[Steven S]

What options are in the WS6 package for a 78 Trans Am??
I talked with a fellow forum member a week ago and was told that the WS6 cars came with 3/4" rear sway bars, so after the phone call I checked mine and it is 3/4". but I would like to find out some of the other clues to look for.
Thanks in advance for any info.
steve

[Steven S]

Sorry! I should have posted this in the "77-81 TECH" section.

[TransAm525]

- 1.25" front sway bar
- .750" rear sway bar
- Higher rate front and rear springs
- Rear disk brakes (with specific brake booster, master cylinder, proportioning valve, and brake pedal)
- 15 x 8" snowflake wheels
- High ratio steering box

[Tom Vaught]

Agree with Trans Am525, I owned a 78 TA at one time.

Tom V.

[thumper78]

4 wheel disc brakes were not available until 1979.

[Steven S]

So there were 5/8" 3/4" and 7/8" rear sway bars??
It has 1.25 front bar.
Can spring rate be determined by number of leaves(sp?) or front coil dia.??
It does not have 4 wheel disc.
original wheels are gone
original motor is gone(already had a 455 when I got it)
3.23 rear
what is lock-to-lock on a WS6 steering box??

Most likely this is just a plain TA, right?

[Ollie]

Send for the PHS package for your car it will show exactly how the car came from the factory.
http://www.phs-online.com/order.htm

[SD73]

Originally Posted by thumper78

4 wheel disc brakes were not available until 1979.

I'm pretty sure they were available late '78, but are fairly rare.

[TransAm525]

Rear disk brakes were available in 1978, and only on the WS-6 equipped vehicles. I have even heard a rumor of a few late 1977 cars running around with rear disk brakes, but I can't verify this information for sure.

For the steering gear box, my data sheet states 15.0-13.0:1 gear (14:1 for WS-6) and 16.5-14.3:1 overall.

As far as the 3.23 rear end, this means your vehicle was originally equipped with an automatic transmission and a W-72 option Pontiac 400 (not the base L-78). Standard transmission vehicles had a 3.42 ratio. Non-W-72 vehicles received 3.08 or lower (numerically) gears.

The only two rear sway bars available for the 1978 Trans Am were the .625" bar for base Formula and Trans Am models and the .750" bar for WS-6 Trans Ams

[bobzdar]

Higher rate rear springs for automatic cars (25 lb/in higher), larger rear sway bar (3/4" vs 5/8" for regular) and 15x8" snowflakes (vs 15x7" for regular), front springs and sway bar were the same, rear discs not availalbe until '79. It may also have front lower control arm mount reinforcement bars, goes from the rear lower control arm mount to farther back on the subframe to preven deflection, unsure if that was intro'd in '78 or '79. I think the sway bars (front and rear) also got polyurethane mounts vs rubber for stock, the shocks had higher damping and the steering box was 14:1 vs 16:1 variable ratio for the regular cars.

In '79-'81, ws6 got rear discs, never heard of a '78 with factory rear discs. It's an easy swap, though, I have them on my '78.

forgot to add, tire size was 225/70r15 vs gr70x15. Look for the tire placard on the left door if it's there, if it says 225/70r15 it should be ws6, but 3/4" rear bar would also indicate ws6.

[Steven S]

Thanks *TransAm525*
You had me real confused for a bit, your first post said 7/8" rear(.875)
I didn't think any come that big stock.

[Steven S]

Thanks *bobzdar* more great info.
The tire placard is long gone also.
but it sounds like there is still a chance it might be a ws6 car, that would be great

[Lloyd-TX]

Originally Posted by Steven S

You had me real confused for a bit, your first post said 7/8" rear(.875). I didn't think any come that big stock.

FYI: 70 1/2 through '72 T/A's and Y99 equipped Formulas were OEM equipped with 7/8" and 13/16" rear bars. Later models with RTS dropped down to 5/8" and 3/4" rear bars due to the different handling characteristics of radial tires.

[MalteseFalcon]

I've never seen any documentation on rear disks being available in the 1978 model year, and have allways understood that it was not. I'd love to see some documentation on that, either from an original owner with a build sheet or some other verifiable source. I disagree with the statement that some cars had them in 1977, unless you are talking about the 8 Trans Ams that Herb Adams built for Pontiac that led the Fire Am project. Those were not production cars.

It certainly was not normal for 1978 WS6's. My car is a 1978 WS6, built May 1978 in Van Nuys, and it has rear drums.

I think that there probably were quite a few tuners or owners who converted 1978s to rear disks with factory parts, so saying you bought a used 1978 with rear disks doesn't count.

By the way, WS6's also had small braces from the rear of the lower control arms to the subframe.

[Skip Fix]

I ordered my 78 new, NO 4WD til the next year, otherwise the WS6 listing is correct.You can look through the sales brochures also and see that.The front sway bars had harder white nylon end link bushings vs the rubber on others.Also I think I read where most of the rear spring difference was really the front spring eye bushing durometer stiffness, these were not available separately as they were pressed in at the factory.The steering box was not only a slightly quicker ratio but it was a fixed ratio not variable like the standard TAs. Also Polysteel tires and shocks valved for that specific chassis and tire package were part of it also.

[larry davis]

NO rear discs until 79.
My 78 Y88 / WS6 gold SE is thoroughly documented and had drum brakes.
I swaped it over back in 89 w/ a 79 rear disc assembly.

[Tom Vaught]

opps, missed the part about the brakes, I was thinking about the sway bars and the steering box. My car was definately rear drums.

Tom V.

ps I even think on the door of the 79 cars it had a sticker that said 4 wheel discs or something like that.

[thumper78]

Originally Posted by Tom Vaught

ps I even think on the door of the 79 cars it had a sticker that said 4 wheel discs or something like that.

I believe there was a sticker on the door handle, at least on the TATA's.

Not to start a big arguement over this, but
I would love to see documentation also.
People made lot's of changes to suit their needs. That's why we're hotrodders. I'm sure 4 wheel disc made it onto many a pre 79 TA, but not as an option from the factory, IMHO .

I took delivery of my special order WS6 TA on Aug 23, 1978. Serial number 195123. Don't know how many were made after that, but new car lines usually debued in Sept.

Maybe John Wilkes could chime in.

I was checking my build sheet.
How do I determine the build date? Upper left hand corner shows 08-09 in SCHED. NO. DATE box (#10)

[Skip Fix]

They missed the WS6 on my order, and I was a month too late to get a 220 hp TA 6.6 with an auto.

Yep, mine now sports 81 4WD. A WS6 steering box from Pontiac, 15x8 honeycombs, had the rear bar, but I like the handling of the "plain" bar better. even found a X7 code 220 hp motor I have on a stand to make it how I ordered it if I want!

The WS6 nylon end link bushings break down with age unlike aftermarket similar urethane bushings.

Mine is # 171858 build date 05-20. Paid right a $7000

[Thomasmoto]

I've got a 79 TA WS6 W72 400 4 speed 4 wheel disc brake car that I want to put the Energy Suspension sway bar bushings on and my question is this: I have measured the front bar by sliding a 15/16ths wrench onto the bar and it fits perfectly, but all the info I see everywhere else says these cars came with much bigger sway bars? Am I measuring it incorrectly? I already put the end link kit on it and I bought both the size their website was correct for this car and I bought one that was slightly shorter. When I took the stock links off, neither kit was the exact same size that came on the car. I put the longer ones on and they fit fine, but I think the links are a little more forgiving of a slight deviation from stock whereas the bushings will need to be exact. Any help is appreciated.
David T