Going to be changing trans fluid and filter here soon. While the pan is off and I’m under there. Is there a trans seal kit I can purchase? Or do I buy them separately? If purchased separately, which ones can I do with trans in car on jack stands? I know most if not all of them leak. So I’m thinking shift shaft seal? Dip stick seal? And of course pan gasket. Anything else for the TH400 I should pick up for when I’m down there? Really don’t want to think I’m done. Then find out there was something else I could’ve replaced while under the car. Gravel driveways and my back and knees aren’t friends. Who would you recommend for purchasing these parts from? 1970 Electra 225 Thank you, Paul
If you want to replace all the trans seals you need to pull the trans to get at them all (in particular the ones on the front pump). But I get what you are saying, what can I fix without pulling the trans. The dip stick tube is likely sealed with an o-ring though there may be a cup style seal instead. The seal for the shifter (manual shaft seal) can be changed without pulling the trans but you will need to do a bit of disassembly before you can get it out. Not impossible but I wouldn't attempt it if you are not confident in your wrenching skills and do not have a reference on how to put it back together (there are some small parts that can get lost). Pan gasket is straight forward. Tip there is don't over-tighten the bolts, torque them to the required value. There are a few other seals that can be replaced but if they are not leaking I would just leave them alone. Most auto part suppliers will have the pan gasket. You may need to go to a dedicated transmission supplier for the others. Just search the web, plenty of them out there.
I wouldn't fix something that isn't broken. If it is leaking somewhere, figure out the leak source. Then you can tell whether the transmission needs to come out or not to fix the leak.
There’s a lot of fluid and dirt buildup on engine and trans, not certain what kind yet for some of it. Though I do have my suspicions. while under the car, noticed the valve covers have been leaking for some time. Crud build up near back of exhaust manifolds. And can see it’s coming from valve covers. Such a simple and cheap fix. Don’t know why people let those things go thinking it’s okay to let it persist. I can see red fluid drops hanging from here and there on the trans as well. Found the speedometer cable to be quite lose. Saw a couple of TH400 vids where the shift shaft seal was replaced. Looked pretty straight forward. I still haven’t driven the car at all yet. I have a 70 mile round trip to make to get the rotted exhaust system replaced. Just want everything as secure as possible before taking it out on its maiden voyage to get that done. Found 1/2” of sludge at the bottom of the master cylinder in both wells. Wrong gasket used for cap. So that’s allowed moisture into the brake system. A simple and cheap part like that and the wrong style of gasket was deemed okay. Found Walmart sticker and receipt for oil change in 2017. Using customer’s oil and filter. Thinking not much was done to her by previous owner since he got it. So, made laundry list of things to inspect, clean and or replace before taking her out. Carb rebuild kit Valve cover gaskets Brakes and bearings Another coolant flush with some type of rad and coolant passage cleaner I can use with water after last freeze has passed for Spring. Brake line flush Trans filter & fluid change Differential fluid and gasket change Pressure wash engine, diff and trans to get better idea as to where and if other areas might be leaking. Get rear coil springs back onto their perches. New shocks on all four corners. Just not taking anything for granted with this car. Spent too much money to buy it and waited a long time in life to save for it. I don’t want to do any damage to the car because I missed something that has gone on for too long without any preventative maintenance. Appreciate the responses to my questions. Paul
That comment there speaks volumes about the previous owner and explains some of the issues you found. You got a good list there, I'd throw in a tune-up if you haven't done one already. Another tip on the valve cover, make sure the sealing flange is flat. People over-torque them and knock them out of flat. Then they wont seal properly even with a new gasket.
