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I wanted to introduce the forum to a tool I designed, explain how it works, and share a story as to what made me realize it was necessary.

As anyone finding this post probably knows Oldsmobile engines were offered in a lot of Cadillacs over the years. The 350 or 5.7L was used for the EFI Sevilles and Eldorados. Later the 307 or 5.0L was offered in the Cadillac Brougham. When I created this tool, as far as I know, there had never been a tool designed specifically for Oldsmobile valve springs. This tool works both on an assembled engine (changing valve seals for example) and as well with the heads removed.

The first time I changed Oldsmobile valve seals was around 1999/2000. A friend and I changed valve seals on an Olds motor with an adapted Chevy tool because we couldn’t find any Oldsmobile specific tool. We were working on removed heads so we had easy access to both sides. Removal of the old parts wasn't too bad because a magnetic pick-up could be used avoiding fingers being placed where they could be snapped if the tool let-loose. During assembly the first 3 cylinders went pretty well but the cam action of the tool required my friend to stabilize the tool in the perfect position, working against the spring pressure, while I carefully placed the keepers with my finger tips exposed to a mousetrap like situation if the tool were to slip. On the 4th cylinder the tool slipped and the spring retainer suddenly nipped the end of my finger as it shot up against the tool area. I went from being nervous to shaking which made the job spiral downward. While doing the second head the adapted chevy tool released causing the valve spring to fly between our foreheads with enough energy that it hit the peak of the pole barn barn metal roof, about 15-20 feet, and ricocheted off. I remember saying to myself I will never do that job again without a better tool.

In the 2014-2015 I needed to do valve seals on my 1979 Eldorado (Oldsmobile 350). I had flashbacks of getting my fingertips snapped and a valve spring flying between our foreheads so I created my own.

Fast forward to August/September 2020 and a professional builder saw an old post I had on another forum and asked if I still had any tools for sale. I didn’t, all of the original tools sold on the Oldsmobile site in about 1 week. He told me a similar recent story involving a spring letting loose while using a tool designed for something else. I had always wanted to make one further improvement to the tool which has now been incorporated.

The 2014-2015 version had no machining other than tapped threads in the bottom plate (I considered it but it made the build cost too expensive). Since the Oldsmobile valves are on a 6 degree angle the 14/15 tool wasn’t centered well over the valve retainer over the entire stroke. This new version has a slot in the top plate and a machined pocket. The combination allows the top plate to move better with the angle and the machined pocket prevents the top plate from sliding.

Double studs were used because the distance between the Olds valves springs is tight and second because two separate studs allows tipping the plate slightly. If you are having trouble removing or installing the keepers you can walk one nut down more than the other which will tip the top plate slightly to help expose one side or the other. For clarity one of the photos posted shows the tool assembled on a spare head.

I made a total of 50 kits to get the cost per kit down and I’m now selling them for about what it costs to make/assembly the kit.

If anyone who reads this has my 2014-2015 of my tool version please contact me. I made extra "H" plates to upgrade the prior version tool.

    • 304SS 3/8" Top Plate "H" and Base Plate "T" << (Machined and cut in the USA of US Steel)
    • M8x60x1.25 Din 913 45H closed flat point end studs (2) << (Foreign: Taiwan)
    • Class 10.9 steel M8x1.25 nuts (2) << (Foreign)
    • Grade 8 bolts 5/16-18 x1 1/8” (2) << Made in the US (Photo with "JH" on head is not the bolt in the kit)
    • Grade 8 thick washers (2) << Made in the US
    • 4mm Allen wrench (Tool) (1) << Made in the US
    • Full set of instructions written in English (1)



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