Because of agrazela’s fantastic work that saved me a ton of time & trouble, I figured I would go on to add things that might further help someone else. After a months worth of research, gathering parts, and making my engine & trans fixtures, I was able to knock out the whole job in a couple of weekends largely thanks to him. (they were seriously busy weekends though) Hopefully, it’s useful to you.
The main thing I came away with from this job was the logistical challenge, i.e., it’s a lot of parts and better yet, a lot of bolts, bearings, and washers of various lengths and sizes. The baggie organizational system and some pictures here and there will save your butt.
The car: A surplussed 2004 Police Impala from Nashville, TN’s finest with 141,000 miles. I put on 36,000 of them and it ran great most of the time, albeit shifts generally felt inconsistent. It seems to have had a nice life as apparently it was a sergeant’s car, i.e., no cage, just lights. It looked like it had never carried an arrestee, ever.
About me: I've been messing with anything mechanical I could get my hands on since I was a kid, did about everything you can think of in high school auto shop (had a great auto shop teacher, Rod Collard), and I also went through Chrysler’s school (MoTech) and worked in a Chrysler dealership in my younger years. Generally speaking, there isn’t much on a car I haven’t done, except for rebuild an auto-trans outside of school. I have done several manual transmissions, however. I'm pretty handy with a torch & arc welder too. (I'm not a total newbie on this kind of job)
Your last warning before you start: If you don’t find transmissions fascinating and aren’t big on doing things to the letter and really studying how these things work, you probably should leave your transmission alone or perhaps just R&R a rebuilt one. And if you aren’t too comfortable with taking a car apart and putting it back together and don't have the time to get that way, you probably don’t want to R&R one either.
Here was my experience:
Main symptoms:
• Bang starts, usually in the first 10 minutes of operation for the day. Got to where it was doing it a little bit when hot. It appears that a combination of the input clutch short lipped seal and perhaps some worn teflon rings caused this.
• About 25,000 miles prior to the rebuild, it did the classic harsh shift / P1811 code and was “fixed” with a TransGo shift kit and Dexron VI. I don’t know how much the Dexron VI had to do with the “fix”, but it did take most of the bang out of the slip bang starts. With Dexron III, it would be like getting rear ended as most people experience. I'm guessing that a rebuilt accumulator would have taken care of the problem, and ironically, is cheaper than a shift kit.
• In the last 1,000 miles before the rebuild, it started bang starting a little bit frequently after warmed up and second gear became “slippy” on steep inclines. Reverse would slip a lot on a steep incline as well.
• Third, fourth, and TC lockup seemed completely fine.
Key parts replaced:
• Rear planetary (thrust washers almost gone)
• 1-2 / 2-3 Accumulator (pins and their respective holes in the pistons noticeably sloppy)
• All clutches and bands (probably unnecessary)
• Chains (unnecessary)
• Driven sprocket support bearing (well on it’s way out)
• Input Shaft support bearing (looked fine but replaced it anyway)
• Driven sprocket (bearing surface damaged by support bearing)
• Torque Converter (as a precaution)
• Extension housing bushing (noticeably worn)
• Sonnax boost valve kit (original seemed fine, but a recommended upgrade)
• Torque converter clutch control valve kit (same as above)
• Valve body plate with bonded gaskets (you’ll need this for a newer trans; don’t attempt to reuse it or scrape the gaskets off)
• All solenoids (as a precaution)
• Master Kit (probably could have gone with a seal only kit)
Everything in the trans appeared new or nearly new except for these items:
• Driven sprocket support bearing.
• Driven sprocket; bearing surface was damaged by the respective bearing.
• Rear planetary thrust washers; put in a rebuilt from wittrans.com
• 1-2 / 2-3 accumulator pins; put in a rebuilt accumulator from wittrans.com
• Extension housing bushing; got just the bushing from wittrans.com
• Various seals.
• Channel plate sleeve due to the channel plate sleeve bore misaligned with the input shaft. The surfaces of the sleeve that contact the Teflon rings were fine. Left the damaged sleeve in place because a new sleeve would be ground out by the input shaft just like the original, sending metal debris into the trans. Apparently this is a common defect. Torque Converter operation was perfect before and after the rebuild, so apparently it is a harmless defect.
Recommendations for anyone considering a trans rebuild:
• Don’t try to be slick and anticipate all parts needed so that you can knock it out in a weekend. You’ll save money by tearing it down and inspecting before ordering parts; I could have saved a few hundred on things I didn't need. Plus, I didn’t anticipate the driven sprocket support bearing, bonded gasket valve body plate, or rear planetary and had to order parts any way.
