Lubrication for tranny and rear end for 1939.

[Bruce W Jones]

Guys do you use the tranny and rear end lube suggested in the 1939 owners manual or do you use modern synthetic gear oil. 

 

Transmission - Lub chart calls for SAE 90 and to change twice a yr. IS it really necessary to change twice a yr. considering I will not drive the car but maybe <1000 miles a yr. ?

 

Rear end suggest use SAE 90 hypoid lub. twice a yr. again seems excessive.  Is the use of hypoid lube critical?  I must admit I had to go to Webster to see what HYPOID was.

 

I assume since I will not be putting that many miles on the car, the twice a yr is a mute point.

 

Thanks for entertaining a newbie's questions!

[Spinneyhill]

Use a SAE 90 synthetic gear oil. You won't need to change it for the rest of your ownership. Just make sure the synthetic oil is suitable for baulking ring synchronisers in the gear box (assuming that is what it has). Any synthetic oil should be good for hypoid gears.

 

Also, make sure the Copper Strip Corrosion Test ASTM D130 result is 1a. 1b will do but not as well. Use a GL-4 oil unless it says it is safe for all yellow metals (i.e. copper containing).

Edited March 2, 2019 by Spinneyhill (see edit history)

[Bloo]

Use oil intended for synchronizers in the transmission. Use hypoid gear oil in the rear axle. In 2019 those should probably not be the same oil.

 

Hypoid gears require a very tough film strength for protection because the teeth are sliding across each other and it tends to scrape the oil off right where its needed. Synchronizers on the other hand are little brakes. They have to scrape through the oil to work. Hypoid oil was so bad in the 30s it could just barely do its job, and as such worked ok in the transmission. That is unlikely to be true today.

[Matt Harwood]

I use StaLube  SAE 140 GL4 gear oil available at NAPA. The 90 weight won't be thick enough for your transmission and it'll have a hard time going into 1st gear. I used that the first time in my '41 but when I switched to the 140, all problems disappeared. Same stuff in the transmission and rear end, no issues, all gears quiet.

 

 

You're not driving it in winter, so you don't need a multi-vis and the heavier oil will be fine for warm weather driving. Changing it every five years should be sufficient as long as you keep it topped off as necessary. PLEASE, do not go digging around in your rear axle looking for problems. if it works properly and isn't noisy, leave everything inside alone. Just change the fluid. Don't take it apart, don't worry about looking at the bearings, don't take things off just to see what's going on inside. I was goaded into doing that when I first changed my rear end oil and ended up breaking a bearing retainer that was completely irreplaceable and sidelined my car for more than a year. I finally had one made at considerable expense and was able to get the car back on the road. Again, if it is healthy and quiet in there, LEAVE WELL ENOUGH ALONE!

 

 

 

Edited March 2, 2019 by Matt Harwood (see edit history)

[Bruce W Jones]

2 hours ago, Matt Harwood said:

I use StaLube  SAE 140 GL4 gear oil available at NAPA. The 90 weight won't be thick enough for your transmission and it'll have a hard time going into 1st gear. I used that the first time in my '41 but when I switched to the 140, all problems disappeared. Same stuff in the transmission and rear end, no issues, all gears quiet.

 

 

You're not driving it in winter, so you don't need a multi-vis and the heavier oil will be fine for warm weather driving. Changing it every five years should be sufficient as long as you keep it topped off as necessary. PLEASE, do not go digging around in your rear end looking for problems. if it works properly and isn't noisy, leave everything inside alone. Just change the fluid. Don't take it apart, don't worry about looking at the bearings, don't take things off just to see what's going on inside. I was goaded into doing that when I changed my rear end and ended up breaking a bearing retainer that was completely irreplaceable and sidelined my car for more than a year. I finally had one made at considerable expense and was able to get the car back on the road. Again, if it is healthy and quiet in there, LEAVE WELL ENOUGH ALONE!

 

 

 

I will be driving occasionally in  winter but in s.c. winters not that harsh so will the NAPA 140 still work. I like the idea of one lube for both applications, keeps it simple. Thanks to all who responded.

[Bruce W Jones]

4 hours ago, Bloo said:

Use oil intended for synchronizers in the transmission. Use hypoid gear oil in the rear axle. In 2019 those should probably not be the same oil.

