Transmission slip shift 1 - 2

[Mangler]

Thanks to TDR again, this one was a quick fix.



I was having a slip shift 1-2. The problem was really noticeable accelerating with what seemed like a loss in power and increase in RPM shifting from first to second. The transmission was slipping and would not quickly shift to second gear. I would let off the pedal wait for the shift to second, then accelerate. After towing it was so bad I thought I was in for a rebuild, but I had not adjusted bands in a while so that was going to be my starting point. I researched TDR and others mentioned changing the governor pressure sensor and solenoid as well.



What I did: 1) Replace governor pressure sensor and solenoid 2) Adjust bands per service manual 3) replace transmission filter 4) New ATF+4. I have to say the drain I installed previously and the reusable gasket made this job go very smooth and quickly.



The result was amazing. I have my truck back. HUGE difference between 1 and 2 shift... it was crisp and strong. It has been two weeks and towing twice no issues.



I still have a 1-2 hunt in traffic, but that is something different... guessing valve body, but the performance under normal to heavy acceleration is great.

 

[Missouri Mule]

What a little maintanence will do!

Glad you got it working again.

 

[Prairie Dog]

Glad that fixed it. Seems like trans threads lead to spending big buck too often!
BTW, is there more than one band in the 47/48's?

 

[cerberusiam]

BTW, is there more than one band in the 47/48's?

Yes, two. The rear band is manual 1st and reverse and it is a really heavy unit. Seldom needs adjustment and if it does something bad always happens. It also does not ever come into play in the normal shifting routines. The intermediate band is the one that takes a beating because it is 2nd gear.

 

[Prairie Dog]

Yes, two. The rear band is manual 1st and reverse and it is a really heavy unit. Seldom needs adjustment and if it does something bad always happens. It also does not ever come into play in the normal shifting routines. The intermediate band is the one that takes a beating because it is 2nd gear.

Thanks for the info Cerb.

 

[Superdawg]

I have 120k on my 2004 and had been having occasional 1-2 shift problems. It would shift and 15 then seem like it would wind up a little after the shift. I recently purchased this from Electrical Advantage.net:



"Heavy Duty Upgrade Governor Solenoid and Sensor Kit

This is a kit we created due to the high failure of the original oem design solenoid.

Optimal flow & Reliability is attained using this

New Design Billet Pressure Manifold accompanied by the New Borg Warner Solenoid .

Also a New Oem Governor Pressure Transducer is included ( lower right corner )

strongly recommended replace these as a kit /set "



I had my trans guy install it, adj the front band and change the fluid. What a difference it made! It seems to shift so much better, like a new trans. I just came back from a 2k trip towing a 10k trailer up and down mountains and it shifted beautifully. Even downshifting seemed to be a little better.

This particular item was well worth the money paid.

 

[PKnight]

I recently had a 1-2 shift problem (see picture). It shows the band apply wedge out of place and binding the front drum. I think the problem started with the governor solenoid. Now I'm doing a complete rebuild.

 

[cerberusiam]

More likely the band anchor broke a side out of the pocket where the adjuster screw sits and then they get pushed out of alignment.

 

[PKnight]

Yes, the "pocket" where the adjuster screw fits is broken out on two sides but not visible in the photo. But before that I got some "hunting" between 1st and 2nd at slow speed, causing me to think the govoner solenoid was chattering. The 47 RE lasted just under 200,000 miles without repair and appears in good condition except for the band and wedge.

 

[cerberusiam]

Yes, the "pocket" where the adjuster screw fits is broken out on two sides but not visible in the photo.

That is the typical failure. One of the first things to do is get a billet anchor and band strut to address the weakness issues. Between the anchor wanting to break, the strut wanting to bend, and the flex band stretching it is a wonder it works as well as it does.