Hotchkis TVS Stage 2 - '79 Trans Am

[mrandig]

Hi all. Decided to make my first post here.

I've got a '79 Trans Am that was having some suspension issues. To remedy this, get better performance and a slightly better stance, I decided to go with a full replacement (front & rear), buying the Hotchkis TVS Stage 2 kit from Summit.

Part of this kit includes front and rear sway bars (#2236). The rear sway bar installation requires drilling into the frame, installing mounting plates, and then bolting in dog bone end links, and then finally attaching the rear sway bar. Easy peasy...

When it comes to drilling the frame and installing the rear sway bar mounts however, my Trans Am doesn't seem to match the instructions. I'm missing line tabs / holes, or they're not where they should be, and I've also got the connection between rigid to rubber brake lines bolting right to where the mounts should install on the driver's side.

Before I get creative and free style this installation and start putting holes and parts where I think they should go, I just wanted to check and see if anyone had this setup and similar issues.

Any guidance is appreciated. Thanks in advance.

203156
Passenger side (above) - tabs in wrong place / tabs too high

203157
Driver's side (above) - brake line connection in mounting location.

Also, what's the story with the three connecting holes on the sway bar? Only one hole is shown in the instructions. What difference can I expect between these?

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How things are supposed to look when completed...

[mrandig]

I finally just went for it...

I ended up drilling two 3/4" holes with a uni-bit inboard of the passenger side frame rail.

203309

Then I installed the provided mounting plate. The two holes are only on the inboard side of the frame rail, so I'll use the mounting plate as a guide to then drill all the way through. The clamp helped to get the plate seated correctly.

203310

I need a 1/2" bit to drill through, but I don't have one with a reduced shank to fit my right-angle air drill. I'll have to pick this back up tomorrow, but everything looks promising so far.

[mrandig]

Got a new drill bit, but even best-case scenario, it's going to be really tight fit. Jeffe Hex isn't a familiar brand to me, but was delivered next day by Amazon, and worked almost OK.

203311

Barely enough room, but it did fit...

203312

Just doing a quick mock-up for now, and I'll tighten everything up later. There's a few more pieces and parts to install before this side is finished, but at least it's all coming together.

Overall, this has been a pretty tough install, and the passenger side seems easier than the driver's side is going to be. We'll see soon enough.

203313

One more view. This time from the passenger side outboard.

203314

[mrandig]

Here's both the passenger and drivers' side complete.

Passenger side, with all hardware installed:

203315

Driver side. I don't think this side lined up as well, but it's done now.

I still need a fix for mounting the brake line, but I'm over it for tonight. Zip ties are not the permanent solution.

203316

I never found out what the three mounting holes were for, so I just decided to go with the middle one, and call it good.

[marolf101x]

The three holes allow you to adjust the stiffness of the bar.
Closer to the rear end, the more rate the sway bar has.
Further away from the rear, the less rate it has.

[mrandig]

The three holes allow you to adjust the stiffness of the bar.
Closer to the rear end, the more rate the sway bar has.
Further away from the rear, the less rate it has.

Thanks! That was what I figured, just wasn't sure about which direction had what affect. The middle sounds like a good starting point.

[BonzoHansen]

my Trans Am doesn't seem to match the instructions.

I ran into that too with my 77 z28. Just another example of a company assuming all 2nd gens are the same. They based it off an older car.

[mrandig]

I ran into that too with my 77 z28. Just another example of a company assuming all 2nd gens are the same. They based it off an older car.

Ease of installation on this kit is 3/10. So far, I would not recommend this kit for small children. We'll see how the front install goes.

At least I don't have to worry about torque specs, as none were provided, other than make sure all hardware is "fully tightened"? I guess I'll just put the car down on its own weight and take a "swag" at it.

[79T/Aman]

why didn't you keep the Hellwig bar?

[mrandig]

It's amazing how fast a year goes by. Here's the completed rear end with the Hotchkis TVS kit installed.

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[mrandig]

Over the last year, I did get most of the front end replaced. Obviously, it was only a few hours of work, but there's been a lot of distractions along the way. Here's the suspension with new Control Arms, Springs, Shocks, etc.

Not much to note with the installation of the front; however, a couple of the upper control arm bolts (to frame) did need to be pressed out for clearance. Just takes a C-clamp and a large socket.

Any hardware that wasn't replaced with the TVS kit, I actually replaced with NOS, just because what's there was almost 45 years old.

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[mrandig]

One of the delays here has been ordering the steering gear. The Hotchkis outer ends have been on backorder for a long time, so I finally decided to mix-and-match the Hotchkis inners with Moog outers (P/N #ES441RL), and just paint everything black to match.

The inner and outer tie rods were not included in the Hotchkis TVS kit. I should've gotten an entire front end kit from Proforged at the start.

The tie rod sleeves (P/N #1612) did come with the Hotchkis TVS kit. They're definitely an improvement over the factory split-seam adjusters.

210695

Of course, when everything was finally ready to assemble, the jam nuts provided weren't correct. They've since been replaced in the picture, however. Just more time waiting on the mail...

[mrandig]

While I was waiting for the mail, I decided to also upgrade the brakes. These are Wilwood D52's dual piston calipers (P/N #140-11291-R); they're direct fit and they look pretty nice.

