Transmission Output Shaft Swap

[JamesT_SS]

Before I start this I should point out that I am in fact not a Transmission specialist. I am a general tech who just happens to dabble in everything and try new things. That being said, if any actual Transmission Techs out there want to chime in with pointers, correct me, add stuff, whatever...please do so. I'm not a genius and i'm also writing this up months after i actually did it, so i may have missed something or typed it wrong. I'm not going to cry if you criticize me, I care more that the correct info is out there for the people who need it.

 

The following how-to is a step by step process of how to change out your transmission Output Shaft. This is actually part of a massive retrofit I'm doing over HERE to swap AWD into my RWD SSS. In case you didn't know, the only major difference between an AWD and RWD transmission in your SSS is the output shaft. The RWD has a longer Output Shaft because it has a tail housing going directly to the driveshaft. The AWD has a short "stub" shaft that goes into the NV-149 Transfer Case adapter, then T-case, which connects to the driveshaft. Anyone who has tried to put high HP into their truck knows that these transmissions are actually utter crap and can't handle power.

 

 

Quick bit of history. The silverado used to use the 4L60E, but due to increases in power, especially with the SS version, they revised it into the 4L65E. A few revised parts here and there, and boom a transmission that can still barely handle the power being put into it. Most everyone has had their transmission go out or had a friend's who's did. 70,000 miles here...intake, exhaust, daily driver. Don't get discouraged though, a good reputable builder can build you a 4L65E that can last.

 

Anyway back on point, one of the many weak parts in this transmission is the AWD output shaft. So the long RWD shaft while put under stress actually flexes a bit to help alleviate said stress. The shorter AWD shaft though does not, so when said stress is exerted, say hundreds of pounds of torque suddenly applied, the shaft will just straight break. Luckily you can find shot-peened, cryo-treeted, electrical induction treated, billet, etc shafts all over the internet.

 

Now if you decided to tackle an output shaft replacement/swap you'll find that the ouput shaft is actually close to the back of the transmission and 3/4 of the guts have to be removed to get to it. A real pain, but not all that hard. Much easier than a full transmission rebuild. If you have a manual and patience this can be done in a few hours. For my purposes though i have to replace the RWD long shaft with the short AWD shaft for my build.

Edited July 20, 2016 by marodda (see edit history)

[JamesT_SS]

First off you will need a few parts for this.

 

T50 Plus Torx Bit - This is not a normal torx. DO NOT TRY AND USE A NORMAL T50 TORX.

Tailhousing/Tcase Adapter seal

Servo cover seal

Accumulator Piston seal

Transmission Filter/gasket kit

Input shaft o-ring seal

Oil Pump to Case bolt o-rings

Oil Pump to Case Seal and Gasket

Oil Pump Bolt o-rings

 

Possibly more depending on the state of your transmission.

 

First clean up the transmission well. You don’t want any foreign material getting into it. A good transmission builder will do the build in a dust free environment. Make sure your work area is really clean and closed up (i.e. don’t do this with your garage doors open). Remove the tailhousing or transfer case and adapter, whichever one you are working on at this point (new seal needed). Then grab your T50+ and a breaker bar and remove the 8 bellhousing bolts. They are in there pretty tight, but don’t use an impact.

 

Next remove the bellhousing. Now using either a bench mount or in my case an engine hoist, get your transmission vertical. If using a hoist, make sure you have a lot of chain so there is enough room to remove the oil pump later. There are two lift loops in the transmission case to hook to.

This part is really messy, so have a bucket or pan ready to catch the transmission fluid as it drains out the rear. Roughly 11 quarts is going to drain out.

 

Next you will be removing the servo cover. The manual calls for a special tool to compress the cover, but just grab a block of wood and a mallet and carefully give it a whap until you see the cover depress in a little. (hitting the wood here, not the cover) It won’t take a whole lot so don’t slam it. Once you pop it in a little you will remove the snap ring holding it in. You will probably need to maintain a little pressure against the cover; you can do it with your hand.

 

Now remove the servo cover. It may be difficult to remove. Use a towel and some channel locks to grip it if you need to.

 

You’ll get it out a bit and it’ll likely get stuck. Don’t fret, just grab and cut the seal holding it up.

