matefis

Hello,

I just bought a 1970 Olds Cutlass supreme with rocket 350 and TH350. Car seems to be in overall good condition although I noticed that the transmission is getting quite hot. I live in Florida and it's hot outside (95+), but still... after a short ride (<30 min) the central console get so hot I can barely keep my hand on it. No warning light though, but i guess it might be disconnected (control light lights up in check mode). The trans fluid seems to be in good condition (reservoir is full and color is red not brown or black). There is small leak of trans fluid, just about where the cooling line is connected to the trans and around the pan seal, but it leaks just a few drops when engine started. The AC does not work as and the blower/heater is completely dead too.

I have flushed the radiator m already (lot of rusty water came out). I also replaced the thermostat (Mr. Gasket high performance 180deg) as well as the rad cap (16lbs).

Could somebody advice if it will get better with the outside temp drop or should I take it to the pro? Just to let you know I would like to do as much possible on the car on my own. I already ordered all the literature and am looking into getting my hands dirty.

Thanks in advance for any recommendation and guidance.

Best

Matt

matefis

Hello,

I just bought a 1970 Olds Cutlass supreme with rocket 350 and TH350. Car seems to be in overall good condition although I noticed that the transmission is getting quite hot. I live in Florida and it's hot outside (95+), but still... after a short ride (<30 min) the central console get so hot I can barely keep my hand on it. No warning light though, but i guess it might be disconnected (control light lights up in check mode). The trans fluid seems to be in good condition (reservoir is full and color is red not brown or black). There is small leak of trans fluid, just about where the cooling line is connected to the trans and around the pan seal, but it leaks just a few drops when engine started. The AC does not work as and the blower/heater is completely dead too.

I have flushed the radiator m already (lot of rusty water came out). I also replaced the thermostat (Mr. Gasket high performance 180deg) as well as the rad cap (16lbs).

Could somebody advice if it will get better with the outside temp drop or should I take it to the pro? Just to let you know I would like to do as much possible on the car on my own. I already ordered all the literature and am looking into getting my hands dirty.

Thanks in advance for any recommendation and guidance.

Best

Matt

Fun71

Welcome to the Oldsmobile club!

I'm trying to decipher what your issue is. You think the transmission is getting too hot because the console is hot to the touch, and you are trying to get the engine to run cooler by flushing the radiator. These things don't appear to be directly connected to each other.

The console getting hot could be due to the exhaust pipe running too close to the floorboard in that area, or the heater could be diverting hot air to the floor vents, which are right above the forward edge of the console. When there is no vacuum to the HVAC system, the vents default to the floor position. Even if the blower doesn't work, hot air will "leak" out if the heater box door is open.

My suggestion would be to install a real temperature gauge to be able to monitor the actual coolant temperature. A three gauge setup is good, as it has water temp, oil pressure, and voltage. All of these are very helpful in monitoring the engine and trouble shooting issues.

1970cs

Agreed real temps with gauges or maybe an infrared temp on trans also driving conditions i.e. in traffic or highway. I have the same year car and model. When I am at the Woodward DC I usually grab the base of the shifter or chrome part to gauge how hot things are getting so I know when to get in a place where I can get air moving through the radiator.

Pat

matefis

Thank you for your reply. Yes, you deciphered it well. I am sorry if confusing. The exhausts are routed well below the flooring in fact it's routed real low, right below the transmission. I am not sure the HVAC can cause temperatures like I am experiencing. Once I even had bit of smoke coming out of the arm rest.... when I reach in and touch the bare metal it's smoking hot. That's why I thougth it's the transmission temperature issue, while this metal part is right above the tranny. I can share pictures. I'll certainly start working on the 3 temp gauge an I guess that HVAC is going to be my next step.

matefis

SWEET! any suggestion, recomendation, tricks or tips? I am real newbie making his dream happend. The driving conditions weren't optimal, that's true. It's real hot down here and took me some time to get out of semi congested main streets before I reached open road without traffic lights.

olds 307 and 403

If your transmission is getting hot, plumb an inline large stacked plate trans cooler. I bypassed the one in the radiator all together. I had that Mr Gasket thermostat start closing at high speeds, not good.

matefis

BTW... where do you get parts for your Cutlass? So far I discovered OPGI.com carid.com, found some parts on ebay and amazon as well. Any other sites you recommend?

oldcutlass

First I would get a mechanical gauge and hook it up temporarily or permanent, your choice. This way your not speculating on what temp your actually running. secondly get under the car and see if there are any holes letting heat into the cabin under the shifter. If the fluid is a nice pretty red color I doubt you have a trans issue. If you want to test your idiot light, simply unplug the wire from the temp sensor and with the key on, ground the end and the light should come on. This will tell you if the wiring is good. Its hard to test the sender as it will come on at around 240ish*

matefis

Thanks. I'll look for holes. The mechanical temp gauge seems like a must and it's going to be my next step. Yes, the tranny fluid is nice and bright red.

