Front end rebuild, part two

[MaineShark]

I was looking this over the other day. It seems to me that I can unload the upper control arm, simply by jacking up the corner of the car. Since the spring is linked to the lower control arm, not the upper, once the weight is off the wheel, the upper should be unloaded.

Does that sound right? Just to check it out, I backed the nut off a little. Sure enough, the control arm mount followed the nut. So I know it will move if loaded. I re-tightened the nut, then jacked up the corner and tried again. This time, the mount stayed against the frame.

Seems to me that it worked. I think I would actually have to get the suspension just to the point that the tire is barely touching, to actually have no load on the upper arm.

Thoughts?

Also, would it be a good idea to replace the control arm mounting bolts, while I'm at it? The originals are more than a bit rusty...

If so, would stainless be a good idea? The hardware store has grade 5 and grade 8 steel bolts, as well as stainless. Part of me says to go with the explicitly-graded bolts, but part of me also says "stainless good" Thoughts?

Similarly, even if I go with regular steel bolts, how about stainless nuts?

Joe

 

[sscam69]

Joe

Be extremely careful!! I believe your studying some sort of engineering and can appreciate how much tension those springs are under.

Get a spring compressor and tie the spring to the frame with a chain! Safety first bud, especially when messing with the suspension.

As far as the stainless vs Grade, thats a good one. Stainless sounds very appealing. Was the grade of the SS bolts?

Stainless nuts wouldn't hurt.

Frank

 

[JohnZ]

Be VERY cautious with "stainless" bolts - 99% of the "pretty" or "hardware store" stainless bolts are Grade 2, which is about the same tensile strength as the lag bolts used to attach a farm gate to a post. Don't even THINK about using a "stainless" bolt in any critically-stressed steering, suspension, or brake application unless it's made by ARP, SPS, or the specialized aircraft-grade fastener suppliers; the same goes for the "pretty" chrome-plated "hot-rod" bolts, which are subject to hydrogen-embrittlement unless they've been furnace-annealed after plating (which they aren't).

Stick with good Grade 5 or Grade 8 steel bolts (which have rolled, not cut threads), or ARP/SPS stainless ALLOY bolts, which are 170,000-190,000 psi strength-certified (slightly stronger than Grade 8). Using any other "pretty" bolts is asking for trouble. I've dealt with highly-stressed OEM automotive fasteners and the sophisticated torque-control and torque-angle control tools to use them properly all my life, and some of the "pretty" stuff I see at car shows scares me to death; don't use fasteners based on what they look like - use the ones with the correct strength for the application and torque them properly.
:eek

 

[MaineShark]

Yeah, I think I'm just going to grab some Grade 8 bolts at the hardware store.

I like preventing rust when I can, but it's not like these bolts have to be removed every few months, or anything like that.

I think I will get some stainless washers, though. It's not like the tensile strength matters, there, and it may help prevent seizing.

Another question, though: as-is, there is just a nut and a bolt. It seems to me that there should be some locking system, since this is such a critical component. Would it be a good idea to get a locking system in place? If so, would lock washers be best, or nuts with the nylon lock ring?

Lastly, I'm adding a stiffening bar between the two towers. It mounts off these bolts. Should I place the plates directly against the control arm mounts, or put washers in-between?

Joe

 

[MaineShark]

Back to the top...

I'm fairly curious about whether there is supposed to be some locking mechanism, to prevent the nut from loosening up over time, or whether the torque, alone, is the intended locking system.

If the second is the case, would it be a good idea to install lock washers or lock nuts, anyway, just for added security?

Joe

 

[Jack]

Joe:
As JohnZ ... be wary of fancy-looking bolts for suspension/steering. Anyway ... UCA bolts/studs are splined just under head, so they don’t turn in frame mounts ... kinda like wheel studs. If I recall correctly, Hi-torque alone locks the uppers to frame. Put a dab of blue loctite on the threads for added insurance ... but you really don’t need it.

I may reading too much into it ... but it seems you may be entertaining idea of getting loaded UCA’s out without first breaking spindles loose at ball joints? ... If that’s so ... DON’T! If not, disregard & pardon me. You probably wanna R&R the BJ’s ... and I think you might play heck trying to get loaded UCA shafts back onto the studs.
JACK:gap

 

[MaineShark]

Anyway ... UCA bolts/studs are splined just under head, so they don’t turn in frame mounts ... kinda like wheel studs. If I recall correctly, Hi-torque alone locks the uppers to frame. Put a dab of blue loctite on the threads for added insurance ... but you really don’t need it.

Thanks. I forgot about the splines. I would have had a hard time tightening the new bolts, if I failed to get splined bolts.

