700R4 Overheated?

[PowerSet]

Hello everyone, I appear to have made a pretty big screwup, with several other screwups most likely.
The car is an 88 monte carlo LS, as far as I know it' stock, 305, 700r4 transmission(So I've been told)

So, the car only really got a day of driving, and even that was probably less than an hour and a half, mostly sitting.

I bought it a few weeks ago, seemed to go up and down the street fine, cash as-is, and I expected a project needing a motor rebuild, or some extensive amount of work, but hoped for something not ending in a money pit.

Drove it around town a bit, seemed to drive completely fine, other than me noticing that I couldn't tell if/when it was shifting. It seemed like it was revving high, but I'm also used to a 4 cylinder which sounds a whole lot weaker, it also didn't seem like it was struggling at all to drive around.

The next part was the car running out of gas(my initial drive was about 10 minutes to the local mobil, 1 minute away from it I ran out)

I have never worked on a carbureted car before, and have barely worked on any cars in general. I put about 10 gallons in the tank, and I dumped a bit of fuel into the carb, started it, tried to keep it running, I think it took about 3 goes to get it running on it's own fuel again, but then it continued to run completely fine despite my worry.

Later in the day I decided to take it for a drive around town, and I noticed while going uphill, I could notice it shift(Nothing hard, I just noticed it for the first time) and then I notice smoke pouring out of the side of the car, pull to a side street, stop and shut the car off, and all I can see is what looks like chocolate milk dripping onto the catalytic converter, which is what the ATF apparently looks like at that point. I look around for noticable leaks, no puddles, no big noticable leaks, so I wait awhile, start it up, and it drives fine, gets me home, and sits at an idle for about fifteen minutes like nothing is wrong.

I call my father who has spent alot of time around the older muscle cars, smallblocks, all the goodies, and he mentions that the transmissions have a habit of leaking around the dipstick tube where it meets the trannys. This seems to fit everything, so I assume going up the hill when it shifted it just spilled out of there, no big deal, smoked off the exhaust, and I didn't notice anything else.

Took it for another drive, and then it ended up really slipping bad and barely being movable so I got it towed home.



So with my extremely limited knowledge, my assumption is that there was some bigger issue than a small leak, and that the transmission was overheating and most likely ate up the clutches to a point where they're just useless.

That being the case, I don't know if I'm best off picking up another transmission, I've seen quite a few for 150 or less, I would like to stick at around 100 or less if I were buying a used one since it's nothing I would know about the condition of until it's put in. Or I was also considering getting one of those rebuild kits from summitracing, or elsewhere.

I don't expect it to be an easy thing to do rebuilding a transmission without prior experience, but it seems like there are quite a few good videos and walkthroughs specific to this transmission itself, so I figure it would at least be something managable. I have no rush to get the car on the road, so taking the time to do it right wouldn't be a big problem, and I have a decent size garage to work with.

Just wondering if I should worry about the transmission being unsalvagable from overheating and rebuilding it would be a waste of time, or if the overheating would really only destroy the clutches and seals that would be replaced in the rebuilding, making it seem like a worthwhile project.


Thanks for any input
PowerSet

 

[Skitter302]

...
he mentions that the transmissions have a habit of leaking around the dipstick tube where it meets the trannys. This seems to fit everything, so I assume going up the hill when it shifted it just spilled out of there, no big deal, smoked off the exhaust, and I didn't notice anything else.

Took it for another drive, and then it ended up really slipping bad and barely being movable so I got it towed home.
...

I'm hoping that you refilled the transmission after realizing it leaked! If you didn't that's why the trans stopped working. Low fluid will tear up the friction pads between each gear. Which sounds like what has happened. None-the-less, you need a new transmission. and Honestly, I would leave the rebuilding the to the Pros. Unless you really (I mean really really) want to do it yourself. If I was you, I would pull the current trans out and take it to a rebuild specialist. As long as the case isn't cracked it sounds like you have a good core. Getting a "working" parts yard trans is really rolling the dice.

If the transmission did indeed overheat to its death you will need to figure out what has caused that problem. I would remove the transmission cooling lines and flush or replace them. I would then inspect the transmission cooler and have it flushed.

 

[Intragration]

What did the transmission fluid and coolant look like before you started driving it? What do they look like now, and how are their levels? Based on the limited information you've given so far, I'd guess there's a leak in the trans cooler in the radiator, and coolant is getting mixed into the trans fluid.

With limited experience working on cars, my feeling is that trying to rebuild your transmission isn't the ideal place to start getting experience. Now if it doesn't matter if you're successful, and you don't mind trying and possibly failing, it might be a good way to get some experience. But if in the end you want a dependable car, my advice would be to either take it to a reputable trans shop, or pick up a rebuild and swap that in. You could also try the used transmission, but a used 200-4R (which is what I think you probably have) for $100-$150, if you can find one this cheap, is going to basically be a core.

