Shortened C4 Half Shafts

Finally got my shortened shafts in!
I bought them on ebay for $80 shipped, and paid $120 to have them shortened. So for $200 I lost a few overall lbs, a little less un-sprung weight, a little less rotating mass, and, well they look cool too :waxer: Not too bad :thumbs:



Bolts do contact just a little bit at full droop... I can still turn the wheels by hand, but you can feel a little resistance

that idea looks good enough to steal... thanks man!!:thumbs:

I had the same bolt interference issue too. I replaced the stock bolts with some small-head bolts that gave me the needed clearance.

69427 said:

I had the same bolt interference issue too. I replaced the stock bolts with some small-head bolts that gave me the needed clearance.

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Did you ever drive yours around with the regular bolts? Im wondering how often, if ever the shafts will be at full droop. I did have some notable rear body roll, but I just moved the spring to the highest rate (which also raised the ride height :hissyfit. Going to an auto-x tomorrow so ill see how much travel I get. I used to smell it rub on hard corners...

SuperBuickGuy said:

that idea looks good enough to steal... thanks man!!:thumbs:

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Gotta give credit where its due... I got the idea from 69427 :2nd:

Do you know the weight difference of the shafts?

Unfortunately, no. I would estimate they are almost half the weight of my 3" shafts.
I was able to get up to speed yesterday... no vibrations into the triple digits

I've got a couple spare C4 shafts (with u-joints) that I could weigh. They're obviously longer than a C3 shaft, but we could make a rough comparison if someone could get the C3 shaft weight and length.

not all C3 shafts are created qual, there's 2.5 and 3" ones, thin and thicker wall and the 80-82 units are a different length too. Also in 2.5 and 3" available (3" on manuals and all 82s)

From tech section:

Half Shaft with U-joints and flange: 10lbs 12oz

I weighed one of my spare (stock) C4 halfshafts. The weight, with both u-joints installed, was 7.1 pounds.

A shortened (C3 length) shaft would obviously be slightly lighter.

Back in my dealer days (daze?) the C4's had an annoying "ping" when shifting from R to D. THe TSB fix was a half can of spray undercoat shot thru the vent in the center of the yoke on the outboard end. THen drive it to spread it around before it dried.

I've got a set of 3" shafts I'll get around to someday.. Interesting about the weight difference.

TimAT said:

Back in my dealer days (daze?) the C4's had an annoying "ping" when shifting from R to D. THe TSB fix was a half can of spray undercoat shot thru the vent in the center of the yoke on the outboard end. THen drive it to spread it around before it dried.

I've got a set of 3" shafts I'll get around to someday.. Interesting about the weight difference.

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Bubba writes service bulletins? PhD in mechanical engineering from MIT?

No bubba there. Right from GM. That was the official fix. And warranty paid for it- IF the customer complained.