Swapped the C4 for a TH400:

[93PONY]

I just fired up the car & took her for a test drive with the new TH400.

The conversion went well, although a bit expensive since I wanted the speedo to work (over $300), bought an AJE crossmember ($145), a custom steel driveshaft with 1350 U-joints ($200), Ultra-bell, & Ultra-wheel. Lenny at Ultimate Converter took care of the TC. He swapped the internals of the Ford converter into a chevy housing & had it back to me in 1 week!

I also swapped to 2.73 gears from 3.55's.

First impressions is part-throttle is slugish compared to the C4 with 3.55's....but that's to be expected. Other than that I love that it doesn't pull 3K RPM to cruise at 50mph in 3rd like the C4/3.55 combo did. 3K in first gear is 30mph now.

I'll be dialing in the tune in 2nd gear if I get a chance in the next few weeks. (If the weather holds out when I have some time)

All-in-all, the tranny fits like it was ment to be in a Foxbody.
Only minor mods to get the B&M hammer to work with the TH400, Ultrabell fits great, tailshaft position is great (don't need to shim it to get proper angle on the U-joint). We'll see how she does at the track.....that's the true test.

[lxarlo]

I just fired up the car & took her for a test drive with the new TH400.

The conversion went well, although a bit expensive since I wanted the speedo to work (over $300), bought an AJE crossmember ($145), a custom steel driveshaft with 1350 U-joints ($200), Ultra-bell, & Ultra-wheel. Lenny at Ultimate Converter took care of the TC. He swapped the internals of the Ford converter into a chevy housing & had it back to me in 1 week!

I also swapped to 2.73 gears from 3.55's.

First impressions is part-throttle is slugish compared to the C4 with 3.55's....but that's to be expected. Other than that I love that it doesn't pull 3K RPM to cruise at 50mph in 3rd like the C4/3.55 combo did. 3K in first gear is 30mph now.

I'll be dialing in the tune in 2nd gear if I get a chance in the next few weeks. (If the weather holds out when I have some time)

All-in-all, the tranny fits like it was ment to be in a Foxbody.
Only minor mods to get the B&M hammer to work with the TH400, Ultrabell fits great, tailshaft position is great (don't need to shim it to get proper angle on the U-joint). We'll see how she does at the track.....that's the true test.

why not an aod?

[250mav]

th400s are good trannys. ive got one in my cutlass.

but i am a little curious why you didnt go AOD as well, atleast for the easier instilation

[sixtyninemercury]

Is a TH400 a YVEHC trans?

[250mav]

GM actually, you could have it on ch3vys, olds, buick, ect ect ect... only diffrence was the bell housing bolt pattern depending on family

if you have a GM with an automatic big block it was probably a 400 sitting behind it.

[93PONY]

JPT re-built my MM2 C4 (it was improperly assemebled at Dynamic). JPT lightened everything up & added ~12 or so roller bearings.
It lasted 20 miles....one trip to the track on Drag radials. Ran 10.4 @135mph & 3700lb raceweight. On the way home I raced my wife's GT....she smoked me when I shifted into 3rd. The planetary exploded.

JPT said I'd break any C4 they sent me so they took it in trade for the TH400 (rollerized & lightened as well). I am VERY please JPT took care of me like this. The 400 is most definately an upgrade from a C4.

If I had to do it all over again, I'd probably buy a Lentech 4R70W. We put one in a customers TT 03 Cobra. Came with a non-lockup 8" converter. First time to the track the car ran 9.8 @139.8mph. With 1psi less boost it went 9.9 @137mph. 1/8th mile on this run was identical to my TT 93 Cobra (both cars running the same boost & rear gears), yet from 1/8th to 1/4 my car is slower by 2 mph & 2 tenths. I am impressed with how that thing came out of Lentech ready to go. I've been through 2 converters & 2 restalls with my own TT car to get it *close* to what the Lentech did right off the bat.

[93PONY]

Track update:

Couldn't get the slicks on due to interferance with the wheel & brake calipers, so I had to run on my street tires. (17" DR's)

Had crazy tire shake issues so I pedaled 1st & short-shifted into 2nd on every pass.

Best of the day:
1.86 60ft
10.74 @137.2mph

The tranny held & I had no issues with it. I'm just not 100% sure if the tire shake was due to the DR's or the 2.73 gears.....or perhaps a combination of both.
Hopefully I'll get back out there shortly on slicks & see what she can do.

BTW, LOVE the 2.73's on the street.

[illdrag]

just curious...which dynamic you were dealing with? Connecticut or Delaware?

[93PONY]

I don't remember. Sorry.

[93PONY]

Update:
Car went a best of 10.25 @140.3mph with the TH400....before it blew.

Had problems with reverse shorty after install. Worked ~50% of the time.
Trany started making a buzzing sound so I yanked it & took it to a local shop that's been around for years.

Turns out I got screwed....yet again.
I was told by Jim at JPT that this TH400 would handle over 2000HP, had a lightened rotating assembly, roller bearings & had all the goodies save for an aluminum trany pan (which he said I didn't need till I started pushing a lot more HP).

