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]

I think Mack synchro failures are because the range clutch is so big, it has 14 clutch discs and friction discs plus a thrust washer and a large sliding clutch, that if the range cylinder is at all dragging it causes the clutching teeth to start chipping and then they just dont engage good.  I would like to see an air water filter before the tranny air lines to keep water out of the range cylinders. Also, many do not removed the rear range cylinder and clean and re-lube it annually.

[Joseph Cummings]

2 minutes ago, The Heinz said:

That's been 100% of the Maxitorque failures I've seen in our shop. I assume it's drivers trying to wiz along like an Eaton behind a Cat or Cummins. 

Back when the 2090 first came out the syncros all failed right away. Then there was a revision of the hub, something about pin angles. I kinda remember something about a 5 degree difference. That was  right around the time the V-MAC 1 came out

[cruiseliner64]

9 hours ago, Joey Mack said:

I think Mack synchro failures are because the range clutch is so big, it has 14 clutch discs and friction discs plus a thrust washer and a large sliding clutch, that if the range cylinder is at all dragging it causes the clutching teeth to start chipping and then they just dont engage good.  I would like to see an air water filter before the tranny air lines to keep water out of the range cylinders. Also, many do not removed the rear range cylinder and clean and re-lube it annually.

Joey,does cleaning and re-lubeing the rear range cylinder apply to the 6 speed in our Cruiseliner? If so is it a big job.I would not have any experence with Maxitoqure gearboxes and as our truck was lying up for 14 years this is something that might be a good idea to do...

Paul

[Joey Mack]

Paul,  i dont believe you have an air shifted range clutch. I may be wrong because i have never worked on a cruiseliner.  My recommendation is for air operated shift cylinders.. I appreciate your question sir.  Jojo

[terry]

21 minutes ago, Joey Mack said:

Paul,  i dont believe you have an air shifted range clutch. I may be wrong because i have never worked on a cruiseliner.  My recommendation is for air operated shift cylinders.. I appreciate your question sir.  Jojo

Some six speeds were air operated back box, low, direct, reverse, a 107A, two stick six speed has no air shift controls.  Terry

Edited January 5 by terry

[Joey Mack]

Paul ?  How is the range clutch sifted?  Just curious, do you have a splitter button on the shift knob? 

[cruiseliner64]

34 minutes ago, Joey Mack said:

Paul,  i dont believe you have an air shifted range clutch. I may be wrong because i have never worked on a cruiseliner.  My recommendation is for air operated shift cylinders.. I appreciate your question sir.  Jojo

Thanks for the reply Joey.I seem to have the air operated 6 speed terry spoke of in his reply.I tried to post a picture but it wont post.Theres a large and a small air cyinder on the back of the gearbox.Theres also a filter for the air too which i have changed.It all appears to work ok but if theres something that should be serviced regulary id love to know.

Paul

[cruiseliner64]

4 minutes ago, Joey Mack said:

Paul ?  How is the range clutch sifted?  Just curious, do you have a splitter button on the shift knob? 

Yes a air switch on the shift lever.

Paul

[Joey Mack]

ok well I would leave the air cyls alone if they are functioning good, maybe put a small amout of a light oil in the air filter to introduce some lubricant to the orings.  just be sure the oil is good for rubber o-rings. The o-rings are buna rubber. 

[cruiseliner64]

46 minutes ago, Joey Mack said:

ok well I would leave the air cayls alone if they are functioning good, maybe put a small amout of a light oil in the air filter to introduce some lubricant to the orings.  just be sure the oil is good for rubber o-rings. The o-rings are buna rubber. 

Thanks Joey.We appreciate your help....and thanks to terry too.

Paul

[Vac-Daddy]

Swap is going great. Bought an Eaton Fuller 18918b for 2k. Proper bellhousing for 1k. My transmission guy put new internals in, so she's pretty much new. Transmission is ready to go back in my truck. I have the PTO sorted out. All I had to do was call westech, the company who it took my truck when it was brand new and built the vacuum system. I gave him my vin# he sent me original pictures of the build. Told  me everything i could possibly  know about my truck. There were two choices for the PTO, It was pretty awesome 🙂 PTO is not cheep! $4700 😳 i will have all the numbers $$ once the truck is completely done. Looks like it's gonna be about half of what it would have cost going with a Maxitorque 🥳 i asked him what happens next month when my motor blows up? He said we'll do another swab not a problem 😁

[Vac-Daddy]

On 12/21/2024 at 12:08 PM, Joseph Cummings said:

I borrowed a 4 axle tractor to do moves a couple of times that had a 460 in it. I wasn't very impressed. I think my juiced up Big Cam IV would give it a good run. It was a nice enough truck, but it wasn't what I expected out of something that was a 460

Actually 30,000 hours 🤣 lol gutless but runs good, if the motor blows up next week, I will do another swap 😎

[Joey Mack]

I expected worse looking sliding clutches, and the range clutch still has lining on it. Sure wish the old parts were spread out and a clear picture taken.. just curious..

[Joseph Cummings]

5 minutes ago, Mark T said:

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.

I borrowed a 4 axle tractor to do moves a couple of times that had a 460 in it. I wasn't very impressed. I think my juiced up Big Cam IV would give it a good run. It was a nice enough truck, but it wasn't what I expected out of something that was a 460