 

As you remove your 2-4 servo take note of how it’s all assembled. It’s fairly straightforward.

 

Remove your transmission pan bolts and pan at this time. Next remove and toss your old filter (if you are feeling curious pry it open and check to see whats inside. This will give you an idea if there is something wrong with your transmission). Remove your filter seal. It’s a rubber neck where your filter inserts. It may be on your filter or still stuck in the tramission. Your filter/gasket kit should have come with a new one.

 

Disconnect all of the electrical connectors. Be careful.

 

Remove the clip holding the left hand shift solenoid in.

 

Remove the left hand shift solenoid. It’s in the way of the next step.

 

Remove the bolts holding the lock-up solenoid in place, then remove the solenoid.

 

Once you do that you should be able to carefully remove the harness from the valve body. It may be bolted on, but in my case it was just slipped on. You can choose to remove the main wire harness plug on the outside of the case and pull the whole wire harness off, or just hang it carefully aside like I did.

Edited July 20, 2016 by marodda (see edit history)

[JamesT_SS]

Remove the 5 bolts from your pressure switch assembly, then the pressure switch itself. FYI these bolts and all the other valve body bolts are specifically sized and in specific locations for a reason. Do not mess this up. Make note of where they go.

 

Remove the bolt holding the manual lever detent spring on, then the spring itself.

 

Remove all the valve body bolts. Again remember the position of the bolts. Oh, and the built transmission I had didn’t have the yellow arrowed piece, which is a dipstick stop. Odd piece but chevy added it for a reason, so I stole it from my donor.

 

And if you didn’t listen about the bolts, here you go. Position and torque sequence. Your welcome.

 

Next parts a little tricky/fun. Before you remove your valve body, take note that there are detent balls that are free floating underneath between the valve body and the gaskets/spacers. Get ready to catch them if you have your transmission vertical. They should stay in thanks to fluid friction, but just in case. There are 7. (note this picture is of the backside of the valve body).

 

Also the valve body is attached via the manual link/valve so you will need to maneuver that out. Once the valve body is clear and you have accounted for the check balls, remove the 3 bolts and spacer plate support plate.

 

Remove the 3 bolts holding the 1-2 accumulator on. Get ready for some more trans fluid. This part is important. As you remove all of this pay attention. First, there is another check ball under here.

 

As you pull the accumulator off take special note of orientation, order, etc. This is variable among models, years, and aftermarket/factory. Put it back the way it came out. In my case I had a factory transmission from an 04, and a built transmission for an 06. I had differences. This is only half the assembly. You’ll see in the assembly portion.

 

Remove spacer plates.

[JamesT_SS]

At this time you will be moving up to the Oil Pump. You should take end play measurements of your input shaft if you are so inclined. It should be between .015” and .036”. If you want to be safe, take this measurement as a comparison for when you reassemble to make sure everything is proper.

 

Remove the O-ring seal from the end of the input shaft.

 

Remove the 7 Oil Pump bolts

 

Remove the Band Anchor Pin. Technically you are supposed to do this after the Oil Pump removal, but I popped it out prior as it was holding my pump up.

 

Remove the Oil Pump by pulling upwards. There is a special tool that grabs it for you. Its called your hands. Seriously though there is a tool (J39119). If you are cheap like me though you can VERY carefully pry the pump up with a hard plastic tool, making sure not to damage the mating surface.

 

Next grab that input shaft and pull the input housing and reverse input housing out together

 

Remove the 2-4 band assembly that you can see sitting near the top in the above picture. Make sure you are inspecting all these parts for damage. You can see some damage on this one, luckily this is my donor transmission.

 

Account for your input sun gear. It should be in the bottom of your input carrier housing, but may be in the bottom of the case.

[JamesT_SS]

Now finally you are at the output shaft. This part may or may not be a pain. It should be noted there is a special tool that will hold your output shaft in during the next step, but if you just hold the shaft while you do it, that will suffice.

 

Down on the output shaft, inside the planetary, there is a snap ring.

This is the tool you will need to remove it. These are Lock Ring Pliers.

 

If you are lucky, your output shaft will come out at this time…..IF. I got lucky on one, not so lucky on the other. Go figure. If it did come out skip the entire next section and go to reassembly.

