Engine/Transmission (1998.5 - 2002) Six speed needs help

[GParsons]

I have a NV5600 in a 2001, 2500 4 wheel drive. About 300,000 miles. Just had new clutch installed and transmission rebuilt. Before the rebuild 5th gear was a problem shifting up and down. After rebuild have worse poblem with 5th and a problem with sixth. The guy has had transmission out twice, no change,



Anybody got some suggestion I could pass on to the guy?

 

[RickFox]

Is the guys putting in the right kind of Fluid? That is about all I can think of... oh and I am glad that it is that guy that is taking that heavy ******* in and out of the truck I have had mine out once, and about to do it again this week and I am not looking forward to it.



Rick

 

[AFoulk]

I'd say either he has the wrong fluid in it, or maybe a bent shift rail or fork

 

[Grizzly]

I have a NV5600 in a 2001, 2500 4 wheel drive. About 300,000 miles. Just had new clutch installed and transmission rebuilt. Before the rebuild 5th gear was a problem shifting up and down. After rebuild have worse poblem with 5th and a problem with sixth. The guy has had transmission out twice, no change,

Anybody got some suggestion I could pass on to the guy?

Is that 300K with the original clutch? What does the NV5600 weigh?

 

[GParsons]

Original clutch, I'm the only driver. Weight- to much.

 

[n7gxz]

The NV5600 comes in at about 400 pounds + transfer case if it is left attached.



Kevin

 

[AFoulk]

you should try pulling an eaton transmission or better yet, a mack transmission sometime... talk about heavy

 

[Grizzly]

you should try pulling an eaton transmission or better yet, a mack transmission sometime... talk about heavy

No thanks, The NV5600 is heavy enough. What does the G56 weigh?

 

[PAckley]

I have learned about these trans the hard way. Just replaced trans with rebuild from Standard transmission in Ft. Worth, TX. 2000 trans had 1 1/4" output shaft, I upgraded clutch/flywheel to HO flywheel from Southbend Clutch. Then bought the 1 3/8" later model (after 2000) trans. Fortunately I received the $1,000 core refund, usually they say the trans they receive are toast.
The rear bearing fails first, causing 6th synchro to not work, then they get progressively worse and 5th synchro fails. Gear noises followed. I tow a 10,000 race trailer, Trans did not like load and high torque of engine options.

New trans works like a dream. Cost was $4400 + 450 for remove/replace. These are expensive transmissions and will become quite rare very quickly!

I will install the Genos trans coolers that go on PTO, as trans temps while towing get to 210 degrees with Amsoil trans fluid.

I bought a 6 speed thinking I would avoid the failure cost of the automatic and discovered even higher repair cost.

 

[chazj]

PAckley: Am curious is you tow your 10K trailer in 6th gear at all?



I pull a 10K trailer . My truck is stock (except for guages, 4in exhaust & EB) . At 55-60 mph my RPM's hover just around the low end of the maximumn torque of 505 ft lbs. However drop to 5th. the truck is running near the top limit of the torque curve of at 2200 RPM.



Power doesn't seem to be an issue even at the lower RPM's in 6th gear. I don't, however, want to cause a problem in the transmission and can learn to enjoy the "roar of the Cummins" at 2200 RPM if that's what it takes to avoid problems with the transmission.



Thanks for any input on this matter.

 

[blacksheep4x4]

Make sure you have added Mopar anti slip differential fluid to the fluid in your trans. If you don't it will not shift correctly. The syncros in the 5600 need it to operate properly.

 

[PAckley]

Chazj: I am not an authority here, and will be towing race car trailer to Nelson Ledges (near Cincinnati, OH) next weekend. Have installed Geno's fast coolers, and have only Amsoil synchromesh fluid (extra quart+). I always previously towed in 6th gear as the power would take any hill in 6th. So I will first be able to report the decreased trans temps from the fast coolers. I will start to use 5th gear on hills more often instead of brute torque to be easier on trans, which shifts fine without the Mopar anti slip diff fluid, although Blacksheep is an Amsoil Dealer and should know what works best. Since I have "over-filled" trans as suggested to help the rear bearing, no room for mopar antislip fluid

 

[Gordon Maney]

Make sure you have added Mopar anti slip differential fluid to the fluid in your trans. If you don't it will not shift correctly. The syncros in the 5600 need it to operate properly.

Is that correct? Does Chrysler recommend that, or is this something others have suggested?