TH350C been sitting a few years

[scenic760]

Hey All!

I bought an 81 Suburban that had been sitting for 5 or so years and my made for TV hopes of putting in some new fluids, starting it up and running it for a while to see what breaks and replace it didn't go as planned.

I ended up pulling the engine that was stuck, banging on it with two sledge hammers to get it moving and then realizing I was simply trying to polish a turd when I had to hammer out several lifters that were stuck. I'm having a new 4 bolt put together at a local machine shop and going to install it soon.

The questions I have on the trans, I pulled the dipstick and the fluid looks bright red (it looks overfilled but I'm assuming after sitting so many years gravity got the best of the fluid too and it's all in the pan?). Should/can I hookup the new engine and run it to see what I am dealing with and are there any precautions I should take before I fire it up?

Or should I just take it out now (while the engine is out) and rebuild? I'd probably rebuild the trans myself.

 

[Bextreme04]

Hey All!

I bought an 81 Suburban that had been sitting for 5 or so years and my made for TV hopes of putting in some new fluids, starting it up and running it for a while to see what breaks and replace it didn't go as planned.

I ended up pulling the engine that was stuck, banging on it with two sledge hammers to get it moving and then realizing I was simply trying to polish a turd when I had to hammer out several lifters that were stuck. I'm having a new 4 bolt put together at a local machine shop and going to install it soon.

The questions I have on the trans, I pulled the dipstick and the fluid looks bright red (it looks overfilled but I'm assuming after sitting so many years gravity got the best of the fluid too and it's all in the pan?). Should/can I hookup the new engine and run it to see what I am dealing with and are there any precautions I should take before I fire it up?

Or should I just take it out now (while the engine is out) and rebuild? I'd probably rebuild the trans myself.

I'd pull the pan, drain all the fluid and clean it out, then put a new filter and gasket on it before filling it up and sending it. Cheap insurance and easy to do while you have the motor out.

 

[Matt69olds]

^

What he said. As long as the fluid is red (or even a little reddish-brown) your probably ok. Trans fluid states to look like a strawberry milkshake once water gets in it. As long as you don’t have any milkshakes in the pan your probably ok.

Pull off the converter while he engine is out, turn it upside down to drain a few days. Might as well get as much of the old nasty fluid out while you can. Change the filter and refill. If it was good when it was parked chances are it’s hood now.

 

[scenic760]

Sweet, thanks for the replies...send it, love it!

 

[idahovette]

Maybe put a new seal in it before you re-install the converter?...and be gentle on the converter install!!!......3 clicks?

 

[scenic760]

Maybe put a new seal in it before you re-install the converter?...and be gentle on the converter install!!!......3 clicks?

The last project I worked on was an '83 K5 about 25 years ago so I'm probably a little rustier than the rat urine soaked timing chain I pulled off this one.. I did a couple of web searches but if remember correctly the torque converter should just slide off? On the reinstall it kinda like screwing on a big nut and the 3 clicks you mention and then it just spins?

 

[Matt69olds]

Lay a straightedge across the bellhousing. Measure from the straightedge to the converter mounting flange. It should measure about 1 1/8 inch. If it’s less than that, the converter isn’t seated in the pump.

Once the bellhousing is up the engine block (before tightening the bellhousing bolts!!) try to spin the converter. the converter is locked in place, the converter isn’t seated. With all the bellhousing bolts tight, the converter should spin. It might hit the balance weights on the flywheel (preventing it from spinning completely around) but the converter should spin freely. If not, find out why. If you start the engine with the converter not seated in the pump, you will be doing it again after buying a new pump.

 

[Raider L]

@Matt69olds,

Matt, aren't you the trans rebuilder? I remember you were the one who helped me when I was having all those trans problems. And, I've seen this before, and yeah I could look it up on the internet, but I'd rather ask someone who works with the stuff, I'm old school like that, What is a TH350"C"? What kind of TH350 is that?

 

[Poppy 87]

@Matt69olds,

Matt, aren't you the trans rebuilder? I remember you were the one who helped me when I was having all those trans problems. And, I've seen this before, and yeah I could look it up on the internet, but I'd rather ask someone who works with the stuff, I'm old school like that, What is a TH350"C"? What kind of TH350 is that?

The "C" indicates clutch, as in lock up torque converter (TCC)

 

[78C10BigTen]

The "C" indicates clutch, as in lock up torque converter (TCC)

You just learned me...thanks

 

[Poppy 87]

To the OP, unless you know it was drive able prior to purchase, and you are capable of rebuilding this transmission, I would rebuild it now while the engine is out of truck. You then know things are all good.

 

[Matt69olds]

The th350 and 350C are basically the same, with the exception of the case, pump, valve body and forward clutch. Everything else s pretty much identical.

I’m not a professional rebuilder, but I have been working with most RWD Ford, mopar, and GM transmissions for about 20 years. I do build a lot of racing transmissions for friends, those twin turbo LS engines make a easy 1500hp. Seems like someone is always tearing something up!!

 

[Raider L]

@Matt69olds,

I just have a regular TH350 in mine with a TCI 2,000 stall converter in it. I know the regular 350 can handle a lot of horse power and torque, probably for a little while at least. All I want to do to mine is find someone who is competent. I called five or six trans shops and most of them didn't act like they wanted to fool with it. They were saying things like, "They're soooo old." and "Can you get parts for those things anymore?", and "Well I don't knoooow. It'll be $1500 that is if I can get parts for it."

It's like, the TH350 is the most widely rebuilt transmission in the history of transmissions. Except maybe the 400. But a close second is the 700R4, or like they call them these days 4L60E. Which I think is a R4 but is electronically controlled. Oh yeah, and a Ford C4. So what are they saying to me Matt? They don't want to fool with it?

 

[Raider L]

@Matt69olds,

Or am I to far behind the times. I buy performance magazines all the time and that's all I see are shops telling you how to build a 350, or places who want to sell a 350, or who will build your 350 for you. So where's all this "we don't do those anymore." is the other thing I got from some of those shops I called. Are they crazy? I think between where I'm at and Houston Texas are about 50 million pickup trucks! And most of them are Chevy's with 350's in them.

 

[78C10BigTen]

@Matt69olds,

I just have a regular TH350 in mine with a TCI 2,000 stall converter in it. I know the regular 350 can handle a lot of horse power and torque, probably for a little while at least. All I want to do to mine is find someone who is competent. I called five or six trans shops and most of them didn't act like they wanted to fool with it. They were saying things like, "They're soooo old." and "Can you get parts for those things anymore?", and "Well I don't knoooow. It'll be $1500 that is if I can get parts for it."

It's like, the TH350 is the most widely rebuilt transmission in the history of transmissions. Except maybe the 400. But a close second is the 700R4, or like they call them these days 4L60E. Which I think is a R4 but is electronically controlled. Oh yeah, and a Ford C4. So what are they saying to me Matt? They don't want to fool with it?

The local trans shop ( bout 10 miles away) quoted me $900 for a 2wd th350 rebuild about 2 years ago.... i opted for a junkyard th350 swap.