Transmission Adventures Continue.

[asdf123456]

Ok so I'm on another long road trip. The trans has already stopped working once before the trip (has had fluid/filter changes) but I had to go anyway. Had hard shifting before the trip. About 500 miles into the journey the car went into violent seizures. I traced it to the overdrive function "EP" mode. I found out that if I tapped the EP switch when I wanted to shift into top gear then quickly switched to SP mode without accelerating, it would hold that gear and not down shift. So that worked and got me there. On the way back 4th gear started shuddering at high speeds, reverse made a horrible sound, and there was slippage at low speeds. I tried some Lucas additive that didn't do much but I made it home barely. I think I was dazed or something but I wondered into the auto parts store to buy more additives that don't work. Out of the 5 choices I suppose I guessed right. I picked up a bottle of Greased Lightning. I didn't expect much and figured I had nothing to loose at this point since I'm buying a rebuilt one very soon anyway. The stuff is magic. It brought my gears back, killed the noise, and no more hard shifting. Overdrive still doesn't work right but it's better.

The moral of this story is: Everyone says not to add anything but Dextron to your trans because that's how it was engineered blah blah blah. Up until today I would agree. I'm going to buy a second bottle and see if it fixes the rest of the problems. Every shop in the area says it's dead and needs to be rebuilt. I'll post my results and see how much extra life it adds before it totally dies. It should be dead already. For less that $8 my car is fun to drive again and I get to keep my money this month.

Anyone know what would cause shudders in EP but not SP in top gear?

[jeffreyb4me]

sounds as though your torque converter lock-up clutch is failing [functional in EP, locked-out(not operated) in SP]

IF that elixor fixes it, I want to buy the company.

[asdf123456]

All the stuff really is is PTFE I think. I guess it's how they blend it and suspend the particles. It's now Tuesday and I'm still driving the thing 40 miles+ everyday in a mixture of stop and go and highway traffic. I'm able to drive in EP mode now, but I can't really accelerate without violent shudders. Before this Cure all Elixir if I even touched the EP button on the interstate my car would go into a seizure. I'm not expecting this stuff to fix anything. It does keep me happy and buy me time before the big transmission swap. Could be a few more days, could be a few more months. Either way it's $8 well spent. They make an engine formula and radiator juice that use the same DuPont PTFE in them. I'll sacrifice my car to science and test them out. I should have some data by Monday. The name of the product is stupid and that's why I never bought it before. I used to clean floors with a product called Greased Lightning and I sure as hell wasn't going to put it in my car. But, it turns out that they are 2 different companies that just both happen to have stupid names.

Can you explain a little bit more about the torque converter lock-up clutch?

Here's a brief history of the transmission:

153k: felt like fast shifts but didn't feel scary yet.
155k: hard shifts, whiplash like.
155k: partial fluid change
156k: 1,600 mile road trip. Car shifts smoother after driving at 80mph+ for a while.
156k: after trip car shifting harder than before with some shudder. Full fluid change. Car is silky smooth for a week then failure.
157k: I put in a new filter and more new fluid. Car runs but feels sickly. Shifts are hard and power is lost.
158k: another long trip 1,800 miles. Violent shudders after 500 miles in EP mode. Tapping EP to shift gears then SP (without accelerating) gets me to my destination.
158.5k: reverse make aweful noise. Next morning lower gears start slipping. Car still runs steady once in top gear at steady speed.
159k: Shudders develop in SP mode at speeds in excess of 90mph (maybe 3,300 rpm) LUCAS transmission stuff added. Not sure if it helped but I got home without any new problems.
159.5k: Some fluid drained and Greased Lightning was added. Noticable power restored, shifting greatly softened, EP halfway functional if at steady speed and not going up hill, reverse noise silenced, 20.5mpg on daily commute compared to 16-18mpg before.

You can see why I'm excited about this product.

[jeffreyb4me]

TQ lock-up clutch, if your refering to it's function, well, it goes back to the '80's when fuel mileage became a concern in the US. American's preference
for A/T's and demands for better mpg without the european sacrifices of smaller engines & manual transmissions lead to their developement I think.
Torque converters eliminate the need for a clutch due to designed in slipage rates and allow the use of a high axle ratio due to it's torque multiplication effect. The dissadvantge has always been big loses in efficiency due to all the slippage....once a shift's complete the autotrans. itself is as efficient as a manual actually...of the 'fluid coupling' part of the torque converter. To compensate for this, a 'lock-up' clutch was add to the torque converter which allowed a direct mechanic connection between the engine and trans. during 'highway cruise' situations. The problem has always been chosing what was an appropriate 'cruise situation'.
Anyway, @ say 45 or 50 mph, say, at steady throttle, the converter locks to the crankshaft and presto, increased mpg. Hope this helps..........jeffb.

[asdf123456]

Yea I could care less about a mile or two more per gallon. I could drive in SP mode all day. The prroblem is the engine revs too high because it's only designed to operate in 3 gears. It never shifts into 4th gear on its own in SP mode.

That does not explain the horrific noise in reverse though does it? I was leaning more towards the A clutch pack since that seems to be the first thing to go with that particular ZF trans/BMW combination. It's crazy, in the driver's manual it says not to let the engine warm up to operating temperature while idling. Why? Because the A clutch pack fills with fluid because the hole is blocked when in park, neutral, or reverse especially if the engine is revved. That's why BMWs were blowing their transmission back then at emission stations. It's a good transmission because I know other different make cars with the same model trans without the clutch pack problem.

I want a manual conversion so bad but no one in the area will even consider it or thinks it's possible.