 

[PowerSet]

What did the transmission fluid and coolant look like before you started driving it? What do they look like now, and how are their levels? Based on the limited information you've given so far, I'd guess there's a leak in the trans cooler in the radiator, and coolant is getting mixed into the trans fluid.

With limited experience working on cars, my feeling is that trying to rebuild your transmission isn't the ideal place to start getting experience. Now if it doesn't matter if you're successful, and you don't mind trying and possibly failing, it might be a good way to get some experience. But if in the end you want a dependable car, my advice would be to either take it to a reputable trans shop, or pick up a rebuild and swap that in. You could also try the used transmission, but a used 200-4R (which is what I think you probably have) for $100-$150, if you can find one this cheap, is going to basically be a core.

I ideally would like to do as much of my own work on the car as possible, regardless of it being time consuming, not always the cheapest route, and an overall pain in the butt.

I have had a 90 miata for three years, when I got it I knew nothing at all about working on cars, but slowly worked with redoing the brakes, new calipers and rotors all around, and when the engine blew I replaced the engine, clutch, all the hoses, etc. It was a small nightmare worrying about screwing everything up, or what if it didn't work, but I'm glad I did it, and it is a good feeling knowing that you made sure every piece was just right so you're trusting yourself, granted that's not always as good as trusting a pro.

The fluid did look like chocolate milk initially, but to be completely honest that's on my own lack of knowledge. The atf dipstick is where the oil dipstick has been on my newer cars, and with the car sitting for so long, when I asked about the oil looking milky, I was told it was probably moisture still sitting in the oil and that it would probably take a few oil changes to get it looking normal. This was when I had mistaken the dipsticks, so it was the ATF that looked milky. I did put more fluid in it, but every time I checked the level there was always fluid in it. I definitely assume I drove it too dry, or while it was overheating for some other reason, it's really hard for me to pinpoint considering I just got the car, changed the oil, and was driving it around for it's first time, combined with the fact that my only other mechanical work is on an indestructible little japanese car that is a whole different world than the mighty v8 platform of the monte,


I definitely accept the possibility of getting everything, attempting to rebuild this transmission, and having it end in failure. I would just like to rule out the possibility of it being unsalvagable(can I disassemble it, and inspect certain areas that could be potential problems?) I do have confidence enough in my abilities, and with the multiple videos I've watched through it definitely seems like something reasonable to do with patience and careful work.(Although you said you believe it is a 200-4R, It is an 88 monte carlo LS I don't know if there is another way to determine what is in it, or if I can tell once I pull out the transmission)

 

[BPTTONE420012]

are you SURE its a 700-R4??? pretty sure the montes came with the 200-4R... at least the half a dozen i have owned have... and i would say its TOAST... after you bought the car did you check your coolant before driving it? our trans are cooled by the radiator and crappy coolant will raise both engine n transmission tempa... also did you check the adjustment of the TV cable before driving it??? proper cable adjustment is key to our transmissions, and with the soft shifts to where you couldnt even feel it shifting, sounds like you had the tv adjusted improperly and cooked the transmission.... as for buying a trans for $100, i wish you the beat of luck, but for $100 you will be lucky to end up with a good core... bite the bullet, and spend the money to have a REPUTABLE transmission shop that specialize in AOD transmissions rebuild yours... i personally wouldnt attempt to tear down n rebuild a 200 or 700-r4 WITHOUT prior experience, cause after you pull it apart the trans shop will charge you more to fix whatever you ****ed up... lol... i just built my engine from the pan to the carb, but i wouldnt try n rebuild a trans unless i had a spare to destroy... they are not an easy beast to tame...

 

[BPTTONE420012]

and your transmission will have an ID tag that says what it is, might say something like CZF...

 

[King_V]

Check this out: Transmission identification

 

[PowerSet]

are you SURE its a 700-R4??? pretty sure the montes came with the 200-4R... at least the half a dozen i have owned have... and i would say its TOAST... after you bought the car did you check your coolant before driving it? our trans are cooled by the radiator and crappy coolant will raise both engine n transmission tempa... also did you check the adjustment of the TV cable before driving it??? proper cable adjustment is key to our transmissions, and with the soft shifts to where you couldnt even feel it shifting, sounds like you had the tv adjusted improperly and cooked the transmission.... as for buying a trans for $100, i wish you the beat of luck, but for $100 you will be lucky to end up with a good core... bite the bullet, and spend the money to have a REPUTABLE transmission shop that specialize in AOD transmissions rebuild yours... i personally wouldnt attempt to tear down n rebuild a 200 or 700-r4 WITHOUT prior experience, cause after you pull it apart the trans shop will charge you more to fix whatever you ****ed up... lol... i just built my engine from the pan to the carb, but i wouldnt try n rebuild a trans unless i had a spare to destroy... they are not an easy beast to tame...

