Hi everybody,

Driving up a slight hill unloaded yesterday at about 40mph constant pedal pressure the truck shifts into neutral...at least that's what it feels like. Revs go up and no power. When I take my foot off the pedal the transmission catches and drives fine. There is no bucking or hard shifting, just that slipping. Does anyone have any ideas as to what it could be?
This problem arose suddenly....never had any problems prior.
It is not an issue that has gotten worse over time.
I'm looking at upgrading to a more recent model this summer, but need to get this fixed to sell it!

Thanks

 

I would start with checking your fluid level, assuming you have an automatic.

 

Fluid has been checked and is fine...no check engine light on either

 

Just took the truck on another test drive. Once it starts to rev and I lose power it lasts for about 1 - 2 seconds. Whether I leave my foot on the gas or I ease off the tranny gives a light squeal....literally for a quarter second and then "re-grips"

Fluid is super clean even though it has never been changed and the truck has 200kms on it. No metal particles and no burnt smell either.

Where do I go from here?

Yes it is an automatic.....sorry

 

I'd start with new fluid. Make sure to only use MERCON SP or MERCON LV.

 

wow, well, time for a fluid change for sure. and filter. Should have happened a while ago.
HOW did you check it ? With the engine running, correct?

 

No! I warmed up the engine and drove the truck for about 10 minutes to get the transmission up to temp and then shut the truck off and checked it.
Am I supposed to check it with the engine running?

 

I do believe so but double check your owners manual.

 

Yes check it running, you are probably low.

 

Trans fluid must be checked with the trans warmed up, the shifter in P or N, and the engine idling. Any other way will give a bad reading.

 

Checking automatic transmission fluid (if equipped)
Refer to your scheduled maintenance information for scheduled
intervals for fluid checks and changes. Your transmission does not
consume fluid. However, the fluid level should be checked if the
transmission is not working properly, i.e., if the transmission slips or
shifts slowly or if you notice some sign of fluid leakage.
Automatic transmission fluid expands when warmed. To obtain an
accurate fluid check, drive the vehicle until it is at normal operating
temperature (approximately 20 miles [30 km]). If your vehicle has been
operated for an extended period at high speeds, in city traffic during hot
weather or pulling a trailer, the vehicle should be turned off for about
30 minutes to allow fluid to cool before checking.

1. Drive the vehicle 20 miles (30 km) or until it reaches normal operating
temperature.

2. Park the vehicle on a level surface and engage the parking brake.

3. With the parking brake engaged and your foot on the brake pedal,
start the engine and move the gearshift lever through all of the gear
ranges. Allow sufficient time for each gear to engage.

4. Latch the gearshift lever in P (Park) and leave the engine running.

5. Remove the dipstick, wiping it clean with a clean, dry lint free rag. If
necessary, refer to Identifying components in the engine compartment
in this chapter for the location of the dipstick.

6. Install the dipstick making sure it is fully seated in the filler tube.

7. Remove the dipstick and inspect the fluid level. The fluid should be in
the designated area for normal operating temperature or ambient
temperature.

Low fluid level
Do not drive the vehicle if the fluid
level is at the bottom of the dipstick
and the ambient temperature is
above 50°F (10°C).

Correct fluid level
The transmission fluid should be checked at normal operating
temperature 150°F-170°F (66°C-77°C) on a level surface. The normal
operating temperature can be reached after approximately 20 miles
(30 km) of driving.

You can check the fluid without driving if the ambient temperature is
above 50°F (10°C). However, if fluid is added at this time, an overfill
condition could result when the vehicle reaches normal operating
temperature.

Fluid levels above the safe range
may result in transmission failure.
An overfill condition of transmission
fluid may cause shift and/or
engagement concerns and/or possible damage.

High fluid levels can be caused by an overheating condition.
Adjusting automatic transmission fluid levels
Before adding any fluid, make sure the correct type is used. The type of
fluid used is normally indicated on the dipstick handle and also in the
Maintenance Product Specifications and Capacities section in this
chapter.

Use of a non-approved automatic transmission fluid may cause
internal transmission component damage.

If necessary, add fluid in 1/2 pint (250 ml) increments through the filler
tube until the level is correct.

If an overfill occurs, excess fluid
should be removed by a qualified
technician.

An overfill condition of
transmission fluid may cause shift and/or engagement concerns
and/or possible damage.

Do not use supplemental transmission fluid additives, treatments or
cleaning agents. The use of these materials may affect transmission
operation and result in damage to internal transmission components.

 

Ok so I checked the fluid with the proper procedure (engine running) as was suggested and the reading was very different. What looked to be at the top of the hot zone is in fact all the way at the bottom of the recommended area. I'll top it off today and give an update!
Thanks all!

 

So I topped off the transmission fluid and got no change in performance. What can I check on my own....if anything before I bring it in to the shop?

Does the truck have shifter solenoids that I can check?

 

Exactly how clean is it? Any used ATF has metal particles in it. How many, and what size? It's measured in parts per million (PPM) and microns. If you haven't had the fluid analyzed to know this, read my suggestion below:

There ARE metal particles in your fluid. Ones that are too small for you to see can make the solenoids sluggish and cause this problem. So can other things that will take a rebuild to fix.

As I see this problem you have three choices. You can change the fluid and hope that it cleans out the solenoids (I've seen this happen several times,) or replace the solenoids and the fluid, or rebuild the trans, replace the solenoids, and of course, new fluid.

 

How long have you owned it ? what's the history on the transmission?