New duramax vs new Cummins

[horse123]

Originally Posted By: 440Magnum

Ford not in contention? The new 6.7 seems to be doing fine also.


I don't mean to start anything, probably will, but I hate Ford for the image their drivers give off. I'll leave it at that.

Between Ram and Chevy, I guess if I was going to buy a HD truck this exact second it would be a Chevy, mostly because I've heard lots of people, even cummins fans saying that the new duramaxes are great, and also that they handle the most like a car. However I don't have the money or need for it this exact second, but I suspect I will be looking for a new or slightly used HD truck in the near future for work and personal use.

 

[Clevy]

I've had every brand truck out there. Always used. No diesels. Of every one I've ever owned I like my current C3 the best.
Not get me wrong. My 04 quad cab hemi ram was great but this truck just feels better.
If I was buying a new truck it would be a hemi. Mds is too good to pass up. I looked at all of them this spring and the TT 3;5 was nice,but I like simple.

 

[clinebarger]

Either one would be a good truck, I have owned both. My last Dodge was a '03 2500 Common Rail 5.9/47RE, My current truck is a '06 Chevy 2500HD Duramax/Allison.

Both trucks use the same AAM 11.5" rear axle, Very good unit.

Both trucks use a AAM 9.25" front gear set, GM is independent, Dodge is live axle.

When the Duramax first came out in '01, They had serious Injector issues, That got fixed in '04.5, Then popped up overheating & head gasket issues. By '06 the LBZ Duramax was as reliable as the Cummins ISB. With the upgrades to the latest LML Duramax.....Who knows?

Transmissions...

The Dodge 68RFE is a "decent" unit, Though I'm starting to see them come in for rebuilds in the 150K-250K range. Based on its smaller gas version cousins 545RFE/65RFE. Not what I would call a heavy duty transmission.

The Aisin AS69RC used in Dodge 3500 HO/Cab & Chassis only, Is a good robust HD transmission. Dodge should use this unit instead of the 68RFE in regular 2500/3500 diesel trucks.

The Allison 1000, Also a good HD unit. Probably has the longest life expectancy in the segment if power levels are left stock. The Aisin may be better....Time & mileage will decide that.

 

[horse123]

When I was looking up the 68 vs Aisin, most people seemed to think the reliability was the same between them, and the extra price for the PTO on the Aisin wasn't worth it unless you actually needed it.

 

[clinebarger]

Originally Posted By: horse123
When I was looking up the 68 vs Aisin, most people seemed to think the reliability was the same between them, and the extra price for the PTO on the Aisin wasn't worth it unless you actually needed it.


I did say they are decent units....For the design constraints that got put on the engineers to make a HD trans out of a LD trans. Most make it out of warranty. I guess it works out.

The Allison & Aisin are designed & built as HD units.

It all depends on how long you keep the truck? 100K & out? Get the Dodge if its cheaper. 200K, 300K....Get one with a HD transmission.

 

[Jimzz]

I doubt either engine will have problem is taken car of. The biggest problem I saw as a tech on trucks like that was the transmissions.

So get the one that has the best trans and take care of it and the engine.

 

[totegoat]

I enjoy my Cummins but if I were buying new today, I would look at GM closely.

The DEF fill is under the hood on GM and next to the diesel fill on the Ram.

Enjoy shopping.

 

[Artem]

A coworker has a Duramax GMC and swears by it.

When I was shopping for a new truck, Max towing capacity was what gave Ram the edge, so I bought a 2014 Ram 3500HD with Aisin transmission for it's 30,000 pound towing. The Duramax was a close second with Ford's Powerstroke coming in as a last choice.

I'm very happy with the Cummins so far with 30k on the clock within a few month of nonstop towing @ full capacity. Only time will tell how it holds up but I'm definitely hoping for half a million of highway use before I'll be content with rebuilding something, if needed. If it starts breaking before then, I won't be too happy, that's for sure.

So far I've been on top of all the maintenance, as per the manual. 15k Axle flushes, fuel filters and just did a transmission flush @ 30k. I must say, the Aisin got ALOT smoother with just one simple drain and fill of the oil pan. I thought about dumping the factory fill earlier but thought that 30k like the Ram recommends was also quite a short interval, so I left it in. I'll definitely be draining the transmission often, in order to help keep it alive for as long as possible, considering the heavy use it sees.

Only time will tell...

 

[nthach]

Isn't DMAX==Isuzu? Also, doesn't Mitsubishi Fuso, Isuzu, Hino and UD use the Aisin tranny in their LCF trucks?

 

[clinebarger]

Originally Posted By: nthach
Isn't DMAX==Isuzu? Also, doesn't Mitsubishi Fuso, Isuzu, Hino and UD use the Aisin tranny in their LCF trucks?