As I have already been informed, it is most likely a 200 and not the 700. I don't have the exposure to cars from before I was born, so most knowledge I have so far is based off of what I have been told, and what information I have found and read. Would make alot of sense since I couldn't find much on monte carlos with the 700r4. And again no on the TV cable adjustment, it is a car I bought, changed the oil, and was just driving for the first time. There is no further delving into the car, and I still don't know all the little details to look out for as this car is meant to be a car for me to learn everything on, the same way everyone learned what they were doing fixing their cars back in the day.


Maybe I should be a bit more specific about the fact that this car is in no way shape or form intended to be a reliable daily driven car. I would like this to be a car that I learn to restore on my own, regardless of time or difficulty. I don't expect it to ever be perfect, but I also have no intention of throwing thousands of dollars at the car for labor at any point.

I assume the TV cable was out of whack along with many other things. I bought the car "as-is" but when I went to check it out I collected it from someone who took it out and drove it occasionally even with the shifter being extremely sloppy, so I unfortunately assumed that since the guy who owned it was still driving it around, it probably wasn't going to kill it if I drove it for a day.


The prices of around 100 for a replacement trans, seems to be pretty common for what I see around here for 700r4 transmissions, the 200r4 are definitely a bit steeper in price. My father has always been in the groups of guys with all nice old muscle cars, with all sorts of smallblocks and smallblock goodies, so if I were to get a replacement I would most likely try to find one from someone I or he knows.


This is also, above all else a car I paid 700 dollars for that I intend to keep as budget friendly as possible. Just dropping the transmission off at a transmission shop will cost more than I intend to put into this car right now.

 

[Intragration]

I ideally would like to do as much of my own work on the car as possible, regardless of it being time consuming, not always the cheapest route, and an overall pain in the butt.

I completely "get" this, but the reason I would suggest not doing the transmission yourself has nothing to do with it being time-consuming, expensive, or a pain in the butt. Yes, it would be all these things, but it is also something that requires specialized knowledge, the ability to recognize small variances in internal transmission details through experience, and highly-specialized tools to some extent. If you were talking about rebuilding the suspension, or doing brakes, or replacing an intake, yeah, those things all meet your three criteria and I'd agree that it's something you might try tinkering with on your own. A transmission is a different animal.

This was when I had mistaken the dipsticks, so it was the ATF that looked milky.

I mean absolutely no disrespect, but this is an indicator that maybe you should hold off on doing the transmission. You made a mistake here. It's a big mistake. Not earth-shattering in this case, and we all have to learn somehow. Sounds like there's been a transmission problem since well before you bought it, so it's not like you caused this. I'm just pointing out that the difference between the trans and oil dipsticks is pretty basic, and there are a ton of much more sublime things going on inside a transmission, and watching a video on Youtube about rebuilding a transmission isn't going to teach you these things. Again, with brakes, sure, dig in. The worst thing that's going to happen if you pay attention to the video and do things generally right is that the parts aren't going to go together right, and you'll figure it out and put them together the right way and they'll fit, or the brakes are going to squeak when you're done. A transmission? That's an awful lot of work and money in parts to pull it, tear it apart, put it back together, put it back in, and discover that it's still not working right, and you have no idea why.

To reiterate, I mean zero disrespect to you and your abilities or initiative. I think it's great, and I generally think you're going to do fine with the car. I have decades of experience working on these cars, and my advice is to take a transmission to a pro. Maybe I've been wasting my money all these years doing this, maybe I could have been doing it myself all along. But I've also had such good experience doing it this way with transmissions that my healthy respect for their complications remains. I believe that unless the case is cracked, your transmission is salvageable. But one of my concerns is that if you tear it apart and put it back together, that you may damage parts that could otherwise be reused, and end up costing yourself more money and more headaches in the long run. It's your car though, do what you feel is best. Maybe someday you'll be rebuilding my transmission.

Check out the attachment to see the differences between 700-R4 and 200-4R pans.

 

[Intragration]

Maybe I should be a bit more specific about the fact that this car is in no way shape or form intended to be a reliable daily driven car. I would like this to be a car that I learn to restore on my own, regardless of time or difficulty. I don't expect it to ever be perfect, but I also have no intention of throwing thousands of dollars at the car for labor at any point.

Ok, I get it now. I guess I'd agree then that, if you're just looking to tinker, and maybe have it work and maybe have it not work, then you might as well try doing it yourself. My only thought is that doing brakes is like changing a roll of toilet paper, and rebuilding a transmission is like taking a fine pocket watch apart and putting it back together. As long as your expectations aren't very high, you'll get some good experience out of it and probably be no worse off. The time and money invested will be an investment in experience though, rather than an investment towards a reliable or maybe even functional transmission.