jkstray

So I have a 97 C36 with 159k on the odometer and recently noticed the transmission acting funny. 1 to 2 is always very smooth with no problems and 4 to 5 is usually very smooth as well. 2 to 3 is almost always a hard shift until the car warms up and until the tranny has gone through the whole range of gears a couple times. Once the tranny has cycled through the gears a good 3-6 times, the 2 to 3 shift usually gets a bit smoother but is still noticeable finicky and can flare up at any time (usually a random flare). 3 to 4 is not as hard of a shift as 2 to 3 but flares up more after the tranny has cycled through the gears. After reading through the forum and the internet, this 2 to 3 and 3 to 4 shift problem might be related to a broken solenoid pressure regulator valve spring in the valve body.

My question to you knowledgeable folks on this forum is, how much would this cost an Indy to fix? I've found the Sonnax spring online for under 5 bucks but would this be a worthwhile investment? I would like to keep this amazing car but on top of the paint job (I have cracking clear coat on every vertical surface) and regular maintenance items that need addressing soon, I do not know if the money spent on the the pressure spring would be a lasting fix to kleep this car going to 250k.

I drive this car very grandpa-like at the time being because of the 2 to 3 and 3 to 4 hard shifts and it doesnt seem like the problem is getting worse. But if I am going to keep the car this would need to be fixed. Bc if not, I might be parting with my bone stock C36 to someone up to the task.

Any input appreciated.

Ausmbtech

Firstly make sure the transmission oil level is correct, they are sensitive to being low or high.
My suggestion would be to get a replacement rebuilt valve body with part number A140 270 0606. You would have a very early valve body and the "0606" is the latest version for early 722.6's and would be the best way to ensure the longest life rather than just replacing the pressure reg spring.

The pressure reg spring will usually give soft shifts through all gears and not just 2-3. There are wear issues with shift overlap valves but these are usually wear in the valve body and not a spring issue so an exchange valvebody might be a good option.

There may be other causes but this is a good place to start.

Super B

Thanks Ausmbtech, really great info. As far as the spring it's super cheap and as Ausmb pointed out it feels soft on all shifts. The most noticeable on my car was the down shifts into second for some reason it dragged while shifting gears.

Changing the spring is really quite easy, its just a little more work while your inside the trans changing the filter. There are several wright ups on it if you do a google search. I check mine every 40k miles while doing an trans oil/filter change.

jkstray

Giving this a little bump..

On the way to work this morning, the transmission went into mechanical limp home mode and was stuck in 3rd gear. Luckily, this happened before I got out of the neighborhood and I was able to to make it back home. I pulled in the driveway, stopped the engine, and then restarted. After the restart the transmission acted normal and I was able to make it to work (only grandmpa driving and shifting around 2K RPM). No Check engine light but surely there is a transmission code in the ETC I need to get checked out after going in to limp mode.

Sound like anything familiar to any members? Any advice is welcome. It seems that the shifts are much smoother once the engine/transmission fluid gets to operating temps. Makes me think it might be the fluid level.

Any help is welcome!

benzslo

i would not worry about it personally, i would save my money and time for other repairs that are actually needed.

Super B

Have you gotten under the car and checked the plug where the wiring harness twist locks into the transmission? That is a super common failure that let's oil into the wire harness which in turn will wick up the wires and get into/onto the transmission control module. Not saying it's your problem or solution but something to check.

jkstray

Just wanted to give an update...

Took it to my reliable indie and he went with the fluid change first to make sure it wasnt the fluid level causing the problem. After changing the fluid and inspecting the connection pin (it was good with no visible leaks), the problem still remains after two weeks of driving. Guess its time to swap the conductor plate out! My indie is very familiar with 722.6 trannies and said he has no qualms about dropping the valve body to inspect and also change the conductor plate. I'll update on the tranny after all this is done next week.

Cheers