anyone know about automatic tranmissions?

[psycoreefer]

I'm wondering if there are any automatic transmission gurus out there in XS land. The 4L60 in my SWMBO's truck just gave up and I'm unemployed at the moment so I was considering doing it myself. I consider myself good at wrenching and I've rebuilt motors and manual transmissions before but this will be my first auto and I'm a little scared. If I do it I'm going to get the ATSG books and use those as a guide. I'm looking for input on what parts to replace for sure and what parts are usually OK to leave as well as input on if I should go with a "heavy duty" rebuild type kit with corvette servos and such or if I'd be better off with a "standard" rebuild. We don't do much towing and this one lasted 200,000 so I'm leaning twords standard.

[The Lorax]

I know they have 200+ moving parts, and somewhere in the neighborhood of 6 different clutches, but that's about it, beware of little parts jumping out when you remove the pan (I've heard stories). I don't see any reason why you can't do it, get a good manual and read it thoroughly, I suspect you'll be fine. it's a machine, a little differnt from an XS, but still a machine. I'd never rebuilt an engine before my shift fork decided to break, so why not? take your time and all will be well. have a nice day and ride safe

[oseaghdha]

I did my 700R4 about 5 years ago, still works great.
Do get a good book. Shop around for a kit.
Usually, it's just the clutch packs that get used up, but I don't know how it failed. Mine lost 3rd and 4th about 50 miles from home with my two dirt bikes on a trailer. Took a long time to get home in 2nd.

You may be able to borrow special tools from the Zone, I dunno.
Best if you have a big long bench to lay it all out on.

Main thing is keep everything clean and be careful with the seals.
If it had a major failure, you may need a rebuilt converter.
I'll look in my garage and see if I have the 4L60 book or not.

Oh yeah, you will need about 10-12 quarts of fluid with a new converter.

[b.walker5]

They're basically a hydraulic pump with a number of clutch packs to facilitate gear changes, and it's the hydraulic side that stops most people from tearing into them. They normally require a bunch of specialised tools to check pressures and preloads etc which most would be home mechanics don't have access too. That being said I've been inside the Turbo 400 in my old hotrod to replace the front clutch pack and band and got away with it, that was done through the front, and I've had the valve body out of the trans in my Maxima, to replace a broken spring on a detent lever. The T400 was pretty simple but the Maxima job was a nightmare, mostly due to the front wheel drive, and theres a lot of bits that can fall out of place if not careful. Whats actually wrong with yours, has it given up driving completely or only one gear, It could be simply a blocked intake filter in the pan which is stopping oil pressure. Pull the dipstick and check the colour and smell of the oil. Dark and burnt is usually a sign of clutch trouble, bright and sweet is good. Of course this depends on how long it's been in there, hopefully not the full 200,000. As Lorax said, get a good manual and take your time and you should be fine. Thoroughly read the diagnostic section of the manual to isolate your problem first !! it could be a simple problem that doesnt require too much digging. If you do have to dig deep take lots of photos on dissasembly, theres always a part left over Lets us know how you go.

[psycoreefer]

It failed about a block from home, a thunk then loss of power, it now makes a whirring sound when its in any gear but park and I have no reverse but forward 1st works ok. From the reading I've been doing I think the "sunshell" is broken, it is one of the weak links in this trany and the usual mode of failure matches my symptoms, no reverse and no 2/4th. the fuild is still nice and red and clean. No matter whats wrong I've got to pull it out of the truck and with 200,000 on it i'm not going to go to all the work of taking it out and not have it rebuilt or completely rebuild it myself.

[TopCatGr58]

It's been a few decades since I was in the Turbine 300...(similar 2 speed autotrans like a Turboglide) in an old firebird I had. I thought it was slipping, had 65K on it, but turns out it was just the nature of the beast, high stall speed and high geared 1st, could go from 0 to 80mph at close to redline!!