 

Hypoid gears require a very tough film strength for protection because the teeth are sliding across each other and it tends to scrape the oil off right where its needed. Synchronizers on the other hand are little brakes. They have to scrape through the oil to work. Hypoid oil was so bad in the 30s it could just barely do its job, and as such worked ok in the transmission. That is unlikely to be true today.

Did you mean non synchronized? I thought this old 39 was NON synchronized, I looked at some lub oil. That stated for non synchronized tranny. Thanks for your reply.

[Robert Engle]

You should have sychronizers in your transmission.  My 1932 Buick has a sychromesh transmission.  Low gear will not have sychronizers, but second and third will.

 

Bob Engle

[Bruce W Jones]

Guy that owned the car for 20 yrs. Used this in tranny and rear, it is hypoid application 85w140??  U R Correct on second And third being synchronized. Think this lubricant Is OK to use. Thanks for you guys help, this 39 is very new to me.

[Bloo]

A 39 will be synchronized on second and third, but not first. I am unfamiliar with the wolfs head product.

 

I have a 1936 Pontiac with a transmission that is very similar to the small Buick transmission (Buick Special, series 40). I am using Redline Synthetic 75W-140NS in the transmission. So far that is working out great. It is a fairly thin oil, and time will tell whether it leaks out too much. Matt Harwood mentioned that thin oil doesn't "stop" your unsynchronized first gear very well at stoplights. That is true, but I just "touch" one of the synchronized gears (usually third) before shoving it into first at a stoplight.

 

The first time I changed the transmission oil I used Master Pro SAE140 GL4 gear oil, as several people elsewhere in these forums have reported good results with it. I couldn't stand it. Shifting was balky, and I couldn't use second at all when the car was cold. Maybe I'm spoiled. To it's credit, it did "stop" first gear better at a stoplight. It was definitely a downgrade compared to the unknown oil I drained out. I drained the Master Pro out and put the Redline in, and now it shifts fine like it did with whatever oil I drained out.

 

In the rear axle I am just running some ordinary hypoid gear oil. The slipperier the better. The only reason not to do this is if your rear axle has any brass in it. My Pontiac axle does not. I will have to defer to the Buick experts in here about whether the 39 Buick rear axle has any brass in it. If it does you need to pick something safe for "yellow metals".

 

Which model is your 39 Buick?

 

 

Edited March 2, 2019 by Bloo (see edit history)

[Matt Harwood]

The Wolf's Head you have pictured should be fine for the rear end as long as it says "hypoid" on it somewhere. You absolutely need that for the rear gears. Transmission doesn't care what you put in it as long as it's gear oil.

 

Don't get bogged down in this. I can already see this discussion heading off into the hinterlands of estoerica about esters and carbon chains and yellow metal and oxidization and friction reducers and viscosity indices all the other stuff that everyone geeks out over. Don't go there. Don't over-think it. I spent weeks looking at all the varieties out there and reading everything I could on oils to make sure I got the right stuff. I put the oil that all my research told me was the right stuff into my Limited and the rear end got noisy and the transmission shifted like crap. I drained it out and I put in the StaLube stuff that I found on the shelf and it has been good ever since. As a bonus, the StaLube is just about the cheapest oil you can get, too. 

 

Everyone will have their own favorites and none are wrong. But this is a subject that is incredibly easy to over-think and paralyze yourself into knowledgelessness. Don't. Yours is a simple machine that was ridiculously over-engineered and made from very durable parts. You won't hurt it with oil, I promise. Hypoid in the rear end, anything you want everywhere else just as long as it shifts the way you want it to.

[Bruce W Jones]

47 minutes ago, Bloo said:

A 39 will be synchronized on second and third, but not first. I am unfamiliar with the wolfs head product.

 

I have a 1936 Pontiac with a transmission that is very similar to the small Buick transmission (Buick Special, series 40). I am using Redline Synthetic 75W-140NS in the transmission. So far that is working out great. It is a fairly thin oil, and time will tell whether it leaks out too much. Matt Harwood mentioned that thin oil doesn't "stop" your unsynchronized first gear very well at stoplights. That is true, but I just "touch" one of the synchronized gears (usually third) before shoving it into first at a stoplight.

