mnypitTA

I am currently supporting, maintaining and insuring 2 cars because I sit in traffic most of the time to and from work to the tune of about 100 miles a day. IT SUCKS with my current T56 set up with the stage 3 kevlar clutch. So I bought a beater auto Cherokee. I cant afford a 3rd car payment and it keeps breaking down, so I am looking to swap to an automatic in the Z. I have seen people put in turbo 400s but was wondering how much work this would take. Will the speedo ever work again?

Is there a swap guide on the internet somewhere? Can someone give me some instructions and what I will need?

Thanks
John

WJH'sFormula

Why do you have a Star Stage III in your car? Unless I missed something in your sig you just have bolt ons correct? IMO, an LT4 or SLP would suit you much better and have much better manners in traffic. Hell, even with my cam (XE230/236) my car behaves very very well in traffic with the LT4 setup....

Unless you have big plans, there is no need for a TH350; you'd lose a gear and fuel efficiency not to mention having to deal with a the swap itself. A 4L60E would be best suited for your current application. Your best bet would be to find a board member with an auto wanting to swap over and simply trade hardware.

JOE96Z28SS

Can I swap HUH HUH HUH? I'll give ya my 4l60E AND a PCM for it

LOL

mnypitTA

Well I put in the stage 3 clutch because I got a helluva deal on it and I could not get a standard stock clutch as cheap. I did not intend to drive it daily after the install. Plans change. Secondly I never mentioned a TH350?? I think I mentioned a TH400. If I am not mistaken that provides a 4th gear. Also, I am not losing one gear with a TH350, I am losing 3. Or 2 with a 400.

Did you have any answers to my questions or just criticism??

I would go with a 4L60E if it werent for the fact that I have seen tons of them fail under hard driving conditions with NO mods, let alone bolt ons. I drive it hard. I went through 3 performance rebuilds of a 700R4(which is basically the same junk) in an 88 GTA in less than a year. Only minor bolt ons.

By the way I dont need a computer. I will simply have mine reprogrammed.

I want to know how to do it and what is involved, not criticism. The car will be paid off in a year and I dont want to have to backtrack and remove a junk 4L60E(assuming it survives) and do this over again when I start the bigger mods.

Injuneer

You are mistaken.... the TH350 and TH400 trannies are both non-overdrive 3-speed units.

M6 to a TH400 is fairly straight forward. You need a new flex-plate, a convertor, the TH400 tranny, a pan, dipstick, trans cooler and shifter/cable. The VSS can be made to work if you have the correct reluctor on the output shaft and the correct sensor. You will need an A4 program, but only to get the speedo set up.... obviously you will not get any other sort of computer interface on the shifting. That means you need to program all the A4 codes out. Or use one of the A4 "simulator" setups to keep the PCM happy.

The M6 cross-member can be modified to hold the TH400. Most people claim they can just slot the mount holes with a short output shaft tranny. I had to add about a 5" extension on the M6 cross-member to make it fit.

There are no interface problems with the tunnel. You will need a new driveshaft, longer, with a TH400 input yoke. You will need to get an aftermarket TA like a Spohn that mounts somewhere beside the tranny tailshaft. I think someone might now sell an apapter for the stock TA. There is a Lokar dipstick that fits, but really isn't long enough - it ends up under the cowl. Madman sells one tha fits, and the tranny cross-member. Actually, I think he has a complete kit for the TH400 install, but his stuff tends to be high $$$$.

Losing the O/D can be problematic with steep rear gears. I run 4.10's and with street tires, the engine was humming along at a shade under 4,000rpm at 70MPH. I added a Gear Vendor O/D unit to bring them down to a little over 3,000rpm. But the GV essentially doubles the cost of the swap. I was able to sell my T56/Street Twin/bellhousing blanket/Pro 5.0 shifter for decent $$$, so that paid for a big chunk of the TH400 alone.

In all honesty, I think the previous respondent was simply trying to point out that certain things, like TH400 or even a TH350 swap are generally only useful and cost effective for 500+ HP setups. There seems to be people running some really nice times with "built" 4L60E's. No, not as reliable as a TH400, but a lot more "user friendly".

TH400 + Gear Vendor

WJH'sFormula

Sorry if I came off as critisizing....Freddo was right as I was just trying to point out there isn't much of a point to the 3spd auto unless you are running(or plan to run) big power. I was merely asking about your clutch since having had an opportunity to drive a few cars w/ SPEC stage III/IV clutches, I could see where driving in stop-N-go would be a PITA...

It is a toss up with the 4L60E; I trashed my original by 86k miles and eventually went to a 6spd by 96k.



-Jason

mnypitTA

That was exactly what I was looking for, info like this. I could have sworn the TH400 was an overdrive. Maybe a 4L60E will be the solution for the next year then change it over after the car is paid off. Does anyone sell the complete changeover kits? Or should I just use a local salvage yard. The guy that programmed my origional computer can reprogram it for me again, I am sure.

I would guess the 4L60E is probably easier to swap in anyway??

Thanks for the help. Sorry I got hasty with you Jason.