Swap Mack T318LR tranny for Eaton 18 tranny

[Vac-Daddy]

I was hoping on getting some insight on doing a swap, Mack 18 to Eaton 18. My Mack tranny needs to be replaced and parts are hard to get and very expensive. I can purchase a very good Eaton 18 For quite cheap from a good buddy of mine. What's everybody's thoughts, please help? 2007 Mack Granite.

[Joey Mack]

'07 Granite??  CV-713??   So you have an MP-7 engine?  and not an ASET-IEGR? 

[Vac-Daddy]

You bet

[Vac-Daddy]

[Joey Mack]

ok..  I was just curious..  Love the picture.  get the Eaton and have the driveshaft re-done..  Thoughts??  Eaton's kick a$$.  Mack's are tough, but cost a fortune to repair.. as you well know..  

[Vac-Daddy]

Do you know anybody who's done this swap? I'm worried about the gearing, if i'm gonna be okay or not? Like, if i'm fully loaded, will I still be able to take off out of a driveway on a steep hill...... Are my pto's all gonna be different.  This potentially puts me out of business, depending on the outcome $$$$$$$ I'm terrified 🥺 this is the info on my truck.

[Joey Mack]

I dont have the Eaton book that tells the ratios, But I do have the Mack Book..  I will try to post a picture of the ratio's.. 

[fjh]

11 hours ago, Vac-Daddy said:

Do you know anybody who's done this swap? I'm worried about the gearing, if i'm gonna be okay or not? Like, if i'm fully loaded, will I still be able to take off out of a driveway on a steep hill...... Are my pto's all gonna be different.  This potentially puts me out of business, depending on the outcome $$$$$$$ I'm terrified 🥺 this is the info on my truck.

I have a concern here Is your buddys trans Out of a mack? The bell housings is a diffrent set up for mack and western star ! being a 2007 this is a change over year are the rear  engine mounts  actually on the engine or the trans!?Your doing the right thing by going eaton BUT you need to do your home work as you are doing here! 

[Joey Mack]

fjh,, he has an MP-7.. so mounts are on the engine..  I dont have a lot of info for him, but can probably post the ratio's from the book.. That will be as far as I can help.. jojo

[Mark T]

1 minute ago, Joey Mack said:

fjh,, he has an MP-7.. so mounts are on the engine..  I dont have a lot of info for him, but can probably post the ratio's from the book.. That will be as far as I can help.. jojo

That's a CV   ain't no MP7 in that one. AMI on a vac truck ? I foresee a hole in the side of the block where a wristpin gave up.  Personally, I don't think this is a good choice for a man depending on an income...Fuller, Mack or any transmission 

[Joey Mack]

I asked him in the beginning of the post and he said ''you bet''..  If not, well then I am wrong.. 

12 hours ago, Joey Mack said:

'07 Granite??  CV-713??   So you have an MP-7 engine?  and not an ASET-IEGR? 

 

11 hours ago, Vac-Daddy said:

You bet

 

[fjh]

24 minutes ago, Joey Mack said:

fjh,, he has an MP-7.. so mounts are on the engine..  I dont have a lot of info for him, but can probably post the ratio's from the book.. That will be as far as I can help.. jojo

I thought I read 460 ai Earlier?

[Geoff Weeks]

Eaton ratios are available online, depends on the age of the transmission in question. Starting in the low end will unlikely be a problem, top speed may be depending on rear ratio.

PTO is going to have to be changed out, and matched to needed speed.

Not going to be a cheap, swap.

 

[fjh]

1 minute ago, Geoff Weeks said:

Eaton ratios are available online, depends on the age of the transmission in question. Starting in the low end will unlikely be a problem, top speed may be depending on rear ratio.

PTO is going to have to be changed out, and matched to needed speed.

Not going to be a cheap, swap.

 

it  will be least be more reliable ! 

[Geoff Weeks]

here are eaton's ratios

https://www.eaton.com/content/dam/eaton/products/transmissions/vehicle-transmissions/eaton-transmission-specifications-catalog-en-us.pdf

[Geoff Weeks]

13 hours ago, Vac-Daddy said:

Do you know anybody who's done this swap? I'm worried about the gearing, if i'm gonna be okay or not? Like, if i'm fully loaded, will I still be able to take off out of a driveway on a steep hill...... Are my pto's all gonna be different.  This potentially puts me out of business, depending on the outcome $$$$$$$ I'm terrified 🥺 this is the info on my truck.

This post is where the confusion starts!

[Joseph Cummings]

7 minutes ago, Geoff Weeks said:

This post is where the confusion starts!

eah I saw that late last night and thought Oh God. Lots more info needed. Not to mention, that 18 speed Eaton better be cheap or free

[Geoff Weeks]

14 hours ago, Vac-Daddy said:

Do you know anybody who's done this swap? I'm worried about the gearing, if i'm gonna be okay or not? Like, if i'm fully loaded, will I still be able to take off out of a driveway on a steep hill...... Are my pto's all gonna be different.  This potentially puts me out of business, depending on the outcome $$$$$$$ I'm terrified 🥺 this is the info on my truck.