• Wittrans.com is the place to go for most things, particularly rebuilt planetaries and accumulators.
• For the most part, don’t bother with eBay parts. For me, they were all terrible. I ordered an entire planetary set and a loaded input clutch housing, both listed as excellent (I was anticipating a bad input piston and bad input sun gear). Both were pretty much scrap or perhaps good for cores.
• Just take strut & lower control arm loose as a unit. It's a lot easier and you'll need the room to feed the trans out the side.
• Make a decent engine support fixture; see pictures below Your life depends on it after you remove the sub-frame.
• Making a "transaxle support fixture" will really speed things up too.
Teflon ring installation:
• Get some spares to screw up with from wittrans.com. They’re cheap.
• Do the green ones on the back of the input shaft last after you've had practice. wittrans doesn't seem to stock extras and they are the hardest. I screwed up a bit with them, but amazingly they came out okay. On the outside groove (the hardest one), I suggest using rolled up soda bottle to go past the destination groove, slide the ring on to the bottle plastic, and then come back to the groove to drop it in.
• Stretch using a long funnel.
• Slip over shaft to destination groove using a piece of 2 liter soda bottle rolled around the shaft ( use the flat middle section of the bottle)
• The sides of the ring and top of the ring are important parts. You can scrape up the bottom.
• Resize into groove using electrical tape. They will seem to “bunch up” at first, but keep guiding them into the groove and after plenty of wraps, they will resize nicely. Agrazela gets the credit for this idea.
• The rings are pretty tolerant of stretching and compressing. No worries about compressing them for too long or too much. It seems that the more you compress them, the better.
Clutch seal installation and testing:
• Mostly pretty easy except for 2nd & 4th. 4th will try to wrinkle on you and 2nd is a complete b*tch. Perhaps de-burr / slightly bevel the edge of the inner sealing surface on the 2nd gear drum.
• The 2nd gear sealing rings on the driven sprocket support are very leaky, but that seems to be okay (I don't see how they couldn't leak). Fill the passages with fluid before you test, and while you'll hear a lot of leakage, you'll also hear the clutch apply.
• The input and 3rd clutch Teflon rings will leak less the longer they are installed. They went from leaking quite a bit to very little / not at all fairly quickly. Be sure to fill the passages ( a time or three) while testing.
Interesting tidbits:
• All clutches were in close to new condition.
• Forward and reverse bands were close to new.
• 2nd gear coast band was worn on a corner from rubbing the reaction drum in normal operation.
• Chains were like new, .342” clearance.
• Sprockets were like new except for the bearing surface of the driven sprocket. The driven sprocket support bearing was on its way out. There was no outward symptom of this.
• Input clutch piston was fine. Inside short lipped seal was barely touching the piston.
Atleast one gotcha:
• You'll need to get a new valve body plate with bonded gaskets for newer transmissions. Don't know why this isn't mentioned anywhere.
Info sources:
• The awesome 4T65e post by agrazela. It was massively kind of him and saved me a ton of time & trouble.
• Alldatadiy.com for tightening torques of various car components and procedures.
• ATSG 4T65E manuals for rebuild procedures; it’s pretty much a reprint of the factory manual with handy quick reference material. Worth getting. I mostly followed it to the letter. The “update” manual was only marginally useful.
Vendors used:
• tripleedgeperformance.com (lots of good info and decent prices on some things). Spent about $600 with Dave.
• wittrans.com (probably the handiest site overall). Spent about $250 with them.
• transmissionpartsusa.com (great for solenoids and other items). Spent about $200.
• My local Chevy dealer for the driven sprocket bearing. $50
• eBay for the ATSG manuals and clutch compressor. $90?
• and zzperformance.com (for Dex VI) $80.
Total spent: roughly $1,300, including $150 or so in extra tools and hardware and about $80 worth of Dexron VI. Dexron VI was the one of the largest single expenses. Yeah, I could have gone with a rebuilt, but it wouldn't have been as much fun now, would it? Plus, you can be fairly "sloppy" and one will still last the typical 12,000 or 24,000 mile warranty. So, you may well as do it yourself if you're a high mileage driver (I do around 35,000 miles / year).
