68 front suspension, steering and clutch rebuilds

[David M.]

Hi all,
We have some questions.
We're refreshing the front end on a 68 small block, stick shift, driver, April built car. This includes all bushings, BJs, and all power steering components, minus the box and tie rod assemblies.
We need guidance locating the following items:
1. We need 4 correct style/grade bolts that hold the front sway bar brackets to the frame.
2. Upper shock bushings 4ea. Polys are ok. Shocks are fine don't want to replace them, just the bushings.
3. Correct style/grade lower shock mount to lower A-Arm mounting bolts, 4 ea.
4. Inner skirt splash guards. Are the 69s the same shape (die cut) as 68s? The 69s have the holes punched for the plastic rivets. Is that the only difference? We're thinking of using the 69s mounting technique to avoid the hassle with the staples. Who supplies the Stainless staples for the 68s? Ecklers and Mid-Am don't have them, at least not online. Any tips on removal and installation of the staples if we decide to use the OEM style 68s?
5. Outer tie rod ends dust boots. The rod ends are fine but I'd like to put new poly boots on while it's apart.
6. We think we need a clutch. It makes a rapid tink tink tink noise just off-idle when not fully engaged. Chatter is very minimal. It will be pulled to inspect it and the T.O. bearing while it's on the lift. This is a factory 3 speed car. What do the masses recommend for a good high perf clutch and throw out bearing? FInger-style or diaphragm style? Ecklers offers a standard small block clutch. But the small block is built to L79+ specs and is pushing about 375 HP. If we need a new flywheel we could use guidance here as well. Hoping to just resurface the OEM but don't know if its thick enough for another cut, yet. We'd prefer a clutch that an elephant doesn't need to stand on to disengage. Is this engine internally or externally balanced? I have an engine vibe in neutral at 1500-2000rpm. The harmonic balancer is 10-15 years old at most.
7. It's a factory Saginaw or Borg (Ford?) 3 speed car. Does anyone have the front/rear trans case seal numbers? Would like to get HD seals ahead of time. What gear oil should we use? Multi or single weight? 90W?
8. Lastly regarding the steering control valve. Should it simply be threaded all the way onto the center link until it butts up to it? I counted the turns out removing the original, 16. Just wondering if there any trick to assembling the new unit? Is this adjustment there to "center" the steering wheel during alignments?

Apologies for the novel. Thank you in advance,
Dave

[David M.]

Re: 68 front suspension, steering and clutch rebuilds

Ok FYI I found the fasteners at Corvette Central. My questions about the inner skirt dust shields and clutch still stands if any can speak to that?

[Joe L.]

Re: 68 front suspension, steering and clutch rebuilds

Hi all,
We have some questions.
We're refreshing the front end on a 68 small block, stick shift, driver, April built car. This includes all bushings, BJs, and all power steering components, minus the box and tie rod assemblies.
We need guidance locating the following items:
1. We need 4 correct style/grade bolts that hold the front sway bar brackets to the frame.
2. Upper shock bushings 4ea. Polys are ok. Shocks are fine don't want to replace them, just the bushings.
3. Correct style/grade lower shock mount to lower A-Arm mounting bolts, 4 ea.
4. Inner skirt splash guards. Are the 69s the same shape (die cut) as 68s? The 69s have the holes punched for the plastic rivets. Is that the only difference? We're thinking of using the 69s mounting technique to avoid the hassle with the staples. Who supplies the Stainless staples for the 68s? Ecklers and Mid-Am don't have them, at least not online. Any tips on removal and installation of the staples if we decide to use the OEM style 68s?
5. Outer tie rod ends dust boots. The rod ends are fine but I'd like to put new poly boots on while it's apart.
6. We think we need a clutch. It makes a rapid tink tink tink noise just off-idle when not fully engaged. Chatter is very minimal. It will be pulled to inspect it and the T.O. bearing while it's on the lift. This is a factory 3 speed car. What do the masses recommend for a good high perf clutch and throw out bearing? FInger-style or diaphragm style? Ecklers offers a standard small block clutch. But the small block is built to L79+ specs and is pushing about 375 HP. If we need a new flywheel we could use guidance here as well. Hoping to just resurface the OEM but don't know if its thick enough for another cut, yet. We'd prefer a clutch that an elephant doesn't need to stand on to disengage. Is this engine internally or externally balanced? I have an engine vibe in neutral at 1500-2000rpm. The harmonic balancer is 10-15 years old at most.
7. It's a factory Saginaw or Borg (Ford?) 3 speed car. Does anyone have the front/rear trans case seal numbers? Would like to get HD seals ahead of time. What gear oil should we use? Multi or single weight? 90W?
8. Lastly regarding the steering control valve. Should it simply be threaded all the way onto the center link until it butts up to it? I counted the turns out removing the original, 16. Just wondering if there any trick to assembling the new unit? Is this adjustment there to "center" the steering wheel during alignments?

