VCCA Home Forums TECHNICAL - 1945 AND NEWER 1946-1948 "48 Transmission Removal

How tough is it to remove a transmission? My '48 Fleetline's tranny is making a noise and my mechanic suspects that the main bearing is going bad. Still shifts fine, but the noise is pretty disconcerting. Occasionally, it slips out of gear, but I've always attributed that to the vacuum assist. Still has the original engine and tranny.

Although my mechanic could do all the work for me, space/storage for him and commitments to other vintage customers' cars, puts the work wait pretty far in the future and I'd like to get it done sooner than later. I have the shop manual and it doesn't look TOO complicated. I'll leave the rehaul to him, though, because it looks like you need some special tools and knowledge to get the bearings off and on, and, more importantly, to assess any other problems it might have.

I have moderate mechanical skills, but have never tackled a tranny removal before. I don't have a lift, but do have ramps. I was looking into getting the transmission rebuild kit from The Filling Station, which seems to be the only complete one available. It would also save me some coins taking it out and reinstalling myself. I could also get help from a friend that is more mechanically experienced than myself, since Murphy is usually by my side when I attempt something. Any advice?

Hi,

Please take the time to read the procedure for removing your transmission in your manual. I am providing you a link to a previous post covering transmission removals. You should do a search of our old posts to find out more information about the steps involved.

The posts will point out that transmissions are usually removed through the passenger compartment of the car not by dropping them from under the car. Under the car you will only need to disconnect the transmission linkage, emergency brake, and the driveshaft before removing the transmission. It is common to remove the front seat so you can get to the transmission to lift it out. The transmission is very heavy so it must be lifted carefully.

Why are you so sure your problem is a bearing in the transmission? Maybe it is the universal joint, clutch, pressure plate, or throwout bearing that is causing the noise. I assume you have checked the fluid level of the transmission? I have yet to see a bad bearing in the 5 or 6 transmissions i have taken apart.

Until you do a visual inspection of the transmission I would not assume you have a problem that can be solve by ordering a few parts in a rebuild kit.

Removing a transmission

I have done a fair share of transmission work on my 41. Please feel free to call me with your questions. (989-832-7634).

Good luck, Mike

Mike - thanks for the info and links. I did a search for "transmission removal" in previous posts, but the search engine is less than stellar with its search results sometimes.

I don't know for sure that the bearing is bad. I'm relying on my mechanic's preliminary guess (and that's all it is at this point) and give him much credence, since he's been working on vintage cars for 25 years and currently owns 12 of them, including a 51 Chevy. He's someone I trust and have confidence in. I'll have to look at the manual again, because I don't recall it saying anything about removing it through the passenger compartment. Ugh. The fluid level is full.

Now I'm rethinking all this to letting him just take it apart so everything, including the other items you mentioned, can be inspected and the problem can be fully diagnosed. My problem is that I just don't have the experience to fully diagnose any issues. I'd like to learn, but do so by watching and doing, more than by reading. Makes it tough when all the activity happens in a garage and you're not there to watch, though.

Hi Conwayde,

When doing a SEARCH follow the tips under "Keyword Search Terms" You will see in blue text Look HERE for Advanced Search Tips Using the plus symbol (+) before each search term works great. So search the terms +transmission +removal this will give you a good selection of previous posts on your topic.

It is awesome that you have an experienced mechanic to deal with. My concern is that you take some baby steps before removing the transmission or taking it apart.

You may even want to remove the side cover of the transmission where the linkage attaches and do an inspection of the gears and check for obvious part wear or damage.

When removing the transmission linkage it is very important to not upset its adjustment. So mark the correct positions for each part.

Please give us some more info on the noise you are hearing? When is it occurring? Does your vacuum shift work at all? How long have you had your car? Do you hear the noise only at a specific time say when driving in 1st gear?

Slipping out of gear could be a linkage adjustment problem, vibration problem (missing, broken motor mounts), transmission mount rubber gone bad, worn bushing on drive shaft).

