[coreywj454]

Hey guys. I know this question has been asked many times. I recently bought compact loader/backhoe and trailer. I bought it out of state and when I went to pick it up I borrowed my friends 2016 2500 HD cummins. The thing is bad ass and I thought, dammit, maybe it is time for me to bite the bullet and get a new truck. But then the check engine light came on, and I had to ad DEF and all these electronics... I got back into my IDI (see sig) and I thought, forget a new truck, I don't wanna deal with all that crap and pay 60K for it! anyways, what I want to do is buy another IDI, preferably a crew cab F350 and set it up to handle towing the tractor. i am getting lazy these days and was leaning towards getting an auto tranny. however, seems to me that most people prefer the ZF-5 for towing. so my question is - C6 with a GV unit or built E4OD? I am not a fan of the non locking TC on the C6 but I am a fan of its simplicity and lack of electronics. if you could have the ideal auto tranny for towing what would it be? or should I just sack up and get a ZF?

 

[Mark Kovalsky]

A well built E4OD can be extremely reliable.

 

[LMJD]

I LOVE the ZF 5 speed. With its close ratios you have a gear for every occasion as I like to say. It's easy to stay in the power band when towing no matter what speed or how steep the grade. And years ago I was talking to a high volume trans shop owner and he said he never sees the ZF 5 speeds, in other words they're bomb-proof. I guess the E4OD can be rebuilt nowadays with better components, but years ago I lost count of friends who's E4OD's broke down with moderate towing and no abuse. Plus a truck mechanic I worked with bought a used 7.3 F250 with the E4OD and when he took me for a ride, the thing free wheeled when letting off the throttle at highway speeds which didn't make sense for a truck built for towing. No engine compression to help slow you down when descending a grade. I once asked Mark above about that but never got an answer.

 

[coreywj454]

the dodge i borrowed had an engine brake. it was sweet. can you put those on an IDI? if you switch off OD in the E4OD it won't help hold back the load? i read somewhere you can get a computer for the E4OD that will allow you to select gears. Know anything about that?

 

[oldrebuiltdodge]

I LOVE the ZF 5 speed. With its close ratios you have a gear for every occasion as I like to say. It's easy to stay in the power band when towing no matter what speed or how steep the grade. And years ago I was talking to a high volume trans shop owner and he said he never sees the ZF 5 speeds, in other words they're bomb-proof. I guess the E4OD can be rebuilt nowadays with better components, but years ago I lost count of friends who's E4OD's broke down with moderate towing and no abuse. Plus a truck mechanic I worked with bought a used 7.3 F250 with the E4OD and when he took me for a ride, the thing free wheeled when letting off the throttle at highway speeds which didn't make sense for a truck built for towing. No engine compression to help slow you down when descending a grade. I once asked Mark above about that but never got an answer.

I have to second the ZF 5. Both of the E4od transmissions I have been involved with failed @ around 250,000 miles, I had one ZF 5 that went for 750,000 miles with only a clutch replaced. All of the others I had (and I've had and used several) never had any trouble at all.

 

[Mark Kovalsky]

Plus a truck mechanic I worked with bought a used 7.3 F250 with the E4OD and when he took me for a ride, the thing free wheeled when letting off the throttle at highway speeds which didn't make sense for a truck built for towing. No engine compression to help slow you down when descending a grade. I once asked Mark above about that but never got an answer.

When in overdrive (4th gear) there is ALWAYS engine braking. The problem with the 7.3L diesels is that without an aftermarket exhaust brake there is very little engine braking. Due to the design of the transmission is is impossible to freewheel in overdrive.

 

[LMJD]

Mark, I can't say if he was in OD or not but we were going about 55 and it was obvious the truck was free wheeling every time he let totally off the throttle. Then as he pointed out, and I could easily feel it, as he gave it a slight amount of throttle (not enough to accelerate) the trans would re-engage (lock up?) and the truck would decelerate due to engine braking. Not being happy with this feature, he did this a few times as we went down the highway and each time with no throttle the trans would free wheel like you put the lever in neutral then lock back up with a bit of throttle. What say you, was this normal or maybe he had a trans problem? At that time he'd just bought it a day or two before.

 

[Mark Kovalsky]

The only way I can see that happening is if the overdrive clutch seal is failing. If the trans is working as designed it cannot freewheel in overdrive. At 55 MPH coasting it would have to be in overdrive.

 

[LMJD]

Thank you, Mark, I always wondered about that one. Shortly after that, he moved out of state so I never knew the outcome, hopefully he found it wasn't normal.

 

[LMJD]

if you switch off OD in the E4OD it won't help hold back the load? i read somewhere you can get a computer for the E4OD that will allow you to select gears. Know anything about that?

Mark would be the guy to answer that. I'm not an auto trans guy at all and I've always respected Mark's opinion when it came to automatics due to his background. I used to overhaul the huge 500lb. Detroit/Allisons that were in some mid/heavy duty trucks and some heavy equipment but those are a different breed than pickup/car automatics.

 

[Trucker87]

I used to overhaul the Allison V730. Got them from a junk yard that scrapped out the GM Greyhound busses. Installed them in older GM busses that where manual and made into Motor homes, the Old guys couldn't push the clutch in anymore, including me. One drove me crazy when the adapter plate didn't have the baffle in it to direct the oil back into the trans., oil kept filling up the Detroit engine even tho the rear main seal was changed to a two way seal.