VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 Transmission shop recommendation in the N/E

It's in need of a rebuild and I'm looking for a reputable shop. Im in Connecticut. It is from my 1936 Chevy low cab. 3 speed. Thanks..

Your 3 speed transmission has very few parts and would be an easy way to get your hands in. I would take a few pictures as you take it apart and get an exploded view chart and give it a try. Any transmission shop could do it if they can get the parts.

If the gears aren't all boogered up, you can get a rebuild kit from one of our vendors and do it yourself. What have you got to lose?

Cheers, Dean

I have a 36 and see gears quite a bit on epay.

There are a couple of good books out there. "Chevrolet Mechanics' Repair manual 1932 - 1936 by Altero Press, 355 Fourth Street, San Francisco, Calf. 94107 and Chevrolet Six Car and Truck by Page. They can be found at AbeBooks.com Also, 1935/1936 Chevrolet Repair Manual from many places like Chevy's of 40's, etc. The first two show detail type photos. Hope this helps.

Ask for Dan Ryan
A Advance Transmissions
397 E Main St, Smithtown, NY 11787
(631) 366-0022

Top shop here on Long Island
On Angie's list

Mtelow,

Required to "rebuild" that transmission is an assortment of the spacers that set the 2nd & 3rd gear synchronizers at 0,.025"- 0.035" end play.

It's highly unlikely that any rebuilder will have those. Restorers have them all now.

What you will get from a "rebuilder" is new bearings if you are lucky, the outside of the case painted and a big bill.

Those units are very simple so you can do it yourself if you can find the spacers.

I think in your transmission there is no synchronization and In the book it looks fairly simple. You can watch ebay or call a few supply houses for needed parts. you are rebuilding it for what reason?

J Franklin,

I've had the same '36 pickup since 1965 and have looked quite a few of them. All the ones I've seen have either a 4-speed crash box or the '32-'36 style synchro box. The synchro version has the odd feature of the 3rd gear synchronizer ring being smaller in diameter than the 2nd gear part. That yields less friction area for synchronizing and a rougher shift into 3rd than into 2nd.

Mine works best on a cold morning indicating it wants a more viscous oil. "600" weight is the "thickest" I've found but it wants something even a little more viscous. There is a Chevron gear oil more viscous than the "600" steam cylinder oil the car parts vendors sell but the minimum quantity is 5 gallons for about $100. That's enough for several lifetimes.

I wonder if the other guys who are buying "600" oil realize that it's not formulated for gears, but is for steam cylinders. I worry about that in using it in my '36 trens.

Fords of that era had a differnt synchronizer design that works a lot better.

Mtelow & J Franklin

Listed right now on ebay is a front (3rd gear) synchronizer for that transmission, item # 321415150997. Notice the 3 spokes in its center. That is where the spacer goes to adjust the synchronizer - gear end play at .025" - .035". It's those spacers that are necessary for an acurate "rebuild" but they have been extinct for decades. The ones I have came out of good used transmissions that I've acquired over the decades.

Mine seems to work best warmed up. During the first shift from 2nd to 3rd it will sometimes grind and not want to go into 3rd gear. Once it does, it doesn't repeat itself until the next drive. Sometimes it doesn't do it at all. Really, my only complaint is the synchromesh. I find I have to allow the RPM's to drop just right for it to slide nicely into gear. Maybe this is normal for this type of transmission? What oil do you recommend? I haven't tried changing it. Maybe that would help my dilemma? Thanks....Mike

I would definitely change the oil before thinking of rebuilding the tranny. If you haven't changed it, it needs to be changed!

Check the owner or shop manual for an oil specification. I use Mobil 600W in the steering box, u-joint, tranny, and rear end on my '27 and '28 Chevy trucks.

Cheers, Dean

Mike,

I've tried SAE 90, 85-140, 140 and "600" weight and Mobil "600 W Super Cylinder Oil ISO viscosity 460. The ISO 460 is slightly less viscous than "600" weight offered by the various vendors. So far the "600" weight is the best when engaging 3rd gear. Second synchronizes perfectly but 3rd not so well once the trans is hot.