Anyways, I went to AAMCO, and asked to buy one of their kits. They asked if I'd ever worked on a tranny before, I said nope! They said that they didn't think I could do it! I said, look, if I do get it done, then you've at least made the profit on the kit, IF I don't get it right, you'll see me anyways! They sold me the kit!

The clutches were in a nice pak on the main shaft, removed the pump assembly from the front, dropped the pan for oil changes and to put in a SHIFT KIT, put it all back together...but missed a valve body "PIN" that had fallen out of position, NO torque, 1st was reverse, or such, but was able to limp it to the AAMCO, they dropped the pan, and repositioned the valve, and viola, it worked flawlessly.

Nothing ventured, nothing gained or lost! Go for it!!
T.C.

[andysutt]

Im not chevrolet expert, but from what I've read up on the corvette servos, you shouldn't use them. The stock ones are better for regular driving. I forget what happens with them, but heard alot of bad things on several forums last year.

Buy the book and take your time, Im sure you can do it.

C4 and C6 ford transmissions, and Turbo 350 and 400s are easier, but the overdrive ones can be done with a bit more patience

[Yahman]

I used to rebuild transmissions professionally and while many are rebuild-able by a novice, I would not call the 4L60 one of them. They require some special tools and there are a lot of parts. It needs to be rebuilt in a very clean environment and every part has to be very clean. The result of its failure is this very fine gunk lodged in every nook and cranny. This comes loose once it's reassembled and can really cause some headaches.

If you do decide to rebuild it, make sure you have lots of space to lay things out. Also do plenty of research before hand, a good shop manual is a must have. I'm not sure it can be done without some of the special purpose tools.

Larry

[psycoreefer]

As I said I do plan to buy the atsg books for it, and I have a good clean work space to use once the transmission is out of the truck. I also realize there are some special tools, a couple of clutch pack compressors and some seal installer/resizers that are needed. I figure I don't really have to count the tool investment because after I'm done I can re-sell the tools on e-bay.

[red bandit]

I bought a cd for rebuilding the T400. The guy walks through EVERYTHING step by step with very good visuals. Well worth the $30 and a lot better than a book, for me anyways. Just a thought.

[Crazcnuk]

The 4L60E is the electronic version of the TH700R4, I believe. Just like the 4L80E is the TH400 electronic version.

The TH700s are not considered to be a very good transmission, but the 4spd is nice.

I spent $600CDN for a beefed up TH400, right from the rebuilders. They put a heavy duty sprag, and some different plates, or something.

To get a TH700R4 built to the same specs was $1900CDN, to give an idea of how much has to be done. Th700s are far more common than TH400s, so rarity is not the issue.

You just have to be very careful that you keep each sub assembly complete and seperate. A bunch of ice cream pails will help, and don't be shy about taking lots of pictures as you go.

While you're in there put in a good RV style shift kit (not the shift improver, a full kit).

[psycoreefer]

This is the kit I'm thinking of going with if I decide to do it myself. I'm still not sure, I'm going to pick up a book or video and watch it first. Thing is that there is a local shop that said they could do it for a "worst case" of 1300 and more like 1100 probably. That said If I spend 500 on the kit and another 200-400 on the special tools I'm only just a touch cheaper then them and they've got the experience etc. I'm hoping that I can get away with out using the solid seals that need the "resizers" to make them fit properly. If thats the case I can rebuild it for about 600 which is enough difference I might do it myself. Thats why I was hoping to find someone here who does it so I could pick their brain about which tools are really "needed" and which ones just make it easier.

[Yahman]

I'm not trying to discourage you, but using the proper tools is one of the keys to a successful rebuild. Sometimes you can get by without them, if you have plenty of experience and know the little tricks to the trade. Just one cut seal (it's easy to do) or mixed up springs and you'll probably wish you had paid someone else to do it.

Larry

[olebiker]

I consider autos to be magic, seeing that I do not have a wand nor a tophat, I wouldn't touch one.