Crucial tricks and special tool workarounds used:
• Input shaft & driven sprocket bearings: cut the needle bearing holder with a dremel tool and then pry out the holder with a screw driver. This will make it so that you can easily engage the outer race. A harbor freight seal puller is handy for removing the input shaft bearing outer race.. I used a large hammer and a large screwdriver wrapped in duct tape to drive out the driven sprocket bearing outer race.
• I pressed in the input shaft needle bearing with a vise and some oak scraps. Worked nicely.
• I pressed in the driven sprocket needle bearing using a bottle jack pushing against the bottom of the car with the drive sprocket support & bearing on the ground (newspaper on a cement floor). Worked nicely.
• Teflon seals can be installed by: 1) stretching them with a long funnel, 2) using a rolled up piece of 2 liter soda bottle to deliver them to their appropriate groove on the shaft, and 3) use electrical tape to resize them into place. The rings will bunch up on the first few wraps, but keep steering them into their grooves and they will go in compress down to size. It seems to take 10 to 15 wraps. Don’t worry about compressing them too much or for too long. It turns out that these seals are tolerant of being molested. Just try to keep the tops and sides as perfect as possible.
• Bushings—replaced extension housing bushing by cutting it with a hack saw blade and punching it out with a large punch. Got away with installing the new one using both a punch and a hammer that happened to have just the right sized head (the hammer head was basically a big driver).
• Punch out the torque converter seal from the back through a drain hole.
Special "tools":
• Clutch compressor from eBay, same one that agrazela used, in pretty much the same ways (the big wood working clamp).
• The straight middle section of a 2 liter soda bottle rolled around shafts for getting Teflon seals over the shafts.
• Electrical tape to compress Teflon seals.
• My homemade "engine support fixture" and "transaxle support fixture".
• That was about it, believe it or not. The rest was some ingenuity, scraps laying around, and standard tools.
After overhaul anomalies & performance:
• Worked great out of the gate and continues to do so.
• When hot, 2nd gear is sometimes a bit harsh, sometimes not. Never too bad. Perhaps it’s a cop car calibration (it does everything firmly, but not "bangy" like a P1811 code). Or perhaps this is the deal where GM says to replace the entire 2nd gear clutch housing. Maybe I'll deal with it in 70 - 100k miles when it needs a fluid change (I'm using Dexron VI and I'm in no hurry to dump that out).
• Shifts firm and solid. I don’t see a need for a shift kit unless you’re racing. I imagine that most peoples' troubles are due to a worn out 1-2 / 2-3 accumulator, short lipped seals, and perhaps a PCS solenoid. That was all that was wrong in this trans other than a bearing and a bushing.
Notes:
• Channel plate & valve body bolts continually loosen up as neighboring bolts are torqued. Keep checking & re-torqueing them.
• I Loc-tited the stator support bolts. I noticed that the stator support squirms back and forth on the case.
• I didn’t goo the check balls or pump shaft ring as agrazela did. I’d say it’s probably better if you didn’t. For atleast a 2004 trans, the valve body plate has plastic “Christmas tree” thingies to hold the plate to the valve body, thus holding in the check balls. The pump shaft seal is easy to deal with without the goo.
• Be sure to “oil” things as you assemble them, particularly bearings. I suggest a new el cheapo oil can loaded with Dexron VI.
• Don't bother with trying to pop the ball joint loose. Take out the strut & control arm as a unit. You'll be glad you did after you discover that the control arm bolts have loosened significantly in the last 140,000 miles, a 100k of them by the cops. The loose bolts also explained the occasional torque steer. If you don't have the car high off of the ground, you need the strut out of the way to slide the trans out the wheel well.
By the way, it worked on the first try and with about 3,000 trouble free miles in less than a month, I’m guessing I did a good job.
Here are some pictures of tidbits that made life nice for me. The "support fixtures" were a bit time consuming to make, but I figure it's easier to spend the time making the tools than spend it struggling to do the job and putting one's life at risk.
Since I couldn't find a picture of a decent home made rig, here you go, my "engine support fixture" side view:
Someone had cut up their home gym and cut it about the right lengths. (wasn't me)
A lip hangs down so it can't kick out the front:
Front view:
Just take the strut & lower control arm out of the way. Very handy to slide out the trans:
And hang it in the corner. Wire the control arm to the spring so that it doesn't over extend the ball joint:
Trans is out. BE SURE THAT YOU STRAP IT TIGHTLY! A piece of plywood between the lift and trans was very handy to balance it going back up.
Trans is in the "fixture":
GM provides this bolt boss for a fixture. I've done better welding. Shut up.:
It balanced pretty well:
In the stand and draining some more:
