Fluids for my 55 super

Getting ready to do some maintenance on my 1955 Buick Super. Still has all original motor, trans , rear end etc. Just turned 70,000 miles.

I have a couple of questions;

What type of fluid should I use to replace the fluid in the rear end ?

Should I start to use a full synthetic high zinc motor oil ? Such as AMSOIL Z-Rod ???

Any suggestions on a lead additive for the gas ?

Any tips on replacing the motor mounts ?

Thanks

For the diff oil, use an old-fashioned dinosaur oil with the viscosity recommended in your shop manual. Pull off the cover, clean the bottom of the housing out well, and seal it up using sealant on the bolt threads.

One trick to do before you drain it: pull the fill plug, and if fluid comes out, you have an issue of trans fluid finding its way in, and this can cause expensive problems for your diff. Or if you see any red color in the diff oil, same problem. The seal at the front of the torque-tube is bad, and allows ATF into the tube, and down into the diff, diluting the thicker oil and ruining a good ring and pinion. Not good.

Yes, use zinc in your engine oil. It keeps the cam happy.

Forget about lead in the gas. It does not bother Buick engines for several reasons: smaller valves, low spring pressure, slower revs, better metal in the block and heads. If you ever rebuild, do not let anyone tell you that you need hardened valve seats.

For motor mounts, but a jack under the oil pan with a piece of wood to distribute the weight across the width of the pan. Pull the generator and front tires for easier access to the mounts. Undo the bolts and nuts on the mounts, and jack the engine up enough to swap in new mounts. Use a screw driver or large drift/punch to align the holes as the engine comes down, so as to make sure everything lines up again. DO NOT forget to replace trans mount and thrust pad as well. It makes a big difference in how the car behaves. If the engine mounts are bad, so are the thrust pad and trans mount.

Have fun!!

Thank you for the response Fr . Buick. I did pull the plug over the summer to check the level on the differential and the fluid was like tar. No trans fluid though. That's why I want to make sure that I change it. BUT.....the owners manual does say " Under no circumstances should the factory lubricant be drained from the rear axle to be replaced with any other type of lubricant ". I think they'll cut me some slack being that its 60 years later.

Then it goes on to say "Only Factory Hypoid Gear Lubricant " is recommended. Lead soap-active sulphur type. However, SAE 90 may be used. Since I drive the car A LOT, I want to make sure that I use the right fluids to prevent any issues. Looking for a good recommendation ????

Also would like to see if anybody has used any "FULL SYNTHETIC" Motor oil. I know there are oil manufacturers that have high zinc synthetic oils. Don't know if I should make the change on that issue.

As far as the gas lead additive, I did find one that also increases the octane . I figure better safe than sorry.

Thanks for you help

Tony M

Regarding the rear axle lube "do not change" issue . . . It was somewhat common for owners of new cars to run them a little while and then change all the fluids, front to back. Machining operations were not quite as "clean" as they are in more modern times, so the idea was to get all of that "machining junk" out of the oil and replace it with fresh oil (for longer life) . . . OR there always seemed to be some new "whiz bang" lube that was alleged to be far better than anything the factories were using back then, so put the better stuff in there for all kinds of alleged benefits. PLUS there were different compositions (additive packages) in the available greases, then and now, so if you didn't change it during the warranty period, and the rear axle kaputted, then Buick knew that it was not "lube related", so they'd cover it. But if the lube had been changed to something other than the factory item, then the owner probably paid for the repairs. Also, the reason for the "lead soap-active sulphur type" specification (now, they use "GL" numbers to ensure the lube does not affect the long-term durability of particular metals inside of the assembly. PLUS, all of the "perceived gurus" back then, probably didn't know that magnets were usually inside of the axle housing to catch any metallic bits in the grease.

Given the age and consistency of the rear axle lube, you might change it and run it a few hundred miles, then change it again. I would suspect that might get all of the old stuff liquefied enough to drain out well and then be replaced by more "new stuff". As stated, I'd follow the recommended viscosity with normal hypoid greast.

Engine oil? There's an old thread in here about experiences with synthetic motor oil and the drive from Washington State to the Buick Centennial in Flint. No issues were noted by those who made that trip with synthetic motor oils, even in the straight 8s.

I know that Amsoil is a long-time source for synthetic motor oil and now has their Z-ROD oil for older engines, with flat tappets. Your judgment call, BUT you can get synthetic motor oils WITH equal or greater amounts of zddp in readily-available (at almost all discount chains, nationwide!) with Shell Rotella T 5W-40 motor oil. The "5W-40" viscosity is unique to synthetic diesel motor oils, although there are also some VW approvals for 10W-30 synthetic motor oils, too. Seems like there is a Rotella T in 10W-30, too? Chevron Delo400 is another option, too. I know, these are diesel-designed/rated motor oils, but they also meet gasoline engine specs, too. I would also recommend no oil heavier than "40", personally, due to the added power absorption of the multi-vis "50" motor oils. I used Castrol GTX 20W-50 in my 305 Camaro for over 400Kmiles, but when I got it replaced with a 350, the initial fill was with 30 viscosity motor oil. Then I changed it to GTX 20W-50. I noticed an immediate "dogginess" in throttle response from the 6Kmiles on 30 motor oil. I ran it a while to make sure I was feeling what I thought I was feeling, then put 10W-40 in it and found all of the throttle response I had lost. It takes more power to pump that heavier oil with no other real lubrication benefit, by observation. This is one reason all of the newer-spec engines are using oils like 5W-20 and such.

