Ken Stapel's Corvette Obsession - Project: Wrap-up II

I'm still workin on it...

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07-23-04 - To all those thinking of modifications - It just never ends!

I guess I should expect it though, after all I did build a hot rod and not a comfo-cruiser; and when you build hot rods you're never really done. You might be out of money, but you're never done with the project.

The lastest, but not the greatest news:

I followed my TEC3 rep to Venice today so he could drop his Porsche off at Beach Boys Racing - Venice Beach Auto Body. On the ride back Rick was able to monitor the engine functions on my laptop while I drove and he tweaked. The driveability issues are just about solved, with the exception being my "Intermittent Cam Synch Sensor Failure", and we're still banging our heads against the wall on that one. We'll get it one of these days.

In the meantime, it's running fine as stated above.

But ...

As I pulled out onto Pier Ave. to head down to Ruby's, I saw another Ruby's regular right behind me in his '67 Chevelle. He pulled alongside as we cruised through downtown, and he commented that he liked my 40-series Flowmasters, as opposed to his 50-series. Of course, I like hearing things like that, so in order for him to fully appreciate it I goosed it to the tune of about half-throttle for a half-block or so.

As I shifted, actually, as I was accelerating still, I could hear a howling noise. That howling noise grew as I increased speed. That howling noise was even more apparent when I disengaged the clutch; whether it was in neutral or whether it was still in gear - pushed in the clutch and the noise got louder.

At first I thought transmission because I know I have a bad synchro in second, but the transmission is shifting fine in all gears without any unusual noises. However, if I lean between the seats and cock my right ear a little, the noise seems to be coming from the third member. What the heck could go wrong there?? I installed the 3.73's back in 2001 and drove the car across country that summer; surely that broke 'em in.

I didn't even hammer it that hard; I hammered it harder earlier today on Lincoln Blvd. and didn't experience anything unusual.

The only things I did to it today was check my troublesome spark plug boot (and that was holding up fine), and I raised the rear again approximately a half-inch. Raising the rear end certainly ain't gonna cause no howling noises, that's for sure!

I gotta get it up on a lift now to try and track down the source of this latest conundrum. Damn, I could understand it if I was smokin' the tires or something...

07-24-04 - Initial diagnosis.

I put it up on jackstands today and, while using a stethoscope, I was able to rotate the wheel/axle assembly while I listened to different parts of the drivetrain. I checked both sides of the carrier at the axle yokes, and all the way up to the transmission. The noise (which is a "clicking" noise while suspended, instead of a "howl") appears to be centered, literally, on the center portion of the carrier assembly.

I checked the service manual and after thinking about it for a while, I'm pretty sure I'm dealing with a bad pinion bearing.

My first indication was the fact that the noise was a steady, consistent click instead of being a sound heard once a revolution. The second clue is the difference in sound when the wheels are unloaded (off the ground); the noise is much less pronounced - less load on a bearing = less noise, no?

The third clue is to be found in the Helm service manual:

Problem: A continuous low pitch whirring or scraping noise starting at relatively low speeds.

Cause: Pinion bearing.

Looks like I'll be pulling the third member soon; I gotta cut costs, and performing my own labor when possible is first step in accomplishing that goal. Wish me luck.

07-26-04 - I'm tired, but the rear end's out of the car...

Looks like it's the ring and pinion after all. This unit was rebuilt with the 3.73's in early 2001, by Guldstrand's shop, and I put approximately 10,000 miles on it since. I guess it's a case of improper installation, eh? Someone obviously didn't set the lash right, now I gotta do it again.

This makes two fiascos I've been through with that shop; the overdrive install was another **** up someone made that I had to pay twice for.

Now I gotta figure out how I'm gonna come up with the money for this - and the second gear synchro in the trans still needs to be repaired.

07-28-04 - In retrospect ...

Ya know, it's weighed heavily on my mind ever since I uttered (typed) the words, but to be fair, I cannot honestly say that the rear gear failure was due to improper installation by Guldstrand's shop. After all, it was over 10,000 miles ago and my engine's torque rating has significantly increased since those gears were installed, plus I installed the ROD 6-speed with a 3.28 first gear, so I could have stretched things a bit while beating it up these past few years - what with my mis-shifts on the track and who knows how many burnouts!

