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Ok guys, I've had tons of help and support from y'all in the past and as some of y'all may already know... I do EVERY form of truck repair in-house for our small business. A few months ago we did an allison HT740 4 speed automatic swap in a 1991 e-7 CH613 that had a 9 speed Mack trans... The operation and all wiring was a success, the truck has been working ever since and we have noticed at our family owned dump truck business that this setup has given us great results not only in maintenance but in driver comfort as well!

Now we're ready to tackle another swap!

I'm looking at an HD4560 because it is 6 speed with double over drive and a low first gear. I know it is VERY electronic and requires a control module but we are comfortable taking on the challenge. What do y'all think about the swap? What are the biggest problems I would encounter? Anyone have any wiring diagrams to this trans?

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Well the whole intention is to have overdrive in order to gain more speed than the truck I already did the swap on. I have another 1996 CH613 that I plan to use for the swap. All of our trucks have 4.17 gear ratio and run tall 11r24.5 rubber. The one that currently has an ht740 only speeds up to 58 MPH. If it had atleast a .75 overdrive I'd be happy. What other transmission would be recommended for the swap? I understand all 6 speeds will be electronic. Oh by the way, the hd4560 I can get my hands on will come out of a 2002 Mack MR688 with E-7 etech. They seem to be durable.

One of my 03 Oshkosh hd4560 is costing me more then 15k$ in two years on repair. First was a broken hub ( there is an updated version) that lead to a complete job of 10k$ and this spring the same issue but we only changed the broken hub and it was 5k$ parts and labor. That dint mean theyre all bad but my ht740 are always on duty with no issue. We fill them with 15w40 but the hd series need that Alison oil so it's about 500$ to change the oil.

96 bulldog have you thought of putting an auxiliary behind your hd750?

We have a hd45 in a granite(factory) had a few problems at first but has been reliable for the

Most part. We have an 83 mack rd with an hd750 in it that will only run 63 mph. We don't use it much anymore.

post-1247-0-21222200-1399000018_thumb.jpI have 12 different trucks with allisons", all former garbage trucks, I have also reconditioned and sold approximately 25 trucks to customers over the past several years all autos. I pound the hell out of them and know them like the back of my hand, I would agree that the 740 is a better choice as far as reliability, I have a mix of both, I like the 4560's because of the wide gear coverage. The auxillary box would be the way to go to get the over drive. The only problem is the extra weight. I would suggest an ATR box, basically a 13 speed back box with an input shaft put on it, takes up about 27" of drive shaft space, the over drive operates just like a 13 speed flipper, but with the addition of a 3.5 to one low speed for crawling out of a tough spot...

the computer part of the 4560 swap would not be that bad, they are not that hard to figure out, most of the info would be available online... The problem will be interfacing with your engine to get it to communicate with the tranny to shift up and down appropriately, If your truck is mechanical Allison makes a cable potentiometer that you can hook up to the throttle linkage, Allison will virtually give no help when it comes to the programming, because they will want engineering approval from mack for driveshaft speeds hp and torque curves etc, etc.. Most of my "former garbage trucks" are set up as 5 speeds, I wanted to have my computers reflashed to make them 6 speeds, yeah right, its like I asked to build a bomb toting truck for the Taliban using all Allison parts....

  • Like 1

Maxville I agree about the auxillary. The only thing negative about them is the high geared reverse. Its not fun if you have to back up with a load on off road. The aux, like you said, would be perfect for that both backwards and forwards.

My uncle has a KW with an 8v92 and an HD750 he put a 4 speed aux behind it and it works slick.

  • 3 years later...

I’ve been reading this post with tons of interest since I am considering a swap to the 750 DRD in my 03 RD 688S tri axle dump

how do these trucks perform off road compared to a similarly equipped truck with a 8LL ?

my truck has the 8LL and 4.42:1 ratio, I realize this would limit my top end speed, most of my work is local  stone delivery and site work with a little highway driving and most of that in a 55 mph speed zone. I did reflash my ECM with the AMI 370 software that moves my max rpm from 1950 up to 2150

However I’m not sure I want to run down the road at 2100 rpm to run 55 ish mph

also thought about the auxiliary trans route to get overdrive but was told I would have issue shifting that since I wouldn’t have a clutch.

i am looking to you guys for some real world experience to help with making the leap.