The calipers are powder-coated, but the "Wilwood" logo only seems painted on. I doubt they will look this clean for long.

I didn't change the rotors, as they're still in pretty good shape (seems the wheel bearings are OK also). I will eventually upgrade the rear from drum to disc, so I may change them in the future.

210696

And back to waiting on the mail again. The Wilwood Brake Flexline kit (P/N#220-10509) didn't come with banjo fittings, so another order had to be made. The kit came with 90 degree fittings, but they were a different size. The 7/16-20 banjo fittings are a separate item (P/N #220-11565).

210697

[mrandig]

I think while I'm at it, I might as well replace the body mounts. The current ones are fine, but since this project has already gone on for a year, why not a few more days.

These particular bushings are Proforged Billet Aluminum Body Mount Bushings (P/N #134-10005).

I don't know if I mentioned this originally, but one of the reasons for this upgrade was the rattling noises the car was making. Being that it's a t-top car, my guess is that it will still rattle when all is said and done...


210698

I'm about tempted to put subframe connectors on it while I'm here also. Why not?

[mrandig]

And here we go again. The new Hotchkis sway bar and the old idler arm are touching. I don't know how, but I almost didn't notice this.

The replacement idler arm can be found from Classic Industries part #18753

We'll replace the idler arm, and well as the center link (just because), sometime this week, I hope.

210699

[mrandig]

I'm going to take a swag at torque values here. I've got an assembly manual, but the reproduction quality is so poor I can hardly read it.

I'm doing this off the top of my head - let me know if these look OK, or if I'm missing anything.

Front End
Cross shaft to Frame Bolts 50 ft/lbs.
Lower control arm bolts 75 ft/lbs
Upper Ball Joint 50 ft/lbs
Lower Ball Joint 70 ft/lbs
Tie Rod Ends 35 ft/lbs
Idler Arm to Frame Bolts 75 ft/lbs
Disk brake calipers 35 ft/lbs

Rear End
Front Leaf Spring Mounting Plate 30 ft/lbs
Front Eye bolts 80 ft/lbs
Rear Eye Bolts 55 ft/lbs
Sway Bar @frame 75 ft/lbs
Sway bar @links 35 ft/lbs

[mrandig]

Better. New banjo bolts installed, and entire system bled. These new hoses seem almost too short, but I can turn lock-to-lock, and this is also at full droop, so I'm calling this part of the project complete.

Having trouble posting photos, so that's all for today.

210723

210725

For tomorrow...
245 /45 R17 BFG G-FORCE COMP 2 A/S PLUS (front)
275 /40 R17 BFG G-FORCE COMP 2 A/S PLUS (rear)

The wheels are 17" X 9" cast aluminum black "Snowflake" wheels with 5-1/8" Backspacing. From Year One (P/N #SFW179BLKV2S).

These tires are speed rated "Y" to 186 MPH, which might be a little more than needed...

210724

[mrandig]

I forgot that wheel caps were needed. I didn't plan on RTV coming to the party, but no worries. It's my fault for not reading the instructions before starting.

I need to let these cure for a while, so the wheels may have to wait until the weekend.

210730

210731

[mrandig]

Wow, that's still a pretty tight fit...

Here's the new idler arm from Classic Industries. It's an improvement, but not much room left.

210882

Everything else is now installed also, so it's almost time to torque down, put the pins in, and grease. We might be road-ready this weekend!

[mrandig]

Something just doesn't seem right...

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210886

Are these inner tie rods reversed? If so, this would mean they had been incorrectly installed this way for years...

I just matched the new against the old and didn't bother thinking beyond that. When I look at the pics however, it seems some research is going to be needed.

[BonzoHansen]

And here we go again. The new Hotchkis sway bar and the old idler arm are touching. I don't know how, but I almost didn't notice this.

The replacement idler arm can be found from Classic Industries part #18753

We'll replace the idler arm, and well as the center link (just because), sometime this week, I hope.



lol i had this issue too. The Moog style idler is larger. With my hotchkiss bar i simply loosened the idler & sway bar mounts up, pried them apart and tightened this down. The grease boot might have touched the bar, but i ran that for like 10 years no issues. I now run a pro forged idler which offers more clearance.

[KatWade]

Awesome work buddy [emoji122] [emoji122] Building that I’m just a little over a year is impressive. My boys should take a cue from you

[mrandig]

The inner tie rods were in fact, reversed. Not sure exactly when this happened, but it's been like this for quite a few years.

Here's everything completed and installed.

211012

[mrandig]

Moving on to the rear end, I decide a gear oil change wouldn't be a bad idea, just because there's been so many other surprises up to this point.

Everything looks OK. Too keep the mess down, I should've taken the wrapping off the rear sway bar, but lesson learned.

211013

[mrandig]

I also replaced the rear cover, just because the old one was in horrible shape.

Just plain old, stamped steel and some new ARP fasteners, and we're good to go.

211014

[mrandig]

It's been over a year since we started, but here's the first time we're back on the ground.

There's still a lot more to do, but here's the full Hotchkis TVS kit installed, new Wilwood brakes, new wheels and new tires (and much more).

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