MAINTENANCE

[LAS VEGAS DAVE]

The service manual calls for draining the rear axle oil TWICE a year. Each time they want you to remove the rear axle cover and wipe the inside of the housing with rags. If anyone does this I believe the rear axle should last the life of the owner and his kids and grandkids. I just did this after 4000 miles and it was perfect inside the housing, no debts or sludge. I did it two years ago when I did the overdrive. It is a messy job, there is no drain plug at the bottom of the axle housing. The lowest bolt on the axle cover will drain most of the oil but any debris or sludge will still be beneath that bolt. I followed the service manual word for word this time but it is a messy job and I don't think I will do it again for three more years. I was lucky and my local NAPA store still had the ten bolt gasket for it. I use STA LUBE 85/90 MULTI PURPOSE HYPOID GL4 gear oil in mine. Next I greased all the front end grease fittings, another job better done if its on a lift. I don't have one so I'm on the floor with barely enough room to move. Wipe each fitting, grease it, wipe again and go to the next one. Another messy job but one that needs to be done, thankfully I have no blocked fittings. Next will be to drain and refill the transmission and the overdrive. Finally after I get all this done I'll drain and refill the radiator and block with fresh coolant and corrosion inhibiter. Everything will be good for a while.

Edited May 10, 2017 by LAS VEGAS DAVE
should be STA LUBE 85/90 HYPOID GL4 (see edit history)

[Matt Harwood]

I'm gearing up to do the rear end, transmission, and motor oil on the '41 Limited this weekend. I changed the transmission and filled the rear end with 80W90 last year, but the rear end has gotten noisier and the transmission is very hard to get into 1st gear, neither of which they did before the switch, so I'm going to go with thicker 85W140 Royal Purple synthetic and see if it helps. The synthetic doesn't have any sulfur so it's safe for yellow metals inside the transmission. My 1993 Mustang 5.0 doesn't have a rear end cover gasket, the shop manual says to use RTV sealant instead, so I'm going to do that on the Limited as well and see how it works. The rear end on the Limited is HUGE--takes nearly a gallon of lubricant...

 

On your overdrive, Dave, it's critical to keep an eye on the fluid levels. It only holds like two pints--very little--so it's easy to forget it and have it go dry. The one on my '29 leaks like hell and I have to top it off before every long drive, which is a pain, but otherwise you risk damaging the flywheel that engages the overdrive. I think that's part of why mine failed (three times): on long drives, it leaks enough to drain itself dry within about 200 miles. On the other hand, it never really worked properly in the first place so it's hard to say what the cause is. At any rate, I have reverse-engineered a mechanical linkage to eliminate the solenoid and it seems to work a lot better, but keeping an eye on the fluid is a real pain. I'm thinking of rigging up a fill tube and tucking it in somewhere like the battery box so I can just pour the oil in without getting under the car. I sometimes even jack up my Cadillac on the right side to make it lean a bit so I can add extra fluid to the overdrive. Long story made short: keep an eye on your fluid levels in that overdrive.

[LAS VEGAS DAVE]

MATT, I have been lucky with the overdrive. When I check the oil it is always right up there, I never added any. I changed it once already and I will change it again now but so far no leaks. Did Lloyd do your overdrive? Also when I first installed the overdrive the original solenoid kept quitting. I decided to buy the brand new aftermarket six volt solenoid and since then its never given me a bit of a problem. 

[Grimy]

A cautionary tale here from fully 20 years ago: In 1997 I drove my 1936 Pierce-Arrow 8 from Oakland, CA to Cleveland, then to Detroit where I left it with a friend for two months, then to Superior, WI for the PAS Meet and then home via US 2.

 

I talked with a Sta-Lube PhD chemist who assured me that there was no sulfur or anything else injurious to yellow metal in their 85W-140 synthetic, so that's what I put in my differential (only).  In Wyoming I crawled under to refill a leaking rear shock and found the pumpkin to be as hot as the hinges of hell.  I quickly found a parts store and bought GL-4 and a drain pan.  I was aghast at the sight of the yellow sparkles in the draining synthetic.  SOMETHING in the synthetic was attacking the yellow metal.  I changed the oil again while visiting friends in Des Moines to get a better flush.  No problems thereafter....  I think I dodged a bullet...  Yes, this was exactly 20 years ago, almost to the day, but I have never used synthetic gear lube in a vintage car again--nor will I.  Much may have changed since then.  I strongly recommend you check for the dreaded yellow sparkles.

