Shifting problems?

Ok so my truck has problems shifting it shifts late bogs going up hills until it loses a lot of speed then the rpm jumps and it takes off up the hill. the OD shifts way late (like 50mph)if at all. If I let off the gas like around 40 then it shifts rough in to OD. I brought it to a tranny shop an the guy said its the 33's. I am taking it to another shop soon but wanted to know if any of you have had this problem?

its a 89 bronco with a 302, AT, and 33" tires

Thanks!

I just have a hard time believing that 33's can effect it that much?

Brad,

I have 33's on mine, and had very similar symptoms. My problem was a faulty TPS throttle position sensor, or VSS, Vehicke speed sensor (frankly I forget) but either could cause your issues. SInce I repaired it, it is incredibly better. The shifting pattern is not perfect, and it does run better at 65 than at 55 because of the 33's, but it is like a new truck compared to how it was.

You can pull DTC's and that may point you in the right direction.

http://broncozone.com/topic/14269-code-reader/page__p__74587&?do=findComment&comment=74587

BroncoJoe19 said:

Brad,

I have 33's on mine, and had very similar symptoms. My problem was a faulty TPS throttle position sensor, or VSS, Vehicke speed sensor (frankly I forget) but either could cause your issues. SInce I repaired it, it is incredibly better. The shifting pattern is not perfect, and it does run better at 65 than at 55 because of the 33's, but it is like a new truck compared to how it was.

You can pull DTC's and that may point you in the right direction.

http://broncozone.com/topic/14269-code-reader/page__p__74587&?do=findComment&comment=74587

Click to expand...

Joe, the reason it runs better at 65 than 55 is that the engine is designed to run best between 2000 and 3000 RPM. Increasing the tire size, can drop you below that range at 55 MPH. Here is a chart from BGY which covers gear selection and tire size. Also included is one for selecting the proper speedo gear if a truck has one. I believe yours only has a sensor on the rear pumpkin vs a speedo gear in the transmission tail. Not sure which one the 89 has.

Thanks Fred. You are exactly right. I believe that the 89 is like my '90 regarding the location of the VSS, and RABS. It was in 1992, that they went to a single sensor in the pumpkin to serve both functions, and they dropped the use of the gear driven speedometer, and went to a programmable Speedometer Odometer. PSOM.

Now that you pointed out that it is an '89 we are talking about, I don't know if he has an E4OD or AOD. The E4OD is electronically controlled. I don't really know how the AOD is controlled. Thinking vacuum... I'd give her a good look for a vacuum leak. Pull diagnostic codes, (maybe MAP sensor?).

I do believe you are correct Joe. If he has an AOD then he has a vacuum modulator and probably should 1. check the vacuum lines especially line to it and if that is OK 2. get a new modulator. Take the old one out as you will need to know what the color of the modulator is.

Good luck,

>-

Thanks for the help guys, I will do some searching. >

yo Brad!

We need to know what tranny is in there; I went thru all of your posts here and didn't see any reference to it or a pic of the shift indicator

AOD - E4OD Identification;

If the shifter has a:

P-R-N-(D)-D-1 shifter pattern, it is an AOD

note, OD is actually a (D)

Trans code: T



pic by trigger

=============

P-R-N-OD-2-1 shifter pattern, it is an E4OD



pic by Chris A

Trans code: E

----

& for others that may need to ID their Bronco's automatic tranny

P-R-N-D-2-1, shifter pattern, it is a C6

Trans code: K

http://www.broncolinks.com/gallery_images/C6ShiftIndicatorpic.JPG

pic by miesk5 at broncolinks.com/gallery

Ok I have a 1990 351 eddie bauer bronco with a e4od tranny, My speedometer is not working and it shifts erraticly. I have changed the vss and still nothing. Any ideas on what it could be????

yo,

You're one of few I have heard of that has the E4OD in a 90 Bronco.

Does the shift indicator look like this?



pic by Chris A

Trans code: E

Or



AOD Trans code: T pic by trigger

This problem could be caused by a # of thangs;

Do a DIY Code scan test such this by my pal BroncoJoe19 @ http://broncozone.com/topic/14269-code-reader/page__pid__74587__mode__threaded

There are two types of Tests, Key On Engine Off (KOEO) & Key On Engine Running (KOER).

The engine temperature must be greater than 50°F (10°C) to pass the KOEO Self-Test and greater than 180°F (82°C) to pass the KOER Self-Test.

Run it around to heat the engine up and shift thru all gears incl Reverse. Then turn off all accessories/lights, etc.

Make sure A/C is off and transmission is in Park (automatic) or in Neutral for a Manual & release clutch.

Do Key On Engine Off (KOEO) portion first.

Look Codes up in my broncolinks.com site using the new Search function.

And Post em here according to

KOEO

& KOER

This is also shown in:

Automatic - Electronic Transmission Diagnostic And Repair Diagnostic & Repair Process Chart TSB 91-6-4 for 90-91 Bronco, 89-91 Econoline & F SERIES, 91 Taurus & ****** & 89-91 Probe Source: by Ford via Chilton

ISSUE An Electronic Transmission Repair Process Chart has been developed for service use. The addition of electronic controls to automatic transmissions (E40D, AXODE, 4EAT, etc.) adds to the complexity of diagnosis and repair. Avoiding repeat repairs depends on properly identifying all the root causes of the concern.

ACTION Use the Electronic Transmission Repair Process Chart, Figure 1, to assist you in developing a routing system for electronically controlled transmission repairs. Using this routing chart will help in determining the "root cause" for the concern and repeat repairs.

i think the aod trans this year just had a throttle valve cable but no vacuum modulator. if the cable is out of adjustment it can cause late or early shifts and harsh or soft shifts.

fordsohc46 said:

i think the aod trans this year just had a throttle valve cable but no vacuum modulator. if the cable is out of adjustment it can cause late or early shifts and harsh or soft shifts.

Click to expand...

yo,

Correct.

AOD Trouble Shooting, COMPREHENSIVE; "...from the AOD service manual..."

Source: by duanemyhre at http://www.sccoa.com/forums/showthread.php?t=30511

WARNING!!! The proceedure for adjusting the TV cable on the TCCOA site does not usually work…if ever!? If you use this procedure, you stand a good chance of burning up your tranny. To accurately adjust the cable, you need to measure the pressure from the TV port on the side of the tranny.