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We have recently acquired a ’96 Dodge RAM B2500 Conversion Van.
Since winter came around it developed a strange problem just after starting – if we try to put it into reverse with the transmission cold it would sit for around 40-50 seconds doing nothing then it would “bump” hard into gear.
With the AT fluid hot everything works as it should, the Reverse engages smoothly as soon as we move the lever.
Any idea why this happens and how we can fix it?
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From what I have seen on Chrysler transmissions that is from one of two things.
A sticking reverse band actuator valve which usually can be cured with a fluid and filter change.
Or a bad anti-drainback valve in the cooling line
All Chrysler-built transmissions from the early eighties up have what’s called a Anti-drainback valve in the system. This prevents the draining of the torque converter of fluid during long cool-down periods, such as overnight. Draining of the torque converter causes internal fluid loss and makes repriming of the torque converter problematic at start ups. This usually manifests itself as a lag before engagement after the transmission is placed into gear. Over time this can cause damage.
The anti-drainback valve is found either in the return cooling line or at the outlet port on the vehicle radiator. As transmission fluid becomes oxidized and contaminated with friction material silt and other particles, these anti-drainback valves are susceptible to becoming clogged. This can cause a partial or complete pressure loss resulting in lack of lubrication to the transmission’s internal parts and eventually lead to various component failures.
Removing the anti-drainback valve from the system eliminates a potential problem area, but it can also cause other problems long term. The way to manage this situation is regular routine transmission maintenance, which basically means replacing the transmission filter periodically and the subsequent 4-6 quarts of ATF. Depending on the severeness of duty, they should be changed at 50,000 miles, or for severe duty vehicles, 25,000 miles. Personally, I recommend changing the filters at 25,000 miles on all vehicles.
Complete fluid flushes are also recommended under certain conditions. On vehicles that have not had routine service, I would advise replacing the anti-drainback valves along with the routine service. In some cases the entire cooling lines must be replaced if they have a build-up of silt.
I usually recommend someone with your symptoms to get a transmission service and a new drain back valve installed. But, be forewarned Chrysler transmissions are not the most durable out there and have been known to fail completely after a fluid change.
Thank you Raistian77! I have already ordered the the AT Filter & ATF +4, hope this would fix some of this problem.
Any idea on how we can get as much of the ATF oil changed? This van is in Europe and there aren’t many US-made automatic transmissions around here so we have to explain to the repair shop what and how to do this right.
It’s a 3.9L Magnum V6 engine. The transmission code on the plate under the hood says “DGA”. The only thing I know about it is that we have a 3 speed automatic without overdrive in this van.
When it comes to automatic transmission I usually know more about them that many mechanics around here and I don’t know much at all. A good guide for changing the fluid properly / adjusting the bands will go a long way in keeping this van alive.
Thank you Raistian for the very useful info! I will change the fluid/filter this week and let you know what we’ve found in the oil pan.
Meantime I’ve attached a picture with the transmission’s oil pan maybe we can identify the type of transmission on this vehicle.
Many thanks!
Looks like you have a 32RH transmission
the pans for the bigger 42Re and 36rh are shaped different
46RE
36RH
I’m more familiar with GM transmissions. Is there a difference between checking the fluid level in PARK instead of NEUTRAL on a Dodge?
So far so good – there was no excessive metal shavings or sludge in the oil pan although the fluid was black – I’ll attach a few pictures.
The new ATF +4 fluid didn’t “cure” the hard to get in reverse when cold issue – next time we’ll adjust the bands to the service manual specs – we just bought the Chrysler Service Manual. Hope an used transmission doesn’t need different adjustment specs…
In neutral, the converter is filled and there are no “controlled leaks,” as when in park. The controlled leaks in park prevent the converter from putting to much pressure on the engine while idling, it does this by not allowing the converter to fill all the way up. If you check the level in park, the level checks higher than it really is.
I checked the level in Neutral and… Voila! – the fluid level was almost on Min mark!
Thank you for the knowledgeable posts – I think you just saved a transmission! 🙂
We have found the 32RH/36RH adjusting procedure in the service manual:
Front Band Adjustment
The front (kickdown) band adjusting screw is located on the left side of the transmission case above the manual valve and throttle valve levers.
1. Raise vehicle.
2. Loosen band adjusting screw locknut. Then back locknut off 3-5 turns. Be sure adjusting screw turns freely in case. Apply lubricant to screw threads if necessary.
3. Tighten band adjusting screw to 8 Nm (72 in. lbs.) torque with Inch Pound Torque Wrench C-3380-A, a 3-in. extension and 5/16 socket.
4. Back off front band adjusting screw 2-1/4 turns on 32RH or 2-7/8 turns on 36RH.
5. Hold adjuster screw in position and tighten locknut to 41 Nm (30 ft. lbs.) torque.
6. Lower vehicle.Rear Band Adjustment
The transmission oil pan must be removed for access to the rear band adjusting screw.
1. Raise vehicle.
2. Remove transmission oil pan and drain fluid.
3. Loosen band adjusting screw locknut 5-6 turns. Be sure adjusting screw turns freely on lever.
4. Tighten adjusting screw to 8 Nm (72 in. lbs.) torque
5. Back off adjusting screw 4 turns on 32RH or 2 turns on 36RH.
6. Hold adjusting screw in place and tighten locknut to 34 Nm (25 ft. lbs.) torque.
7. Position new gasket on oil pan and install pan on transmission. Tighten pan bolts to 17 Nm (13 ft. lbs.) torque.A question for the knowledgeable tech is if this procedure applies the same to a 120.000 miles transmission? Is there anything else to know before adjusting the bands on such a transmission?
Be careful with the band adjustments. Get it wrong, and you’ll be rebuilding that transmission.
Good luck and keep us posted.
Did the band adjustments by spec & a fresh change of Mopar ATF +4 fluid.
Transmission works exactly the same, no change whatsoever getting into reverse when cold.
The only interesting fact we noticed: if you raise the engine rpm in Neutral then it enters smoothly into Reverse. If you let it engage at Idle rpm then it roughly “thumps” into gear after a 5-7 seconds delay…
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