Thread: 4t65e rebuild...the sequel...

I got the tranny back out today. For those not familiar with this, I rebuilt the tranny in my 2000 Oldsmobile Intrigue a few weeks ago with less than stellar results...heh, there's an understatement. Well, it promptly burned out the second gear.

Anyway, I tore it apart and holy cow. I hate to tease those that have been following this, but pics will have to wait a bit (did take several for your viewing, laughing pleasure) because I have to run to town. Give me an hour or so. You won't be disappointed.

Not laughing here - that sucks man.

Please post pics tho.

Yeah, I know what you meant five...that was pretty funny, and believe me, I needed the laugh.

Here you go:

As suspected, the problem is definitely in the 2^nd clutch hub. I don’t know if it’s cracked or not, and don’t really care at this point. I’ll explain my reasoning in a minute. But first, some pics…


Um, those that are squeamish might want to turn away…

Something was getting HOT!!!:



Didn’t have a problem with third, but what rides against the 3^rd housing? The 2^nd housing:



Why did the 2^nd and 3^rd housings get so hot? Well, there’s your problem:






See where I’m pointing? When I originally air tested the clutches, I heard a lot of air leaking. I never inverted the 2^nd clutch by itself while testing. If I would have, as I did today, I would have seen where the leak was. I filled the apply passage with fluid, quickly inverted it, and hit it with 40psi. Fluid blasted out of the space between the 2^nd clutch shaft and the driven sprocket support shaft:


And finally the cause of all of this:


Do you see it? I didn’t think much of it during the original rebuild. Shame on me.

Remember what the original problem was…no second gear. Rebuild failure, no second gear. The new clutches were completely destroyed (when the originals were not) because of one little detail. I added an extra steel to the 2^nd clutch stack to tighten it up some. I made sure it was within clearance specs as advised by Dave. The extra steel didn’t cause the problem, but consider: Originally, there was a lot of clearance in the 2^nd clutch stack; enough, in fact, that the loss of pressure kept the clutches from engaging at all. The new clutch stack was much tighter and was able to partially engage, but slipped like mad making it feel like a mis-shift.

Of course everything has to be cleaned now and I need some new 2^nd clutches along with the hub, but at least I know what went wrong. I just wonder if I should also replace the 3^rd hub as well. I think I will, just to be safe.

For those that don't see the problem:



The arrows are pointing to wear marks inside the 2nd clutch hub. Those wear marks coincide with where the sealing rings ride. Between those seals (indicated by the dots) are the apply holes for 2nd gear. The wear is severe enough to allow substantial leaking.

Originally Posted by dsmuts

You're going to do all this and that 3.5L is gonna blow a head gasket lol

That's not even funny. Actually, it is. I told the wife the same thing...LOL!

I thought long and hard about rebuilding my tranny myself. This is why I chose not to. I was terrified of being a victim of my own tranny ignorance. I don't know the fine line between acceptable wear and unacceptable wear. I think trannys are the line of demarcation where I leave it up to the professionals.

I'm really sorry this happened to you - it totally sucks.

I know how much of a pain it is to drop your tranny. I cant imagine how much it would suck to tear back into a tranny you thought you would never crack open again.

I know I have my cradle cleaned and re-painted, all my wires all tucked up neatly, the engine scrubbed with simple green and rags, all the hardware wire-wheeled and cleaned waiting for my rebuilt unit. If I have to drop it again, even though it's under warranty, I would be very disappointed (actually irate).

It sucks that there isn't a bench dyno or something for a tranny that would allow you to see if it works before reinstalling.

Yeah, I know what you mean. I didn't know the difference between acceptable and unacceptable either. I have nobody to blame but myself. I saw the wear marks and wrote it off. At the very least I should have been more aggressive in my testing procedures. However, even with the failure and replacement parts (if it works this time) I will still come out cheaper than buying a rebuilt tranny, and learned something along the way. I was definitely worried about doing it myself, and believe me, I didn't want to. But, money being what it is, I was backed into a corner. It certainly sucks, but maybe it will work this time. Lesson learned; any wear is unacceptable.

Originally Posted by agrazela

Tomorrow I'm tearing apart a donor parts 4T65E from my Mother-in-Law's 1998 Olds 88 for some stuff for a rebuild of my own, mostly bolts whose heads I've stripped. Let me know if you need any hard parts, if I don't need 'em they're yours for the cost of shipping.

EDIT: dead before I began. Stripped some of the Torx 40 bolts, not gonna get this thing apart today.

I know what you mean. I stripped one of the channel plate bolts myself. If you get in that far, maybe you could hook me up. Also, if the 3rd hub looks OK, I would be interested. I'll put new teflon rings on it. As you can see, mine got pretty hot and I just don't trust it now.

I appreciate it guys. I should have a complete list tonight.

It's not tonight yet.

Now it's tonight...

Here is a list of parts I need. I have to assume the entire 3^rd hub assembly was destroyed by the heat. The drum is severely discolored so I’m taking no chances. There are only a few hard parts. The 2^nd clutch pressure plate is the one that rides against the top snap ring (it has a bevel on it).

*Valve body gaskets
*Channel plate gaskets
*2^nd clutch sealing rings
2^nd clutch hub
*2^nd clutches
2^nd steels
.090 2^nd steel set
2^nd clutch pressure plate
*2^nd piston
3^rd clutch hub
*3^rd/input Teflon sealing rings
*3^rd clutches
*3^rd piston
*3^rd inner lip seal
*Input inner lip seal
*Input outer lip seal
Rear input drum bearing
Could use a Channel Plate, but not desperate for it.

*Denotes new parts only.

Any help is greatly appreciated!

Gonna try to crack open my donor trans this Sunday. Will let you know if successful. Looks like I need nothing out of it myself, was planning to eventually break it down for scrap metal value anyway, so you can have anything you want out of it.