4x4 Transmission rebuild

[Thebrownturd]

Can anyone point me in the right direction for a th350 rebuild kit? There are so many options I would like to know if anyone has had good luck with any kits and if there is any I should stay away from.

The truck is a 3/4 ton 4x4, with a stock 350 motor and will see towing duty and off roading.

I am also not sure what stall speed for my torque converter to get. This is my first time working on a transmission.

So far I've read about upgrading the rear sprag/roller clutch from a 4l60 to spread out the stress a little better.

Not sure if staying stock or getting some kind of shift kit would benefit me in any way?

I know its a lot of questions but any input is appreciated so I can move on to buy the parts I need and get the tranny back in before the snow flies. Thanks

[mongocanfly]

It's been along time since I've rebuilt a auto trans..but I always used b&m kits with good luck...as far a stall ,unless your building a big cam engine a stock converter should be fine...

[Thebrownturd]

What would the factory stall speed for a 350/350/np205 and 4:10 gears be then? I can't seem to find that info anywhere

[sweetk30]

do a transtar reman kit .

and a transgo sk350 kit .

then have your convertor remand or swapped out .

dont forget a can of cooler flush to rinse the lines and cooler out .

[YoungPup1977]

On a stock 350 engine which may see some towing time, I would make sure you have extra cooling other than the cooler in the radiator. There are several nice trans coolers on the market, take your pick.

Grab a Master rebuild kit with steels produced by transtar, transgo SK350 shift kit, upgrade your intermediate sprag, bushing kit, thrust washer kit, adjustable modulator, band, filter and a stock TC.

Bushing kit (buy the one that has the wider direct clutch drum bushing), weak point on a factory T350.

Governor springs from SK, use YELLOW/YELLOW.

Direct drum pressure plate is thicker than the Forward clutch pressure plate.... they are used for clearance purposes. Always check your clutch clearances.

If you like nice firm shifts "ONLY", you can do a few of the following suggestions which does not cost much:
1. Take the waved plate out of the "intermediate clutch pack" and replace it with a steel these steels fit into the case of the trans, which is used for second gear, clutches spline into the intermediate sprag assembly.
2. remove and discard the accumulator spring.
3. remove the spring under the piston in the VB that applies the band.

Thats enough free advice for now.....GOOD LUCK !

[Chevyrestorerman]

Originally Posted by Thebrownturd

Can anyone point me in the right direction for a th350 rebuild kit? There are so many options I would like to know if anyone has had good luck with any kits and if there is any I should stay away from.

The truck is a 3/4 ton 4x4, with a stock 350 motor and will see towing duty and off roading.

I am also not sure what stall speed for my torque converter to get. This is my first time working on a transmission.

So far I've read about upgrading the rear sprag/roller clutch from a 4l60 to spread out the stress a little better.

Not sure if staying stock or getting some kind of shift kit would benefit me in any way?

I know its a lot of questions but any input is appreciated so I can move on to buy the parts I need and get the tranny back in before the snow flies. Thanks

Are you planning on rebuilding this th350 yourself ?
Is there anything wrong with it today that is stopping you from using your truck. Do you have a plow on the front of it

[Thebrownturd]

Originally Posted by Chevyrestorerman

Are you planning on rebuilding this th350 yourself ?
Is there anything wrong with it today that is stopping you from using your truck. Do you have a plow on the front of it

Yes I plan to do it myself since the quote I've have in town to rebuild my trans is 1400. Seems steep for a 350. I took it out to replace main seals since it was leaking all over. You can see the oil stains all the way on the real axle. It always seemed to struggle when shifting into R or D and would sort of stall before actually engaging then it randomly engages and jolts pretty hard. Not sure if the cause but definatly was a trans issue since I repacked the u joints which were also the cause of some of the jolting.

[sweetk30]

a th350 reman job and you have it out already for 1400 bucks = bend you over and dont use the lube please .

[Thebrownturd]

Do any of you have the part number for the full rebuild kit from transtar? Will this include all basic stuff or most of it? By that i mean washers, steels, bearings, bushings etc.

[Bigdav160]

Transmission kits are usually sold by the piece.

Paper and rubber,
Add clutch choice (here they call them 'banner' kits)
add steel plates (masters)
Bushings extra
Band extra
Filter extra
bearings/thrust washers extra
any hard parts or shift improver kits extra
Converter? extra

[Chevyrestorerman]

Sounds like you may have a front pump issue as well, the th350's are bad for having bad pump/stator issues....which does not come in a master kit.

google the master kit for a th350....amazing what the internet can do for you as far as the part numbers, it may take some of your time to figure what you want to spend and order using part numbers that you can find on the internet. Do your homework yourself this way you can only blame self for ordering the wrong part.

