Most reliable transmission.......

[geusterman]

I thought I had done plenty of research in finding the most reliable pickup on earth (had a good mechanical 6. 5 Chev with 4L60E) and was watching new developments as the years went by. Now, I know the deal on DuraMax's quite well but the price and mileage were irritating. Reliability was there but way too electronic. Cummins releability and Dodge body improvements led strongly there but the auto did not have the integrity. The 6 speed came highly recommended. I now have a nice HO 6spd made this April. HOWEVER, I was reading Texas Diesel's signature (thank you, George, for your integrity and love your Mad Max bumpers!) and noticed there ARE some issues with the 6 speed. Am I paranoid? Out of context? What weak areas should a newbie to Dodge expect to watch out for as the miles come on the odometer. Great thanks for all your inputs. George Eusterman, newest noicemaker on the block. (Remember the playing cards in the spokes on our bikes? )

 

[TowPro]

The only thing I would recomend checking (every oil change is good) is the fuel pressure. Do a search on lift pump and you will see what I am talking about.



Also watch your wallet, that money you spend to join this BB was just the start

 

[geusterman]

Thanks. Watch my wallet. I know from experience those are good words. So far I am Rhino'd and Toyo'd (195's) and I am going to take this real slow. There is so much great information here. I know the performance route is pretty much air in and out, guages, fuel and clutch (learned on the Diesel Page) but the inherent (few) weaknesses are my focus right now. Thanks for the fuel pressure tip. Is a boost pump the cure? A better lift pump? What other wimp spots seem to show up? Thanks, George

 

[TomGolden]

Howdy George, and welcome to the Dodge/Cummins world.



I have owned my 6 speed since Sept. 2000, it was made in August 2000. I have as of this morning, 43,700+ miles on it. I switched to Amsoil series 3000 5W-30 full synthetic in the transmission at something like 25K miles, and added a set of "Fastcoolers" www.fastcoolers.com about 2 months ago to the transmission. The only problem with the 6 speed trannies that I recall hearing about is several members complaining of gear lash ocassionally, but I don't think it is a large number of folks experiencing that problem.



You can see what else I have done to the truck in my sig below.



I don't sled pull (yet..... ) and have only made maybe 10 passes at the drag strip so far. I don't tow or haul much on a daily basis. I am not as hard on my truck as some are, but I do use the power regularly



I have had absolutely zero problems with any component on my truck, including my lift pump (fingers crossed, knocking heavily on wood... . )



You can find tons of lift pump posts here. Several different guys are expirementing with all sorts of after market pumps and fueling systems. So far, I do not believe any of them have gone more than maybe 6 - 8 months before konking out, so as yet, I do not think there is a highly reliable lift pump replacement option.



Thanks, and Welcome!!



Tom

 

[Evan A. Beck]

83,000 miles on my '01 6-speed. Zero problems. Excellent transmission.

 

[Texas Diesel]

I'm not as experienced as many on the TDR are but here is my opinion. The 6 speed is a good gear box, most of the grinds/clash complaints seem to be in the cold weather. I had a Mitsubishi crash box that was awful until it warmed up, was that way for 150,000 trouble free miles. My original 5600 had a problem from day one, the new one is great, it's a dream to tow with. I would suggest you add a Fastcooler to the driver side PTO and a Eaton PTO filter on the passenger PTO. A Fastcooler AND FILTER wont work together on the same side. Get a drain plug ordered for a NV-3500 (Dakota) and use it as your 5600 fill plug, it has a nice strong magnet inside. As far as expected problems:

lift pump

trac bar (4wd)



Add a some lubricant at each fill to help keep the VP-44 well oiled, I use Marvel oil.



Throw your blow by bottle away!!!



Thanks for the flowers re: the Mad Maxx bumpers, they have already paid for themselves much to the dismay of a Corolla and minivan :-{}

 

[lgibson]

4L60E???

I thought GM used the 4L80E's behind the diesels and larger engines. I would think that the 60 would be to weak to handle the torque of the diesels.



geusterman, welcome aboard.

 

[Gary - K7GLD]

Since the question was related specifically to the 6 speed transmission, I'll give you MY opinion, as a new owner with less than a thousand miles on mine...



As far as I can tell from posts here, ther are precious FEW complaints about the 6 speed (which was WHY I chose one!), and that's more than can be claimed for ANY of the other of the Dodge/Cummins trannies, other than the original 727 3-speed in my early '91 (no OD!)



The complaints you WILL hear relate to internal noise from the 6 speed, and less than instantaneous shifting ability... But LISTEN guys, this AIN'T no drag racing transmission, wasn't INTENDED for Monte Carlo or Daytona, it's a TRUCK transmission, intended to live behind a strong engine while doing SERIOUS work!



If you'll just crawl under yer truck, and inspect the brute size of that transmission, and try to visualize all the rotating mass inside that must be halted and properly meshed each and every time you shift, SURELY it will generate SOME respect for the syncros, and a bit more understanding as to why it doesn't do a good imitation of an indy car!



