Engine/Transmission (1998.5 - 2002) Searching for gears, 1999 2500 Automatic

[REdmon]

My "1999" 2500 club cab searches for the right gear. If starting to go up a slight incline, if may deop down a gear and then shift back up, over and over again. It doesn't always do it, its sporadic. I took it into the shop and the mechanic checked everything out but couldn't find anything wrong. He said to drive it until it breaks. Any ideas on what I should check myself?



Thanks,



Ron

 

[firefighter_2000]

Sounds like

Sounds like the typical torque converter lock/unlock problem. I did the suncoast rewire and the DTT noise filter and it solved my problem. One of the other problems that causes this is alternator noise and batteries. Make sure your batteries, cables, and connections and in EXCELLENT condition and this includes full charges.

A few people have been able to wrap their battery cables with aluminum foil and stop this. I did the following two items and havent had a problem since.



The suncoast rewire can be found here:

http://www.suncoastconverters.com/images/APPS ground rewire.pdf



The DTT Noise Filter can be found here (it must be ordered):

Its the (NOISE FILTER KW5535)

Diesel Transmission Technology - DTT Performance Diesel Transmission and Power Accessories



Hope that helps.

Craig

 

[JCyrbok]

Yep the DTT noise filter worked for me for $45 after the dealership threw abot 500bucks at the problem with out any success.



J-

 

[cerberusiam]

If starting to go up a slight incline, if may deop down a gear and then shift back up, over and over again.

Hmmmm..... its seems pretty clear its shuttle shifting under a light load but that may be my interpretation. That would probably be a problem with gov pressure solenoid and\or transducer.



Maybe the OP can clear this up and tell us whether it happens at a steady throttle at road speed and he starts up an incline, or, when he starts from a stop up a small incline and it sin the lower gears.

 

[REdmon]

The seeking of gears occurs at a steady throttle speed (around 40-50 mph) and then going into a slight incline, it begins dropping a gear and then back and forth without me increasing the throttle. Hope this gives a little more detail to help me figure what I should do.



thanks for your help



Ron

 

[cerberusiam]

The seeking of gears occurs at a steady throttle speed (around 40-50 mph) and then going into a slight incline, it begins dropping a gear and then back and forth without me increasing the throttle. Hope this gives a little more detail to help me figure what I should do.



thanks for your help



Ron

Is it actually dropping out of OD or do you have OD locked out?



How much rpm fluctuation are you seeing?



If you are not dropping a gear you will only see a couple hundred rpm fluctuation, then its the TC locking\unlocking. There are several solutions, some easy, some more involved depending on what your problem really is.



The easiest is take the wire that runs from the passeneger side battery across the top or back of the alternator and wrap it in tin foil anywhere near the alternator. See if that makes a difference.

 

[CumminsMatt]

you could also install a tc lockup switch, it's cheap effective and it works, Just make sure you use it at speeds 50 and above and don't have it engaged when upshifting or it could end badly for your input shaft. I had the same issues a couple months back and did the lockup switch and haven't had a single problem.

 

[REdmon]

Is it actually dropping out of OD or do you have OD locked out?



How much rpm fluctuation are you seeing?



If you are not dropping a gear you will only see a couple hundred rpm fluctuation, then its the TC locking\unlocking. There are several solutions, some easy, some more involved depending on what your problem really is.



The easiest is take the wire that runs from the passeneger side battery across the top or back of the alternator and wrap it in tin foil anywhere near the alternator. See if that makes a difference.

It's actually dropping out of OD. The RPM fluctuation is probably 200 rpm so I will make sure the batteries are in good shape and try the tin foil.



I will report back later.



Thanks,



Ron

 

[cerberusiam]

It's actually dropping out of OD. The RPM fluctuation is probably 200 rpm so I will make sure the batteries are in good shape and try the tin foil.

Thats not enough rpm drop for a gear change, its the TC unlocking. Manual take it out of OD at a steady throttle position and its more like 700 rpm drop IIRC.



Check the batteries, check batterie connections, check grounds, and try the tin foil trick before spending money.

 

[JCyrbok]

That would probably be a problem with gov pressure solenoid and\or transducer.



.

thats what the dealer replaced in mine when it did it, did not solve or lessen the problem. The DTT noise filter did immediately and has since I installed it over 5 years ago.



May want to throw $45 at it instead of a couple of 100 and see. Dealers are even selling a DC version put out by DC when they saw that the DTT and other noise filters were working.



J-

 

[fox]

It's actually dropping out of OD. The RPM fluctuation is probably 200 rpm so I will make sure the batteries are in good shape and try the tin foil.



I will report back later.



Thanks,



Ron

I bet it is unlocking the converter clutch.

Do a search.

It will be cured with one or more of these.

Clean batter posts.

Replace bad battery.

add a filter to the electronics. ( DTT sells one).

Check all grounds. ( I found the passenger battery ground loose at the block. )

There are more.

 

[REdmon]

Update, I cleaned the battery posts and wrapped aluminum foil around the ground lead of the alternator back toward the battery post. Worked like a champ and no more problem.



Thanks All



Ron