I hereby relieve Dick Guldstrand of any responsibility in regards my rear gears, but that still doesn't let him off the hook as far as my overdrive fiasco went.

They should have accepted more responsibility for that one; they are the ones who sent the unit out to another shop to have the overdrive attached to the transmission. That shop installed an incorrect O-ring and I lost all fluid, thereby burning up the overdrive, while out there in the middle of the country. (I was on my way to Bowling Green).

Live and learn. Then die.

Oh yeah, by the way, so far there have been two people who tell me that "Tom" himself, at Tom's Differentials is a bugger to deal with. He's the no-nonsense type I hear, but a general PITA to deal with I guess.

Quote:

We at Tom's Differentials assemble each rear as an individual custom unit. There is no mass production close enough stuff here. I demand care careful attention be paid to each and every unit that leaves our shop. So if you're interested in just a so-so unit, please don't bother me. We have always had and will continue to have the best of reputations and no compromises will be accepted. My personal preference is to service American made vehicles so you will notice very little for imports in my catalog. You will also notice that the majority of components we offer are made in America. I love my country and support it when ever possible. BUY AMERICAN!

07-29-04 - Man, this old body just doesn't bounce back as fast, nor as well, as it once did ...

It's Thursday evening here, and I still ain't healed up from Monday enough to get back under there and do anything! As soon as I do I'll post a bunch of pictures showing the removal/installation procedure as well as some of the differential carrier and case, both inside and out.

Should make for some good "before and after" pictures too as far as cleanliness goes.

07-31-04 - Piece-by-piece, it's getting clean again ...

Today I finally got enough strength back to tackle removal and cleaning of the remaining suspension pieces. I dropped the third member off at Unitrax in Anaheim Friday; hopefully they'll get started rebuilding it come Monday morning, bright and early.

Here are a couple of "before" cleaning shots of the suspension pieces:

08-01-04 - I was very lucky!

I forgot to mention yesterday that when I went to remove the half-shafts I discovered the bolts for the right shaft u-joint were basically just finger-tight! Grease was about the only thing keeping them from working their way loose and falling out, leaving me with a half-shaft swinging around destroying everything in its path.

08-02-04 - Spent a few hours cleaning things up a little..

After spending hours cleaning the knuckle assemblies, I'm beginning to wonder if it really made a difference. I took a lot of dirt and grease off but I can't really see much of an improvement. I guess I'll just have to take satisfaction in knowing that I cleaned it.

08-03-04 - Got my rebuild price quote today ...

I'm either the most gullible person, incapable of making correct judgements, or I just threw money around like it didn't matter.

Just got a call from Scott at Unitrax; it'll be done Thursday or Friday to the tune of around $575. He said the gears were bad, but he also said everything was worn normally for a 100,000 mile car; bearings, clutches, etc. That tells me that the only change made in 2001 was a ring & pinion gear change - nothing else. What do you think that should normally cost?

So, I'm looking right at my receipt from Guldstrand, dated January 22, 2001. In the main body of the repair order, there's a description for "R&R Third Member (swap from 3.07 to 3.73)". In the upper-left of the receipt, where the breakdown of parts list is, it reads: "Rebuild 3.73 Third Member", with a sale amount in the next column reading $1450.

Fourteen-hundred and fifty dollars!! For a simple ring and pinion change??

If I looked at the receipt before, I assumed the complete rear end (differential as well as gears and bearings) was rebuilt! There I go again - ASSUMING. I made an ass of myself again!

Hey look! Here comes Ken - let's take his lunch money.

08-07-04 - Some after cleaning, before re-assembly pictures...

08-09-04 - Monday's update on the weekend's work-in-progress ...

Got the third member back last Thursday but didn't get around to installing it until yesterday (Sunday); I've been taking my time, cleaning everyting I can, including hand-polishing the half-shafts, as well as the camber and toe-rods. The only things left to install now are the above-mentioned parts and the rear spring - then I bolt on the wheels and I'm ready to go.

More pictures will follow as the assembly comes together.

08-10-04 - Reassembly is complete!

Got it back together today, tomorrow it should be on the road again.