 

Dave, you say you're using GL-1, which is great for trannies, BUT I believe you have a hypoid differential which requires Extreme Pressure (EP) gear oil.  Correct me if I'm wrong, but EP is only in GL-4, GL-5 (for limited slip, not good for our cars), and GL-6 (synthetic).  Does your owner's manual call for EP lube?

[LAS VEGAS DAVE]

GRIMY, YOU ARE RIGHT, I AM USING STA LUBE IN THE REAR AXLE MULTI PURPOSE 85/90 HYPOID GL4, MILLER CLASIC GREEN OILS ARE IN MY OVERDRIVE AND TRANSMISSION. I DONT KNOW IF GL4 IS OK IN THE REAR AXLE BUT THAT WAS ALL I COULD FIND IN HYPOID OIL. IT HAS BEEN IN THERE SINCE I PUT THE OVERDRIVE IN. WHAT DO YOU THINK? 

[Grimy]

Hi Dave, I have been using GL-4 in all my hypoid diffs, but GL-1 (straight mineral oil) in synchromesh trannies.  For NON-hypoid diffs (last of those in Pierces was 1928) and in crash box transmissions, I use 600W.

 

My 1948 Jeepster owner's manual is VERY explicit that "straight mineral oil" (GL-1) is the only oil to be used in the transmission and overdrive, but EP lube is to be used (only) in the diff.

 

By the way, if the pinion enters the bottom of the pumpkin, that's a hypoid differential; if the pinion enters at the center of the pumpkin, that's NON-hypoid.  Not scientific, but a good rule of thumb.

 

I'm quite sure you have the correct lube in your differential.

 

Best regards, George

[LAS VEGAS DAVE]

THANKS GRIMY, I am sure the STA LUBE GL4 85/90 is good also for the rear axle only. I use the GL1 GREN MINERAL OILS in the OVERDRIVE and the TRANSMISSION.

[LAS VEGAS DAVE]

1 hour ago, LAS VEGAS DAVE said:

MATT, I have been lucky with the overdrive. When I check the oil it is always right up there, I never added any. I changed it once already and I will change it again now but so far no leaks. Did Lloyd do your overdrive? Also when I first installed the overdrive the original solenoid kept quitting. I decided to buy the brand new aftermarket six volt solenoid and since then its never given me a bit of a problem. 

 

MATT, I am letting the OVERDRIVE drain as I am typing this but before I drained it I checked the level again and it was not down but a tablespoon. It did not leak any when I removed the plug and the hole is to little for my fingers to get in and feel for the level but as soon as I added any to it it ran out the fill plug. I fill mine using the large 1 7/16" breather cap that the breather tube hooks into which is slightly above the filler cap until oil runs out the filler cap which is the proper level.  I have been very lucky with this overdrive as it has been trouble free other than the solenoid since the day I finished installing it. Matt it seems my overdrive only holds one pint not two. Mine seems to hold about 475 ml. Two pints would be 900 or more ml. My overdrive book says they hold 4 pints! I will call Lloyd tomorrow and see what I am doing wrong.

 

Edited May 10, 2017 by LAS VEGAS DAVE (see edit history)

[MCHinson]

11 hours ago, Matt Harwood said:

I'm gearing up to do the rear end, transmission, and motor oil on the '41 Limited this weekend. I changed the transmission and filled the rear end with 80W90 last year, but the rear end has gotten noisier and the transmission is very hard to get into 1st gear, neither of which they did before the switch, so I'm going to go with thicker 85W140 Royal Purple synthetic and see if it helps. The synthetic doesn't have any sulfur so it's safe for yellow metals inside the transmission. My 1993 Mustang 5.0 doesn't have a rear end cover gasket, the shop manual says to use RTV sealant instead, so I'm going to do that on the Limited as well and see how it works. The rear end on the Limited is HUGE--takes nearly a gallon of lubricant...

 

Matt,

I recently started having a bit more trouble getting my 1937 Century to go into first silently so I realized the transmission was a little low. I decided to drain it and change the transmisison oil. I decided to use Pennzoil Synchromesh GL3. I think that is a 85w90 product. As soon as I drove the car I was unhappy. It was too thin an oil for the transmission. It took too long after coming to a stop for the gears to stop spinning for me to get it into first without noise with my driving style. If I waited an extra second or two, I could shift it into first without noise. A few days later I drained it again and switched to a Masterpro GL-4 140 Gear Oil that I found on the shelf in a gallon jug at my local O'Reilly's. That made my transmission shift smoothly and quietly again.