Got a call from ATO today.....
2nd gear is gone, 3rd is on it's way out & he said he was surprised I had reverse at all.
Looks like I was sold a stock TH400 with the following:
TCI Reverse-manual valvebody with brake (not properly modified for reverse to work correctly)
Rebuilt with a good set of clutches & bands
Everything else is stock.
So....it blew.

All the stock Iron components are being replaced with Billet steel like they should have been from the get-go. Valve body is being modified with a check valve so reverse works correctly (& doesn't bleed off all the oil back into the pan like it's been doing). 3rd gear is being upgraded to the 6 clutch setup (like it should have been), pump is being upgraded to a high-volume unit (should have been done) & the case is being modifed as well for more strength in the retainer groove area.

I'd advise staying away from JPT in Michigan.
I should have known better. It's always best to stick with local shops.

[BADASS03SVT]

yikes...sorry to hear of all the issue's man. all worked out yet?

Lentech 4r here....about 3k miles and maybe 100-125 passes all in the 10.7-10.8 range and a few 10.2 passes. runs absolutely perfect.

[93PONY]

Threw the ATO built TH400 in the wife's all-motor 347 to test it out....both performance & drivability.
It's a good thing too.....there was a minor machining operation that was missed & it sent aluminum shavings through the trans. ATO took care of it & the converter is at UCC getting a freshen up.

The car is scheduled to be at the Pinks All-out Event in 4 weeks.

[FATNFAST]

How much horsepower are you pushing through the th400?

[FX331]

I am in the process of this swap now.... What Headers did you use> I have been told that my Bassani LT's wont work.

[eamblk50]

I just fired up the car & took her for a test drive with the new TH400.

The conversion went well, although a bit expensive since I wanted the speedo to work (over $300), bought an AJE crossmember ($145), a custom steel driveshaft with 1350 U-joints ($200), Ultra-bell, & Ultra-wheel. Lenny at Ultimate Converter took care of the TC. He swapped the internals of the Ford converter into a chevy housing & had it back to me in 1 week!

I also swapped to 2.73 gears from 3.55's.

First impressions is part-throttle is slugish compared to the C4 with 3.55's....but that's to be expected. Other than that I love that it doesn't pull 3K RPM to cruise at 50mph in 3rd like the C4/3.55 combo did. 3K in first gear is 30mph now.

I'll be dialing in the tune in 2nd gear if I get a chance in the next few weeks. (If the weather holds out when I have some time)

All-in-all, the tranny fits like it was ment to be in a Foxbody.
Only minor mods to get the B&M hammer to work with the TH400, Ultrabell fits great, tailshaft position is great (don't need to shim it to get proper angle on the U-joint). We'll see how she does at the track.....that's the true test.


What minor mods did you do to the hammer shifter? I just did this mod with a B&M hammer and cant get park to align properly?? 1 2 3 N R all line up, but when i shift to park the trans lever still has more to go to fully be in park.

[eamblk50]

I just fired up the car & took her for a test drive with the new TH400.

The conversion went well, although a bit expensive since I wanted the speedo to work (over $300), bought an AJE crossmember ($145), a custom steel driveshaft with 1350 U-joints ($200), Ultra-bell, & Ultra-wheel. Lenny at Ultimate Converter took care of the TC. He swapped the internals of the Ford converter into a chevy housing & had it back to me in 1 week!

I also swapped to 2.73 gears from 3.55's.

First impressions is part-throttle is slugish compared to the C4 with 3.55's....but that's to be expected. Other than that I love that it doesn't pull 3K RPM to cruise at 50mph in 3rd like the C4/3.55 combo did. 3K in first gear is 30mph now.

I'll be dialing in the tune in 2nd gear if I get a chance in the next few weeks. (If the weather holds out when I have some time)

All-in-all, the tranny fits like it was ment to be in a Foxbody.
Only minor mods to get the B&M hammer to work with the TH400, Ultrabell fits great, tailshaft position is great (don't need to shim it to get proper angle on the U-joint). We'll see how she does at the track.....that's the true test.


What minor mods did you do to the hammer shifter? I just did this mod with a B&M hammer and cant get park to align properly?? 1 2 3 N R all line up, but when i shift to park the trans lever still has more to go to fully be in park.

[93PONY]

What minor mods did you do to the hammer shifter? I just did this mod with a B&M hammer and cant get park to align properly?? 1 2 3 N R all line up, but when i shift to park the trans lever still has more to go to fully be in park.

That's normal.
Don't worry about it. Park still works just fine.