For the most part Isuzu designed the Duramax, They are manufactured by Dmax LTD in Moraine, Ohio. GM is the majority shareholder, Isuzu owns the rest.

GM uses Allison 1000's because GM owned Allison at the time, GM sold Allison but kept the rights to the 1000.

Just about all medium duty Japanese trucks use Aisin transmissions.

European manufacturers use ZF for the most part.

American manufacturers use Allison.

 

[440Magnum]

Things will get substantially more interesting in the transmission department if Ram elects to put a heavy duty ZF with 8 or more speeds in the Ram.

Also, the Allison installed in pickups hasn't been quite as totally indestructable as you might expect given the Allison name- its obviously a cost-reduced version of the true medium-duty commercial truck Allisons. So if you take a "standard duty" pickup truck transmission and beef it to get the 68RFE, or take a medium duty heavy truck transmission and cost-reduce it to get a HD pickup truck transmission, you kinda end up in the same place. Don't get me wrong, I agree its advantage to the Allison here, but not by an earth-shattering margin. The Aisin appears to be pretty much the same thing that goes in all those Hino, Fuso, Isuzu, etc. trucks.

I'm just glad the days of glass-jawed late 1990s transmissions from all of the Big 3 are over. :-/

 

[Jarlaxle]

Originally Posted By: clinebarger
Originally Posted By: nthach
Isn't DMAX==Isuzu? Also, doesn't Mitsubishi Fuso, Isuzu, Hino and UD use the Aisin tranny in their LCF trucks?


For the most part Isuzu designed the Duramax, They are manufactured by Dmax LTD in Moraine, Ohio. GM is the majority shareholder, Isuzu owns the rest.

GM uses Allison 1000's because GM owned Allison at the time, GM sold Allison but kept the rights to the 1000.

Just about all medium duty Japanese trucks use Aisin transmissions.

European manufacturers use ZF for the most part.

American manufacturers use Allison.


I recall that US-market Hinos and Isuzus use Allison transmissions.

 

[Joel_MD]

For heavy towing it's hard to beat the Cummins. I spend a lot of time on the Cummins Forum and there are a lot of guys who push theirs very hard; towing 30,000-lb trailers in the mountains. Many of them have the G-56 manual transmission, which is the most problematic part of the truck if you tow heavy. One guy on the forum complained that the odometer quit working at 620k miles!

Being a straight six design, the Cummins has fewer moving parts and a lot of maintenance/repair items are easier compared to the Duramax. I understand that changing the water pump on a Duramax is a 6-hr job for an experienced mechanic. On the 5.9/6.7L Cummins a guy who has never done it before can replace the water pump in 30 minutes, and the new OEM pump is only $60. A lot of Cummins owners change their water pumps every time they flush the cooling system because it's so easy.

 

[hattaresguy]

I just can't get over the cost of a modern diesel pickup, up here they are all north of $60k sticker, some over $70k++.

 

[RISUPERCREWMAN]

Originally Posted By: hattaresguy
I just can't get over the cost of a modern diesel pickup, up here they are all north of $60k sticker, some over $70k++.


That's why I went gas with my new Ram 2500. The gas version fit my towing/ work needs just fine.

 

[Fordtrucktexan]

At the risk of getting flamed, I think if you do proper maintenance and treat the engines the way the OEM intended, you won't see a real advantage of one motor over another. Both the Cummins and Isuzu-made Duramax are great engines backed by years of development.

Where you will see a difference is in the platform-specific items.

Dodge provides you with a solid axle suspension, but has a notorious history of poor interior quality, and poor body fit and finish. Granted, their fully loaded Laramie Long Horn edition is thousands cheaper than a Denali or King Ranch/Platinum.

GM provides you with a more modern interior, loaded with many digital 'toys' to play with. Body fit and finish is better, and the ride is more refined - due to the independent front suspension. Whether GM has solved the long-known issues with sending diesel-level torque to so many moving components has yet to be seen. In the past, it wasn't uncommon to pay a visit to the parts counter in search of new tie rods after engaging 4wd in a Duramax-equipped truck. The Allison 1000 transmission is also well known for it's shortfalls.

Do your homework and pick wisely... the early Ford 6.7 owners endured the pain of a high truck note on a shop queen.

 

[clinebarger]

Originally Posted By: 440Magnum
Things will get substantially more interesting in the transmission department if Ram elects to put a heavy duty ZF with 8 or more speeds in the Ram.