 

http://www.oreillyauto.com/site/c/detail/MP03/80040.oap?year=1989&make=Buick&model=Electra&vi=1017425&ck=Search_80040_1017425_2494&keyword=80040

   

I have not decided exactly what I am going to use in my differential yet but need to do that next. 

 

 

[Daves1940Buick56S]

MC

I did a LOT of research into this last year and you are exactly correct, the Pennzoil Synchromesh oil is too thin for our cars, it is meant for modern transmissions. You are fine on the Masterpro, as long as you are using GL4 or GL1 in the trans the syncros are safe. GL4 is what we should be using in our hypoid rears. I suppose since the only brass we have there are the washers that GL5 would work but I am not taking the chance.

 

Cheers, Dave

[MCHinson]

Dave, It would be really simple for me to just use the same GL4, 140 in the rear end, but I was thinking that maybe a 90 wt GL-4 might be a better idea. Any thoughts on that? 

[jvelde]

A couple of years ago I found MasterPro 140 Gear Oil (GL4) at O'Reilly Auto Parts, which has worked better than anything else I found. The syncros in my transmission prefer the heavier weight, and the mild temps here in the winter don't seem to make shifting too hard when cold.  I use this in the differential as well. 

 

Edited May 10, 2017 by jvelde (see edit history)

[MCHinson]

Thanks. That is encouraging. It would be nice to just use it in the differential as well, since I already have it in the garage. 

[Matt Harwood]

I put the 85W90 GL4 in my rear and it was noticeably nosier, which is why I'm going to something thicker. Before I go with the Royal Purple synthetic, I think I'll go see if they have the 140 GL4 at O'Reilly's because I think that's the best solution for both rear end and transmission.

 

Thanks for the tips!

Edited May 10, 2017 by Matt Harwood (see edit history)

[MCHinson]

Glad to be able to help. If the rear on your 1941 Limited is too noisy with the thinner gear oil, that answers my question. I am happy to learn this. I was planning to do a story in the next issue of the 36-38 Buick Club's newsletter on this issue so it looks like I just need to change the differential oil, take a few photos, and write it up now.

[LAS VEGAS DAVE]

I been using STA LUBE 85/90 HYPOID GEAR OIL in the rear end in my car available at AUTOZONE and NAPA for the last two years with no problems or noise that I can hear. I use 140 CLASSIC GREEN MINERAL GEAR OIL GL1 in the transmission. I don't think the weight is a big deal as it will work with either one. I like the MASTER PRO 140 OIL shown in the post above, I might put it in my rear axle. Is extreme pressure the same as HYPOID?

Edited May 10, 2017 by LAS VEGAS DAVE (see edit history)

[MCHinson]

1 hour ago, LAS VEGAS DAVE said:

 Is extreme pressure the same as HYPOID?

 Yes.

[LAS VEGAS DAVE]

I Found out that my BORG WARNER R10 OVERDRIVE that Lloyd Young modified to fit onto my 38 Buick torque tube actually only holds 1 pint. The 38 Buick Special transmission only holds 1 3/4 pint. I was surprised how little oil is in these components. The rear end only holds 3 pints.

[Gary W]

Looking for your opinion of the MEROPA 680 Gear Oil that I use in my Model "T" Ford differential, and in my Model "A" steering boxes, transmissions and differentials.  It's thick stuff but the car does shift nicely.  It's the last post on page 12.

Edited June 5, 2017 by Gary W (see edit history)

[DonMicheletti]

I have 90wt in my '38 Special and it shifts beautifully

[MCHinson]

2 minutes ago, DonMicheletti said:

I have 90wt in my '38 Special and it shifts beautifully

 

When I used something lighter, I had to wait a bit before shifting into first to pull away from a stop or I got a bit of grinding. When I switched to the Masterpro GL4 140 Gear Oil, I can immediately shift into first without any noise. I really like the 140. I suggest you consider giving it a try next time you need to change yours.

[dibarlaw]

I have had Kendal SAE 140 in the 37 special for 5 years and am ready to change out before the trip to Brookfield. She seems to shift well but as it gets a bit low you can quickly feel the difference.

