Game ova

Ok, so I'm thinking of building my first automatic transmission. I'm looking for people that have built their own transmission, and for them to give me their impressions on the level of difficulty of getting it right. I'm fairly mechanically inclined, if this helps any. Reason I'm wanting to do it myself is simple, it's cheaper this way. I don't like paying people for things that I can do myself.

forcd ind

iTrader: (7)

I do my own, the hard part is actually looking at a part and deciding if its good or not-you can rebuild the clutch packs with most tools people have in the shop, and knowing how to set the clearances, along with a set of bushing drivers-there are little tricks you can do building one that adds to its life.
There may be some books out, the old 400 book by Ron Sssions has been out of print, I have had mine for years
Even the best builders can sometimes have to go back in one, so if you screw up the first time don't feel bad, lol.
I am not good enough to take a pile of parts and put it together, I have to take it apart, lay it out just like it came apart, rebuild each section

Jays_SSZ28

iTrader: (2)

the th400 is about the easiest GM trans to work on in my opinion.

There are things to know though. The first one I did broke the second gear roller clutch, since then I use an early th400 or any 4L80E direct drum with a sprag instead of roller clutch.

Game ova

Yeah, there are a couple of things that I'm afraid of. One is getting it wrong, and killing the transmission....along with my new $1000 torque converter. Another is, getting it wrong....and killing the thrust bearings. I have to admit, I'm pretty nervous about it. But then I think, maybe once inside it's really not all that complicated. Decisions decisions.

Game ova

is the 4l80 direct drum a simple swap with no modification?

Game ova

When that roller clutch let go, did it send anything through the converter?

Jays_SSZ28

iTrader: (2)

No, it was in a friends truck and he didn't run it much after he realized there was a problem.

The 4L80E direct drum always went right in for me, I have one ebay right now But the one I have has a 16 element sprag instead of the 34. There are a lot on there now for a decent price.

One other thing I did wrong was use rags/towels on parts. That transmission wouldn't go two days before lint got stuck in the downshift solenoid making it not upshift.

98CayenneT/A

I rebuilt my own about 10,000 miles ago. I was tired of paying trash local shops to do a rebuild so I dove in head first. Although mine was a 4l60e, it was quit fun and interesting and honesty my car has never felt so solid with the help and advice of a few that hang out in this section.

I absolutely beat the **** out of my car/transmission and it's awesome to know when it goes out I can deal with it myself. Another plus is turnaround time.
Paying a shop is 1-2 weeks turnaround. Fix it myself if absolute need be could be a two day turnaround depending on what broke and not doing a complete rebuild.

I went into it blind for the most part besides reading previous threads on here.
Here is my 4l60e thread if ya wanna see some of the things rookies run into
https://ls1tech.com/forums/automatic...e-rebuild.html

clinebarger

You can't condemn 34 element sprags just because you broke One, A good drum with a New Borg Warner Sprag is a pretty tough set-up!

Jays_SSZ28

iTrader: (2)

What the hell are you talking about?

Where did I say I broke a 34 element sprag?

Game ova

LOL, I thought it was just me that was confused. Maybe it's just another name for the part that you broke?

Game ova

Thanks man.

Game ova

So I checked your thread out. And man, by the 2nd or 3rd page I had a migraine. Felt like I was reading Japanese, I'm discovering that transmissions are a whole different world from let's say a motor or rear end.

98CayenneT/A

I hear ya man, but in general once you get into it, it is not as over whelming. Just stay organized.

As you can see in my thread I had plenty of room and a nice table to set things during disassembly. I think I had the transmission gutted in a few hours and set out. Then from there I just took each individual assembly one piece at a time. As in the pump, then put that back on the table then went threw the input drum, pulled the valve body apart and cleaned and inspected for bore wear ect. just one section at a time.

Imo I say dive in head first. It was kinda fun. And honestly what's the worse that can happen? The good for me is that as long as I'm rocking a 4l60e I will never have to pay another $1,500 rebuild bill. And say I had a track event coming up in a few days but was bashing on my car and the 3-4 clutch pack or something went out. I'm am not stuck being down weeks and missing events, I can bust *** and get my transmission out, fixed, and back in and still make it to my event.

clinebarger

Sorry, I read your statement wrong, The early th400 part threw me off because you don't see many sprag type TH400 drums anymore.

forcd ind

iTrader: (7)

LS engines do seem to not like the thrust bearing being pushed on, I lost one, and have seen others write about losing one-some have no problem, and there are some tricks used to get the bearing more oil.
Converter charge pressure??? measured at the cooler line can be controlled diff ways-I did a monkey see monkey do deal, lol, drilling and tapping the pump and installing a restriction to help.
Maybe one of the more experienced builders will comment on that

Game ova

Yea, that crossed my mind as well. I've seen (read) people who had that issue, but maybe it just comes down to paying attention...I dunno. What I do know is, it would suck to kill a transmission....and in the process, take out my motor too lol. Havent cried in years, but I believe that I would that day. But then I think, I could do like 98CayenneT did and really lean on the knowledge that some of these guys here in this room have. Sometimes I think I get in my own way, there's nothing wrong with asking questions about something I really know nothing about.

truckdoug

iTrader: (25)

do eet. get the atsg and crack that sucker open.