A little noisier and slower to shift than a Corvette? Perhaps, but when was the last time you dragged a 12,000 lb. trailer over the Rockies behind a Corvette?



At least it doesn't puke out the lock-up clutches like the auto transmission - or drop off 5th gear like the 5 speeds - so count yer blessings, and leave the racing to yer Viper...

 

[Diesel Freak]

over 64K here on my NVG5600.



Thus transmission can not be shifted like a ZF six speed in a 'Vette!



The clutch pedal has to be on the floor board and your foot all the way off the fuel before you even move the gear shift. It takes a deft touch, and responds very well to double clutching.



Mine gets notchy and does not want to go into gear easily if I abuse it (street racing takes it's toll) If I shift it like it wants to be shifted, and not force it, it is butter smooth. When the temperature drops, it is a little notchy going into 3rd untill it warms up. I am using the OE transmission oil... replaced 15K miles ago.



Loaded up and pulling like it is designed the transmission works and shifts even better..... dont ask me why... maybe it is how I am driving when I am over 15K GCVW



The clutch is good for about 650 FtxLbf, so if you plan to bomb, you better have an extra $1K set aside for a clutch.



BTW, I have been bombed over 350 HP and 800 FtxLbf for a while now, and I am using a SBC Con FE clutch.



if left un bombed, your transmission "SHOULD" last as long as the engine..... so, if you want to make sure things are reliable..... keep the engine stock... .



bottom line... . the NVG5600 is a great transmission..... and you will not get into a ******* match over Torque convertor and valve bodies when discussing it!

 

[BLACKRAM]

The most reliable transmission is the DTT modified auto trans. Oo. Oo.

 

[geusterman]

Wow you all. Great responses. Thanks Tom Golden, I feel welcome and enjoying this adventure. Thanks for the fastcooler link and your observations regarding the lack of solutions for the lift pump. Hey you capitalists out there, here is an opportunity! Get with it!

Thanks Evan Beck for a trouble free report. Nice to hear. Is that truck stock?

Texas Diesel, you have a lot of tips there. Is all the effort on cooling and filtering your 6spd because you had one die or is it common for Hi Horse upgrades? What is a trac Bar, a VP-44 and a blow-by bottle? Gotta go a little slower for me. Do those bumpers have twin brothers anywhere?

Igibson, you are right. My transmission was a 4L80E. I don't understand how I do that sometimes. Never had a problem:117K. Was going to build a nice 18:1 300hp mechanical to run with the DM's but my brother needed a truck and I got my Dodge. Was looking for a 98 12valve quad cab but never found one. Yikes!

Diesel Freak--right on with that slow shifting. Bill Heath from Performance Diesel in Ellensburg WA won a trailer tow hill climb in Missoula MT with his proprietory chip/pipe he does and slow shifting (clutch wouldn't slip that way!) he whipped em last year.

So 2000ney, what is a DTT? You saying there IS a tough auto for our trucks? How much moula?

Thanks, greasy guys. George Eusterman

 

[geusterman]

My last post left out a line to Gary regarding my reasons being the same for choosing the 6spd. Reliability. Gonna use that 7 year warrentee! And I think you are right about the last good one which is my reason for buying 2002--all the bugs should be worked out by now (unless they were saving money--yikes!). They are starting over next year with Gen 3 and I don't want to help them. I HATE problems with my vehicles. I feel like such a slave to all the crap I own now that I just want to surround myself with a few really good things: Like Sony, Glock, Kubota, Bushmaster, Cummins, Jesus, Trek, Garden Way, Honda, my good wife, etc. You know, just stuff I can rely on. Thanks for your tips--keep em coming!

 

[Mark_Kendrick]

There are a few tough Auto's around but. . The NV5600 is for the most part trouble free. I had a little with mine under warranty.



The real problem is the clutch. Call Peter at SouthBend Clutch. He IS your friend. Unmatched customer service and excellent clutches.



I slipped my clutch on Nitrous last weekend and he is handling it without the mention of money. I hope he will ask for some but I don't expect it.



Later,

Mark

 

[DHawthorne]

Have 76k on my 6 speed. No problems with the exception of a little grind in third every month or so for no apparent reason. Third is the gear everyone has troubles with, especially when its cold. The six speed is not a race box as mentioned above. I like it with my 5fer and bought it for that reason. Five speeds are good but the six speed is twice as heavy as the 5sp box. Must have some bigger gogs in there. Bigger is better for down the road.

The extra gear getting out on the hyw helps. It helps the engine get up to RPM a little faster in my opinion.



Dave

 

[geusterman]

Thanks Dhawthorne. Sounds like the 6 spd is the most reliable STOCK transmission. As to the other issues that may hamper a wonderful truck relationship please check my list for imperfections:



The lift pump can't hack it--short life--needs help. Pressure pump about half the life of a 12v but much cheaper and way more hotroddable.