Koda

If I were to guess, I would say your cooling circuit on the transmission is not working or isn't there. Do you have two hard, brake line looking, tubes going into the back side of the radiator below the cap, one high, one low?

Koda

Here's my reply on your other thread. Please make ONE thread per issue.

" If I were to guess, I would say your cooling circuit on the transmission is not working or isn't there. Do you have two hard, brake line looking, tubes going into the back side of the radiator below the cap, one high, one low? "

Also, your temp gauge measures engine coolant temperature. It does not measure ATF temp. If your cooling circuit is not working right, the engine temp will not matter to the transmission. Next time you stop, lie down, and
carefully see how hot the transmission pan is. It should be warm, or maybe hot, but not boil water hot. Don't burn yourself.

matefis

yes, I do. They even seems to be properly connected (as far I can see) and not leaking. My second guess was that they might be clogged as the raditor was full of corrosion thus doing deep flush right now as the quick rinse seems not helping.

matefis

sorry for the double post, but so far different people were replying and to be honest I do appreciate any input.
Tomorrow I wIll check the tranny pan temp, that's good diagnostic procedure prior to temp gauge install. Any experience with cleaning the tranny cooling circuit? Is it hard to reach the tubes back where they connect to transmission? I am about to take it apart if the deep radiator cleanse won't work. Is there anything else other than these two tubes to be cleaned?

1970cs

I get most of it from Fusick, they show up at the nationals and Homecoming in Lansing. I tell them to bring the item so no shipping costs!

Another suggestion that the other guys are talking about is feel the trans lines at the radiator. Try a quick touch to both so if things are as hot as claimed so you don't roast your hand. If things are flowing one should be hotter than the other.

Pat

oldcutlass

I merged your 2 threads, no need for multiples about the same question.

matefis

thanks

matefis

So I had it lifted this morning at local AAMCO. And here is the result:
1. Transmission cooler lines are bad- someone cut it in half and replaced the rear portion of it with rubber tubing and fixed it in place with cable straps.
2. Tranny servo leaks and needs to be replaced
3. Rear seal is no good as well and seems to be leaking- due for replacement
4. From what I undestand the rear transmission mount is missing and the tranny lays directly on the transmission cross member.

They are asking $350 to fix all above mentioned. They do not know if it will fix the overheating though.

So my questions to you guys:
Should I pay them $350 and see what happens?
or
Should I look for another shop?
or
Should I have it overhauled? If so, how much am I looking at?
or
Should I start looing for new/overhauled one?

I know these TH350 are not expensive and there should be tons of them, what concerns me is the labor cost. Anyone here with TH350 swap experience?

Thanks!

Fun71

None of that would result in the transmission being too hot.

No need to rebuild/replace the transmission unless it is not shifting correctly.

Cut metal lines spliced back together with a section of rubber hose is acceptable, assuming the hose is power steering hose and not fuel hose (which is not resistant to trans fluid). Hose clamps should be used to secure the rubber hose.

Trans mount replacement is fairly easy. You can buy the mount at your local auto parts store.
AutoZone has one for $8:
https://www.autozone.com/drivetrain/...3544_0_0_91675

The rear seal is similarly inexpensive and fairly easy to replace.
https://www.autozone.com/drivetrain/...71359_0_203236

Your call on if you want to spend money for someone else to work on your car.

matefis

IMHO it shifts great, up down even kick down done ease with no excessive noises, vibrations, shruds or sudden pulls.

I'll look closer into fixing it myself. I know the parts are not expensive. I'll wait for the literature I ordered will, lift it up at home (I have ramps, no arm lift or pit) hope it will be enough and start working on it. When thunking about I'll most probably replace the cooling lines comptely, just for my piece of mind.