Apologies for the novel. Thank you in advance,
Dave

Dave------

All 1963 and later Corvettes used a diaphragm type clutch. I absolutely recommend using only a diaphragm type clutch. All 1968 small blocks with manual transmission used a 12-3/4" flywheel and a 10.4" clutch. This same clutch was used for all C2 small blocks, including 63-65 FI. The clutch is long-discontinued from GM but easily available in the aftermarket. I recommend using a LUK clutch. The repset for your application is 04-021. This includes the clutch disc, pressure plate, and release bearing.

All Corvette small blocks through 1985 were internally balanced.

The front and rear seals for your transmission are GM-discontinued. However, they're still available from National Seals (Federal-Mogul) which, incidentally, supplied the original seals to GM. The front seal is National 7412S and the rear seal is National 9613S.

As far as the P/S control valve goes, it is to be fully screwed onto the relay rod. However, if the clamping bolt cannot be inserted, it may be necessary to back it off just enough so that the bolt can be inserted. The bolt has to clear a relief machined into the relay rod threads.

The adjustment on the valve has absolutely nothing to do with centering the steering wheel. It has to do with centering the valve.

[David M.]

Re: 68 front suspension, steering and clutch rebuilds

Thanks Joe. You are wealth of knowledge!
May I pick your brain a bit more?

Is that 3 speed a Saginaw or Borg Warner? I guess it will be blatantly obvious when I pull it out as its ID should be cast/stamped into it.
How about the crank pilot bushing? Im going to replace it as a matter of being anal even if it inspects ok, Im right there.... What about the roller bearing type pilot bearing? Any preference?

Any surprises hiding if I want to do a full conversion to an M20/M22? EG...Bell-housing, fork, output yoke, drive shaft length etc...??? Can the same clutch be employed (likely by what you said about all small block stick cars). I know Ill need the 4 speed shifter plate. Will the 3 speed handle bolt to the 4 speed shift rod assembly?

I was looking at the Centerforce dual friction clutch. You like the LUK over something like that?

If in fact we determine the flywheel will not take another round of surfacing can you recommend a high qual replacement? SFI? Billet or standard steel? 153 or 168 tooth?

Can you provide any in site on the inner shirt dust shields. eg...where to find the SS staples? Is the die cut pattern the same as the 69s?

Thanks for your time and the brain picking!
Dave

[Joe L.]

Re: 68 front suspension, steering and clutch rebuilds

Thanks Joe. You are wealth of knowledge!
May I pick your brain a bit more?

Is that 3 speed a Saginaw or Borg Warner? I guess it will be blatantly obvious when I pull it out as its ID should be cast/stamped into it.
How about the crank pilot bushing? Im going to replace it as a matter of being anal even if it inspects ok, Im right there.... What about the roller bearing type pilot bearing? Any preference?

Any surprises hiding if I want to do a full conversion to an M20/M22? EG...Bell-housing, fork, output yoke, drive shaft length etc...??? Can the same clutch be employed (likely by what you said about all small block stick cars). I know Ill need the 4 speed shifter plate. Will the 3 speed handle bolt to the 4 speed shift rod assembly?

I was looking at the Centerforce dual friction clutch. You like the LUK over something like that?

If in fact we determine the flywheel will not take another round of surfacing can you recommend a high qual replacement? SFI? Billet or standard steel? 153 or 168 tooth?

Can you provide any in site on the inner shirt dust shields. eg...where to find the SS staples? Is the die cut pattern the same as the 69s?

