were supposed to check the ATF level with the truck warm, running and in NEUTRAL not park because the level won't register correctly in PARK. At least on a 68RFE...

 

[Ozymandias]

In Neutral was the old 727 transmission, the 68rfe flows fluid in P.
They finally figured it out that it might be smart to have the capability to cool down the fluid parked idling after a steep grade.

So, it actually doesn't matter in which position you measure the level - but for safety reasons the best position to do so is in Park.

 

[RamVenture]

Reading the TDR Perfect Collection it states that on the 68RFE it can be checked in Park or Neutral. I think there is a port that allows the oil to pass through in Park. If i remember correctly, I think my dipstick says "Check in Neutral"

 

[Ozymandias]

My dipstick (48RE) stated to use Dexron III as fluid, I ignored that too..
Sometimes they print pretty funny stuff on things.

 

[Cummins12V98]

Reading the TDR Perfect Collection it states that on the 68RFE it can be checked in Park or Neutral. I think there is a port that allows the oil to pass through in Park. If i remember correctly, I think my dipstick says "Check in Neutral"

Pull your dipstick and tell us what it says.

 

[Grumpy8811]

basic use of trans dispstick is always with engine running in neutral...

purpose of Cold Check is to get a ballpark reading... aka there is some fluid on the stick in the correct area.and you say Good Enough and I will check it later when it is fully warmed up

then if you have time when appropriate a Hot Check is more accurate, when trans is fully warmed up, in neutral and on level ground..
aka 160F or higher trans temp,so this hcan only be performed after the truck has been driven some distance.

other than that, don't get too nitpicky about the situation, add 8 ounces at a time allow plenty of time to settle and you will eventually get it right.

I've changed the fluid and filters in my 68RFE 4 times now, and depending on the length of time I leave the filters removed the amount of fluid it takes to get the level right has varies anywhere between 8 point something quarts and 11 quarts..

 

[Signal73]

 

[brcbruiser]

No, the truck was off, it had sat overnight.

I inspected the dipstick more closely and there is no o-ring (on mine). The plastic molding has a ridge and two vent hole notches at 12 and 6 o'clock. I'm guessing from the factory it's not setup to be a super snug fit like the oil dipstick.

This morning, I pumped out 2qts of AFT to bring level down from above the HOT mark to about 1/2in above COLD top dot. I thought about taking more out, but didn't want to overdo it before. The temp outside was about 90F (AZ) when I was done. I took the truck out for a drive and got the transmission up to 160F. Got back home, let the truck sit for a few minutes then checked again. The oil level was just below the lower "HOT" mark. I expected the oil level to read higher since I didn't initially pump enough to get it down to the COLD mark. The dipstick has marking stating 170F is hot. I didn't get the temp this hot so I'll check again when I'm pulling my trailer.

I went back and reviewed my notes from when I had to transmission serviced last. I have a note that it took 8qts. Reviewing the Cummins service procedures, it states total 68RFE capacity is 17.5qts with service refill to be 5.5qts to 6.5qts. With the 2qts removed this put me at 6qts.

Man, you've gotta read the manual. Only check the transmission fluid with the engine running. Put your foot on the brake and shift between all the gears and let it sit in each position for a couple seconds before returning it to park. Then with the engine RUNNING pull out the transmission dipstick, wipe it, then check the fluid level.