You have a lot to weigh and make choices.

From the sounds of it this is your sole means of support. Down time can bankrupt a business or individual.

Can you rent a truck to service your customer base?

If not down time may trump other considerations.

Always faster to go back "like for like".

 I have no info/thoughts on the Mack 18 as I have no experience with them.

In an ideal world, building the truck from a clean sheet of paper, I would have 2spd rears and a 13 up front. Keeps the overall reduction at the back and allows for a smaller and less stressed driveline.

That said you have to start with what you have.

Even the most simple looking swap is going to kill you on the details, new PTO, has to match the operating range of what you have now. It will be in a different locale and require building a driveline for unless all hydraulic. Main driveline will require replacement of at least a section, and then there are the controls and air plumbing.

 All totally do able, but all take time and most can't be started until the lump of the transmission is in place. The are downtime killers.

It may be desirable in the long run to do the swap, but unaffordable in terms of downtime at present.

In an ideal world, you'd have a parts truck just like yours with the Eaton that you could rob all the little in consequential, but time consuming parts you need to buy to complete the change over.

everything always takes much longer than planned. one little part that is un-obtainable  can grind the whole operation to a standstill until found.

quick search online shows that trans has PTO on both the front and rear case, the Eaton will only have on the front case (in most all of them) and so you are limited to a single speed from the engine, if you need more than you'll need a multi speed PTO $$$$

Edited December 21, 2024 by Geoff Weeks

[Mark T]

2 hours ago, Joey Mack said:

I asked him in the beginning of the post and he said ''you bet''..  If not, well then I am wrong.. 

 

 

You are correct Jojo, just more the reason this dude needs to run the other direction. He has no idea what he's getting into there. I'd rather be called a d!ck for posting this than see the guy go broke with that truck.

[Joey Mack]

I too, dont want to be a Dick..  I try to post with an open mind, and i tend to ask questions that I know the answer too, just in case I missed something, or the guy posting may not know what he has..  even though an Eaton will serve him well, and is cheapper to maintain..  Like GW is saying,  there will be a bunch of small's that will cost him time and $$, as well as limited PTO options for him.. That said, with my limited knowledge on swaps and mod's....  I say fix what he has..  it will last a long time as long as it is driven right...  Jojo

[Mark T]

That's another thing that makes me wonder. That's alow mileage chassis. Really shouldn't need a transmission yet. Unless ??? it's had a lifetime of a frustrateed driver (s) trying to get that POS AMI moving.  or  something like that.  Man also asked if the truck was good idea as a foray into self employment.  Tranny is the least of his worries with that one. Even a knowledgeable guy with an equipped shop and a swollew bank account'd have trouble keeping that truck going to be dependable in 2025. Also like Geoff pointed out, stuff you don't think of. Hole in the top cover, PTO(s) alterations to the driveline. Just the transmission swap could blossom into a five digit figure in the blink of an eye. 

[Geoff Weeks]

Found this:

If you need to drive off the rear case PTO and select front trans ratio to get the speed you need, the Eaton may be a problem in matching the PTO needs to the available options.

[Joseph Cummings]

1 hour ago, Geoff Weeks said:

In an ideal world, building the truck from a clean sheet of paper, I would have 2spd rears and a 13 up front. Keeps the overall reduction at the back and allows for a smaller and less stressed driveline.

Yeah, these were all 13 double overs with two speed rears. Easier on the driveline, and easier on the frame and engine/transmission mounts. None of that driver's side steering tire coming off the ground on a hard pull.

 

[fjh]

1 hour ago, Joey Mack said:

I too, dont want to be a Dick..  I try to post with an open mind, and i tend to ask questions that I know the answer too, just in case I missed something, or the guy posting may not know what he has..  even though an Eaton will serve him well, and is cheapper to maintain..  Like GW is saying,  there will be a bunch of small's that will cost him time and $$, as well as limited PTO options for him.. That said, with my limited knowledge on swaps and mod's....  I say fix what he has..  it will last a long time as long as it is driven right...  Jojo

Time wise correct jojo!

[Joseph Cummings]

1 hour ago, Mark T said:

That's alow mileage chassis

I bought a big Vac truck off of Occidental chemical one time that was like 15 years old with 5000 miles on it. Never even titled, but a ton of hours on it running the pump. I don't think that is all that unusual in this application

[Mark T]

Exactly. That's apt to have 20000 hours on it. If it's anything over ten thousand ?   Probably more copper than babbit showing on the bearings and wrist pins. AMIs were someone's idea of a good bandaid , and they were junk.  Now 20 years after the fact ?   I don't think this is a good choice for this man. Too much exposure to high cost repairs.