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Discussion Starter · #1 ·
A question for you transmission experts......
I have a GM Factory rebuilt trans [P/N: 24204974] Installed Jan 1999
Trans has 204,000 miles on it! Only modifications are a deep truck pan, and no TQ converter dust shield, no programming, no shift kit. I have used a B&M Shift+ switch when drag racing. Fluid/filter has been done at least every other year, sometimes every year. Reline ATF. The trans has and still does perform without any issues. Engine is also stock (Fresh air, cat back,etc.) I have 3.42 gears.
The car has been driven very hard! but maintained very well!

It's time for another filter change and i was wondering: Would I be wasting my time / money installing a transgo shift kit and sonnax accumulator pistons while the pan is off? I'd be throwing approx another $250.00 + my labor at it.

My goal is simply to extend the life of the trans and I wouldn't mind the crisper shifts.

Have I already asked too much of the trans? Would this quicken it's demise?

Thanks in advance
[email protected]
 

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I would do it. Your regular fluid changes have likely kept it clean and alive.
 

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Do it, I installed a transgo in mines at 185k when I did my LT1 swap and now the tranny has about 210k and still shifts like new.
 

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Do it. I installed mine at 147XXX miles and found broken springs and accumulator pistons. That alone made it worth it since the busted parts would cause trouble.

The trans performs so much better with the kit installed.
 

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I (with help from this forum's members) installed a little different kit. I used the Transgo "SK" kits in my 199,000 mile 96 SS and my 149000 mile Roadmaster Sedan.

On the Impala, I realized it had a GM reman trans, after doing the kit. I did not do the 2-4 servo. I did install a new .500 boast valve.

On the Buick, I installed the whole kit. I'm glad I did because it's "band " was l little loose and the kit brought it in to spec.

I too, found a broken 3/4 accumulator spring, upon teardown. The bore was scored and I used a repair sleeve kit, and new pistons/springs.

I prefer the shift feel of the SK kit's "boost" springs to the .500 boost valve (which shifts a little too firm for me.

The SK kits are not designed to change the shift feel/ or points. SK kit is claimed to correct known pattern failures.
 

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I didn't use the washers supplied in the full Transgo kit. Shift firmness was only slightly altered. However, the overall feel of the trans improved greatly.
 

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Would I be wasting my time / money installing a transgo shift kit and sonnax accumulator pistons while the pan is off?
No, not a waste at all. Can't speak to the sonnax replacements though.

My goal is simply to extend the life of the trans and I wouldn't mind the crisper shifts.
Barring anything unforeseen and presently on it's way out, that'll do it. Transgo+deeper pan+regular maintenance=happier, longer living trans.

Have I already asked too much of the trans? Would this quicken it's demise?
No and no. Again, provided nothing's presently on it's way out above the valvetrain.

+1 vote for retaining stock 1st accumulator and spring and not using the transgo springs and washers. W/ the above, crispness will still be achieved, just not neck jarring.
 

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Installing a trans go with that many miles is a bad idea... The boost valve alone will likely blow a lipseal in that thing. With that many mileage do you realise how brittle those seals are?
 

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No, not a waste at all. Can't speak to the sonnax replacements though.




+1 vote for retaining stock 1st accumulator and spring and not using the transgo springs and washers. W/ the above, crispness will still be achieved, just not neck jarring.
I used the Sonnax pistons and they are TOP NOTCH :)

I used everything but the washers from the Transgo kit, to include ALL springs) and it shifts just fine.
 

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Ok let me rephrase my earlier reply,

Do it if you dont care if you have to rebuild your transmission sooner than later.


If you just want your trans to last.. dont expect a trans go to help any with that many miles.
 

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Discussion Starter · #11 ·
Fwiw...

I spent about 1/2 a day Sunday doing the Trans-Go 4L60E-HD2-C
Install. Installed everything you could with the pan off and R&R 2nd piston. I installed only 1 of the band adjust shim, with both installed it was too tight. With the Sonnax Pinless accumulator pistons I was
not able to assemble the 2nd accumulator per the instructions.
The Sonnax piston would not allow the use of the lower "BLUE" spring, so I installed the piston without the spacers or spring seat and retained the stock "Yellow" spring under the piston. I did install the "ORANGE" spring above the piston. Only other deiation was that
my transmission did have a valve body with the oversized converter valve so I retained it. If the trans lasts til next years filter change I'll order the Trans-go one and fit then.

If not - I should have listened to Dustman! :)

I am quite happy with the install car runs and drives nice. Firmer shifts but not at all harsh. Previously on a cold day from a standing start I could get the car to "bark" the tires during a 1-2 WOT Shift. about 25% of the time. I have driven the car about 100 miles and pretty much can make it do the same "whenever I wanted" - (Mileage on this tank is going to suck).

Hope to see some of you folks in Dallas this weekend!

Regards,

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