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Discussion Starter · #1 ·
To Build or Not to Build that is the question.
After reading many posts for and against any and all types of transmission my decision is done. So PLEASE i have no need to debate the choice i have made.
So some so-called history. Condition unknown. Previous owner claims it to have been rebuilt and has less than 1000km (600 miles) on it since build, then pulled for an engine and trans swap. This trans has been sitting now for over 2 years that i know of. Always been full of orig fluid during storage and it seams to be very clean and fresh. I have not been inside an auto for over 30 years now.
Upon reading the book on trans rebuild by Ron Sessions (to refresh my memory) i am reminded during build you need to soak the friction plates prior to assembly. I know the reason for this is to ensure plates are lubed prior to assy and initial use.
I do have a complete rebuild kit on hand and was wondering do i rebuild using all new plates,bearings etc or just purchase a reseal kit?
As this trans is unknown and been sitting for a long period of time i feel the oil has drained and dried off the uncovered area of the plates.
Do i need to at least refresh the seals, both internal and external?
Can it go into service without anything being done?
How long can it sit out of service before i need to open up?
How long after rebuild can i safely leave out of service ( still doing chassis out build) before i have to put into service?
If i need to rebuild, Do i wait till a later date ( when i am closer to actually placing into service)?
Replies greatly appreciated thanks
 

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If you could mate it to an engine and run the auto through the gears it will tell you exactly what needs to be replaced.

From experience if the trans was rebuilt but has been sitting usually the seals dry up get hard and cause leaks.

The friction plates, steels should still be good, they would only need replacing if worn to the point that their burnt out.

You have a couple of choices run it first, if you have problems then pull it back out & go through it.

BTW the turbo 350/400`s are pretty straight forward when doing a reco :anim_25:
 

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transmission

If it was mine I would put a front seal in it an a quart of TRANS-X to make sure a valve is not stuck in the valve body.You could take the pan off to remove any initial breakin wear that is in the pan.
 

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TH-350, run it or rebuild it first?

Do you know how many years ago it was rebuilt? Also was it stored indoors in climate control for the past two years? Even if it was stored inside, put a new front pump seal on it, and a new output shaft seal. Pull the pan to inspect for residue and fluid condition in the pan, and to put a new pan gasket on. These are just precautionary steps, because both of those seals get disturbed during install and removal. If the fluid is not cherry red and super clean, rebuild it now. If it does not have a shift kit in it now, and you like a firm but not harsh shift, buy a TransGo 350-2 kit for it

http://www.summitracing.com/parts/trg-350-1-2

and put that in while it is upside down on the bench.

Once the clutches are soaked in fluid for the first time they are good virtually forever. They don't completely dry out even after many years sitting idle. The soaking is necessary to lube the clutch some, but more importantly, to transfer surface heat away via the fluid. Running a totally dry clutch friction disc will glaze it during the first few apply cycles, until the fluid slinging around inside the trans works its way into the discs.

Unless it has been 10 years or more since rebuild, the internal seals will be fine. They hold up well during storage, and will take a proper shape again the first time they are warmed up.

Worst case scenario is that the PO was not honest about the rebuild and service history, and you have to pull it and rebuild. Not hard to pull a 350 because they are relatively light.

Driver.
 
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