I may reading too much into it ... but it seems you may be entertaining idea of getting loaded UCA’s out without first breaking spindles loose at ball joints? ... If that’s so ... DON’T! If not, disregard & pardon me. You probably wanna R&R the BJ’s ... and I think you might play heck trying to get loaded UCA shafts back onto the studs.
JACK:gap

I was curious whether raising the car would unload the control arms, but I think I've given up on that idea. I'll probably put the car on jackstands, then use a jack to compress, disconnect, and slowly release the spring. That sounds like the easiest method I've heard so far.

Joe

 

[Jack]

I'll probably put the car on jackstands, then use a jack to compress, disconnect, and slowly release the spring. That sounds like the easiest method I've heard so far.Joe

Joe:
Yep ... that's the ticket. Once safely & securely up on stands .... take the calipers off ... w/ picklefork, knock the tie rod ends loose (but keep em lightly attached to spindles & centerlink w/ only 2 threads) & remove shocks & loosen sway bar from LCA ... THEN ... lightly compress LCA w/ floorjack & loosen both upper & lower BJ-spindle nuts until there's only about 2 threads holding ... then remove floorjack ... then take your picklefork to separate both U&L ball joints ... using coil springs' pressure & whacking w/ picklefork, they'll pop loose from spindles but the 2 threads you left will hold it together ... then slowly & carefully loosen the LCA BJ-spindle nut ... then the UCA BJ-spindle nut ... THEN the whole mess will come apart easily.

NOTE: This method uses the coil to help break the bj studs loose from spindles ... so don't loosen the CA's from frame first ... DO loosen CA's from frame AFTER spindles are completely removed from CA's. Just at the point the bj-studs have just broken loose from spindles but are held by 2 threads ... you'll probably see that the coils' pressure is greatly reduced. Safety First!
JACK:gap

 

[MaineShark]

Thanks, that sounds easy enough.

Joe

 

[MaineShark]

Update: With a little help from a buddy of mine, I have the right front corner pulled apart (except for the idler arm - we ran out of time). My next question is: how do I get the original bushings out of the control arms? I got the bolts out (side note: never use an impact gun when you have a headache... it's not much fun), but I can't tell how to get the bushings out, and I don't want to damage anything important in the process by prying on the wrong spot or something...

Additional notes for anyone who wants to do the same thing:

The spring can be handled fairly easily with a jack and some chain. Put a jack under the lower control arm, with the jack handle coming out under the nose of the car (so you won't be in the way of the spring, if it lets go). Jack it up as far as you can (probably until the car starts to lift off the jackstand - don't want to go any farther than that), and run some good chain through the spring. Start at the highest spot that you can, feed the chain though the coil, and down the center, then bring in back out through the lowest spot that you can, and run a bolt through the two links of chain. It can be helpful to let the jack down or up a bit to get the links to align correctly. Slowly lower the jack, and make sure no one is to the side of the car, where the spring might hit them if the chain doesn't hold.

I actually used a long chain, and made two loops, just for added safety. Once you get the spring secured, you can remove the lower control arm. I kept the jack under spring, with a little bit of pressure, to held support the control arm wile my buddy slid under the car and removed the two bolts that hold the front of the control arm mounting spindle. He also removed the nut that holds the rear, but the thing didn't want to come out. This is where the jack was helpful. By pumping it up and then lowering it a few times, the spindle finally broke free.

After the control arm was dropped, the spring came out. I used a pair of strut compressors (now that the spring was out of the car, they work fine) and my impact gun to compress the spring a bit, remove the chain, and then slowly relax the spring. This way, I don't have to store a "loaded" spring.

Last bit of info: I found that everything on my car was bolted, except the upper ball joints, which are still waiting to have their rivets drilled so that I can remove them from the upper control arm. I find it odd that the rest would have been replaced, but not the upper ball joints.

Joe

 

[pws69]

I was looking this over the other day. It seems to me that I can unload the upper control arm, simply by jacking up the corner of the car. Since the spring is linked to the lower control arm, not the upper, once the weight is off the wheel, the upper should be unloaded.

Does that sound right? Just to check it out, I backed the nut off a little. Sure enough, the control arm mount followed the nut. So I know it will move if loaded. I re-tightened the nut, then jacked up the corner and tried again. This time, the mount stayed against the frame.

Seems to me that it worked. I think I would actually have to get the suspension just to the point that the tire is barely touching, to actually have no load on the upper arm.

Thoughts?

Also, would it be a good idea to replace the control arm mounting bolts, while I'm at it? The originals are more than a bit rusty...

If so, would stainless be a good idea? The hardware store has grade 5 and grade 8 steel bolts, as well as stainless. Part of me says to go with the explicitly-graded bolts, but part of me also says "stainless good" Thoughts?

Similarly, even if I go with regular steel bolts, how about stainless nuts?

Joe

Lars' paper "How to rebuild a C2 front suspension" is probably one of the best references you will find on this work...

 

[Johan]

pws69,

Do you have a web adress where this can be found?

