VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 1926 - Gears Grinding

Hey Guys, looking for some tips here for a 1926 4-Door Superior. Brief history: My great-great-grandfather (who I obviously didnt know) bought the car new and passed it to my great-grandfather (who I was lucky enough to know for the first 14 years of my life) - I have great memories of riding in the car when I was very young. Anyway, the car runs well other than it needs a new muffler. I'd also like to extend the exhaust since it is original and only extends about halfway down the car. I'll take any advice you have on that, but the real reason I came is due to grinding gears. When stopped and out of gear, the car will absolutely not go into gear without some awful grinding. I noticed the clutch pedal had a lot of play in it so I adjusted that and was hopeful that would fix it, but it did not. The clutch pedal now has less than a half inch of play in it and it still grinds. Any ideas on what could be causing this? I will say the shifter seems very loose - it obviously moves side to side when out of gear, but even in gear, it has an excessive amount of side to side play. Could the transmission just be worn out? To me, it seems like it has to be the clutch since the gears move freely without grinding when the engine is not running, but I dont understand how it could be still engaged with all the play out of the clutch. Thanks for any help you can provide - driving season is here!

I'm sure you're aware that Chevrolet didn't have synchromesh till 1932 Master. There may be trash in your clutch causing it to not fully disengage when depressed. If you haven't inspected the clutch and transmission after it has been setting for a long period, that's a place to start. A rats nest could create enough friction to cause grinding when going into low at stop. Also good time to clean out rust, water and grease the pilot bearing.
Good luck, Lou

Clutch definitely not fully disengaging if at a complete stop. It's not a transmission problem.

Hi Dude,

Welcome to the VCCA website! What a wonderful heirloom!

I had a similar problem with my 1928 truck after it sat for over 50 years in the previous owner's garage. When I first got the engine running, it would not go into gear without crunching the gears. The problem that I finally found was that there was enough rust on the splines of the transmission input shaft so that the clutch would not slide away from the flywheel and therefore did not disengage.

Along similar lines, but a separate issue, is shifting gears when you drive the car. When you shift up to the next gear, don't wind up the engine. Shift earlier than you might think you need to. If your engine is revving up too high, the gears will grind. When downshifting, acquire the skill of double clutching. There's a good description of how to do this in the owner's manual. If you don't have one of these booklets, I suggest you get one and a repair manual too. Many vendors carry them and you'll find them on ebay too.

Cheers, Dean

Thanks a ton for the quick replies - I had a feeling it was a clutch issue. The clutch was replaced in 2005 the same time the engine was rebuilt and both have very little miles on them since then. I guess there's no way to get to the clutch without pulling the engine?

Thanks for the advice on shifting. I actually have a Model A that is from my same great-grandfather so I'm somewhat familiar with shifting an unsynchronized transmission; although certainly no expert. I will say, I love how the Chevy shifts (after it goes in gear) compared to the Model A - the Model A feels more sluggish.

The transmission can be dropped out of the car without removing the engine. I've done this many times (long stories). ;-)

When you jack up the car, place the rear jack stands under the chassis, not the rear axle. That will allow the axle to hang further down, which in turn gives you more room at the u-joint to disconnect it and move the torque tube out of the way.

While you have the tranny out, I highly suggest replacing the carbon throw out bearing with a new ball bearing type that is sold by many vendors, such as Billy Possom, the Filling Station, and others. With the new bearing in place, you won't have to worry about the carbon disk overheating.

Cheers, Dean

Since you are 'new' to the car, be aware that the oil pump does not deliver oil to the rocker arms. They need a squirt of engine oil (10w-30) manually. I give my toys a squirt before every drive and, if I'm going on a long drive, every 50 miles.

The owner's manual and the shop manual have a great lubrication chart that will give you all the maintenance details.

Cheers, Dean

You could try wearing in the clutch a bit (controlled riding/feathering of the clutch) to see if that helps.

Also, just thinking out loud, is it possible that the pilot bushing is a little tight? If that is the case, you could put the car in gear while stopped and the engine running try to wear in the bushing a bit. If that doesn't work, you'll probably need to pull the tranny.

One last thing, what are you using from transmission fluid? If you're using 140w fluid, it may be worth trying a thicker 600W replacement before you pull the tranny. I've had good luck with this stuff: https://www.mikes-afordable.com/product/GL1500.html. The thicker oil helps slow the gears down for easier shifting.

-Tyler

Using the correct gear grease is important. If it is too thin, it won't cushion the metal parts. If it is too thick, it will heat up and soften the metal gears making them wear quickly. After a drive in your standard trans mission car the transmission should be around 120 F. If it is too hot to hold your hand on, you need a different oil. Don't be fooled by multi weight oil. The additive to make it multi weight is NOT a lubricant so don't get too large a spread. If you use 90 weight in your NV4500, It will get hot enough to discolor the gears. .
Your new clutch plate might be bent causing it to drag. . .

I really appreciate all the generous advice. In general the clutch used to work fine with no grinding and then just one day, it started being rough going into gear while stopped.

Rustoholic,
Thanks for the tip on the rocker arms. There is no felt pad or valve cover - is this ok or should I snag a felt pad from one of the vendors? I'm sure there are other parts of the car that could use a good oil and grease job so I'll check that out.

TJ,
Not sure I follow what you mean regarding the pilot bushing. Are saying put it in gear with the car stopped and just let it run for a bit with the clutch pushed in? Could it get too tight on it's own if it was working fine previously? We havent had a great track record of keeping the car running so it has sat for extending periods over the past 10 or so years (probably as much as 3 years at a time). For gear oil, I'm using a 600W oil that I had on hand for my Model A.

Hi again,

Your '26 engine should have both a felt pad and a rocker cover. Get a new felt pad from one of the vendors.

Before you look for a rocker cover, I suggest verifying that your engine is from 1926. Many original engines were replaced with later ones because of a failure.

There are casting dates on the engine that you can check. One is on the side of the block, near the distributor. It will be a three character string. The first character will be a letter, indicating the month (A=Jan, B=Feb, etc.). In the middle will be a one or two digit number, which represents the day of the month. The last character will be a single number indicating the year (6=1926, 7=1927, 8=1928).

If your engine is a 'number matching' one, the same casting date should be on the head.

Now that you've determined the year of the engine, you can post a 'Parts Wanted' ad for the correct rocker cover. I'm sure someone has one in their stash that they will sell to you.

Cheers, Dean