Thanks for your time and the brain picking!
Dave

Dave-----

The original 3 speed transmission used for your application was a Saginaw-manufactured unit. Nothing on the transmission will say Saginaw, though. There should be "GM" and GM part numbers. Saginaw was a division of GM at the time.

A bronze pilot bushing is supplied with the LUK kit I mentioned. Unless you're absolutely sure that the alignment of your transmission with the engine is perfect (and, you won't be unless you go through the effort of measuring it), I'd go with the bronze bushing rather than the needle bearing unit.

Conversion to a Muncie 4 speed is essentially bolt-in as long as a 1966-70 Muncie is installed. Bellhousing, fork, output yoke, driveshaft are all the same. The same clutch is used. However, you will need a completely different shifter and shifter rods. The 3 speed and 4 speed shifter and rods are different.

For a Corvette, especially a C3, I like to use only stock or stock-equivalent clutches. That's why I recommend the LUK. The GM clutch is discontinued and the LUK is about as close to the original as you can get.

All 1968 Corvettes with small block originally used a 12-3/4", 153 tooth flywheel. It was last available under GM #366860 but it's now discontinued. LUK may have a replacement available, though. Original flywheels were of nodular cast iron, never steel or billet. I'm sure there are steel and billet flywheels available in the aftermarket but I'd be reluctant to use any. That's because their conformance to the exact dimensional specs of the original flywheel my be "off". That can cause problems with clutch operation. Personally, I wouldn't chance it.

The early 1968 fender skirt seals were very similar in configuration to the late 1968-82 shields. However, they were not exactly the same. Dr. Rebuild offers EXCELLENT reproductions of the early 68 shields which are retained by staples. Dr. Rebuild also sells the WIRE to make the correct staples. Making the staples and installing them can be quite tedious, though, unless you have the equipment they had at St. Louis. It's highly unlikely you'll have this.

[Jim D.]

Re: 68 front suspension, steering and clutch rebuilds

I agree with Joe regarding Luk clutches but will add - I HIGHLY recommend that you have them balanced before installing them. I've installed many of them over the years and while most came balanced "close enough for most", the last one was way out of balance and would have caused a very noticeable vibration requiring everything to be done over again.

[Joe L.]

Re: 68 front suspension, steering and clutch rebuilds

I agree with Joe regarding Luk clutches but will add - I HIGHLY recommend that you have them balanced before installing them. I've installed many of them over the years and while most came balanced "close enough for most", the last one was way out of balance and would have caused a very noticeable vibration requiring everything to be done over again.

Jim------


Good point. Any flywheel should be precision balanced before installation. This includes GM flywheels. Also, the clutch, including GM clutches, should be precision balanced before installation. Yes, balancing represents a significant cost and one would expect that new parts be right out-of-the-box. It's absolutely not worth taking the chance, though, as, otherwise, one may have to "go-back-in".

[David M.]

Re: 68 front suspension, steering and clutch rebuilds

Great info guys, Joe, Jim, thank you! What Im gleaning here is that I need to take the new clutch and flywheel to the shop and have it spun as an assembly... great advice. This could be the vibe I feel.
I think the path of least resistance will be to use the 69 dust shields. Our goal is a reliable safe driver with as many correct looking (to the untrained) functional parts as possible. Shes mostly numbers matching but know where near a bow tie car. Just a great looking fun driver. I did the shields in my 68, 442, they are stapled as well. This car is a nut and bolt, numbers resto. What a royal PITA that was. Ever need any BOP tech advice, especially Olds, info Im here to help you.

[David M.]

Re: 68 front suspension, steering and clutch rebuilds

Hi all,
To maintain the thread I have an up date.
I had real good luck finding everything from Corvette Central. They have all the correct little stuff such as fasteners and other OEM replicas, even the early 68 staple style inner fender dust seals WITH the staples. Strange on an April build car. Those will go in Saturday. Wish me luck as Ive done this before on a 68 Olds so Im familiar with the fun.

We haven't inspected the clutch/trans yet. One system at a time.