[DirtyD0g]

I think on a 5.0 liter I would consider the c6 over the 400. Stock for stock the c6 is just plain stronger. I'm surprised the 400 didn't have better parts. Most people don't realize that most of the better parts for them are just 4l80e parts so they aren't terribly expensive custom built stuff. The power of knowledge I suppose. For what it is worth I think people who are making the amount of power to much transmissions should buy a spare for their car and learn to build that transmission themself. That could be just me having little faith in most transmission shops. After over 14 years of working with them and for them you see some pretty rediculous stuff. Junkyard transmissions painted resealed and installed. People getting charged $4000 for a solenoid replacement that took 1/2 hour and a $200 parts. One Aamso I worked at kept about 3 cars a week because the owners couldn't afford the repair. The best was a guy stealing his own car that had never been touched because the shop foremen said it was done just needed to be test driven....made it 1/2 a mile and got arrested for stealing his own car.
I am interested to see how the 400 works for you, generally I think if a c4 won't take it you need a glide. I don't like heavy transmissions on high rpm applications.
Alan
Alan

[93PONY]

Alan,
Thanks for the insite.
Lucky for me the local shop I've been working with (ATO) does buisness just like me. Trans get torn down & he calls to have the customer come in & check out the damage. New parts are ordered & when they arrive he calls the customer to check out the new parts.

Unfortunately my TH400 has been apart 3 more times. The Billet Aluminum Drum had clearance isues that didn't show up till fluid pressure & power was put through the trans. 3rd gear was also getting some fluid pressure when in 2nd & was getting torn up. Jim at ATO has taken care of it every time at no charge. Although it's not fun pulling the trans every time, I'll gladly do it (I own a shop with a couple lifts). Taking care of a customer like that is rare.
This last time around Jim found another problem. On both my TH400 & another customers. The drum splines aren't a 'tight' fit on the shaft & there's nothing else to support the drum. It was wobbling on the shaft which allowed fluid past the seals into 3rd gear (when not in 3rd). I guess it's a design issue with the 400's.... Jim made a bronze ring to stablize the drum. He also swapped out the modified Iron valve body (from JPT) for a custom Billet aluminum piece with shorter fluid passages for quicker response.

We shall see. I just re-installed the trans yesterday.

I have a feeling this TH400 may NEVER be able to handle my car. Car weighs 3650lbs in 'race' trim going down the track. Another 100lbs in street trim (which I plan on running from now on). 2.73 rear gears, 28" tall drag radial in street trim. Peak HP at 5500RPM & peak TQ around 3500RPM, so a tight converter is called for.....& I just upgraded the fuel system & installed a boost controller & plan on turning up the wick.
That's a LOT of torque with the gear/tire combo to push through any transmission.
I've been told a PG may be the only trany strong enough to handle the car....but that's what I was told about the TH400. LOL

[darkhorse]

Wow that's crazy!


What is needed to get the speedos to work?

This notch is a 557BBF n/a car and runs a box stock th400 with Rossler brake VB

www.gnlmotorsports.com (http://www.gnlmotorsports.com)


The red convertible is a 408" PT88 turbo car that put down near 1000rwhp and runs a full roller Vince Janis built TH400 w/Rossler brake

8.50's - street driven :shock:

http://www.youtube.com/watch?v=dSKwHDWl6Z4
http://www.youtube.com/watch?v=mLF2uOajkn8&feature=channel
http://www.youtube.com/watch?v=BZd0GAt4uFA&feature=channel

[SilverFox]

I think the C6 is a transmission that, like the AOD has a bad name for crap reasons, and that the 400 has a good name for no reason. The C6 is a quality trans that with a little work is a beast for sure.

[DirtyD0g]

Unless your goal is sub 8 second 1/4 mile passes the 400 can be built to handle it. I know of several grand nationals running them that are well into the 8's
Alan

[darkhorse]

I've spoken with Alan in regards to the C6 and it's strength, he's confident that a C6 can handle anything that I would throw at it.

Biggest problem is that it's hard finding someone willing to put the time into properly building one, and finding a /brake VB seems to be harder than finding Bin Laden :?

TH400 is everywhere in any configuration that you could possibly dream up.

[93PONY]

My TH400 is identical to the Ultimate Vasco unit from Mikes:
http://www.mikestransmission.com/catalog2.html
With the following exceptions:
Modified case for better bracing in the retainer groove area.
Extra roller bearings (from when JPT "built" it)
2.48 straight tooth gear set
6 Clutches instead of 7 in the forward drum
Braced Forward drum for better seal control
Billet Aluminum Custom valve body with brake (Reverse-manual)
High Volume pump
JW bell indexed to the block
Steel 'truck' deep sump trany pan. (10.5qt total capacity)
Bar/plate trans cooler with -6an Teflon lines

ATO has been building these things for over 30 years....everything that can be done, has been done, including custom modifications specific to this TH400. If it doesn't hold, we tear it apart & figure out why. As it sits there's a design 'flaw' that makes the TH400 weaker (in heavy cars with low gears & lots of low-end TQ) than the PG. Something about the 3rd gear clutches rubbing together when in 1st & 2nd? & some other issue when used in 7500+rpm setups.

I currently run Type F fluid.

[darkhorse]

93Pony - what is needed to get the speedo working on the TH400?

[93PONY]

93Pony - what is needed to get the speedo working on the TH400?

I had a custom setup made at a Seedo shop....but I can't remember the name, or where it's located. Mid-west or East coast?

It cost over $300 with VSS hookup.
I posted in a thread on this site with the name of the company... Good luck finding it! LOL