Jump to content

Swap Manual to Automatic?


earthmover
 Share

Recommended Posts

I'm just curious and couldn't find the answer anywhere....Is it feasible to swap a 13 speed Mack transmission with an Allison Automatic in a 1999 RD 400HP E7? Any idea on cost? I know automatic adds around $15K to a new truck.

My buddy and I were having a discussion on this the other night and he bought a automatic truck and couldn't stop saying how much he liked it. I'm just wondering if its a possibility when my truck needs a new/rebuilt trans.

Edited by earthmover
Link to comment
Share on other sites

Trans, Flex plate, starter, mounts, front drive shaft different length, front yoke, transmission cooler and lines followed by shifter assembly, neutral safety switch, calibrate speedometer and hope its not over or under geared for the auto. Stick with the stick. Paul

  • Like 2

"OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK"  Thomas Edison

 “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’

P.T.CHESHIRE

Link to comment
Share on other sites

I have a lot of time with Allison HT740's which are bombproof, as well as the newer 4000 "world series" trannies with the integral hydraulic retarder. This is a really nice feature, however it tends to heat up the ATF really fast- especially if you do a lot of start-stop city driving or have a PTO- many residential trash collectors are now doing away with their integral retarders in favor of Jakes or even Telma retarders.

If you do a LOT of local driving, it might be something you want to seriously think about. But if you do more road work than local work, stick with the stick.

  • Like 1

TWO STROKES ARE FOR GARDEN TOOLS

Link to comment
Share on other sites

Its a 99 so its got an electronic engine and therefore both engine and body controllers that would have to be reprogrammed to work right after the swap. I like the Allison but its gonna be expensive, as long as the gearing is below a 4.64 you should be ok there especially if your running 22.5's. I would leave it alone unless you have a wore out trans and need a clutch, at least then your gonna be there already.

"Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin

"If your gonna be STUPID, you gotta be TOUGH"

"You cant always get what you want, but if you try sometimes you get what you need"

Link to comment
Share on other sites

I did the swap on a 1991 Mack with an e-7 Mack 9-speed. The donor truck was a 1996 Mack mr model trash truck with a full mechanical e-7 the transmission was an allison ht-740. All that was needed from the donor was: transmission frame mounts, flexplate, complete transmission assembly, liquid heat exchanger, and the shifter control tower for the cab. The only problem we ran into was having to replace the air modulator for an electronic kind ($90) and installing a micro switch under the accelerator pedal to signal the transmission to up shift or downshift at 75% throttle.... The speedo has to be recalibrated using the jumper pins behind the cluster, and it is important that you get all the nuts and bolts involved in the donor truck. Remember, the driveshaft will have to be relenghtened and depending on your rear hear ratio you will lose top speed. Our truck now only reaches 59 miles per hour because it has 4.17 rear end gear ratio and the ht-740 trans does not have overdrive.

Link to comment
Share on other sites

Also our truck runs 11r24.5 rubber... It was an interesting swap and definitely rare to see an older ch-613 set back axle tandem dump truck with an automatic transmission.... It runs absolutely great with the exception of it's lack of top speed... It has globs of power and torque to take off especially in those boggy construction sites. We use it for local work and I basically only sees road time when driving to the site itself. Typically 400 miles a week of highway time, the rest is all local. The ht740 is definitely a solid trans in my book. All in all with parts, oil, and beer, the cost to build was close to $3000..... Considering we did all the work by ourselves in our own shop

Link to comment
Share on other sites

Also our truck runs 11r24.5 rubber... It was an interesting swap and definitely rare to see an older ch-613 set back axle tandem dump truck with an automatic transmission.... It runs absolutely great with the exception of it's lack of top speed... It has globs of power and torque to take off especially in those boggy construction sites. We use it for local work and I basically only sees road time when driving to the site itself. Typically 400 miles a week of highway time, the rest is all local. The ht740 is definitely a solid trans in my book. All in all with parts, oil, and beer, the cost to build was close to $3000..... Considering we did all the work by ourselves in our own shop

Very interesting. 3,000 not bad if I had the mechanical knowledge to do it in house I would do it in a heartbeat. It's not worth the big money to have someone do it though. The truck runs good the way it is but I was just had the idea for less maintenance and fatigue. When I add another truck it will be an automatic!

  • Like 1
Link to comment
Share on other sites

  • 2 weeks later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...