Gearbox Double Trouble! Disassembling the Second Box

[@cratecruncher6687]

That box wasn't as bad as I thought when you started. The salvage yard gave you a smokin' deal I'd bet!

[@midwestmotoring]

Actually rescued it from a dumpster. It was being thrown out.

[@williamlucas8793]

Great video as always. I am about to start a gearbox overhaul myself. Do you think a typical ~$50 harbor freight or Amazon gear puller will work? Yours appears bigger and better than the typical pullers I see on-line.

[@midwestmotoring]

I can say with certainty that it will since my gear puller is from Harbor Freight. What you're looking at is technically a "bearing puller." It's got some pieces you can attach to pull from much farther away. The other thing of note is that the bolts between the 2 halves may not be long enough. I picked up a couple longer bolts from a hardware store so I could pull larger size bearings.

[@williamlucas8793]

Thanks for the quick response! Off to Harbor Freight I go.

[@jamcdona]

To my very amature eye, this gearbox is mostly still servicable- just needs new bearings and that layshaft? How's the mainshaft look to you- can you polish? Gears missing teeth? You got a lot of work done with the kiddo and doggo around. It took me 1.5 yrs to rebuild my first engine, partly due to taking my time and only purchasing parts when I could afford them, but it seemed like I had to 'earn' my garage time. And be pulled from it if needed LOL.

[@midwestmotoring]

Between the 2 gearboxes, only one mainshaft is in good shape. The other has some scoring at the front where it fits into the needle bearing and the input shaft. No missing teeth, though reverse gear is chewed up quite badly (that's actually extremely common, and they're readily available). The little guy is 9 months old, so he's in that sweet spot where he's old enough to be interested in playing with toys and young enough where he can't walk yet. I have to work fast--and trust me, there are plenty of cuts. If you watch the channel, you'll see I'm often wearing different clothes between cuts. :)

[@randygibson7538]

Good morning. I hope this finds you well? My name is Randy Gibson. I live in Atlanta, GA. I was out driving my 1971 TR6 yesterday and I had to cut my ride short because I smelled gas. When I got home and raised the hood I noticed that my ZS CD175s were the culprit. On the top left of each carb. towards the wheel there is a connection that goes to the carbon cannister. My car does not have the carbon cannister so the connectors on the carbs. are open/blank. This is where the gas was coming out of. It was not a steady stream but more of a "spitting" of gas irregularly. Do you have an idea what is causing this and how to repair it? Just an FYI, I have an electric fuel pump with a regulator and pressure gauge. The fuel pressure is set to 3PSI. Any help would be appreciated. Thank you so much

[@midwestmotoring]

Hi Randy, That port on the side of the carb is a vent. It seems like your carbs have been replaced by ones from a later car, but that won't be a problem and the vents should remain open. Technically, you could force the vents to always be open to the air cleaner (as the carbs in earlier cars would be) with a drill... but then you'd be leaking gas into the air cleaner instead, which still isn't good. The real issue is likely too much pressure in the float bowls. Try reducing the pressure on the regulator. You can verify it's letting through what it claims to be with a pressure gauge--not all of these are accurate. Even at 3psi that may be high. 2 should be more than sufficient for these carbs. Remember that the pressure of the fuel is not the same as the volume. Hope that helps!

[@randygibson7538]

@@midwestmotoring Thank you for the quick response. I thought it might be the fuel pressure. I bought the car in December 2021. The guy that I bought the car from told me he had preplaced the ZS CD175s. So you were exactly correct about them not being original to 1971. The pressure regulator is an in-line type from Mr. Gasket. It came on the car. It is chrome with increments that read between 1-5 with 1/2 marks. I had it set on 1. The pressure still read 3-4 PSI. Do you have a suggestion for a better low pressure regulator and pressure gauge? I think I should look to upgrade. I REALLY appreciate your help. I hope to be able to return the favor one day. Best Wishes, Randy Gibson

[@odl21]

why is overdrive so common in the us?

[@midwestmotoring]

I guess just a lot of cars had the option spec'd. It's a great thing to have though. I drive my Spitfire on the highway often, which might be at 70 MPH. At that speed, it's the difference between about 3600 RPM and about 4500. HUGE reduction in both noise and engine wear, and better economy to go along with it.

[@odl21]

Good reason to stick to non highways! I usually try to avoid driving cars like this on motorways. And the overdrive adds a fair bit of weight and complexity. I never even considered one here in Switzerland.

[@midwestmotoring]

Unfortunately, it's not practical to avoid highways in much of the US. Even just going to my office would take an extra half hour each way. Also, early Spitfires have a 4.11 differential ratio, as opposed to the 3.89 in later cars. That makes for high RPM at pretty much any normal road speed, even close to towns. I have had later Spitfires without overdrive, and it wasn't a major inconvenience... but I always recommend them for the round tail cars.@@odl21

[@frankmgallo]

That was a big mess. Needs lots of cleaning and lube and a few new parts it will good as new

[@midwestmotoring]

Yes I agree. Turns out the bearings were all rusted solid, which is why it wouldn't turn. I'm probably going to have to junk the laygear cluster since the needle rollers have welded themselves to the inside. Luckily, I have a spare for that too.