 

The first time I changed the transmission oil I used Master Pro SAE140 GL4 gear oil, as several people elsewhere in these forums have reported good results with it. I couldn't stand it. Shifting was balky, and I couldn't use second at all when the car was cold. Maybe I'm spoiled. To it's credit, it did "stop" first gear better at a stoplight. It was definitely a downgrade compared to the unknown oil I drained out. I drained the Master Pro out and put the Redline in, and now it shifts fine like it did with whatever oil I drained out.

 

In the rear axle I am just running some ordinary hypoid gear oil. The slipperier the better. The only reason not to do this is if your rear axle has any brass in it. My Pontiac axle does not. I will have to defer to the Buick experts in here about whether the 39 Buick rear axle has any brass in it. If it does you need to pick something safe for "yellow metals".

 

Which model is your 39 Buick?

 

 

40 series and I don't think the wolf head brand would matter, he just gave it to me and said he used it in tranny and rear. It is hypoid gear oil. Thanks

[Bruce W Jones]

18 minutes ago, Matt Harwood said:

The Wolf's Head you have pictured should be fine for the rear end as long as it says "hypoid" on it somewhere. You absolutely need that for the rear gears. Transmission doesn't care what you put in it as long as it's gear oil.

 

Don't get bogged down in this. I can already see this discussion heading off into the hinterlands of estoerica about esters and carbon chains and yellow metal and oxidization and friction reducers and viscosity indices all the other stuff that everyone geeks out over. Don't go there. Don't over-think it. I spent weeks looking at all the varieties out there and reading everything I could on oils to make sure I got the right stuff. I put the oil that all my research told me was the right stuff into my Limited and the rear end got noisy and the transmission shifted like crap. I drained it out and I put in the StaLube stuff that I found on the shelf and it has been good ever since. As a bonus, the StaLube is just about the cheapest oil you can get, too. 

 

Everyone will have their own favorites and none are wrong. But this is a subject that is incredibly easy to over-think and paralyze yourself into knowledgelessness. Don't. Yours is a simple machine that was ridiculously over-engineered and made from very durable parts. You won't hurt it with oil, I promise. Hypoid in the rear end, anything you want everywhere else just as long as it shifts the way you want it to.

I agree, I am a retired 42 yr. Yr. Nuclear industry guy and we over analized everything x3.  Will Definitely. Use hypoid in rear. My tranny and rear are very quiet. Thanks again.

[Bruce W Jones]

Hopefully last question:  Does the 39 have a rear end  gear oil drain plug??  I have looked and don't see one.  I see a plug on the right side about 3/4 way down on differential housing/cover.  I think I read that you had to suck the gear oil out or remove the cover.  Is this factual?  If so that is one dumb design, geez.  I thought my 17 corvette had some crazy designs but ........  I thought things were made simpler back in the day, guess not.  I don't think I will be removing the cover, looks like it has had some gasket sealer used on it at some time so don't want any new leaks if I can avoid it.

Thanks again guys for all your comments, I am learning a lot from this forum.  U guys R the best.

BJ

[Matt Harwood]

The plug is the fill plug--pump oil into there until it starts to run out the hole, then reinstall the plug. The only way to drain it is to remove the rear cover and let it run out. Sometimes removing the bottom bolt will let it drain, but this is a good opportunity to re-seal the cover and clean things up. Sealing it up with fresh RTV isn't a big deal, just read the instructions, run a bead around the perimeter and around each bolt hole, maybe smear a little on the threads of the bolts themselves, then reinstall. No big deal. 

 

Here's a thread on me changing the fluid in my Limited (please disregard the part where I reinstall the cover incorrectly and over-fill it):

 

 

Edited March 3, 2019 by Matt Harwood (see edit history)

[Bruce W Jones]

10 hours ago, Matt Harwood said:

The plug is the fill plug--pump oil into there until it starts to run out the hole, then reinstall the plug. The only way to drain it is to remove the rear cover and let it run out. Sometimes removing the bottom bolt will let it drain, but this is a good opportunity to re-seal the cover and clean things up. Sealing it up with fresh RTV isn't a big deal, just read the instructions, run a bead around the perimeter and around each bolt hole, maybe smear a little on the threads of the bolts themselves, then reinstall. No big deal. 

 

Here's a thread on me changing the fluid in my Limited (please disregard the part where I reinstall the cover incorrectly and over-fill it):

 

 

Thanks so much the write up and picks were great.

[billorn]

I remember that thread. Mistakes happen. Just be careful and ask questions if need be. Hopefully nobody making fun of learning like they did there.