Lube chart says SAE 160 for summer driving.

[LAS VEGAS DAVE]

More maintenance again. Last night I changed the coolant. The old coolant looked fine, probably a waste of time and money. I even aired all the tires, must have been really bored last night.

[Gary W]

If someone out there could help me clarify:

 

My MEROPA 680 Gear oil is  ISO 680 ,  AGMA is  8 EP.

The Lube chart that Larry furnished above calls for  SAE - 160  EP Gear Oil in the Transmission and Differential. (Summer)

 

 

So I researched tonight and this is what I found:

 

This is the data for the MEROPA 680 Gear Oil.  You see it is AGMA Grade 8 EP /  ISO Grade 680.

 

 

This viscosity chart clearly equates ISO 680 with AGMA 8 with SAE 140 Gear Oil 

 

So the question.......  Can I still use the MEROPA 680 in the Buick Transmission and Differential?  I've been using it over 24 years in my Ford's Steering Box, Gear Box and Differential.

[MCHinson]

Here is what I posted on this subject in your restoration thread:

 

I think that it is "in the ballpark". Personally, I would want to know more about what additives are in it. If it is not labeled as "GL3" or "GL4", I would be a bit paranoid and avoid it. Basically, before I would use it, I would want to know if it is rated as "GL4" or "GL5". If it is rated as "GL4" it should be safe for yellow metals and should be OK. If it is rated as "GL5" you should not use it.

 

The Masterpro 140 GL4 from O'Reilly's is my personal preference. It is rated GL4, it is inexpensive, and in my experience, it works well.

[Gary W]

Thanks!  It's the synchros that are the new part to me.  So the viscosity is not so much the issue as is the additives.  Got it!  A little thick in the head sometimes!

I'll run down to AutoZone today to see what GL3 / GL4 gear lube they carry.  

Appreciate the advice, thanks for the clarification!

 

[LAS VEGAS DAVE]

Gary it looks to thick to me. Gut feeling is why risk the 680, why not just use what is easy to get at Auto Zone. I have had no problems and I just use StaLube 85/90 GL4 in my rear axle some use heavier. I use MILLERS CLASSIC GREEN GEAR OIL 140 GL1 in the trans and overdrive unit. I order the Millers online from AMAZON.

[Gary W]

This is what I ordered.  I'll use it in both transmission and differential.  Thanks!

[LAS VEGAS DAVE]

 The correct choice for the transmission is MILLERS CLASSIC GREEN GEAR OIL GL1 140.  Each has a different GL rating and while GL4 is correct 

for the rear axle it is not good for the trans which calls for GL1. I am fussy and even though its a PITA its just better to use the correct oils especially after 

all you have done and are still doing. 

Edited June 8, 2017 by LAS VEGAS DAVE (see edit history)

[Janousek]

I think that is a fine choice for the axle and transmission.   That will flow into the needle bearings and bushings better than the 680.  This is where the lubrication is needed. 

[MCHinson]

16 hours ago, LAS VEGAS DAVE said:

 The correct choice for the transmission is MILLERS CLASSIC GREEN GEAR OIL GL1 140.  Each has a different GL rating and while GL4 is correct 

for the rear axle it is not good for the trans which calls for GL1. I am fussy and even though its a PITA its just better to use the correct oils especially after 

all you have done and are still doing. 

 

Dave,

 

While that is a totally acceptable gear oil for the transmission, GL4 rated gear oils is backward compatible with GL1. GL4 is a designation that came out years after your service manual was printed. There is nothing wrong with your choice, but there are other choices that are also fine for the Transmission. The particular choice that I recommended earlier is fine for both the transmission and the differential.  

[LAS VEGAS DAVE]

The gear oil for the transmission should not be EP is what I was told, that is why I use the Millers and that it says GL1 right on the container, no guessing about it. The rear axle should be EP, this is per the manual.  Maybe I was told wrong but it wasn't hard to get the Millers so I went with it. In my personal view it PROBABLY doesn't matter but why not just follow the manual.

Edited June 9, 2017 by LAS VEGAS DAVE (see edit history)

[Larry Schramm]

If you want to use GL1, go to tractor supply and buy some.  That is what was used in older tractors from what I have read.

 

Here ya go.  A 5 gallon bucket for $59.99.

 

https://www.tractorsupply.com/tsc/search/gear oil GL1