[JamesT_SS]

If you aren’t so lucky, it’s because your output shaft is stuck in the reaction gear. It’s a bunch of parts down. Sometimes builders use an adhesive to lock the two together for assembly, but this is supposed to be temporary. Let me tell you, I couldn’t get mine separated in the case at all. I had to pull the whole thing out and press it out. You’ll need to carefully support the reaction gear to do this to avoid damage. Be careful. To get to this point remove the following.

 

Remove the input carrier and thrust bearing (planetary and washer). Right below that is the input ring gear and thrust washer. Then pull out the reaction sun shell and reaction sun gear.

 

Next up is the thrust washer on top of the low roller clutch inner race. Then the green arrow below is the snap ring holding the next parts in. Remove that.

 

Remove the low roller clutch assembly, red and yellow arrows above. Below is the rollers. Be careful or it’ll come from together.

 

Next up is the anti-clunk spring. This guy is real fun. Take note of location and orientation.

 

Remove all of the low/reverse clutch plates. Keep them altogether and in order. Remove the Reaction Carrier Assembly.

 

And FINALLY, the Internal Reaction Gear and output shaft.

 

Press out your output shaft and reassemble these parts in opposite order. If you are reusing this transmission, you can insert your output shaft now to aid in assembly of all of the low/reverse clutch parts.

Edited July 20, 2016 by marodda (see edit history)

[JamesT_SS]

REASSEMBLY:

 

Alright at this point you have a few options. You have a new shaft/replacement shaft already and its ready to go in; carry on start reassembly. If you are in my position and are doing this for the AWD/RWD swap, you may have just pulled out your replacement shaft. Which means you now have to get to this exact same point on your good transmission. Repeat all above instructions as necessary until you have your unwanted shaft out. Grab your new/replacement shaft and slide it up through the bottom of your chosen transmission until it seats into the Internal Reaction Gear. Make sure your shaft is perfectly clean of dust or contaminates before doing so. Install the small snap ring on the output shaft to attach it to the reaction gear. Ensure the snap ring is seated.

 

Seat your input sun gear onto the output shaft and input carrier. Rotate until seated.

 

Next is your input housing and reverse input housing. Hopefully you didn’t disassemble this. This next part is interesting. You need to index everything prior to assembly. If for some reason your reverse input clutch and input clutch housings separated, you will need to line up all of the reverse input clutch discs so that they slide and fully engage over the input housings gear. Clutches on left aligned to seat over the gear on the input to the right.

 

Now flip the whole assembly over (while maintaining pressure to ensure the two pieces stay together) and align the clutch discs inside the input housing.

 

Three things need to be aligned at this point. 3-4 clutch plates indexed on the input ring gear, input sun gear indexed into the forward sprag inner race, and reverse input housing tangs indexed into the sun gear shell. Yeah that’s a mouthful. Basically once you aligned all those clutch discs above you will grab the input housing by the input shaft and very carefully slide it into the transmission until you feel it make contact with the sun gear or the input gear. Now wiggle it around until you feel the clutches start to engage the gear. And literally start wiggling the crap out of it back and forth until you feel it seat all the way down. Not kidding. If you don’t believe me google a video of someone doing this. Theres no easy way to do this. Just don’t be violent. Once you think its seated it should look like this.

 

Notice the housing is below the oil pump seat. In fact look at it from the valve body side and look for this alignment.

 

Good to go. Install the 2-4 band. Insert the backside slightly first, ensuring this alignment…

 

Then apply a little pressure to the input shaft and pop the rest of the band down in to seat it.

Edited July 20, 2016 by marodda (see edit history)

[JamesT_SS]

Next up go ahead and install the anchor pin that you removed earlier. If you didn’t install the 2-4 band correctly this won’t go in. This pin needs to be just barely below the valve body surface.

 

Next grab your Trans Gel/assembly lube and coat the inside surface where the oil pump resides.

 

Install your new oil pump to case gasket. You can use a little trans gel to hold it in place. Make sure to align all of the holes. Flip your pump and apply trans gel to the pump bore where the o-ring is. You can apply gel to the orange ring to hold it in place as well.

 

Align your pump with the housing and start to drop it in. As you are doing this there are pins that you can install to help. If you are cheap then do this. Grab a phillips screwdriver or equivalent and as you start to seat the pump, drop the screwdriver into a bolt hole until it goes into the casing as well. Let your pump ride it down til its near flush.

