TH350 rebuild tech

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m (moved TH350 transmission rebuild tech to T-350 transmission rebuild tech: I prefer it this way, some formats still F'd up, thnks)
(More clean up, more formatting images and etc.)
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==Rebuilding the T-350==
 
==Rebuilding the T-350==
 
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[[File:TH 350 backXL diagram.jpg|thumb|400px|left|Exploded view of the TH350 transmission.]]<br style="clear:both"/>
 
===Basic rebuild information===
 
===Basic rebuild information===
 
'''NOTE:'''
 
'''NOTE:'''
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*Middle port (red) is 2nd gear pressure.
 
*Middle port (red) is 2nd gear pressure.
 
*Front port (blue) is third gear pressure.
 
*Front port (blue) is third gear pressure.
[[file:T-350_acumilator02.jpg|frame|none|Pressure ports circled]]
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[[file:T-350_acumilator02.jpg|frame|none|Pressure ports circled.]]
  
 
===Low-reverse piston install===
 
===Low-reverse piston install===
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Then push it into the rear of the case evenly by hand, aligning it properly so it will seat (there is a "tang"). Look at the park pawl notch to help index it.
 
Then push it into the rear of the case evenly by hand, aligning it properly so it will seat (there is a "tang"). Look at the park pawl notch to help index it.
[[file:TH350caselowpiston.jpg|frame|none|Low-reverse piston installed into case]]
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[[file:TH350caselowpiston.jpg|frame|none|Low-reverse piston installed into case.]]
  
  
 
Then install the return spring and retainer using the tool pictured.
 
Then install the return spring and retainer using the tool pictured.
[[file:TH350lowspringtool.jpg|frame|none| Tool used to compress the springs & retainer to install the retaining snap ring ]]
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[[file:TH350lowspringtool.jpg|frame|none| Tool used to compress the springs & retainer to install the retaining snap ring.]]
  
 
[[file:TH350caselowtool.jpg|frame|none|Spring compression tool installed into case.]]
 
[[file:TH350caselowtool.jpg|frame|none|Spring compression tool installed into case.]]
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Be sure you have the output ring gear to case bearing in the case.
 
Be sure you have the output ring gear to case bearing in the case.
 
Also be sure on dis-assembly you inspected and replaced as necessary the input shaft to output bushing shown here (circled in yellow).
 
Also be sure on dis-assembly you inspected and replaced as necessary the input shaft to output bushing shown here (circled in yellow).
[[file:TH350outputbushing.jpg|frame|none|check this bushing for wear, replace with new metal bushing or slip in plastic insert.]]
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[[file:TH350outputbushing.jpg|frame|none|Check this bushing for wear, replace with new metal bushing or slip in plastic insert.]]
  
 
==Rear planetary unit install==
 
==Rear planetary unit install==
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Once the low clutches are installed, you can install the anti-clunk spring (or case-saver). Both are pictured, the case-saver is solid and spreads the load over a larger area. Hold in place with assembly gel or vaseline and then install the low support.
 
Once the low clutches are installed, you can install the anti-clunk spring (or case-saver). Both are pictured, the case-saver is solid and spreads the load over a larger area. Hold in place with assembly gel or vaseline and then install the low support.
 
Be sure the low sprag inner race is not brinelled or has any unusual wear.
 
Be sure the low sprag inner race is not brinelled or has any unusual wear.
[[file:TH350lowsupportcasesaver.jpg|frame|none|Photo shows OEM anti-rattle spring and a replacement piece known as a case saver used in cases with heavy wear in case lugs]]
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[[file:TH350lowsupportcasesaver.jpg|frame|none|Photo shows OEM anti-rattle spring and a replacement piece known as a case saver used in cases with heavy wear in case lugs.]]
  
  
 
Once it is pushed into place, install the snap ring, with the ends on each side of the spring or case-saver.
 
Once it is pushed into place, install the snap ring, with the ends on each side of the spring or case-saver.
 
Now is the time to air check the low clutches. You do so by applying pressurized air to the passage at the rear pan area of the worm casting in the case.  
 
Now is the time to air check the low clutches. You do so by applying pressurized air to the passage at the rear pan area of the worm casting in the case.  
[[file:T-350_anti-rattle_spring.jpg|frame|none|Anti rattle (clunk) spring shown in correct location, use assembly grease to hold in place]]
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[[file:T-350_anti-rattle_spring.jpg|frame|none|Anti rattle (clunk) spring shown in correct location, use assembly grease to hold in place.]]
  
[[file:T-350_center_support.jpg|frame|none|Center support, inner race, thrust washer shown]]
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[[file:T-350_center_support.jpg|frame|none|Center support, inner race, thrust washer shown.]]
  
 
Next you install the 4-tang thrust washer into the large splines of the low sprag inner race (picture above), and then the sun shell and gear assembly. Before this step, for HD use, you would have wanted to install additional sun gear bushings, 2 on each end, and re-drilled the lube holes.
 
Next you install the 4-tang thrust washer into the large splines of the low sprag inner race (picture above), and then the sun shell and gear assembly. Before this step, for HD use, you would have wanted to install additional sun gear bushings, 2 on each end, and re-drilled the lube holes.
 
Shown here.
 