One more thing, its best to get the transmission apart and figure what is wrong, than order your parts. Most likely, you will need some hard parts too. hard parts meaning front pump/stator, input shaft where it goes into the output shaft wears the bushing which in turn wears out the input shaft, direct drum is a weak part (bushing wear) because how the stator is designed in the t350. Make sure you check the governor bore in the case once you remove the governor out of the case.

[Myself]

I always buy my parts here...http://www.makcotransmissionparts.com/350-350c.html

I usually do 1 or 2 performance overhauls a year. It's VERY hard to beat these folks prices on quality parts.

And also for a 4x4 that will see towing and off roading stick with a low/stock stall speed.

[Chevyrestorerman]

Originally Posted by Myself

I always buy my parts here...http://www.makcotransmissionparts.com/350-350c.html

I usually do 1 or 2 performance overhauls a year. It's VERY hard to beat these folks prices on quality parts.

And also for a 4x4 that will see towing and off roading stick with a low/stock stall speed.

Makco sells TRANSTAR parts, kits, etc.... Hard parts used to come out of TN by a company called Dacco. The owner used to work there, Mr George.

[Thebrownturd]

Hey guys. First, thanks for the suggestions and help.
I managed to get the tranny rebuilt and put back in. I found burnt clutches, thrust washer scoring a nice grove into the back side if the forward drum (had to get a whole new drum), and the end of the parking linkage that engaged the pawl was literally coming apart. Yes, the cast piece was breaking into chunks, so there was a good amount of hard metal floating around at some point.

I put it all back together last weekend and crossed my fingers as I put it into gear for its first test run. It ran great. No slipping or noise to worry about. Went through all gears but was shifting very early. I know some of this can adjusted through the vacuum modulator.

Today I took it in to town (35 miles), only after getting there I began to notice a noise and some possible slipping when coming to a stop or at take off. I am leaning towards forward clutches slipping. Anyone have any suggestions of things I can check before having to pull it all back out? I have already made sure there is plenty of fluid. I put 1 quart in TC before installing and 9 more after that. Thanks in advance for any suggestions.

[YoungPup1977]

How did the forward clutch pressure test on the bench thru the pump. Did you replace the pump and stator ? With a lot of metal in a 350 most always takes out the pump and stator. Maybe you broke the sealing rings for the forward drum when installing the pump/stator into the case. After you got it warmed up on your 35 mile journey it started to lose pressure in the forward drum/stator area. Maybe you tore a lip seal in the forward drum (that’s why I asked how it pressure tested on the bench thru pump Most likely if it’s slipping there are no adjustments to be made externally Pull it back out I am guessing. Good luck. Oh one more thing. How is reverse ?
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[Thebrownturd]

Originally Posted by YoungPup1977

How did the forward clutch pressure test on the bench thru the pump. Did you replace the pump and stator ? With a lot of metal in a 350 most always takes out the pump and stator. Maybe you broke the sealing rings for the forward drum when installing the pump/stator into the case. After you got it warmed up on your 35 mile journey it started to lose pressure in the forward drum/stator area. Maybe you tore a lip seal in the forward drum (that’s why I asked how it pressure tested on the bench thru pump Most likely if it’s slipping there are no adjustments to be made externally Pull it back out I am guessing. Good luck. Oh one more thing. How is reverse ?
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Every thing pressure tested with the clutch pack engaging. Reverse seems rock solid. I took the pump apart and cleaned thuroghly and didn't find any scoring or damage but that doesn't mean there wasn't any. I have to agree that it seems pressure related, either seals or rings.
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[YoungPup1977]

How did you align the pump and stator before installing it into case ?

[Thebrownturd]

Originally Posted by YoungPup1977

How did you align the pump and stator before installing it into case ?

I for the pump halves i used a screwdriver to line up the holes then bolted the cage down as evenly as possible. Is there a possibility to I could have clocked it wrong? I assumed that they would only bolt down in one position.

[YoungPup1977]

Originally Posted by Thebrownturd

I for the pump halves i used a screwdriver to line up the holes then bolted the cage down as evenly as possible. Is there a possibility to I could have clocked it wrong? I assumed that they would only bolt down in one position.

There is only one way to bolt down but both halves must be aligned by using a band around the edge of the stator and pump body. If they are off a bit when you installed the pump/stator into the case the sealing rings that go into the forward drum could of broke. This creating your slip you are experiencing. You can purchase a couple of large hose clamps and put them together to use to align the pump. Keep it cheap... good luck on finding out why your build went bad.