Transmission

[DoWhat]

Picked up the horse trailer yesterday.
From 1st to 2nd gear I would get a clunk noise. It is an automatic transmission
Is that considered slipping?

If I manually start off in 1st gear, then put it into 2nd when I get to the right speed (about 10 MPH), no clunking.

Any ideas?

 

[GWguy]

Are you letting up on the gas when you manually shift? That might mask the condition.

I'd start by checking the u-joints on the drive shaft. Rule out the easy stuff first.

 

[DoWhat]

Are you letting up on the gas when you manually shift? That might mask the condition.

I'd start by checking the u-joints on the drive shaft. Rule out the easy stuff first.

No.
But it only happens from 1st to 2nd. All the rest of the gears are nice and smooth.

It does not happen when I am not towing the trailer.

 

[frogman123]

Just don't take it to AAMCO, whatever you do...

 

[itsbob]

No.
But it only happens from 1st to 2nd. All the rest of the gears are nice and smooth.

It does not happen when I am not towing the trailer.

Do you have a towing setting??

Sounds like it's shifting too early for a vehicle under load..

 

[DoWhat]

Do you have a towing setting??

Sounds like it's shifting too early for a vehicle under load..

I have the towing package on my truck.
I engage it on the end of the shift handle (push button).

With the towing engaged I do not notice a difference from the problem, but I can tell that the towing is working.

 

[itsbob]

I have the towing package on my truck.
I engage it on the end of the shift handle (push button).

With the towing engaged I do not notice a difference from the problem, but I can tell that the towing is working.

Do you have the right torque settings on your wombulator shaft?

 

[DoWhat]

Do you have the right torque settings on your wombulator shaft?

Good question.
Have have no F'ing idea.

 

[Ken King]

What type vehicle, how many miles on it, have you checked your transmission fluid lately, have you serviced the transmission (fluid change, filter, etc.)?

 

[DoWhat]

What type vehicle, how many miles on it, have you checked your transmission fluid lately, have you serviced the transmission (fluid change, filter, etc.)?

2003 Chevy Silverado 5.3L, 110,000 miles

Never had the transmission fluid or filter changed.

 

[Ken King]

2003 Chevy Silverado 5.3L, 110,000 miles

Never had the transmission fluid or filter changed.

If I were you I would drop the pan, drain the fluid and replace the filter, also gives you a chance to see if there is any debris in the tranny.

 

[GWguy]

If I were you I would drop the pan, drain the fluid and replace the filter, also gives you a chance to see if there is any debris in the tranny.

If it's anything like my 2000 Sierra 4.8, it's a royal pain to get to some of the pan bolts. Cross members in the way.

Although a filter change and inspection is a good idea. And don't take to one of the places offering the "power flush". Too many people wind up with more issues than they started with.

 

[bcp]

I have the Allison power flushed.
but with the Allison its recommended not to change the filter unless there is a problem.
It has an external screw on filter, sorta like a oil filter suffering from dwarfism, that I change every time I do the oil.

 

[Ken King]

DoWhat, is the tranny the 4L60E or the 4L80E?

I've been reading some on these two and it seems that most recommend the fluid, filter change and if the problem still exists it might be the speed sensor causing the hard shift. It was recommended that if the hard shift occurs to shutdown for two minutes plus and try again, if the problem goes away it is electrical and the sensor is suspect.

 

[DoWhat]

DoWhat, is the tranny the 4L60E or the 4L80E?

I've been reading some on these two and it seems that most recommend the fluid, filter change and if the problem still exists it might be the speed sensor causing the hard shift. It was recommended that if the hard shift occurs to shutdown for two minutes plus and try again, if the problem goes away it is electrical and the sensor is suspect.

Thank You Ken for the info.

I have no idea what model transmission I have in the truck.
Owners manual does not list it.

 

[DoWhat]

Just found a Service Bulletin #03-07-30-020 on the same problem.

Bulletin No.: 03-07-30-020D

Date: May 05, 2005

TECHNICAL
Subject:
Transmission Has a Harsh 1-2 Shift, Slipping 1-2 Shift Followed by a Harsh Engagement (Replace Pressure Control Solenoid and Reprogram PCM on Certain Models)


Models:
2003 Cadillac Escalade
2003 Chevrolet Avalanche, Silverado, Suburban, Tahoe
2003 GMC Sierra, Yukon, Yukon XL



with 4.8L or 5.3L V8 Engine and 4L60-E Automatic Transmission (RPO M30)

Supercede:

This bulletin is being revised to replace labor code K5364 with labor code J6355. Please discard Corporate Bulletin Number 03-07-30-020D (Section 07 - Transmission/Transaxle).

Condition

Some customers may comment on a harsh 1-2 shift, 1-2 slip shift that has a bump feeling when 2nd gear engages.

Correction

For 2003 model year vehicles produced prior to April 1, 2003, replace the Pressure Control Solenoid (PCS). Refer to the Control and Shift Solenoid Replacement procedure in the Transmission sub-section of the Service Manual (SI Document ID #825149). Also, reprogram the Powertrain Control Module (PCM).

Will a dealership fix it for free?

 

[Pete]

Just found a Service Bulletin #03-07-30-020 on the same problem.



Will a dealership fix it for free?

Probably not. A service bulletin is different from a recall. A service bulletin gives them the cause and repair for failures that become a trend.

 

[RPMDAD]

Have to agree with Pete on this one, almost all or no service bulletins are repaired for free.

 

[DoWhat]

Probably not. A service bulletin is different from a recall. A service bulletin gives them the cause and repair for failures that become a trend.

Have to agree with Pete on this one, almost all or no service bulletins are repaired for free.

Thanks to both of you.
I will call around and get an estimate for a possible fix.
Thanks to Ken, I think I figured out the problem.
And Kingfish, thanks for the PM. I have called your contact.

But we shall see.

 

[ZARA]

A friend of mine (who is a mechanic) always said after flushing, drop a magnet in the bottom of the pan to catch any loose metal shavings.

Just sharing what I was told. I am not a mechanic, maybe one of the fellas can add their thoughts on it.