The A Arms have been on back order since March 28th and not due for another week! These are coming from Ecklers. They say their supplier of remans has a shortage of lower right arms...oy! Our originals are rough enough it wasn't worth it to try to restore them. Not so much rusty just beat up and undercoated. Who undercoats a vette and the suspension components. And I was attempting to save time. Hows that workin...

I took apart the Spindles, steering knuckles, caliper brackets and dust shields. Cleaned, blasted and painted it all with Eastwoods Zinc and iron colors. The finishes are nice, for a driver. I even found factory inspection paint on the spindles. Orange and white. Im gona try to replicate those just because, once I find an orange paint pen.

Heres the questions. I see the torque specs here in the archives to put the spindle assemblies together.
- The 15/16" Brake bolt, one per side, gets 120lb/ft
- The steering knuckle bolt and nut assemblies gets 70 lb/ft.

Q. Are these torque numbers for a clean dry thread or wet? If dry do we use loctite? If yes Red(permanent), or Blue (removable)?
Q. Ill need the specs for all the rest of the front end. What publication shall I order for this? Main concerns are all the A arm fasteners and tapers for the BJs, tie rods etc...

Thanks for readin my novel
Dave

[Terry M.]

Re: 68 front suspension, steering and clutch rebuilds

Hi all,
To maintain the thread I have an up date.
I had real good luck finding everything from Corvette Central. They have all the correct little stuff such as fasteners and other OEM replicas, even the early 68 staple style inner fender dust seals WITH the staples. Strange on an April build car. Those will go in Saturday. Wish me luck as Ive done this before on a 68 Olds so Im familiar with the fun.

We haven't inspected the clutch/trans yet. One system at a time.

The A Arms have been on back order since March 28th and not due for another week! These are coming from Ecklers. They say their supplier of remans has a shortage of lower right arms...oy! Our originals are rough enough it wasn't worth it to try to restore them. Not so much rusty just beat up and undercoated. Who undercoats a vette and the suspension components. And I was attempting to save time. Hows that workin...

I took apart the Spindles, steering knuckles, caliper brackets and dust shields. Cleaned, blasted and painted it all with Eastwoods Zinc and iron colors. The finishes are nice, for a driver. I even found factory inspection paint on the spindles. Orange and white. Im gona try to replicate those just because, once I find an orange paint pen.

Heres the questions. I see the torque specs here in the archives to put the spindle assemblies together.
- The 15/16" Brake bolt, one per side, gets 120lb/ft
- The steering knuckle bolt and nut assemblies gets 70 lb/ft.

Q. Are these torque numbers for a clean dry thread or wet? If dry do we use loctite? If yes Red(permanent), or Blue (removable)?
Q. Ill need the specs for all the rest of the front end. What publication shall I order for this? Main concerns are all the A arm fasteners and tapers for the BJs, tie rods etc...

Thanks for readin my novel
Dave

Dave

The torque values are given in the 1968 Chassis Service and Chassis Overhaul Manuals. I see the Chassis Service Manual is available from the on-line NCRS store, but I don't see the Overhaul Manual listed. The Overhaul Manual is for assemblies once they are removed from the vehicle. For the suspension work you are dealing with the Service Manual will be adequate, but if you can get the Overhaul Manual also do it.

Joe Lucia will shed more light on torque standards, but in the era of our cars torque values are generally given dry, and thread locking compounds generally were not used in the automotive field. There are "rules of thumb" about reducing torque values for lubricated threads, but I have my doubts about how useful those "rules of thumb" are. I am not sure how much lubrication is added by thread locking compounds, if any. For the Corvettes that are the subject of this thread I don't personally believe there is any value to thread locking compounds in general. That, however, is only my opinion and everyone has to reach their own comfort level with their own work. We tend to value the reuse and sometimes the refinish of fasteners and there is room for significant debate about the wisdom of that practice with respect to critical chassis fasteners. Again, one has to reach some level of comfort with their restoration practices balanced against the potential use of the finished vehicle.

[David M.]

Re: 68 front suspension, steering and clutch rebuilds

Thanks for that info Terry. We wound up going with blue removable Loctite on dry threads. The torque felt right.

