FL 60 Allison transmission

[jimfl60]

Can anyone help... I have a fl60 freightliner

I?m looking into replacing the Transmission in my truck , The problem is the ratio has too big of a gap between the gears , so driving in the mountains climbing the hills , the truck is screaming in 4th  gear and when I shift into 5th  it falls on its face and I have to shift back into 4th to get up the hill screaming to the top , it the same going down the hill 4th screams at 45 mph and 5th gear is too fast going down the hill and have to use the breaks way too much to the point that the exhaust brake doesn't do much trying to keep the truck around 45 mph. I need to split the difference somehow. So I'm looking at may be putting in the MD-3060 6 speed Allison auto transmission.

this seems to be my only choice , I found one that was mounted on 3126 cat motor and I can get all the stuff with it , mounting cross member , bell housing , controller , key pad , wiring harness, so the question is for you is what more will I need from the motor ? , I know to supply it with 12 volts act , will I have to have the ECM programed ,, ect ?

My truck has a Eaton full FS0-8406A std 6 speed with a 3126 cat motor. The trucks also came out with Allison MD-3060   

the truck is a 2000 fl60 freightliner with a Eaton fuller FSO-8406A std 6 speed transmission with a 3126 cat motor.

 

[Henry J Fate]

A transmission with a Hi/Lo splitter may be a good option. That would get you in between gears and still be able to take advantage of existing gears (or close to it) if your load, terrain or your engine ability changes.

 

[Jackiemac]

Hi and welcome to the forum.

I hope someone can help with your problem.

Please note I have removed your other post as it was a duplicate - you only need to post once as members will see it.

Good luck.

 

[Gary RV_Wizard]

I'm no expert on this topic, but the engine ECM and tranny TCU need to be working as a team to manage engine revs properly, so odds are both will need calibration programming.
Have you compared the gear ratios of the MD3060 to the Eaton to verify that it actually solves your problem?

 

[jimfl60]

Thanks all for replying, I have been looking everywhere for a splitter and seems that no one makes one. Yes I have compared the gearing between the std and the auto transmissions and the automatic looks alittle better. I want to do my homework before I commit to buying the automatic transmission.