'39 Special Transmission Rebuild Commences

[JRHaelig]

Well I finally got my '39 gearbox mostly disassembled and will be rebuilding it myself (along with help from y'all).

 

I sacrificed my clutch I think while soaking the trans in acetone/ATF while it was still in the car. The mixture went past any seal and leveled off inside the clutch cover.

I understand a 1995 Jeep Grand Cherokee is a bolt-in substitute (Thanks 2carb40)

 

It took a lot of heat/penetrating oil cycles to get that cylindrical sliding gear loose (name, please?).

Cleaning, honing/polishing & lube will keep it moving fine.

 

The synchro on the left appears to be the source of some problems, though. It's the rear one - are they interchangeable?

 

The guide points are knocked off and the tabs are actually cracked.  I understand later year synchros work.....any specific info available?  I'm going to Carlisle next week.  If no luck I will contact Northwest / BobH or 2Carb40 for further sourcing.

 

Does the wear look OK on the other one?

 

Also - the ball bearings are noisy in the rear housing - where the speedo attaches - how do you separate that from the shaft to get those bearings out to clean up?

 

 

 

Edited April 15, 2017 by JRHaelig (see edit history)

[1939_Buick]

Have you got the drawing from the Buick manuals of the transmission?

Do you have a Buick parts book? This list parts by number, from which you can see what years parts interchange (not many for '39 Series 40)

The cracks on the synchro tabs will be the result of some other problem: unlikely to be the cause

 

I will send you an email in the next day or so with some info

 

Your other threads on this topic

http://forums.aaca.org/topic/290572-39-special-looks-like-i-need-a-new-gearbox/

http://forums.aaca.org/topic/290569-wtb-1939-buick-special-gearbox/

http://forums.aaca.org/topic/288670-1939-special-transmission-availability/

 

Edited April 16, 2017 by 1939_Buick (see edit history)

[Guest]

Front and rear bearings available when I did mine from OReilys. Price was just under 50.00 for both bearings, If you would rather replace, (recommended), than clean up old bearings I can post OReilys part numbers.

[1939_Buick]

1 hour ago, 2carb40 said:

If you would rather replace, (recommended), than clean up old bearings I can post OReilly part numbers.

Yes please.

Are they a manufactures number?

[Guest]

12 hours ago, 1939_Buick said:

Yes please.

Are they a manufactures number?

No they are the OReily numbers you need to feed them so you dont have to stand there with some inexperienced employee like I did till a competent one comes up and finds the numbers!

[Ben Bruce aka First Born]

48 minutes ago, 2carb40 said:

No they are the OReily numbers you need to feed them so you dont have to stand there with some inexperienced employee like I did till a competent one comes up and finds the numbers!

 

  Well, let's see them, Greg!

 

  Ben

[Guest]

Ok, I'll dig them out now that the pesky Easter weekend isn't distracting from the important stuff! Lol! These are those!

Edited April 30, 2017 by Guest (see edit history)

[Bob H]

Here is my version of 1939 Buick Special transmission bearing parts numbers on original bearings. Considering how difficult it is to get the transmission in and out or the car don't even try to clean up the old bearings but replace them while it's easy. The front bearing, the one with the baffle that goes toward the inside of the transmission, is not a sealed bearing but is specific to the installation. It also has a groove around the outside for a snap ring. Bob H

[1939_Buick]

On 4/16/2017 at 1:08 PM, 2carb40 said:

Front and rear bearings available when I did mine from OReilys. Price was just under 50.00 for both bearings, If you would rather replace, (recommended), than clean up old bearings I can post OReilys part numbers.

Thread here on the numbers http://forums.aaca.org/topic/292167-1939-spec-trans-brg-numbers/

 

206 is a common bearing. 3206 in post above

 

From a google search on "national bearing 206" (as2carb40 link-image) https://shop.advanceautoparts.com/p/national-ball-bearing-206/3273024-P

From a google search on "bearing 206" http://simplybearings.co.uk/shop/p13060/SKF-206-Open-Type-Filling-Slot-Ball-Bearing-30x62x16mm/product_info.html

From a google search on "bearing 3206" http://au.rs-online.com/web/p/ball-bearings/2851715/

Edited April 30, 2017 by 1939_Buick (see edit history)

[Jim Nelson]

The front bearing needs to be a 6207-2RS/NR. I am a bearing guy.  I replaced my bearings when I rebuilt my '38' trans.  The bearing needs to be ANY brand BUT Chinese.  Even Russian are better.  Get the bearings from a local bearing house.  The 6207 bearing has a rubber seal on both sides (2RS).  The bearing also has a snap ring grove (NR) that keeps the bearing in place.  The snap ring is on the clutch side of the bearing.  You remove the rubber seal from the transmission side of the bearing.  This is how it gets lubricated.  Don't worry about the grease inside the bearing.  It will get washed into the 85W140 trans. lub. that will keep oil from going forward into the clutch area.  Buick (bearing manufacturers did not have that type available) designed the bearing lubrication within that in mind.  Long story short, use the '2RS' as it is    The '6206' bearing is an 'open' type of bearing.  You can see the balls from both sides.  I owned a bearing house for 18+ years so I figure that means something  :-)).