Would you or anyone reading this know exactly what type of power steering fluid we should be using with the new pump and ram? Dextron 3 or Ford Type F. I don't think power steering fluid is recommended its too thin. Thats what we were using. I suppose we need to flush the box once I get to that point? I learned most cars from the early days of power steering on up to before rack and pinion became popular should use trans fluid. Just had the pump and box rebuilt in the 68 442. That's what the rebuilder recommended for that. He wasn't sure about the Vettes but he thinks its the same.

Lastly, we decided to go with the late 68 style dust flaps (the rubber flap which attaches to the inners above the upper A-Arms). The car is an April build yet it had the stapled flaps? Replacing the staple style just wasn't happening. The original holes were all over the place some not even hitting the glass in a few spots or right at the edge.
So the question is which direction do the push in plastic fasteners face? Logic would say the head should face the engine bay...no? The push in style fasteners is found on all late 68-78s

[Terry M.]

Re: 68 front suspension, steering and clutch rebuilds

Thanks for that info Terry. We wound up going with blue removable Loctite on dry threads. The torque felt right.

Would you or anyone reading this know exactly what type of power steering fluid we should be using with the new pump and ram? Dextron 3 or Ford Type F. I don't think power steering fluid is recommended its too thin. Thats what we were using. I suppose we need to flush the box once I get to that point? I learned most cars from the early days of power steering on up to before rack and pinion became popular should use trans fluid. Just had the pump and box rebuilt in the 68 442. That's what the rebuilder recommended for that. He wasn't sure about the Vettes but he thinks its the same.

Lastly, we decided to go with the late 68 style dust flaps (the rubber flap which attaches to the inners above the upper A-Arms). The car is an April build yet it had the stapled flaps? Replacing the staple style just wasn't happening. The original holes were all over the place some not even hitting the glass in a few spots or right at the edge.
So the question is which direction do the push in plastic fasteners face? Logic would say the head should face the engine bay...no? The push in style fasteners is found on all late 68-78s

Plastic push fasteners for the dust flaps have their head in the engine compartment, as you surmised.

[David M.]

Re: 68 front suspension, steering and clutch rebuilds

Terry thankx again. You or anyone else know the answer as to whats the correct power steering fluid?

[Gene M.]

Re: 68 front suspension, steering and clutch rebuilds

Stainless steel staples will require one hell of a staple gun. I suggest you use steel wire and bend up to size and hand fit them thru the original holes. The originals were not stainless. Those sneaky little judges with their magnets will bust you for stainless.

Summit has good selection of diaphram clutches to choose from. I will caution you to get a USA made throw out bearing to avoid taking it apart again for BAD bearing. There are still offerings of quality USA throw out bearings to use in place of many "Kit" lower end junk stuff. Don't skimp on the flywheel and have everything balanced as suggested. I would expect the upper end quality parts to be balanced as delivered.

[David M.]

Re: 68 front suspension, steering and clutch rebuilds

You hit a soft spot Gene...Couldn't agree more avoiding the chinesium junk. I'm an outspoken proponent of ferreting out USA, Canada, German, Swiss etc... made goods....nothing from china period. Sometimes you simply have zero choices, sad. I've learned there is nothing in HarborJunk worth spending my money on. Not even the tarps and bungee cords, all junk. All you have to do is Google to find "made in the USA". Puts us back to work.
Have to be careful with bearings. Timken and most others offer both USA and offshore. You have to ask. Most of the time there is a mere 5-10 dollars separating the USA from Chinesium.
BDI is a great place for all bearings seals and more. Google them. BUT you have to tell them to quote USA. They always default to the junk first. I've called them out on this countless times.
You have to watch all of the restoration supply houses as well. Several offer gas tanks from offshore vendors. Why would one put a chinesium fuel tank in their pride and joy when Spectrum/Quanta offers high-quality repros from Canada. I also let the resto houses have it too. Its a safety thing or piece of mind for me.

Thanks for the all the tips. We decided to go with the later production push in plastic fasteners. This is a nice driver likely to never see a judge. At least not now. The previous owner put a clip on this April build car. He said it was easier then trying to fix the support rivets and other stress cracks inherent with 68s It was supposed to be a new clip. It must have come with the stapled flaps unless the inners are OEM? They were not SS either. April isn't considered an early build. Its a no history mystery.