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Th350 fresh rebuild start up

TJ1978

TJ1978

I have MANY questions
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I have one quart in the torque converter.
Ive read the TH350 with stock pan holds roughly 10–12 quarts.

So mine is a fresh rebuild, so totally dry other than the 1 quart in the TQ.

So my question is, how to or what procedure is best to fill’er back up to operating fluid level?

Put 4-5 quarts in then start it, warm up and keep adding until the truck is full?

Im thinking if I dump 8-9 quarts in right off the bat the tranny may puke some fluid out. Reason being, it may be too much fluid in the pan and nothing in the valve body or elsewhere.

So basically whats the best procedure to get a totally dry TH350 back to operating fluid level?

Thanks.
 
I know the refill drill as far as a filter change etc. but not sure on a totally dry th350.
 
So basically its the same process as a filter change, other than you’ll just be adding more fluid to fill the entire tranny and not just the pan?

Start with 4-5 quarts in the pan and add accordingly?
 
TJ1978 said:
So basically its the same process as a filter change, other than you’ll just be adding more fluid to fill the entire tranny and not just the pan?

Start with 4-5 quarts in the pan and add accordingly?
Click to expand...

Cooler line length and cooler size, pan size, a spin on filter or not, all are factors that might be specific to your vehicle.
I fill the converter with a quart.
Fill the pan with 4 quarts. Start it and check it. I'll get it to full on the stick then start shifting it with the wheels off the ground. Fill a quart. Check it, run through the gears, repeat until it's full and warm. It's a process. But worth it since I just paid for a new trans.
 
Ah, so I possibly need to get two more jack stands then... I usually just add and move back and forth in the garage/ driveway going through all the gears.
 
TJ1978 said:
Ah, so I possibly need to get two more jack stands then... I usually just add and move back and forth in the garage/ driveway going through all the gears.
Click to expand...
I'm sure that's fine. I don't think that matters much. I just do it that way without load.
 
One transmission mechanic I knew used to rebuild them at his own garage ,after his habit of drinking at lunch got him fired from the Ammaco place he worked at over 15 years..despite his demons,he had a good reputation for being one of the best guys to have fix your automatics..

I met him thru a friend that needed a TH400 rebuilt and he was told to go see him "if you want a good one"...best part back then in the 80's he'd only charge $150-$300 bucks plus the cost of the rebuild kit if you took it to him ..he didn't R&R them himself,he had no lift at his garage.and was getting too old to do that often..he used to keep a few common ones on the shelf all built and ready to go if you preferred too..

He told his customers after getting the transmission all bolted up,to add 4 quarts and start the engine and shut it back off after 20 or 30 seconds--then jack the rear wheels off the ground and start it back up and add more fluid till it read just below full,and put it in first gear and let the tires spin free,for a minute or two,then shift to second,for another minute,then shift to drive,and run it a few minutes --then put it in park,and make sure the fluid level was still correct..

He said letting it "work in" this way helped the clutches to seat better,not having resistance,or possibly slipping due to air trapped in the valve body and cooler lines..
I don't know if this was just his quirk or if it really did much,but he did say he wouldn't warranty one that hadn't been put thru that procedure as he described--otherwise he'd stand behind them for a year,for normal street driven vehicles..

He built a lot of muscle car transmissions that were behind big blocks for the local oval track racers and they had very good luck with them..

Most other mechanics I know just dump in 4 qts and keep adding till its full and dont bother going thru that procedure,and they dont seem to have any issues ...:dunno:
 
Ok, gentlemen fired it up and we’re good to go. After sitting damn near 3 months start up was really good and quick.

I do have a nice leak at the tranny from the bottom cooler line. Flare may not be butted up properly or something.

But Ive havent road tested on account of that leak. But, all gears engage and the truck moves at least 10ft either way.

Once I fix that leak Im sure something else will pop up..

Thanks everyone.
 
TJ1978 said:
Ok, gentlemen fired it up and we’re good to go. After sitting damn near 3 months start up was really good and quick.

I do have a nice leak at the tranny from the bottom cooler line. Flare may not be butted up properly or something.

But Ive havent road tested on account of that leak. But, all gears engage and the truck moves at least 10ft either way.

Once I fix that leak Im sure something else will pop up..

Thanks everyone.
Click to expand...
By the way I found this.
I have 2 shields and plenty crossmembers

20200321_152420.jpg
 
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