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TH350 what mods make it live?

sreidmx

sreidmx

Fortify Offroad
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Hi Guys,

I am swapping to a 2wd th350, the unit I am getting is recently rebuild (stock) and has low miles behind a stock 2wd k5 that wasnt ever beat on, so I know its "fresh" I know the guy and I trust him.
I ordered my converter 2200-2400 stall to match my possible cam choice.

I was eyeballing the transgo 350-1-2 or the -3 reprogramming kit.
I read some stuff about sprags?? No bueno on the stock one for engine braking?
I got a decent cooler, (stacked plate, 11x8x2.5) not using the radiator either.

This has a slip yoke and a 9 inch tail housing.
If possible id like to stay out of the inside.. I can get a th400 but hadn't planned on that for a while..
 
The TH350 trans is a fairly robust unit, and should last as long as you don't put too crazy a motor in front of it in stock form.As you probably know heat is the no. 1 killer of an automatic transmission . I would also get a temp guage and tap in to your cooler line for it.You would also get more cooling for it by using the factory cooler in line with your new cooler, in my opinion.Some people mount little electric fans on their trans coolers for even more cooling.The TRANS-GO shift kit sounds like a good upgrade.
 
No problem. I have a TH350C in a C-10 that I plan on totally rebuilding.I am no expert, and this will be my first total rebuild.So, wish me luck!
 
A lot of racers like 350's cause they are lighter. And , if I am not mistaken th350's have lower gears than a th400. Though the TH400 is designed to handle a lot more power.
 
I live in the Dezert where it's always hot.. I've found that to be detrimental.. Do I really need to hook that up?
 
I'm not a trans expert but I do have a 350 and this is what my trans guy did during the rebuild. Replaced governor gear, vacuum modulator, all new soft parts. My trans already had a shift kit in it but he drilled out a sock plate because he said the aftermarket ones are junk. I believe him due to how bent the aftermarket plate was.
 
A TH350 "C" has a lock up torque converter,that is not interchangeable with a non-lockup one (as far as I know),so be sure to get the right one if you change to a higher stall speed..

Raising the stall speed increases heat,so I agree a good trans cooler is a must..more than anything,frequent fluid & filter changes help any transmission last longer too...shift kits help prolong clutch life by letting less slippage occour during shifts,but one thats too harsh shifting can wound things too...

I've had several Th350's behind a lot of different engines,ranging from 250 straight sixes,to 454's,and only one that died was the one behind a 400 small block in my '77 GMC K2500,which had a 454 when I first got it,and was likely whipped hard and put away wet..
I plowed a lot of storms with that truck,before reverse finally just "dissapeared" one day..
 
My TH350 is pretty much a full race trans



:haha::haha::haha:

I put some newer torrington bearings from a 700. Other than a transgo no yo yo kit. Mine is as basic as it gets

BTW TH 350s do not respond well to neutral drops. Don't do it
 
76zimmer said:
At least get this book..,
http://www.themotorbookstore.com/tu...ra-matic-350&gclid=CL-02IXxsMsCFZUjgQodO_kJ_Q

Also use your factory radiator cooler first then to the auxiliary cooler. This gets the fluid up to temp and helps eliminate condensation in the fluid.
Click to expand...
YEP,this is the book I got, although it is a little dated, very informative and it is what I will use for the rebuild of my th350c-which I plan on converting to regular 350 by getting rid of the auxiliary valvebody /lock up convertor, and replacing with regular th350 parts.
 
blazinzuk said:
My TH350 is pretty much a full race trans



:haha::haha::haha:

I put some newer torrington bearings from a 700. Other than a transgo no yo yo kit. Mine is as basic as it gets

BTW TH 350s do not respond well to neutral drops. Don't do it
Click to expand...
My friend has one in a nova. He has put every racing part known to man in it , and has held up for five years behind a procharged SBC.
 
From the outside there isn't much you can do in terms of durability beyond simple valve body and governor mods to change shift points and shift quality. There is a lot you can do internally to build these to take a good bit of abuse, only limited by your pocketbook. If you have over 450HP and need more durability, the economics of switching to a TH400 become very practical.
 
sreidmx said:
I live in the Dezert where it's always hot.. I've found that to be detrimental.. Do I really need to hook that up?
Click to expand...
sreidmx said:
I live in the Dezert where it's always hot.. I've found that to be detrimental.. Do I really need to hook that up?
Click to expand...
I would get the biggest cooler I could find with an electric fan , and hook it up in line with the cooler in the radiator like Zimmer said.You can actually over cool one, I have heard, in the winter , but I doubt you will have a problem with over cooling where you live.
 
/\ agreed generally it is important in cooler climates as the trans sometimes don't get hot enough to flash off condensation. If you don't make repeated short trips and don't have cooler temps you should be ok with just an auxiliary unit of decent size.
Now about that PS cooler.....:)
 
I have a cooler right now that is a decent size(11x8x1.5 stacked plate), but adding a temp gauge to monitor the output just in case it isn't enough. For what I am using this for it should be simple task if I am nice. My motor might make 300hp if I am lucky.. that would be generous. The last motor I build like this was 238hp at the wheels so whatever drivetrain loss it.. 20% or more.. do the math.

My trans guy and I are going to pull it apart to inspect it, put a soft kit in it so all the seals are good, replace the sprag just in case. If needed Ill put new stock clutches in it also. we may do the int clutch feed mods by removing the center sealing washer on the center support.(I think thats what its called) he knows what I was talking about. I've only been in a few of these so having someone knowledgeable is nice.
Plus Ill know 100% that is kosher to run and not worry if Ill make it down the street or not.

http://www.amazon.com/Tru-Cool-LPD4739-4739-Pressure-Transmission/dp/B00803CTDA

I might run this.

This is the cooler that my wifes 700 is using, in the winter I have to block some of the radiator, we live off the highway so it always sees at least 15-20 mins minimum for use uphill or down. The gauge never goes beyond 200 in the blazing heat towing.. 120 degree day in the hills.
 
Stack coolers are great and that one should be fine
I run a similar one on the Maiden and my trans has been fine as far Astros!
My 99-2500 w 6.0/4L80 has the factory cooler that is about 1/3 that size and towing 10,000+ lbs to Moab it got up yo 200 a couple times otherwise was generally about 175
Also to avoid debate mount the ports on the side or top.....although GM mounts all of theirs with ports down!
 
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