98 Windy: VSS and/or TRS when transmission is warmed up

[QCubed]

Hello all,

First let me say that I love our 98 Windstar. This comes as a shock to most people, but our gently used and well maintained 98 Windstar has paid back in spades with comfort, reliability, utility, and ample power for everything our family has put it through.

Secondly, I have to say that on the odd occasion that I have had an issue, you forum members have been very knowledgeable and have always steered me in the right direction. So, thank you!

Now the issue that me brings me here today:
Recently the Windstar, GL model, 3.8L, has developed an issue with the transmission where after some distance, or some uphills (i.e. tramsmission warms up) it slips out of gear, then goes into "limp mode". Pulling over, shutting down and restarting does not change this. Let the van sit for a while so everything cools down, and it will drive normally again for the short local trips. But, on a longer trip into the city, or a busy day with quick stops, it will soon slip and then only limp along in 2nd gear only.

I checked the transmission fluid and it has that good cherry colour and does not smell. It is right in between the upper and lower hash mark limits.

I have been reading the other posts in the forum and seen that the TRS and VSS are common failure points. I am hoping that replacing those will resolve the issue.

But, before I do, the thought comes to mind that if the VSS or TRS were the issue, the van would not drive normally for a while and then slip. It would slip even from a cold start. And this, then, indicates that actually the problem is neither the VSS or TRS, but in fact an issue with the transmission itself.

Am I wrong to think that way? Would the VSS and/or TRS behave differently when the transmission is cold, and after the transmission warms up?

Thank you all for reading, and for your feedback!

[tomj76]

I can say that from my experience, the transmission in my '96 Windstar is prone to odd behavior. It's been this way for most of the 21+ yrs that I've had it. A lot of my problems have been with TCC engagement issues, but also lots of odd shifting.

If you're getting limp mode, then you most likely are getting a code that can be read by most scan tools. There can be codes stored even though the MIL is not turned on (some codes are non-MIL). See if you can get AutoZone or another auto parts store to read the codes for you. Some transmission shops will do it too. I'm not sure how all that works in Canada.

It might be enough information to help you choose to look more closely at the TRS or VSS.

You don't mention the mileage on the transmission... my first major failure came at ~190,000 miles. The transmission case broke, so the whole thing had to be replaced.

None of the automatic transmissions that I've rebuilt (in my own cars) have needed new clutches, even though that's supposed to be the common wear out mechanism. They've been other things like broken bands, broken springs, broken gears. The main thing I've seen wear inside the transmission is the brass bushings. If your transmission has worn bushings, then the initial symptoms are likely to be related to the operating temperature since the hot ATF will more easily leak out of a larger gap.

However, another reason it stays in limp mode until cool is that the PCM might not allow the transmission to run normal until the temperature sensor indicates a cool engine, sort of a reset. I've seen that on a TCC lockup problem I currently have on my transmission.

BTW, when I've had problems with the VSS (twice lost electrical connection to the sensor), the symptom has been odd shift points, not slipping. I've not had a problem with the TRS (other than accurate adjustment), but I think the symptom would be similar. Also, the TRS is "easy" to check if you have a DVM. As you select the various range settings on the selector, the resistance changes. You'll need to pull the connector to the TRS and probe the correct terminals (I might be able to find the info for my '96 if you decide to do this).

[QCubed]

Hi TomJ

Thank you for your information!

The Windstar has 210,000 Kms (Approx 131,000 miles.)

I have a friend who has a pretty decent code reader. He did not find any codes in the Windstar.

However, reading the symptoms you had with your VSS failure, it seems that my symptoms are not being caused by a failed VSS, which is in line with my thinking.

Readers who have had VSS or TRS failure: what symptoms did you experience, and did you find that the symptoms existed even on cold starts, or did you find that the vehicle drove normally when the transmission was cool, but symptoms returned when the transmission warmed up?

Thanks for your help!

[tomj76]

If the O/D light blinks, I believe (but I'm not certain), that some code condition has been detected. However, there are Pending codes and Mature codes.

"Codes are referred to as pending or maturing codes. Pending codes are caused by intermittent faults or faults that the PCM needs to see happen in two consecutive warm-up cycles to set the code. If the fault does not reappear within 40 warm-up cycles, the code will be cleared from memory."Actually, I think the # of warm-up cycles varies with the code type. Depending on your driving patterns, the code could be getting "erased" if it is not occurring on each drive.

Also, your mileage is lower that I had when my first transmission failure occurred. However, I had mostly highway miles and many miles in mountain driving conditions.



Before the last rebuild, the last symptoms were the transmission would run OK at cold start for the first few miles. After than it would switch to limp mode. The length of time it worked well grew shorter as I continued to drive it over the next year. When I disassembled it, I found a broken wave plate in one of the clutch packs and the worn bushings I mentioned before. As a precaution I replaced most of the solenoids, the internal wiring harness, and the pump shaft. As part of the rebuild I replaced all the internal o-rings and seals, plus the plastic rings.

http://www.automotiveforums.com/vbul....php?t=1081363

http://www.automotiveforums.com/vbul....php?t=1091205