Fuel additives which increase octane probably contain "alcohol", which had turned out to be a bad thing to do, especially when the fuels now generally contain 10% ethanol. Even many fuel system cleaners do to! Check out the additive list at www.fuelkits.com for more information.

I know there can be some advantages to using synthetic oils and such in vehicles. But as long as you use quality OEM-level (even for the model year of your vehicle) specification fluids, you should be fine. In many cases, the reason to use synthetic lubes is not quite "there" for a limited-use type of vehicle, or one that might be more of a daily-use vehicle. Costs will not justify the benefits, by observation, especially if your do a 3K mile engine oil change interval! PLUS, modern oils have much better basestock packages than existed before 1970, much less in the 1950s. To me, this makes the Rotella T/Delo400 oils all that much better of a bargain ... high levels of zddp plus better basestock oils plus much better additive packages, even in the "dino" versions.

Your judgment call.

Enjoy!

NTX5467

Thanks NTX5467. Lots of great info here. Too bad about all the alcohol that is in today's modern fuels and additives. Hope we don't EVER see the 15% ethanol that the government is considering. I'm probably a couple of weeks out before I put the car up to do the work. Curious to see what some of the other input will be regarding synthetic oils and other additives. Thanks again.

Tony M

My 55's: Castrol 20w-50 engine oil; 85w-140 rear lube. I tried lighter products but they just leaked more and there was no performance improvement. A partial engine disassembly at 80,000 miles showed no wear on the cylinders (still had hone marks) and the cam and lifters were pristine. No additives are ever used!

Using any quality product short of synthetic will result in the car outlasting you.

Willie

Thank you. 20-50w seems pretty heavy weight for a regular driver . seems more suited for a racer. I may go with the heavier weight rear end lube though. Also , I feel more comfortable with the zinc additive to give the old parts a nice lube .

This discussion : (http://forums.aaca.org/f115/zinc-motor-oil-338283.html) is to me the most believable after looking inside an 80,000 mile engine!

Probably any available oil will have as much zinc as was present when these cars were contemporary.

You could probably go with 10w-40 for your local driving. My car is driven hard: 65-75 mph cruising, usually in the summer with a/c running and engine temperatures between 190 and 220+. Oil is changed at 3-5K miles.

Accel 10W-40 Motor Oil at WalMart is high zinc, but what is the rest of the product like?

Willie

I used 20W50 in my '73 Oldsmobile 455 for the 28 years I had it. 20w50 is a good choice for year round in Alabama (and Texas)

10w40 might be good for year round in Illinois.

Dad always (starting 1970) used 30w in the Roadmaster . So, I continue with 30w, along with a pint of STP oil treatment in the blue bottle.

Dad also always added 1/2 pint of Marvel Mystery Oil to each fill up of gasoline. I continue with that. I've not had vapor lock, perhaps it's the MMO

For the Dynaflow; Dexron (I think the current is Dexron IV)

90w in the rear

The comment about zddp levels in the '50s era being lower than what many now perceive to be "adequate", is probably very valid. I have seen some comments to the effect that when valve lifts started getting higher, cam lobe lift rates became more aggressive (higher lift, quicker "zero to max lift" intervals, etc.), and valve spring tensions became higher to allow all of this to happen (and the engine speed to rise over about 5500rpm at WOT), then zddp levels increased as a result. Prior to that, even the "Duntov" small block Chevy cam looks puny compared to higher-performance cams of the 1980s (although it was "radical" for its production time AND the size engine it went into).

The OTHER thing is that the whole zddp issue came up when cam failures started to happen with "replacement" camshafts . . . not OEM-spec/quality cams. OEM cams are "Parkerized" treated to help them last longer. It was my earlier suspicion that the replacement cams which were failing (even in racing applications) did not have the same level of treatment as the OEM camshafts received. Therefore, the earlier levels of zddp and a good "break-in" for the camshaft/lifter combination took care of the camshaft "life" issue. This concern seemed to be validated when one of the main hp cam manufacturers started offering an "extra treatment" as an option a few years ago. The other thing is that this same cam manufacturer started selling one of the first zddp additive "treatment" of any cam manufacturer. To help combat the lobe life issue, their recommendation was "Shell Rotella T or synthetic motor oil", prior to them selling their own additive.

Putting all of this together, it appears that if you have a factory-assembled engine or used a factory replacement cam and valve lifters in a rebuild (properly coated the lobes prior to initial fire-up!), then SM/SN levels of zddp should be fine. In their flat tappet crate motors, GM's instruction sheet mention(ed) using SM-rated oils in those engines. Typically, they are run-in on a stationary engine dyno prior to shipment, must like the engines that go to the assembly plants, so any cam break-in issues are done "to specs by the factory". I also have a copy of the GM engineering paper where they validated SM-rated motor oil in a flat-tappet engine they built, at the time. Valve lifter weight (which would relate to wear from the lobe/lifter rubbing activities) were very similar to earlier tests with higher-zddp oils.