Shown here.
[[file:TH350sungearbushings.jpg|frame|none|Double bushings installed. You MUST drill oil holes in bushings]]
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[[file:TH350sungearbushings.jpg|frame|none|Double bushings installed. You MUST drill oil holes in bushings.]]
  
  
 
==Install drive shell and front planetary unit==
 
==Install drive shell and front planetary unit==
 
Drop the sun shell/gear in, spinning in the output carrier until it falls in place.
 
Drop the sun shell/gear in, spinning in the output carrier until it falls in place.
[[file:TH350inputplanetthrust.jpg|frame|none|This shows drive shell installed with planet and thrust washer in place]]
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[[file:TH350inputplanetthrust.jpg|frame|none|This shows drive shell installed with planet and thrust washer in place.]]
  
  
 
Install the input planet next, pictured below with thrust washer installed.
 
Install the input planet next, pictured below with thrust washer installed.
[[file:T-350_front_planet.jpg|frame|none|front planet with thrust washer in place]]
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[[file:T-350_front_planet.jpg|frame|none|Front planet with thrust washer in place.]]
  
  
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Then install the 3-tang thrust washer onto the top ring gear.
 
Then install the 3-tang thrust washer onto the top ring gear.
[[file:3_tang_whr_t-350.jpg|frame|none|front ring gear with 3 tang thrust washer in place]]
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[[file:3_tang_whr_t-350.jpg|frame|none|Front ring gear with 3 tang thrust washer in place.]]
  
 
==Direct drum assembly==
 
==Direct drum assembly==
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The HD applications should also get a heat treated intermediate sprag race. It is darker colored than a stock piece. The intermediate sprag race and intermediate sprag (actually roller clutch) take a brutal amount of force on a 1-2 shift at high rpm. Even more so with harsher shift calibrations. It is the single weakest part of a T-350. This is not to say a T-350 is not tough; they are under-rated and can reliably handle in the 600 HP or lb/ft range based on my experience.
 
The HD applications should also get a heat treated intermediate sprag race. It is darker colored than a stock piece. The intermediate sprag race and intermediate sprag (actually roller clutch) take a brutal amount of force on a 1-2 shift at high rpm. Even more so with harsher shift calibrations. It is the single weakest part of a T-350. This is not to say a T-350 is not tough; they are under-rated and can reliably handle in the 600 HP or lb/ft range based on my experience.
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[[file:TH350intspragraces.jpg]]
 
[[file:TH350intspragraces.jpg]]
  
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This is an example of how I air check the forward and direct drum. After everything is assembled, I place the drums on the pump (above a hole in the bench) with all sealing rings in place, thrust washers or bearings.
 
This is an example of how I air check the forward and direct drum. After everything is assembled, I place the drums on the pump (above a hole in the bench) with all sealing rings in place, thrust washers or bearings.
  
Use a rubber tipped air nozzle to apply air to the passages around the pump circumference. As you apply air to the correct passages, you will see and hear the drums apply the clutches. Be sure there are no leaks from the lip seals. There will be some minor leakage at the sealing rings usually. Iron rings air check better than teflon on the bench.
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Use a rubber tipped air nozzle to apply air to the passages around the pump circumference. As you apply air to the correct passages, you will see and hear the drums apply the clutches. Be sure there are no leaks from the lip seals. There will usually be some minor leakage at the sealing rings. Iron rings air check better than teflon on the bench.
  
 
[[file:TH350aircheck.jpg]]
 
[[file:TH350aircheck.jpg]]
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=Governor=
 
=Governor=
 
Photo of the T-350 governor and cover. Note the direction of the plastic drive gear teeth. If the plastic gear breaks or wears out, there will be no upshifts since the governor is not rotating.
 
Photo of the T-350 governor and cover. Note the direction of the plastic drive gear teeth. If the plastic gear breaks or wears out, there will be no upshifts since the governor is not rotating.
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[[file:T-350_governor.jpg]]
 
[[file:T-350_governor.jpg]]
  
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==Valve body gasket check==
 
==Valve body gasket check==
 
Always check the valve body gaskets against the separator plate to see if any holes in the plate are covered by the gasket. Place the gasket behind the plate and hold both up at light to check for covered holes.
 
Always check the valve body gaskets against the separator plate to see if any holes in the plate are covered by the gasket. Place the gasket behind the plate and hold both up at light to check for covered holes.
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[[file:T-350_v-body_gasket01.jpg]]
 
[[file:T-350_v-body_gasket01.jpg]]
  
  
 
This gasket on a T-350 sits against the valve body. Notice the open line in the gasket that will parallel the support plate that bolts on at front of the valve body.
 
This gasket on a T-350 sits against the valve body. Notice the open line in the gasket that will parallel the support plate that bolts on at front of the valve body.
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[[file:T-350_v-body_gasket02.jpg|frame|none| notice the open line in the gasket, this gasket installs against valve body, not the case]]
 
[[file:T-350_v-body_gasket02.jpg|frame|none| notice the open line in the gasket, this gasket installs against valve body, not the case]]
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==Racing valve body==
 
==Racing valve body==
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[[Category:Transmission]]
 
[[Category:Transmission]]
 
 
[[Category:Good articles]]
 
[[Category:Good articles]]

Revision as of 12:59, 19 March 2012

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