Also, the Allison installed in pickups hasn't been quite as totally indestructable as you might expect given the Allison name- its obviously a cost-reduced version of the true medium-duty commercial truck Allisons. So if you take a "standard duty" pickup truck transmission and beef it to get the 68RFE, or take a medium duty heavy truck transmission and cost-reduce it to get a HD pickup truck transmission, you kinda end up in the same place. Don't get me wrong, I agree its advantage to the Allison here, but not by an earth-shattering margin. The Aisin appears to be pretty much the same thing that goes in all those Hino, Fuso, Isuzu, etc. trucks.

I'm just glad the days of glass-jawed late 1990s transmissions from all of the Big 3 are over. :-/



The Allison 1000 used in GM light duty trucks have a smaller torque converter (To fit inside a standard Chevy bolt pattern bellhousing), This was done because the same Duramax block is used in fullsize vans that use Hydramatic 4L80E/6L90E transmissions. And a parking pawl.....Other than that they are identical to the Allison 2000 used in medium duty trucks.

I rarely see any diesel trucks that are Stock, Most have Tuning/Programmers/Boxes. Up-rating power will burn clutches in an Allison. The TCM has to have an accurate "Input Torque" value from the ECM for the Shift Energy Management (SEM) to work. Allisons are Clutch to Clutch...Every shift has a off-going clutch & a on-coming clutch. The TCM commands the ECM to de-fuel/Or not...during every shift, Manipulating the fueling plays [censored] with the balance of power.

 

[Fordtrucktexan]

Originally Posted By: clinebarger
Originally Posted By: 440Magnum
Things will get substantially more interesting in the transmission department if Ram elects to put a heavy duty ZF with 8 or more speeds in the Ram.

Also, the Allison installed in pickups hasn't been quite as totally indestructable as you might expect given the Allison name- its obviously a cost-reduced version of the true medium-duty commercial truck Allisons. So if you take a "standard duty" pickup truck transmission and beef it to get the 68RFE, or take a medium duty heavy truck transmission and cost-reduce it to get a HD pickup truck transmission, you kinda end up in the same place. Don't get me wrong, I agree its advantage to the Allison here, but not by an earth-shattering margin. The Aisin appears to be pretty much the same thing that goes in all those Hino, Fuso, Isuzu, etc. trucks.

I'm just glad the days of glass-jawed late 1990s transmissions from all of the Big 3 are over. :-/



The Allison 1000 used in GM light duty trucks have a smaller torque converter (To fit inside a standard Chevy bolt pattern bellhousing), This was done because the same Duramax block is used in fullsize vans that use Hydramatic 4L80E/6L90E transmissions. And a parking pawl.....Other than that they are identical to the Allison 2000 used in medium duty trucks.

I rarely see any diesel trucks that are Stock, Most have Tuning/Programmers/Boxes. Up-rating power will burn clutches in an Allison. The TCM has to have an accurate "Input Torque" value from the ECM for the Shift Energy Management (SEM) to work. Allisons are Clutch to Clutch...Every shift has a off-going clutch & a on-coming clutch. The TCM commands the ECM to de-fuel/Or not...during every shift, Manipulating the fueling plays [censored] with the balance of power.


True. Many times the Allison is killed by someone jamming a programmer into the OBD2 port on the highest setting. The 'canned' tunes that come standard on programmers are often the worst for your vehicle. There are tune writers that publish tunes that are "Allison-safe" and provide nice power over stock without the threat of gernading a transmission.

 

[horse123]

So if tuning... no duramax? Unless it's planned to replace many more parts with the tune. Or is it just be careful with who you choose for a tune?

 

[jeepman3071]

With the high price tag of a diesel truck ($70-80k) I wouldn't tune it at all. Tuning voids the warranty and I don't see those tuning companies offering engine/transmission warranties for your vehicle.

My friend has a Duramax with EFI live. I just helped him do his 5th Allison tranny swap a few months ago (which in my opinion is insane and a huge waste of money). Thankfully this one has been built by Alligator performance so it can handle the power, but adding lots of performance tuning to any diesel pickup is just asking for repair bills. With the exception of the very light tunes and custom tunes some of them are very bad for your engine and trans. Don't even get me started on the EGR and DPF systems with tuning. I've seen people melt their entire engine after one romp down the highway. Some of the tuners such as the H&S tuners advance the timing in the engine way too much, and with the additional fuel it is only a matter of time before it melts a piston.

My friend took a fairly bullet proof combo of the Duramax/Allison and made it a complete money pit from all the tuning he has done. His brother has a completely stock and well maintained 6.0 powerstroke which is almost to 200k miles with nothing but regular maintenance and coolant changes. These new diesels get very expensive very quickly, and if I bought one it would stay stock for a LONG time. The only things I would add would be a coolant filter and a fuel additive for the injectors to help lubricate them.