Good luck, Mike

P.S. Most of us are just like you with little or no previous mechanical experience so we have to rely a lot on others. The question is what is the balance between paying someone or trying to teach ourselves. I also am a visual learner and find reading manuals very challenging, but I am limited on how much money I can spend on a repair so try to trouble shoot problems myself.

Mike - I've had the car for about 3 months now, and it was in the shop shortly after I got because the back piston blew. Maybe that was my fault for running it at about 60-65 MPH, or, my mechanic thinks, maybe it was a stuck valve. So I have all new pistons and valves and the engine runs just fine. He told me to keep the speed under 55 MPH from now on.

When he took it out for a test ride, that's when my mechanic first heard the noise which he believed could be the transmission bearing. The noise starts in 2nd, but seems to get worse in third gear. Hard to describe a noise, but it's fairly loud and grating, and sounds like it's coming from underneath your feet, not the engine bay. The noise lets up if you let off the pedal and returns once you give it gas. It's relatively quiet when coasting.

The vacuum shift seems to work fine - pretty easy to shift in all gears. The slippage is intermittent - sometimes in 2nd and sometimes in 3rd. Sometimes, it doesn't slip out of gear at all.

I got the car with about 72K miles with what we believe to be the original engine (at least the block numbers are correct) and tranny. Other than a few odds and ends, it seems to be basically unmolested and probably had an interior restore and a repaint (wrong colors) about 20 years ago, I think.

One thing the mechanic did comment on was that there was absolutely no trace of rust or body repair anywhere on the car. It came with a lot of options and is basically a sound example of a Fleetline. You can see some pics of it that Chevy-Chef posted for me on the New To Chat section under 1948 Fleetline. It's a decent looking car and I'm slowly going to correct any incorrect items as I get the chance (and money).

I'm trying to learn as much as I can about the engine, much through this forum, but I also know my limitations.

It's real easy except if it's a convertible. Convertibles have the "X" frame which causes a reduction in space to work.

Here is the procedure used in Texas:

a. Take everything loose that is holding the transmission in place.

b. Lift the transmission out the hole in the floor pans. (bunch of screws. Talk someone else in removing them for you. A promise of a Lone Star usually works.)

c. Don't move the clutch peddle. This way you can just slip that sucker right back in.

You're welcome and good luck,
Charlie

BTW: Check the transmission for worn parts and replace. Everything in there will come out if you knock the big pins out. Piece o' cake.

BTW2: I got all this here procedure from a Texan.

Thanks Charlie, but I'm afraid that won't work because I'm not in Texas. But maybe I can drive down there when I decide to do it...

Conwayde

By "main bearing" are you refering to the clutch shaft bearing? You also say that it occasionally jumps out of gear. A worn clutch shaft and/or worn synchronizer can cause this. Don't worry about your transmission being full of grease. there is a drain plug so you can empty it before you take it out. You'll need your Big Boy pants or a helper to lift it out.

They are really not that difficult to take apart but first time around a mentor would be handy.

Good luck!!

Conwayde,

Did you hear the noise before you had to rebuild the engine? When the engine was out did you replace the motor mounts and rebuild the transmission mount?

Good luck, Mike

Noise was there before the engine rebuild, and no, they engine was not completely removed, so nothing was done to the mounts. I think the noise has gotten a little louder/worse, but that might be my imagination. I refer to it as the main bearing only because that's what my mechanic called it. From what I can see in the diagram there's only two bearings in the tranny, and I guess he's referring to the front one, closest to the engine?

I had a issue like that in my 47 coupe and it turned out to be a Ujoint issue. So I would check them first. Good Luck

Rich S.
Wolcott, Ct

Thanks Rich - what should I look for in a worn or defective U-joint? That would be a much easier fix than a transmission....

A better description of the noise is needed. A bad bearing sounds nothing like a bad U joint. Is it a growling noise, howling noise, clunking sound, or ???. Is it worse when under power, or when decelerating? Is it worse in one gear than the others?

It's more of a growling noise, which seems to come from under your feet, and gets worse in second them a little worse in third and when under power. Seems to go away when coasting. It is not a clunking noise, which I would think would be more in keeping with a bad U-joint.