Reverse slipping?

[Slacker]

Hey,

I have a ht4100 '82 deville. I changed the fuel pump and replaced a bad brake line and so I finally got a decent "test drive" out of my car. I took it around the block and it had zero problems shifting. When I got home, I went to reverse up the driveway and I noticed reverse gear was slipping. (high RPMs but slow movement). But still all other gears work fine...

Any suggestions? Both transmission and engine were rebuilt before I bought the car. (within the past 12 years. Car has only been driven 10k miles in the past 10 years though...)

Any ideas? Fluid looks nice and red too and not burnt.

[Edahall]

It could be a number of different things from bad clutches to a broken accumulator spring or a leaking valve body gasket. I would start with the easy things such as checking the fluid to make sure it is full. This is done with the transmission fully warmed and while the engine is idling in park. The next thing I would do is drop the pan and change the filter and fill the transmission oil back to full.

[Slacker]

Yeah, I drove it down the block to my friends house so we could shop vac the inside and we noticed it was slipping worse.

I popped the hood and checked the fluid. It was empty! I put some in and the car now shifts fine. I probably should have done that when I first got the car, but I'm still no where near done working on it and only drove it maybe two blocks since I've owned it. (Sat for years before I bought it)

I'm thinking I probably lost a lot of it when I changed out the radiator the day before because it was sitting disconnected for a few days so some might have dripped out from the cooler lines. Also, I did turn it over once w/ no radiator (bad idea, but it was for a quick test b/c we couldn't even get the car to start then). When I turned it on, it sprayed out about 1/2 the oil and I suppose transmission fluid the few seconds it was on out of the hoses.

Chalk this one up to my own stupidity.

Unrelated question, but I figure it's not worth making a new thread over. Today I turned the car on and it ran a bit rough so the SES light was on. (First time since I got it running). I turned the car off, put the car in the "on" position and went to check the codes by shorting the test terminal. When I did the the SES light came on and stayed on and the fuel economy part of the dash just read "0.0". I didn't see any codes blink. Was there a seperate button I had to press to show them? I know this car has some sort of complex diagnostic system built in... or did the codes not save once I turned it off? (I read in my chiltons book that there were two types of ways cadillac had the codes, where they are saved and where they erased after it's turned off... I figure that an '82 should save the codes... my '84 chevy does...)

Any ideas?

[Slacker]

Update:

I managed to get the "off" and "warmer" button press to display codes. I had code 52 in the system. I checked my chiltons book and it said that's a ECM failure. The car idles and runs fine, wouldn't an ECM failure make it run like garbage? Also, after putting the transmission fluid in, it goes from park, reverse, neutral, drive fine. When in drive though, it shifts late into 2nd. It didn't feel so much like a slip, just a late shift point. Could the be related to the 52 error code? Or are there vacuum lines I can check that might be leaking? I can't really bring the car to a transmission shop yet b/c it's not "on the road" and I can't do much more than circle the block until I do.

Thanks.

[Slacker]

2nd Update

Changed the trans filter and fluid. Fluid looked fine and there were no metal flakes in the pan. (Even used a magnet to see if I could find particles... nothing out of the norm).

I did notice the throttle was sticking when the car was idling high, I walked over and moved the throttle to the ISC and it was at a normal idle then. I cleaned up the linkage and the problem mostly went away. The error code 52, after further research was just an ECM reset, probably from when the battery was dead or me tinkering around once I managed to get the diagnostic mode working.

I did get error 30 today which is a ISC circuit problem error. Seeing that the transmission problem vanished once the throttle was working properly I'm wondering now if with the throttle sticking, the TPS, MAF, and other sensors used to set the ISC were reading higher idle and then when the computer compensated by rolling back the ISC throttle pin and with the throttle being stuck thus not moving back to the new idle, the computer figured the ISC wasn't moving correctly. Am I close in my thinking?

To fix the slight stick that's left, could I use a new / slighly heavier spring to keep the throttle pinned to the ISC when I'm not pressing the gas pedal? (The current one is rusted and seems to be well worn...)

Thanks.

[Edahall]

Originally Posted by Slacker

2nd Update

To fix the slight stick that's left, could I use a new / slighly heavier spring to keep the throttle pinned to the ISC when I'm not pressing the gas pedal? (The current one is rusted and seems to be well worn...)

Thanks.

Try lubricating your throttle cable before installing a heavier spring.

[Slacker]

Originally Posted by Edahall

Try lubricating your throttle cable before installing a heavier spring.

I tried doing that with PB Blaster.

While the car was off, I sprayed everything while working the throttle cable.

Is there a better lubricant I can use?

Thanks.