'68LT1camaro

I'm thinkin' about ditchin' the six speed, and getting this TH400----> ***CLICK HERE*** then click TCI-212500

This will be in a daily driver. I'm looking for suggestions from guys that run TH400's or Powerglides with trans-brakes. What do you guys think? Thanks.

Stephen 87 IROC

I used a TH400 for a couple of years. I started having problems by not having reverse or a transbrake. After fighting the problem by even moving the transbrake into a different case I finally installed a powerglide and never looked back.

As a daily driver, you'll want the Th400 just because of the extra gear. It's a much bigger and heavier tranny through plus it eats up more HP. You'll need a slip yoke for the TH400 since it's different than all the other GM tranny yokes. You're also going to need to fabricate or buy a new tranny crossmember because of the TH400's extra length to the rear mount. The full manual means you can't put it in D and drive away. You'll be starting off in third gear and will burn up the clutches. Reverse pattern means instead of PRN321 the gear pattern is PRN123. That means it's impossible to go from third gear to neutral without downshifting first. There's nothing in that listing that says they use the 34 element sprag but I have to assume they do or it wouldn't be for "drag racing" The weak 9 element sprag is easy to destroy.

A typical powerglide uses 18 hp and weighs 97 pounds
A typical TH400 uses 44 hp and weighs 130 pounds

'68LT1camaro

Stephen, did your reverse and trans brake start to act up on you? I'm not sure what you mean by "I started having problems by not having reverse or a transbrake."

Stephen 87 IROC

Using a transbrake means you have the transmission in first gear and when you apply the transbrake, it applies reverse at the same time. When one goes, so will the other. I never did figure out what the problem was. The tranny is still sitting on the floor in my garage. I know all the clutch packs and rear band adjustment were ok so the only other thing it would have been was an internal hydraulic leak somewhere preventing the transmission from applying the reverse gear.

tonyss1

I have been running a TH400 for the last 3 years with a trans brake reverse manual valve body and have never had a problem with it. You can get some lightweight internals for it from ATI performance to help with it not eating up so much HP an aluminum drum will save 6 to 8lbs of rotating mass inside the trans and is good for 1500lbs. of torque. T

'68LT1camaro

Tony,

does your car see alot of street use? My car is a daily driver, and I've heard that it's not very streetable with a setup like this. I had a '67 SS Chevelle with a TH400, but it was stock. Is it the stahl that makes them a hassle to drive, or just no overdrive with big gears out back?

__________________________________________________ ______Raymond

Birdie2000

The stall doesn't help, but in my case it was the lack of overdrive. Going 70 down the freeway @ ~3600-3800rpms in a blower car is not fun. It's noisy and brings the car into boost just for normal cruising. Also, you'll more than likely loose engine braking with the full manual.

FWIW, I have a transbrake and can still put the car in reverse and it reverses. No need to apply the brake.

rskrause

I responded to this already in another forum and advised against it for a car that sees heavy street use. Even with the 3.42's in my car, the combo is damn near intolerable on the highway so I am going back to a T-56. What I wanted to add was that I just noticed mention of a PG in the initial post. As someone who has owned street cars with a 'glide as well as race cars I just want to say: don't even think about a PG for a street car. Much worse than a non-OD 3-speed. I can't tell you how often people swapped out PG's for TH350's or 400's in the old days for street rods. And none of them ever looked back!

Also, a free plug for me: for those who are going ahead with a TH400 swap I am selling mine. It's a top of the line unit from Rossler and has seen ~1,000miles on the street and maybe 20 runs at the track. It was built for street/strip use up to 1,100hp in a 4,000lb car.

Rich

tonyss1

68LT-1 , My car only see's about 300-400 miles of street miles anually though the converter and the trans can handle it with the trans cooler i have. I have had it driving around town at the local cruises in 90 plus degree heat and it never got above 200 degrees though its definetly not a daily driver. I would not recommend a th-400 for a daily driver as there are other trans with overdrive that are more suited for this.

'68LT1camaro

I appreciate the responses guys. I guess I'll hang on to the T-56.

speedmiser

I really like the TH400 on the street - been running a manual valve body TH400 for over 3 years w/ 3.73s - still was a daily driver up to a year after the TH400 install w/3200 converter. I was originally running with 26" tires, so the rpms were a little to high for long trips on the highway. When the 28" tires went on, the freeway driving greatly improved. But, I took it out of daily driver status, when the welds and the cowl hood went on. I could still daily drive the car, but I just don't like leaving it in parking lots anymore, although it still see's occasional commuter trips to the office, when it's nice outside. Of course, it's still not something I would take on a long trip, mainly due to gas milage and the LOUD exhaust tone.

Right now I'm running a 4k stall w/ the s-trim pullied to make almost 14psi. I don't see any boost freeway driving at 70mph - bypass works fine.

Over the years I've driven quite a few vehicles as daily drivers with TH350s or TH400s - never had any problems with the trannies. I guess it all depends on your comfort level of daily driving. But if you've driven the Chevelle with a TH400 and didn't mind it, I don't think it will bother you in the camaro, even with a larger stall. Gas milage will suffer, and you've got to give it a little more gas to get moving, but other than that, there's no significant draw backs to a decent sized street converter.

IrocSS85

what about adding a gearvender overdrive? I know its expensive, but it does offer all the same bene's of the th400, and you can cruise on the freeway. Ive heard of guys with fbodys using this, but have never seen one on a car. I imagine it would be a pain to fit, bt maybe not? anyone got a comment/opinion?

CHRIS

Injuneer

I have a TH400/Gear Vendor setup. The trans has a 5,000rpm flash stall (800lb-ft) converter, reverse manual valve body, Perma-Cool fan assisted cooler and a B&M Pro-Ratchet shifter. The Gear vendor definitely helps for freeway cruising. Running 4.11's and stock 25.65" tires, without the GV it was churning out a shade under 4,000rpm at 70mph. With the GV, this is reduced to 3,100rpm.

The problem with the GV is the added weight.... I'd guess is added another 40-50# to my already bloated car. Even with most of the typcial weight reduction items - no A/C, no bumper supports, no rear exhaust, lightweight wheels/tires, no back seats or stock harnesses, race sear, etc. etc. the Formula still tips the scales at a beefy 3.625# (and I'm only 185#).

The GV is a high quality piece, and performs as advertised. It will hold up to a full throttle shift into O/D at over 1,000HP (not in my car ). The only ratio is 0.78:1... it would be nicer if they offered something closer to 0.70, but I guess they encourage people to use it to "split" the gears, turning a TH400 into a 6-speed.

http://cjcfo.fbody.com/members/injun.../DCP02954a.jpg
http://cjcfo.fbody.com/members/injun.../DCP02957a.jpg

(ignore the rusty front mount for the TA, that was a project for Steve Spohn)

IrocSS85

does the gear vendor also soak up more HP to turn it? and what do you use for a driveshaft safety loop now? custom one on the TA? any clearanceing nec. for the gear vendor to the floor pans?

Injuneer

Gear Vendor fit in fine, no clearance problems. Steve Spohn welded the DS loop to the side of the torque arm for me:

http://cjcfo.fbody.com/members/injun.../DCP03672a.jpg

I don't think the planetary gearset in the GV eats up all that much power. I took a huge hit going from the T56 (12.2% loss at 760HP) to the TH400 before the GV (21.3% loss). The GV was installed a bit later, and by then the HP had been bumped up a little more with a little more juice, so I don't have an exact number for the loss.