When did they switch from tower to gear clamps?

[davepl]

My truck only had a single tower clamp, and it was on the breather hose. By the time I got it, everything else was gear-style clamps.

My guess is that 69 was the last year of tower clamps (my 2+2 and Camaro use them). But I really don't know.

Anyone happen to know?

[FirstOwner69]

When I first replaced the radiator hoses on my 69, I replaced the tower clamps with gear clamps. I THINK the heater hoses may have been the spring type clamps. If not, they were also tower clamps. Mine now has tower clamps everyplace except for spring clamps on the heater hoses. As I recall, that's what the 69 service manual shows. Of course that could have been a carryover from previous years.

Edit: The 70 Chevy service manual shows tower clamps on the heater hoses.

Jim

[cdowns]

the factory never used the gear type clamps anywheres on anything

[davepl]

Originally Posted by cdowns

the factory never used the gear type clamps anywheres on anything

Well, except they did. So guessing doesn't help.

CLAMP, Hose
1969 2468878 - Worm type adjustable stainless strap type [Radiator - 1.75 to 2.25 range]
1969 2494772 - Miniature worm drive type (.25 x 5/8" diameter)

...and so on.

[davepl]

Originally Posted by FirstOwner69

Edit: The 70 Chevy service manual shows tower clamps on the heater hoses.
Jim

In the GMC case there is no service manual for 1970, just an addendum to the 1969. Does the Chevy truck actually have a 1970 manual? Or were you referring to something in the 1970 addendum? 'cus otherwise you're looking at the 1969 book, I think. I'm not an expert on the docs though.

Even so, I kind of wonder if they'd revise drawings for a hose clamp, but they might.

[WIDESIDE72]

I had a 53k mile 71 GMC 1500 custom with a 250 6 cyl/3ott that still had tower clamps. I believe even the heater hoses had them.

[slow-1]

My 72 has tower clamps.

[FirstOwner69]

Originally Posted by davepl

In the GMC case there is no service manual for 1970, just an addendum to the 1969. Does the Chevy truck actually have a 1970 manual? Or were you referring to something in the 1970 addendum? 'cus otherwise you're looking at the 1969 book, I think. I'm not an expert on the docs though.

Even so, I kind of wonder if they'd revise drawings for a hose clamp, but they might.

Below's a link to the PDF manual thread. There is a 1970 Chevy manual. The drawing I looked at is on page 61 of the PDF or page 1A-31 of the manual. As I recall, the same drawing in the 69 manual I have in hard copy shows spring (corbin) clamps on the heater hoses. I can't verify that since that, too, is 150 miles away with the truck. Of course, a drawing doesn't make it fact. I can't locate any drawings of the radiator. In my opinion, you can't go wrong with the tower clamps if you are looking for original (as I'm sure you are).

Jim

http://67-72chevytrucks.com/vboard/s...d.php?t=558016

[NoNeck]

If you are looking for originality, the tower clamps look great. But I have found that after only a couple of hose changes through the years the tower clamps can distort and begin to leak. You tighten them, the tower stretches at the square nut corners and they can leak even more. At least the NOS clamps that I found at a Chevy dealership liquidation years ago did that.

Not saying the worm clamps don't wear, but QUALITY worm clamps would be the ones I would use on a daily driver.

There is a reason you don't see tower clamps on modern cars and trucks.

Just my 2¢...

[FirstOwner69]

Originally Posted by NoNeck

If you are looking for originality, the tower clamps look great. But I have found that after only a couple of hose changes through the years the tower clamps can distort and begin to leak. You tighten them, the tower stretches at the square nut corners and they can leak even more. At least the NOS clamps that I found at a Chevy dealership liquidation years ago did that.

Not saying the worm clamps don't wear, but QUALITY worm clamps would be the ones I would use on a daily driver.

There is a reason you don't see tower clamps on modern cars and trucks.

Just my 2¢...

My understanding is that tower clamps were designed for single use and were to be replaced when hoses were changed or removed then reinstalled. I read this recently, but I'm not sure where. May have been on thhis forum. Makes sense when you look at the design. The gear clamps are a better, reusable design.

[motorcritter]

The '71 Cheyenne has a mix of clamps- probably from prior service work. The tower clamps take up a lot of room (and there's not a whole lotta room in modern engine compartments), the spring clamps are also one-time-usage items, at least they were when I worked for Honda & Toyota. Those nasty wire-style w/ gimmicky screw tensioner-hose clamps on just about every Asian vehicle (usually on smaller hoses) are considered one-time-usage by any Asian vehicle technician, too, but not by the manufacturers. They suck. I use screw-type for repairs & service- no problems, easy to access, cheap- what's not to like, unless you're a 100 point concours restorer.

[mrein3]

Originally Posted by FirstOwner69

My understanding is that tower clamps were designed for single use and were to be replaced when hoses were changed or removed then reinstalled. I read this recently, but I'm not sure where. May have been on thhis forum. Makes sense when you look at the design. The gear clamps are a better, reusable design.

30 or so years ago, while working through college at a local shop, my boss showed me how to remove "tower" clamps.
Take a side cutter, cut the clamp where it goes up the tower, throw the factory clamp away, and put a worm gear style clamp back on. He didn't like paying me for warranty work so we did that on every hose we had to touch.
I executed that move hundreds if not thousands of times.

[68gmsee]

Originally Posted by mrein3

30 or so years ago, while working through college at a local shop, my boss showed me how to remove "tower" clamps.
Take a side cutter, cut the clamp where it goes up the tower, throw the factory clamp away, and put a worm gear style clamp back on.....

Growing up in the 60's, I saw a lot of vehicles with tower clamps, wire clamps, spring clamps but I don't remember seeing any perforated worm screw clamps from the factory. Even now, I don't see the worm gear clamps in cars.

However, I agree with above. The first thing most mechanics and owners did when they had to do any work on an engine with factory clamps is to get rid of them and replace them with worm gear types.

For anyone interested in the original look, here's some similar but not exactly like original on this site.
http://www.cjponyparts.com/scott-dra...FePm7AodCBwAWg

[turp mcspray]

My 87 truck still has tower clamps at the heater core, and what looks to be original heater hoses.