 

[Jack]

I can't tell how to get the bushings out, and I don't want to damage anything important in the process by prying on the wrong spot or something...Joe

If you're replacing CA bushings with polyurethane and your old outer shells are good ... there's no need to press out a darn thing. Use a hole saw with the center arbor bit removed )Take a poly bushing assembly with you to hardware store to get right size hole saw ; about $7) ... hog out the rubber ... Use a pocket knife & aerosol brake cleaner for the remainder. Use pliers to twist the inner shells out. Take your new poly assemblies & With finger-pressure, just pop out the poly bushing & inner shells from your new assemblies ... set aside the new outer shells. With plenty of lube & finger-pressure ... insert the new bushing & new inner shell into your old outer shell & onto CA shaft. Save yourself time & money while eliminating risk of bending/tweaking CA during pressing-prying. I did it as I recommend & there was/is no problem ... many others had same success, both before & after mine. Regardless if you use your old shells or not ... if you're using polyurethane bushings here's a safety tip: clean female threads at ends of CA shafts real well with spray brake cleaner ... same for mating retaining bolts ... absolutely no grease/shmutz in there ... use a dab of loctite.
JACK:gap

 

[MaineShark]

So you're saying that the threads on the mounting shafts should be glued (loc-tite - which color?) to the inner sleeve of the bushing, correct?

Also, anyone have any ideas for re-compressing the spring for installation? I've just painted it, so I'd like to avoid the chain thing, if possible, to keep that paint from being rubbed right off. There has to be some way to re-install a painted spring without scratches, with all the show cars out there...

Thanks,
Joe

 

[Jack]

So you're saying that the threads on the mounting shafts should be glued (loc-tite - which color?) to the inner sleeve of the bushing, correct? Joe

JOE:
NO! DO NOT attempt to glue the inner sleeve to the CA shaft.

What I'm referring to are the small bolts (8 total on car) that thread into each tip of the CA shafts (they hold the 8 bell washers on that in turn retain the poly bushings into the shells) ... make sure shafts' female threads & bolts' threads are very clean & dry ... medium strength loctite (blue?) is fine here. The new poly bushings can pop out if those bolts aren't secured (this not much of an issue when using rubber bushings ... but loctite is a must with poly).

Leave one balljoint loose from spindle ... just place spring in there ... jack the lower CA up until bj stud connects with CA's taper ... put on a nut.
JACK:gap

 

[MaineShark]

Thanks. I guess it's a good thing that I haven't been able to re-assemble the control arms yet, huh?

I'm not sure what you mean, with regards to re-installing the spring. Even at the lowest position that the control arm would swing to, there was still noticeable spring pressure. That may have been due to the arm not swinging all the way down (from what I hear, the bushings can take a "set," and not allow the arm to swing as much as it would with new bushings), so your plan might work, but I think I need a backup plan, in case I get the control arm bolted to the frame, and can't get the spring in place without pre-compressing it.

Joe

 

[MaineShark]

Another question, courtesy of my buddy who's helping me with this:

When installing the poly bushings, do we tighten them part way, then lower the car onto its wheels, then tighten the bushings the rest of the way, or do we just tighten them all the way with the car in the air, or what?

Also, does anyone know what the correct torque is? (not sure if the poly bushings will require different torque than the OEM rubber) Actually, if anyone knows the torque specs for the various suspension bolts, I'd appreciate it. I have a couple repair manuals, but I've found errors in them before, so I'd like a second opinion...

Joe

 

[MaineShark]

Back to the top, and yet another question:

In addition to the question about when to tighten the bushings, and the question about torque specs, another issue arose:

I forgot to mask off the interior of the bushing sleeves when I painted the lower control arm. Is the paint going to cause a problem, or won't the bushings care?

Joe

 

[Jack]

Joe:
Sorry, I've been traveling ... away on automotive mfg QA job in Missouri ... just getting the hang of my new laptop.

I dunno what the tq on the bolts is ... the factory spec would not apply anyway ... it's a whole different deal with poly ... that's why I followed others' suggestion and also recommend a stout installation using loctite.

I tightened my bolts in the air ... no springs ... make sure the CA's have free range of motion. Those are small bolts ... look up a nominal tq rating in a chart ... being small, I estimate no more than about 20 FT lbs with very clean threads with Loctite with poly. The bolts are simply holding the bushing from popping out .... a VERY important function ... but that's all.

I did the same thing with the paint ... just wipe out the sleeves with some brake cleaner on a rag ... it'll disolve most paints.

Once the bj is broken loose .... Just push down on the lower CA & lift up on the upper CA ... the spring should lift out ... it'll be a bit easier going back in because the poly provides full range of motion.
JACK:gap

 

[MaineShark]

Thanks for the help. I was curious about the torque since they are grade 8 bolts.

Any idea what torque I should use on the bolts that mount the various parts to the frame, and the castle nuts, and such?

Joe