I know this is something of a rehash, but 24 entries in the search did not convince me that this is not (at least a little) unique...

My 97 LXI coupe just hit 116k... about 700 mi back... I bought it from a friend who had the fluid/filter changed around 70k or so... Up to this point it always showed proper fluid levels...

Around 116500 I began to notice that it was downshifting quite harshly, unexpectedly, after having been up to speed, and while going up the hill to the house. Not too long after that, the OD failed and it would not operate past 2nd gear correctly if the OD was enabled.. still no change in fluid level.

My old Cadillac had done that after I got it, so since the LXI had 40+k miles on it already, I prepared to change the filter/fluid again.
In the process, the operation continued to get worse and began what seemed to be slipping in 4th... which progressed into 3rd with no obvious 4th gear operation at all...

The fluid/filter change did not help, and within the week 3rd gear seemed to disappear/slip.

All the while, the shift points/behavior has been inconsistent/nonstandard.

Looking thru the search I saw some 'repairs' made by replacing the speed sensors as well as the solenoid pack.

I have little problem with replacing these items before shelling out the bux for an overhaul, but...

Is there anything that can 'prove' that the solenoid pack is at fault here? Or should I simply save those pennies and have the trans rebuilt anyway? I suspect that a complete overhaul does not usually include a solenoid pack, unless I simply am too bogged down in 'old tech'...

In the meantime, I can safely get to/from work with only 1st/2nd gears... but I certainly dont want to make things worse!

BTW.. I noticed that many of the threads searched involved trannies that were around 116k... Is this the typical 'rebuild point' for this unit? Perhaps?

 

That's an electronically controlled transmission. Get it into a shop with the right equipment and have them read the fault codes and maybe pressure check the transmission. There's no point in guessing over the internet. It's not going to fix itself and it's only going to get worse until it's fixed.

 

Dont waste your time asking about transmission issues.

Got it.


Unfortunately I must wait until the motorcycle is working again...

 

After spending alot of time glaring at the parts breakdown of this trans (which I only recently found again due to a bad hard drive), I have decided to replace the solenoid pack first.

I am aware that I could be wasting money here, but without actual disassembly, I cannot see that my issue is failed clutches... and I have ordered a pack for a reasonable price. Replacement of the fluid/filter showed no extreme amount of particulates in the pan that should exist if the clutch material had been that severely damaged.

For the record, the error codes indicate only 'generic' failure (700) and the input/output speed inconsistencies. As long as I keep it from upshifting past 2nd there are no transmission-related errors.

Will advise if any improvement is found.

 

The 700 code is a generic transmission failure code that tells you there are other codes stored in the computer. You need a better reader to get those codes out. A decent trans shop or a dealer will have such a reader.
A transmission that won't shift past second gear is in "Limp mode", a mode designed to allow you to drive to a properly equipped repair facility.
Replacement of the solenoid pack is a relatively easy DIY project, and it's relatively inexpensive. If it cures your trans problems, then you are money ahead.
Here's hoping it does the job.

 

Actually I CAN get the codes... just couldnt remember the numbers.
Limp mode, if I recall correctly, forces ONLY 2nd GEAR (w/o 1st).. which does not happen. As long as I keep it in '2' it does its usual 1-2 shift...
It WILL 'attempt' to upshift if I allow it to remain in 'D'... or more accurately, it releases 2nd, but when it does it simply 'freewheels' nearly all the way to redline. I then have to allow it to slow down enough to give control back to 2nd gear. At this point it resumes its 'normal' 1-2 shift.

As you said... relatively easy DIY... crossing fingers AND toes!

 

Am I correct in believing that the UNDERDRIVE CLUTCH is responsible for the 'engine braking' usually experienced in 'manual 1st and 2nd lever' positions?

This function/clutch works, along with the
1st/reverse clutch (in 1st gear),
reverse/overdrive clutch (in reverse),
2nd/4th clutch (in 2nd gear)...

Thus, the belief that the solenoid pack is at fault.

If Ive missed anything, feel free to add!

I wish I had a book that showed the power flow thru the clutches... Chilton's is WOEFULLY INADEQUATE regarding the transmission... might as well not even HAVE a transmission chapter.

I know that they call it a 4-speed... but with the overdrive seemingly ADDING TO 4th, I tend to think of it as an 'overdrive 5th'...
More complicated that way.

 

It was NOT the solenoid pack... altho replacing it has made 1st and 2nd 'a bit smoother'...

So, unless the computer can be blamed for the problem, I must conclude that the overhaul/replacement is on deck and ready to bat.

Once the exceedingly huge funds are acquired, of course.


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