Transmission

My 1954 chevy pickup makes a noise when driving in second gear. It's not like a grinding noise to me but it's really hard to describe. If I drive in second gear and run the rpm's up, it kicks into neutral. My first thought was throw out bearings? Now that I've fixed the exhaust leak the truck runs much quieter and I can hear the same noise only softer in neutral. When I press on the clutch, the noise goes away. Anyone know what this is??

Sounds like time for a rebuild. I would suspect possibly a synchro, if it has them, or a bearing.

Sumbitch broke.

a light whining/whirring sound at idle in neutral with the clutch out is fairly normal. if its rattling or squealing there could be an issue. kicking out of gear under load is likely a worn (rounded off) or broken dogs in the trans, and will require a rebuild or replacement of the trans.

i other words, sumbitch broke

The grinding in second both under load and in neutral along with the kicking out of gear makes me think its the front main bearing. I am guessing that this is the 4 speed?

It's a 3 on the tree. If I decide to rebuild, is it simple enough I can do it or not? I thought about draining the gear oil and replacing it since it's got a slow leak somewhere and i dont know exactly how much has leaked. Im guessing that could of been part of the problem. It was leaking before i bought it but i didnt realize it until i started working on the truck. I was trying to hold off a lil longer before tearing it apart. I found a guy that has used transmissions for my truck; however they are used and not guaranteed to work.

Good learning experience. I can't think of many vehicles that are easier to work on than an old truck. Get some hand tools, a buddy, and a 12 pack of beer, you will have the new box in before the beer is gone!

I would check all of the linkages and the motor mounts just in case. But you can definitely rebuild your transmission yourself and get results on par with a professional.

All you need to rebuild that box are a hydraulic press, bearing puller, and snap ring pliers. The cheap ones will work just fine. I had very good results using a kit from Novak and keeping everything meticulously clean during assembly.

I would look for an overdrive and a PTO while your at it, but that might lead down a dangerous road.

Where would I find these items? At my local parts store? As far as an overdrive, would that be the same as putting in a four speed?

Dont listen to me about the overdrive and especially the PTO. They are my Unicorns. An overdrive for an old 3 speed or 4 speed truck box like the SM420 can cost as much as 4 or 5 transmissions. On old transmissions the overdrive was a second gearbox that was added to the main transmission and often had its own shift lever. They usually offer about a 25% reduction in highway rpm.

A cheapo press, bearing puller, and snap ring pliers can be had at your friendly neighborhood Harbor Freight, Craigslist, or anywhere else that cheap tools are sold. I would ask a few old guys before I bought anything. Most people will buy these tools, rebuild 1 box on an old Jeep, and then let them sit for years till they get fed up and sell them in a garage sale.

Ah ok, I was wondering how an overdrive would work in that truck. I've heard of pto's but don't think I'd use it. Thanks for the advice. I'll do some digging around and see what I can come up with before buying those. Hell cheap tools can still be exspensive.

I had a 67 Chevy (Old Yeller, straight 6, 3 on the tree) that jumped out of 3rd gear. The transmission was gone through twice and it still did it. A friend of mine that was a professional mechanic suggested the pilot bearing. I sold the truck before trying that.

Pulling the transmission on that truck was super easy. The thing was about the size of a shoe box and weighed practically nothing. At least compared to a Toyota or Mercedes 4 speed.

Just a thought - I have a 4 spd manual Ford trans that is geared like a standard 3 speed plus an OD gear. It's from a '78 granada. I bought it to put in to a 69 F100 but sold it before doing the swap. The shaft.pilot/clutch spline is a direct fit for the old ford 3 speeds.

I know that trans doesn't help you, but maybe GM had a similar box in the late 70s you could source to get the OD without the vintage-correct OD add-on.

Oh, and, yeah - sumbitch broke.

Those are a really fragile gearbox. There is a betteer than average chance you will find chunks of something in the bottom of it.

On the upside, the 3 speed chev box was the same from about 1912 till they quit building it, so find one with the same input and output splines and bolt it in.

I'd say pick up a $50 (plus or minus a fair margin) gearbox to put in there. If you want, you can rebuild the other while it's out. Or...if time's not an issue, you can pull the one that's in there, go through it and decide if you want to rebuild it or buy a used one.

I think I have a manual for the old GM 3 speeds on my home computer. Message me and I'll email it to you. Though, I'm sure I just found it online and maybe you can find it just as easily with google.

I've got one (an old 3 speed GM) awaiting use in a hobby stock circletrack car someday! Wouldn't mind a spare (off to browse craigslist, I go).

Clem

Does it have oil in it? Strange question, I know. But my Mustang lost all of its oil in its first transmission without even dripping (it must have blown out while driving one night). Your truck, being old enough to have a three on the tree, is probably covered with oil on the bottom of the transmission anyway. You might want to make sure there is some on the inside too.

As far as oil goes, I'm not sure how much is really in there. The bottom is covered in oil. Everytime I fire her up and let it run for a lil bit and then shut it off it leaves a few drops under the trany. I thought about draining what's left and putting in new oil. As far as used tranys go, there's a old truck parts store a couple miles away. Jim Carter truck parts or something like that. He has used tranys for $75 but they are not garunteed to work. I was thinking about buying one just for the hell of it and trying it out. If it works great, gives me time to rebuild the old one. An older fellow described what the overdrive looks like for that year and thinks there might be on already or at least hook up for it? He also told me they weren't very good back then? Not too worried about it. Sounds like more trouble than I'm ready for

Here's the factory brochure for a 1954 Chevy truck: http://www.cs.siena.edu/~lederman/truck/Documents/SalesBooklet/index.html It doesn't look like an overdrive was available, and since the truck has a torque tube driveshaft it may be a job to install one.

My G-pa had a '59 Chev Apache fleetside. 235, 3 on the tree, radio delete. Just a basic truck. What he did, he wanted the synchromesh 3 speed, so, he grabbed one from a Chev Vega and modified the shift linkage to keep the column shifter. Granted, he did this back in '72, but maybe that might give you an idea or two.

I'll have to scan my idea of what to fabricate to make the shifter box work with a 4 speed.

I have a cable that's similar to the choke cable that goes down to what looks like the side of the trany. The knob is right next to the cig lighter. One older man told me that has to do with the od, but another said it raises my rpm's while driving on a highway for example?? To be honest I dont know what the heck it is or if it works.

Sounds like an overdrive setup to me.

could be an overdrive, but my grandfather has a similar type of deal that disconnects the driveshaft from the transmission for flat towing his F-150 behind his RV.

Back in the day Overdrives were a very popular option. My dad was a Willys /Jeep dealer and 95% of the 2wd vehicles had them. I became a sort of expert on them.

Ill see if I can post some pics later

pics posted on my profile