Matching an Eaton with Mack EM6

[Mr Black]

I am fairly new to Mack and just working through some compatibility issues. I am restoring a R Model with an EM6 matched to a T2090 9 Speed. The T2090 has an issue and I have been told (by many) not to bother fixing it. I have access to a good Eaton 18 speed (RTLO14718B) but am wondering if it is a lot of trouble to match an Eaton to an old Mack engine such as an EM6. What else do I have to buy to make it mount and work?

Any help/advice would be appreciated.

Thanks

[j hancock]

You will need to get a different bellhousing, change to rear engine mounts between the frame and bell housing and have the drive shaft remade to the correct length.

Mack transmissions are mounted to the frame rails and serve as the rear engine/trans mounts. Eatons do not have this provision and "hang" on the bellhousing and that's why you will need to change the bell and get rear engine mounts.

[farmer52]

What is your application and do you need all those gears?

[BAD DOG]

I threw a good 2090 9spd in with arear cutoff I sold a guy about 3 years ago. Only because I couldn't seem to sell it and I needed the space. I know he just sold the pigs and scraped the rest. Wish I still had it I'd trade you for that 18 spd fuller

I have a 15 in my Superliner and would prefer an 18 but you never come across that stuff when you're looking. I have a Mack 12 spd in the archives that needs a bell housing but it's different from your 9 spd. Bell housing.

[masterwelder]

You are also going to want to find out you're rear end ratio and the 18sp high gear ratio. Go to the Roadranger website and look on the left hand side for the road speed calculator. Plug in your info and see what your road speed will be. You may also need to change the rears.

[Superdog]

pretty sure there is only a .02 ratio difference in the Mack and the Fuller,so that shouldn't be an issue, the Mack is .71 and Fuller is .73 if I remember right.

[Mr Black]

Thanks all,

Seems like I will have to add a fair bit of expense to convert to Eaton. In response to your queries/comments:

Application will be skel/flatbed trailers. However, we may also be getting some low end heavy haulage but may need to upgrade the EM6 for that. So the 18sp is probably not needed right now but could come in handy. Current 9 speed not really versatile enough. A 13sp would probably be enough.

I have checked out the ratios and they should be fine.

Cheers

[masterwelder]

I just put a 13 in mine and I have a E7-300. Best move I ever made!

[Timmyb]

I'm considering doing this as well. I have a 2v e6 300, high reving engine not a maxidyne. It's matched up with a mack 10 speed and 4.42 rears. When the truck is finished and rego'd it will be pulling 50ton or 100,000lbs so I'd like a few extra gears to keep the engine in the usable power range. Also with the double over drive eatons it will lower my cruise rpm at 100km/h from 1800 to 1700. Would like to hear from anyone with a double overdrive eaton and how it pulls after the swap.

[Joe Ditchkus]

I do not think you will be using double over much loaded with 100,000 lbs.with a E6 300. It is a great engine but I think you are looking for performance that will not be there with that drivetrain.Joe D.

[Timmyb]

Yeah thanks for your input Joe. It wouldn't be doing it day in day out, but rather setting it up for the days when it's needed. We only have one other mack to compare it too, which has an e7 400, 12speed and 4.17 rears. It's pulls 42.5ton (85,000lbs) quite well. Was thinking (or hoping) that extra gears and and lower diff gears would make the difference.