backnblack

I changed the trans filter in my 86.5 and now it won't shift out of 2nd gear.
I'm not sure if I need to make a small adjustment to the trans cable or what way to adjust it. but it shifted before I changed the filter.
????

Cheers
Matt

Trying to make it to Sharks in Hell !!!!!

MainePorsche

Hey there.
If you have an absolute inability to shift, it is my believe you have disconnected the mechanics for what is called the Bowden cable.
Easy fix, and not uncommon when dropping the pan and playing around there.

A 'Bowden cable' is the type of cable this cable is. There is another Bowden cable for the cruise control. What the trans 'Bowden cable' is, is the control pressure control cable. This cable enters the transmission on the Right side through a conical white plastic cover. The cable's end has a flat end crimped into to it with a hole in it. Through this hole a lever arm's right angle end passes through. This is one common point for dis-union. The long end of this lever arm is attached to the reversing spring (has nothing to do with Reverse) which is attached to a valve. This is the second point for dis-union.
What you want to do is detach the 'Bowden cable' up on the engine top at its ball/cup joint. This will give you some slack in the cable to work with. You then want to have the transmission pan off so you can inspect what is detached. If the spring is off put it back on. If the lever arm is out of the hole, lift it up from the pan side and re-attched to the cable. If both are off, re-establish both. Then re-attched the cable up on top.

MainePorsche

Add: The white conical plastic cover for the cable is released by turning it counter-clockwise, and releasing it.

backnblack

Crap ! So I have to take the pan off again Man I din't think I touched anything to screw this up .
It does shift from 1st to 2nd but won't go any higher about 3 to 4 grand at 45 mph. Can I re use the pan gasket ?

Thanks for the help !

MainePorsche

If you just put it on, shouldn't be a problem. Torque it correctly and in a cross hatched fashion as you would do your wheels. Start from the center bolts first.

gearz

Are you certain the fluid level is correct? These transmissions are very sensitive to that and won't shift properly if even slightly over or under filled.

Landseer

I'd check to be certain the filter is mounted properly and the level is correct.
You shouldn't have needed to touch anything else, agreed.

Hopefully you were extremely careful to clean the area before you opened up the pan, ie, kept grit out.

The S4 bowden arrangement is a little different than 86.5, btw. Maine has an S4.
With loose bowden my experience is that they upshift quickly through the gears, and it doesn't seem to prevent a 2-3 or 3-4 upshift, so am curious what you find when inspecting that portion.

MainePorsche

Good point.
I was assuming he was adequately filled.

I thought the physical attachment of the cable was the same on the MB 722 transmission in the 86.5 and the S4. Also thought that with his gross symptoms the control pressure control valve was not being appropriately activated via the cable because of separation. Yes, he shouldn't have had to touch anything else, but accidents happen and it wouldn't take much to knock off the reversing spring and render that valve non functional.
Thanks for that info. Chris

GregBBRD

Professional mechanic's creed:

"If a new problem occurs after working on a vehicle.....go back and review whatever you just did. Start completely over, if necessary, looking at everything you touched."

Especially true if the "new" problem has anything to do with what you just did.....like in your case.

Obviously, make sure the transmission is full of fluid. If you drained the torque convertor and changed the filter, you should have put back in a minimum of 6 quarts.

There's a round cork seal on the filter that fits over an opening on the valve body assembly. There's a lip, on the filter, that must fit into a hole and the cork portion seals on the edge of the hole. If you somehow were to compromise/mis-align this, the transmission would suck air and fluid, instead of fluid.

This is really difficult to screw up, but I've seen it, more than once.

Pan gasket will be fine, unless you used your impact, like the guys on all those TV hotrod shows use to tighten everything......what idiots.

backnblack

Thank you for your help !
Quick update. I was under the car looking to see if I could spot something wrong when I saw a vacuum line that was not connected. when I looked a little more I found another one. One seem to come from the front on the 6 / 7 way vacuum connector and then the other seem to run back to the front in the torq tube tunnel. They both seem to go to this brown plastic pices with one nipple on it. Do they both connect to this on a"T" there was nothing connected to the hoses.

Let me know what you think.

backnblack

Pan gasket will be fine, unless you used your impact, like the guys on all those TV hotrod shows use to tighten everything......what idiots.[/QUOTE]


LOL Thanks Greg.

Landseer

There is effectively only one vac line. Runs from engine bay, along top of torque tube, then to the nipple on the red/black modulator valve pictured.

MainePorsche

Matt,
Sorry to set you on the path to re-drop the pan and inspect the control pressure control cable and/or the reversing spring. I took it you filled the ATF adequately and did not have a vacuum line hanging loose.

backnblack

I didn't get that far. I was looking at every other option before I dropped the pan again when I say thing so no problem.

MainePorsche

I am glad you worked it through.