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TH350 Slippage

  
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TH350 Slippage

 
JDerek JDerek
New User | Posts: 21 | Joined: 12/11
Posted: 04/10/13
11:10 AM

I have dropped a very stout 350 into an '83 Malibu Wagon. Ended up not being able to use the Tranny that was behind this engine because it was toast so I have kept the TH350 that was behind the 305 that I replaced. My problem is the same as lots of people and that is money. This swap has taken me almost 2 years to get done because I am no longer able to do major jobs like this. What I want to know is, can I swap out the governor weights and the shift spring to take out most of the factory slippage? I don't want to have to go as far as a shift kit if I can get away with it. There again, money. As savings grow I plan on swapping to an overdrive, again junkyard or Craigslist but until then I need this tranny to survive. This isn't a strip car by any means. Just a good Driver. I've already got a new cooler and fresh fluids/filter in the car. Fighting heat build-up is my main concern hence wanting to remove as much slippage as possible. Any help is greatly appreciated!  

waynep712222 waynep712222
User | Posts: 103 | Joined: 03/13
Posted: 04/10/13
07:42 PM

you might want to play with the MODULATOR adjustment before you start messing with the governor weights..


the modulator controls the shift points..

the valve body and the drilled hose change the firmness of the shift points..

there are articles in some of the many magazines on this site on both governor adjustment.  and on modulator adjustments.

would you like to read some of them..

one thing that will greatly effect shift quality.. is the need to run a metal modulator tube with as little vacuum hose as possible...   factory modulator tubes are usually 1/4" tubing with the ends crimped down..  the one at the back of the intake usually slips directly into the fitting with a hose that seals from the fitting barb to the tubing barb... so there is no expansion and contraction at that end...   at the modulator end .. there is usually a MOLDED 90 degree elbow that comes with some modulators or from transmission parts suppliers...  its still enough to reduce any damping from expanding and contracting of the hose section.

an additional transmission oil cooler mounted out in front of the radiator is the best way to keep the transmission below the damage temps..  you can run the transmission fluid thru the factory cooler in the radiator then thru the aftermarket cooler..



if you decide on going to the 700R4.. then  you will need a carb throttle lever bracket to correct the hook up point for the overdrive transmissions throttle valve cable..  

redneckjoe69 redneckjoe69
Enthusiast | Posts: 388 | Joined: 04/10
Posted: 04/11/13
07:07 AM

is the th350 your using lock-up?   there would be connections for the computer on it.    if its non-computer controlled, my thoughts are its either low on fluid, the filter is clogged, wrong converter, or its on its way out.   the governer controls how fast it shifts to the next gear.   not really gonna fix a slipping tranny.   JMO.  

JDerek JDerek
New User | Posts: 21 | Joined: 12/11
Posted: 04/11/13
10:25 PM

Think we got our lines of commo crossed. I mean something else when I say factory "slippage". The trans I have is what came in the car and it shifted great behind the 305 but it has that same easy gear change that they all have from the factory. That's what I mean when I say slippage. It's not computer controlled at all. It's all mechanical. I haven't gotten the car back yet so I haven't driven it to see how soft the shifts are gonna be. I just know that I want to remove as much of that soft shift as I can without having to go into the trans. I know I can adjust some of the shift points by adjusting the modulator but that will only change when it shifts. I want to change how soft it shifts. The cooler is in front of the radiator and brand new. They used this tranny because the one behind the engine to begin with was toast. That whole two to make one thing.  

68scott385 68scott385
Enthusiast | Posts: 669 | Joined: 05/09
Posted: 04/12/13
07:27 AM

I believe what you want is a shift kit. B&M, TCI, and others sell various kits that will change your transmissions characteristics from soggy to anywhere between mild & very wild.  
68scott385 68scott385 68scott385

waynep712222 waynep712222
User | Posts: 103 | Joined: 03/13
Posted: 04/13/13
12:02 AM

i agree... if the transmission is out...


flip it over and put a shift kit in it...

its NOT that hard to accomplish..

firming up the shifts... so there is less slip between them ... that involves everything included in a shift kit...

there are multiple levels of shift firmness..

there are some TH350 shift kit instructions in PDF form floating around the web...

so you can review before you buy....

in factory shift feel... there is an issue of WHIPLASH Liability..    nobody wants a stocker to shift that hard..