How about the servo? Any advice on that?

matefis

So about 20 min after I came back from the shop today I checked the pan temp. It's not boiling hot. I was able to keep my fingers on it for several seconds without burning my skin. To compare the block of the engine was hotter.

oldcutlass

I use hydraulic hose from the trans to the radiator cooler. I would not worry about the rubber patch. I doubt from your previous descriptions there is anything wrong with your transmission. You can buy new cooler lines from inlinetube.com. Like was said the trans mount and seal can be bought at your local auto parts store and are inexpensive. Stay away from Aamco unless the local old car enthusiasts use them.

matefis

Yeah, I wish there is no problem with tranny except the two inexpensive part. But the heat really concerns me. As already said once there was smoke coming out of the central console and that was the moment I decided I want to know why. I do plan to fix as much as I can. AAMCO was cheap wsy how to have it lifted and inspected. Whe I got the estimate the fix wasn't really option, whilr brand new TH350 comes for about 1K.

matt69olds

matefis

Matt, actually you are amazingly right. Here is the full update after todays troubleshooting and getting to know each other:

The heat I was worried about is getting into the central console around the floor shifter, which is actually not connected at the moment (gear shifts via the column shifter). The grommet is not going to be an issue as there is a hole where three fingers fit. The smoke as Matt mentioned have most probably been the tranny fluid dripping on the hot exhaust from leaking servo or cooling lines and getting into cabin through the hole around the shifter.

So now I'll wait for my literature and start sealing the hole. Not sure yet if I'll keep the console (floor) shifter or stearing column one. Depends on how hard it's going to be to seal the damn hole in the floor. Next will be the leaking servo and leaking tranny cooling lines as well as the rear seal and the mount. BTW: today I discovered a tiny hole in the A/C radiator, so that one will go out too to prevent the cooling fluid from leaking. A/C fix (replacement for modern system) later on. Also I have found gauges with temp meter, volt meter and oil pressure I like and which goes as replacement directly into the cluster instrument but 500 + 100 for wiring is a lot of money for two gauges.

olds 307 and 403

All easy to fix. Just remove the drive shaft, carefully jack up the trans on the pan and bolt a new mount on. I believe the TH350 servo is held on with a snap ring, been a while. I would remove the rear housing, 4 bolts and unscrew the speedo cable. The housing O ring can be reused, I coat it in RTV. You can buy and seal and rear bushing combo or all the seals in the rear housing including the speedo. https://www.ebay.com/itm/TH350-Rear-....c100930.m5375 or https://www.google.ca/search?q=th350...24&bih=600#The bushing is probably worn out and a new seal will leak if it is not replaced. A punch can drive the out bushing out and the new one in. Like I said, you can bypass the cooler in the radiator, in Florida you will never run too cool. Mine is fine in Saskatchewan, Canada. I did just to help the recored 2 core factory radiator, has only got up to 195 here in traffic. Mine was full of scale so I used CLR, I would use a couple of jugs to clean it out. I
have 3 mechanical gauges under the dash, volts, oil pressure, temperature and both idiot lights functional for heat and oil pressure.

matefis

i do not want to bypass it. The main radiator is clogged, rusty and dirty but seems to be working and not lesking. The one that's leaking for sure is the A/C radiator (the one in front) and as long as the A/C and HVAC system is completly bust I guess it won't be missed. I am in process of deep clean of the main radiator..... if unsucessful I do plan to replace it with OEM part (about $200 from autozone), no additional cooler etc. Except the A/C I would like to keep it as "original/factory" look like as possible.

Fun71

I have a gauge trio like this under the dash:

matefis

yeah came across those too, but honestly this is not the way I want to go... at least not now.

oldcutlass

Bosch acquired Sunpro, and those are the same as in my car and work great. Never been fond of the idiot lights.

matefis

This is the gauge I am looking at: https://www.opgi.com/cutlass/C240607/
If anyone knows where to get them for "normal" price I am all ears.

Fun71

There have been lots of posts about those gauges not being much better than the idiot lights.
You can do an under dash gauge trio similar to what's posted above and just remove it if/when you decide to get the repro Rallye Pack. For $40 I would do it to be able to monitor my engine.

matefis

I'll see, if I get them for acceptable price I'll install them if not I'll get those from Bosch and will continue in browsing fro those I like.

matefis

On bit another note. After the diagnosis of what's wrong with my tranny, I am looking for the parts (cooling line, servo, rear seal) all found for good price except the servo. Can someone recommend shop with TH350 (<1972) parts which is selling this servo? I wont mind refurbished or used.

Thanks

matt69olds

Fun71

Is it the servo cover that is leaking? If so, I think that is just an o-ring.

matefis

Thank you!

matefis

Just if someone interested in parts: https://www.transpartsonline.com/TRA...sPartsType=350

matt69olds