Transmission Question

[tvl]

I haven't had too much luck getting the following concerns answered on a Ford forum. I thought someone here might be a Ford guru and be willing to answer a few questions:

1- What is the difference in the 6 speed ZF 6HP26 and the 6 speed 6R75?

2- Are either of the above mentioned models considered to be a TorqShift transmission?

3- On a 2008 Expedition equipped with the 6R75 transmission, what is the recommended service interval for changing fluid under normal driving conditions (we do NOT pull a trailer with this vehicle)

Thanks!

 

[Billy_D]

Under normal driving conditions, you don't have to change ATF until you reach 150k. But, I would advise you to follow the severe maintenance schedule, which calls to change the fluid every 30K.

 

[hate2work]

The gear ratios appear to be the same...

Six Speed Automatic Transmissions
Trans Model First Second Third Fourth Fifth Sixth
Torqshift 3.114 2.218 1.545 1.096 1.000 0.712
6HP26 4.17 2.34 1.52 1.14 0.87 0.69
6R60 4.17 2.34 1.52 1.14 0.87 0.69
6R75 4.17 2.34 1.52 1.14 0.87 0.69

I agree with Billy, do a drain and refill every 30k and you'll be ahead of the game. You might want to use synthetic, many good brands available. I use the Amsoil universal ATF and I like it.

 

[Rustyknife]

The 6r family of trannys are basically the same, you have the 6r60 6r75 and 6hp26 the difference is in the amount of frictions and steels in the clutch packs, letting greater torque be transferred. The difference between the 6r75 and 6hp26 is the the 6hp26 has 7 friction and 7 seperator plates in the low reverse clutch as opposed to the 6r75's 5 of each.

No, neither of these are considered the torqshift, the torqshifts model designation is 5r110. Its a 5 speed transmission....sort of....it has 6 forward ranges but it only uses five at a time, depending on tempreture you may get a different shift strategy.

Every 30K would be ideal, using ONLY Mercon SP

 

[tvl]

Thanks to all for your response! I really appreciate your time!

2 final questions:

As everyone is probably aware, my 6R75 does not have a "convenient" method for checking the fluid ........ no dip stick. On the otherhand, it won't have a very easy method for filling with fluid once the pan has been dropped, fluid drained and pan replaced ............... no dipstick tube going to the top side of the engine. SO:

1- What have you found to be the easiest method for adding fluid back to ther transmission. It appears to be a very tight fit on the side of the tranny where the service plug is located.

2- I have always drained the torque converter when I service ther tranny. Does the 6R75 have a torque converter access plug?

Thanks again!

 

[Rustyknife]

The 6r75 will have a dipstick located right at the transmission. You unscrew what looks to be a 2 inch long nut and theres a stick at the end of it. It right at the front right, where a tube would normally enter on say a 4r70w or torqshift

An oil suction gun is worth its weight in gold for everything automotive...i dont have this exact one, but you get the idea, a good parts store should have one. Makes filling stuff cake

http://www.jcwhitney.com/OIL-SUCTION-GUN/GP_2004282_N_111+10201+600017979_10101.jcw

Torque converter will not have a drain plug. I really prefer flushing to drain and fills as you get most of the old fluid out. I realize this isn't practical for a DIYer, so what I might suggest is once you hit 30k, drain and fill the ATF every oil change for a bit. That will dillute most of the old with good new stuff. Dillution is the solution. Most of us have more time then money, so its not that big a deal, and the pan gasket is reusable, so your not really out anything....

 

[tvl]

Originally Posted By: Rustyknife
An oil suction gun is worth its weight in gold for everything automotive...i dont have this exact one, but you get the idea, a good parts store should have one. Makes filling stuff cake


Thanks RustyKnife!

If I am reading your post correctly, you're suggeating at about 30K miles to drop the pan and drain what I can (I'm thinking about 5 quarts). Of course, while I'm inside the case, change the filter also!

Then, at maybe the next 3 or 4 oil changes simply use the suction gun to pull the fluid out of the port where the short dipstick is located. Then simply refill. Is this correct? Or will it still be necessary to drop the pan?

Thanks again!

 

[Rustyknife]

Well to be honest, and I dont want to hurt anyones feelings here, but changing filters in an automatic transmission is a joke. Ford even tells us that you can reuse them on a rebuild as long as there wasnt a catastropic failure. If you think about it...its a sealed system, not like an engine at all. If theres something that contaminated the filter and plugged it up and needs changing, the tranny needs to come out anyway. Changing a plugged filter is just a great way to get yourself stuck in timbuck2 with a automotive shop you dont trust.

I was suggesting dropping the pan each time to get the most out, and then pushing new fluid into the trans with the suction gun, but your idea of sucking it out and then refilling it is also a great one, and will probly be the least amount of trouble.