I’ve been reading this post with tons of interest since I am considering a swap to the 750 DRD in my 03 RD 688S tri axle dump

how do these trucks perform off road compared to a similarly equipped truck with a 8LL ?

my truck has the 8LL and 4.42:1 ratio, I realize this would limit my top end speed, most of my work is local  stone delivery and site work with a little highway driving and most of that in a 55 mph speed zone. I did reflash my ECM with the AMI 370 software that moves my max rpm from 1950 up to 2150

However I’m not sure I want to run down the road at 2100 rpm to run 55 ish mph

also thought about the auxiliary trans route to get overdrive but was told I would have issue shifting that since I wouldn’t have a clutch.

i am looking to you guys for some real world experience to help with making the leap.

  • 2 months later...
On 4/11/2018 at 11:38 AM, 03' Big Red said:

I’ve been reading this post with tons of interest since I am considering a swap to the 750 DRD in my 03 RD 688S tri axle dump

how do these trucks perform off road compared to a similarly equipped truck with a 8LL ?

my truck has the 8LL and 4.42:1 ratio, I realize this would limit my top end speed, most of my work is local  stone delivery and site work with a little highway driving and most of that in a 55 mph speed zone. I did reflash my ECM with the AMI 370 software that moves my max rpm from 1950 up to 2150

However I’m not sure I want to run down the road at 2100 rpm to run 55 ish mph

also thought about the auxiliary trans route to get overdrive but was told I would have issue shifting that since I wouldn’t have a clutch.

i am looking to you guys for some real world experience to help with making the leap.

Big red, the best I can say is that after swapping the transmission on our older truck with the ht740, the truck became more maneuverable on-site compared to having the manual transmission.   We do a lot of wet concrete hauling for a paving company and the job site leading to the place where we pour isn’t the best.  The automatic does quite a bit better at gliding over rough terrain and maintains speed without having the manual intervention of having to downshift and such in mud holes.  The automatic has also saved us on a lot of maintenance and abuse issues we had in the past, but in turn it has cost us a little bit more in fuel.    The difference isn’t so bad, but it’s enough to point it out.   On our most comparable truck with an e7 and 13 speed manual, we may see about 15-20 gallons of fuel burned per day whereas the automatic may burn 20-25.  Again, the difference isn’t going to break the bank obviously but it’ll add up at the end of the year.   

 

This same truck Was geared 4:17 and would top out at a miserable 56mph at 1950rpm.  I hated the fact that it would run this high in rpm just going down the road, I can only imagine it doing 2150.. much worse.  We chose to do a differential swap and we put 3:86 gear ratio in it.   It was a direct swap into the existing axle housings, but it now reaches 70mph at 1950rpm.  It’s acceptable at this point.   Honestly, I know the trash trucks of the ht740’s era we’re geared at ridiculous ratios like 4:64’s.   It all depends on the speed you’re willing to sacrifice or perhaps you can afford to change your ratio to compensate like we did.  

After working this truck as much as it has since performing the transmission swap, I can safely say the truck has continued to make money just fine , but I can’t say I would do the swap over again.   It was a lot of work, your best bet is to retrieve every single last piece of parts that you will need from a truck salvage yard such as LKQ.  We deal with the Houston Texas location called LKQ Texas best Diesel.   Good guys out there, they will set you up with everything you need including all the little accessories like mounts and shifter cables.  Just an FYI if it’s something you still ponder about doing.  

 

We do believe in automatic trucks, especially for dump truck application, their benefits on-site are endless.  Just remember you will always miss your manual trans once you get down the road lol.  Otherwise they are great transmissions and work hard.   We have bought two more trucks with Allison automatic, a CXU and a CHN, both of which have the 6 speed. Man, talk about amazing driving trucks, almost like driving a pickup truck.  

  • 2 weeks later...

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