I have 2 of these transmissions, both set up with clearances in the middle of the factory specifications and both behave identically.

The clutch releases cleanly so there is no clutch issue.

These transmissions require SAE 160 according to the owner's manual, a non existant product today.

The next more viscous Mobil oil that I have not tried because the smallest quantity available is 5 gallons for $100 is "Mobil Extra Hecia Super Cylinder Oil", ISO viscosity 680.

In my motorcycle racing in the 1960s and 1970s when the forks were primitive I used to mix oils to get a custom viscosity. That is probably what the 1932-36 Chevy synchro transmissions need, a custom blend.

I drove my '36 pickup this morning and the shifting was as sweet as a new car when it was cold. After warming up the shift from 2nd to 3rd was not as good.

This discussion needs input from a lubrication engineer to get the correct answer, not one of the VCCA self proclaimed "Experts". The right product is out there. The challenge is to find it.

Ray, I suppose you, as a nonmember, would make a statement like that. I suppose we should look for an EXPERT in the field of lubrication, we could send you to.

I use 140 gear oil in my standard but have no shifting troubles. Maybe 140 G.O. and a bit of STP might be good to try for a more viscous oil.

I bought Item VT-40, 2 Qts., 600W Gear Lubricant from The Filling Station. It works just fine in my 1936 Chevrolet 1/2 ton truck. Cost is around $15.00 plus shipping.

I'm no "expert" or an oil guru. My 35 works best with 600W which equates to the old 160. I recently read this article that current gear oils can contain copper/brass eating sulfer.
I still use the 600W F/S or Macs gear oil.

"EP gear oils perform well over a range of temperatures, speeds and gear sizes to help prevent damage to the gears during starting and stopping of the engine. Unlike AW additives, EP additives are rarely used In motor oils. The sulfur or chlorine compounds contained in them can react with water and combustion byproducts, forming acids that facilitate corrosion."

Thanks for the oil recommendations. I believe I have 3 quarts of the 600W that I bought for the rear end of my 1930 Chevy 1 1/2 Ton. I'll give that a try. Do you guys flush the transmission with something or just drain and fill?

Antique Mechanic,

If you know of a lubrication engineer it would be nice to hear what that person has to say about matching SAE 160 oil today. It has been my experience that real experts really do help to solve problems.

For example, I have a street rod with a Chevy Vega steering box. Years ago one of its seals started leaking so I disassembled it to replace the seals. The grease I found inside was a very low viscosity "self leveling" grease. That product used to be available from GM dealers but by 2006 all inventory was gone.

I called Shell Oil and spoke with a lubrication engineer and gave him the GM specification for that grease. He crossed that specification to a grease that Shell currently makes but only sells in 5 gallon buckets. Because he liked that it would be used in a restored antique truck he sent me some as a "sample" at no charge.

I had a similar experience with my '36 Chevy PU 3-speed transmission. There is a snap ring that retains 2nd gear on the mainshaft and there is no readily available replacement for it. All the available snap rings are much too thin. Contacting an application engineer at a company that manufactures retaining rings for aerospace yielded a snap ring that is a perfect fit, again supplied as a "sample". So true "experts" are out there and they really do provide indespensible help in solving problems.

So if there is a lubrication engineer following this discussion, what do you suggest?

Wisebri,

I have had that "sulphur attacks yellow metals" conversation with a lubrication engineer. He verified that it does happen but only at temperatures well above those that occur in an automotive transmission application. I have used GL-5 in transmissions with yellow metal bushings and synchronizers with no adverse effects so that verifies what the lubrication engineer told me.

Both of my sons are engineers and the depth of their knowledge in their specialties (one electrical engineer, one mechanical engineer) is way beyond what any lay person would know. When I'm pondering some seemingly difficult issue they give me the answer before I can even finishing asking the question,

Knowledge is power!