Trac bar. Since loosing the zerks it dies fast. PITA Add to that the pittman arm joint.



Noise. I got no hood insulation. Appears some efforts may be made to get a little long-distance quiet.



Well, that's not too bad. Irritating but not too bad. Carry a lift pump, use gauges and watch for trac arm looseness. Get the dealer to put in a quality aftermarket instead when it gets loose. Do a little insulating as we go along. Did I miss anything?



I have intimate knowledge of the new Dura Max (they really are something unless ultra high horse is the goal as 375 rwhp slips the Allison) The extra $11,000 really buys you something but there is great value here in our Dodges. Let me know if I missed anything.

 

[DHawthorne]

Lift Pumps and Guages.



Most of the guys on this web site, not all, butmost are first time diesel owners. If you've driven anything with a diesel in the past for any length of time you'll known they watch themselfs, so to speak. If you modify the engine, you might want to put guages in to make sure its running like you want it. In the stock configuration, its my opinion that all that is nice but un-necessary. I've been driving diesell cars and trucks since 1978. Started with the 5. 7 which I changed head gaskets every 40k miles whether it needed it or not. I've had four diesel trucks since then, I known where they all are, and all are still on the road. No extra guages there. My Dodge 76k on it . No lift pump related issues that I known about. Normal were will catch up with it soon and when it does I will install another one with a filter between the tank and the pump to keep the trash out of the pump. Electric fuel pumps I've installed in the past on other trucks would run about 80k before needing replacement.



Trac Bar ; No comments



Noise in the cab.



After you drive the truck for awhile you won't hear it. In fact if you install a K&N in the airbox and your towing, you may enjoy the turbo noise. Don't need a guage to tell when the boost comes up. It will quiet down after awhile. Don't be disappointed in mileage until you have about 35k on the truck.



The Dura Max is a good effort my GM to have a entry in the market that is good for the job. Aluminum Heads are junk on a diesel. PH problems etc. I saw a tuck load of Allisons headed to a repair facility when I was in towing gear coming back from Morgan City LA. in May. I prefer the 96 thru 98 dodge for a untouchable truck. No computers except in the late 98's with the 24V heads. My Sons truck is a 96 and has 191k on it. Changed the fuel pump once and the on/off relay under the hood.



Sorry the long post. Anymore questions sent e-mail.



Dave

 

[M Barnett]

Diesel Freak has mentioned something that I have wondered about for a long time. He mentioned,"It responds well to double clutching. " I have always done this in my five speed and it helps even though there is nothing wrong with the way my five speed shifts. A few of us here are old truck drivers and understand what is going on when you double clutch. Our trannys are all syncronized but by double clutching it just helps them to do their job, giving a smoother shift. When reading about a little notchy shifting with the 6 speed I wonder if this wouldn't make the problem go away? Some of you fellows give it a try and see what happens. I shift in a pretty unorthadox method, which isn't double clutching, but gets the same results. When I am ready to shift, I start letting up on the throttle with a slight pressure on the shift lever towards neutral without touching the clutch. When the torque neutralizes between the engine and transmission, the transmission will slip into neutral. After it goes into neutral, with the clutch still engaged, the engine and transmission rpms are matched and then push in the clutch and hit the next gear.

Michael

 

[MikeR]

Originally posted by 2000ney

The most reliable transmission is the DTT modified auto trans.

But we didn't have to spend several grand to make the 6spd bulletproof. A stock auto still gets eaten by a stock powered diesel... the 6spd is bulletproof from that factory. Then if we want to pump up the horsepower, we just buy an $800 clutch and we're done.



My ETC/6spd has 76,000mi and I've never had any problems with it, and it has always been BOMBed since 4,000mi. It currently puts out 442hp and I always have this truck powering away on a dyno, and I even take it to the track and bang it down the 1/4mi.

It is still smooth and quiet as ever.



-Mike

 

[geusterman]

Thanks Dhawthorne. You added the maturity of years. I have enjoyed 4 years of used 6. 5TD travel in my mechanical pump 93K2500. Nice truck. Still is. They have a 300 horse potential at 18:1 that never blows a head gasket and still pulls 18mpg with the accelerator in "Normal".



I wish I had found a 98 12valve (QC) as I love the simplicity of mechanical diesels. It is part of the attraction. I found very few and none well kept. My good friend Bill Heath of Diesel Performance in Ellensburg WA (who developed the TurboMaster mechanical boost controller for the 12valve (and 6. 5's) (See ad in new Register) convinced me that the 24v were still quite simple and had the advantage of electronic power increases/no smoke. Additionally, his cost on pressure pumps was less than a grand which more that compensated the cost of the verticle Bosch.



He liked them better from a performance point of view and considered the reliabilty issues well offset by the advantages. My ST reflects my reliability concerns and the hp itch of mid-life crisis.



Lack of zerks still sucks. George