 

Lightly tap your pump down until its seated fully. I used the rubber handle of my hammer. Make sure to do this evenly.

 

Install new o-rings onto the oil pump bolts and install them. Torque all bolts to 18 ft. lbs.

[JamesT_SS]

Go ahead and recheck your input shaft end play and make sure you are still within spec.

 

Pat yourself on the back, the hard part is done. The valve body is next. It’s easier done with the transmission horizontal. I just lowered my hoist carefully until my transmission was lying down on the floor (carefully). First install your one lone check ball into the case where the accumulator goes. Refer to previous pictures for check ball locations.

 

The next part is that one important part regarding your accumulator. Depending on your setup/build it may have a number of setups. There are multiple spring colors, which can be used in either the 1-2 or 3-4 accumulator positions. Aftermarket ones may use a yellow spring and flip the piston. I believe the one RPM put in mine was the transgo mod. I would highly recommend anyone considering stuff like this to look into a lot of these performance parts before buying into them. I’ve read a lot of stuff put out by reputable builders (to include FLT) that would blow your mind about some of this crap, like the ole “corvette servo”. Anyway make sure your accumulator is properly assembled.

 

Essentially it’ll be piston, 3-4 spring, valve body spacers, 1-2 spring, cover. In my case it was 3-4 spring, piston, valve spacers, 1-2 spring, cover. Pay attention to your setup. And don’t forget to replace that accumulator piston seal. Torque bolts to 8 ft. lbs.

 

Go ahead and bolt on your valve body spacer support plate. Torque to 8 ft. lbs. Install all of the remaining 7 check balls onto the valve body with a dab of gel to hold them in place. While carefully reinserting the manual valve link, put the valve body onto the transmission carefully, making sure none of the check balls fall. Also be sure not to damage the protruding screens. Insert all of the valve body bolts (minus the pressure switch bolts) in the appropriate locations (VERY IMPORTANT). If your harness was held on by the bolts, finger tighten them only at this point and torque after installing the harness. Otherwise, torque the bolts to 8 ft. lbs. using the aforementioned pattern.

 

Install a new o-ring on the lock-up solenoid and install into the case. Tighten the bolts to 8 ft. lbs.

 

Install the left hand shift solenoid into the valve body and insert the retaining clip.

 

Install the Pressure switch onto the valve body with the proper bolt orientation. 8 ft. lbs. (starting to see the trend?)

 

Connect all of the electrical connections. Install the manual detent spring and bolt and tighten to 18 ft.lbs.

 

Throw on the new filter gasket, filter, and pan gasket. Install pan and torque bolts to 9 ft. lbs.

[JamesT_SS]

Install your 2-4 servo assembly.

 

Install servo cover with new seal.

 

Apply pressure and fully seat snap ring.

 

Finally install either your extension housing or transfer case adapter with new seal and torque to 26 ft. lbs. Then lastly your bellhousing. Now I had to do some research online to find the bellhousing torque. Best I could find was 48-55 ft. lbs, and possibly use Loctite (I’d use blue). Hopefully someone can verify that?

[JamesT_SS]

If you are reading this as part of the AWD/RWD swap then make sure you install the proper tail section. If you are going to RWD then you need the extension housing and install the vehicle speed sensor as well. For mine since I went from RWD to AWD, I installed my new transfer case adapter.

 

On an interesting side note, now is a really good time to swap out them crappy factory oil cooler fittings and go to an AN line setup. If you look at the picture above you can see mine. You need two 1/4" NPS to 6AN adapters (NPS is the straight thread - people argue that NPT will work, but i've heard of issues where the NPT was cracking the case from going too deep or something). You can find them all over the place online. I ran those, with 45 degree fittings, 6 AN lines to an Improved Racing Thermostat (185 degree, with an fittings available), then you'll need 90 degree AN fittings for your oil cooler with 6AN adapters for whatever type of oil cooler you are using. i have the Tru cool max, so finding adapters was easy. Can't remember exactly what size, but i know that what i was told was wrong and had to run to my local speed shop to find the right fittings.

Edited July 20, 2016 by marodda (see edit history)