It also needs to be mentioned that zddp is NOT the only anti-wear component in the motor oil additive package. It came in to use as it was the least expensive anti-wear additive available. And, like "lead" as an octane booster, it came to be the most-easily-recognized part of the additive package.

In those earlier times, before zddp was boosted, we saw somewhat short oil change intervals. People didn't drive as much/far as in later years, so nobody really noticed. Oil was cheaper than an engine rebuild, too. Therefore, the change intervals somewhat coincided with the time it took the motor oil's basestock to "break-down" or the viscosity improvers to degrade. When 10W-30 motor oil was introduced, many felt that it "wore" back to a 20W oil in a thousand miles or so. In more recent times, better chemistry keeps the viscosity levels much more consistent for much longer run-times. AND, if you "ran it hard and put it up 'wet'", you generally used thicker motor oils for the best protection. Nobody worried about how much horsepower it took for the oil pump to pump the thicker oils, as those things were not considered back then.

Sometimes, the thicker motor oil helped decrease oil consumption a little. When I bought my new '77 Camaro, it needed some oil at 1500 miles. I consulted our service manager what to use. He replied "20W". I questioned that and he added that he ran that in all of his race motors. So I found a quart of 20W and put it in the engine. At 3000 miles, it was ready for another quart. I pondered the possibility that, as it was a Chevy V-8, if this was "the future". I changed the oil and filter and put Castrol 20W-50 in the crankcase. I didn't notice any performance difference as I didn't know to think about such. BUT, at 4000 miles, it was only down 1/2 quart. I was happy. When I pulled the intake off for a cam/intake/timing chain upgrade at 92K miles, I was even happier at the total lack of deposits in the lifter valley AND on the bottom of the intake manifold, compared to what I'd seen of other brands of oil at similar mileages. I kept the cam and lifters, with negligible wear. Timing chain wasn't that bad, either, but the Cloyes Plus Roller I put in was still in the motor when I changed it at 525K+ miles.

ALSO, in the www.bobistheoilguy.com oil forums, it was mentioned that adding zddp to an existing level in motor oil, IF it's too much, can decrease the effectiveness of the detergency part of the oil's additive package. This isn't an issue in "racing oils" for "race track use", as the races are only about 500 miles or so, but can be in a street-driven vehicle with oil change intervals of many thousands of miles. It's "a balance" situation. Another reason I like the diesel-rated oils with more zddp than the old gasoline-rated "SL" motor oils had in them. Plus, their operating environment (in the diesel engine) still has at least as many "rubbing parts" as a typical gasoline engine does AND the need for a great detergency additive formulation.

Old-Tank is one of our resident '55-era Buick specialists. He DRIVES his cars, generally, across country to shows and BCA National Meets, so his knowledge base is quite extensive. AND they are award-winning Buicks, too! 5563 is another one, too, who drives and wins awards.

Enjoy!

NTX5467

My experience has been using 10W40 with a bottle of STP and an occasional bottle of Marvel to top off. Changed oil and filter every 2-4000 miles. Sometimes the seasons oil sits in the car over winter. Used mostly Mobil dino oil in the 80s and 90s when the car was in constant service, then switched to Castrol later. Recently switched to Shell Rotella based on some info shared from board members. Dex 3 goes in the transmission and power steering, and think Castol 80W90 went in the diff.

Stabil goes in the tank in the fall and is filled over winter. I start the car every so often and let it get good and hot. In the spring a can of Berrymans goes in on tank #1 to clean up any varnish that may have formed and I try to use that tank right up and not let it sit because Berrymans is a strong detergent. No lead additives added. Started with 47000 miles on the clock and now have 105,000 after 30 years of service.

Might also add that you drop the oil pan and shovel out the gunk in the bottom. You can check my pictures. This is something I should have prioritized sooner.

My only issue is the dang rear seal, which one of these days am gonna get to...... spit out about 2 quarts on the way to Indiana and back in 2013 - leaks it, doesn't burn it.

Got a pic of your car to post?

Thanks Ken. Lots of good info here. I think I'll be changing the oil once a year with less than 3000 miles. Hopefully that should be ok. I'll probably try the Lucas or AMSOIL products. A little pricey but its not like I will need to do this 3 times a year. Working on getting some picture of the car posted. Computer problems on this end.

Thanks again

Tony M

Oh wow - really sharp looking color combination Tony. Very nice

Thanks Ken. Car was painted over 20 years ago. Titian Red over Cameo Beige. Everything else is original. Which brings me to my next dilemma. What category do I get judged in ? The December Bugle touched on that a little bit.

Thanks Ken. Car was painted over 20 years ago. Titian Red over Cameo Beige. Everything else is original. Which brings me to my next dilemma. What category do I get judged in ? The December Bugle touched on that a little bit.

Well, judging is probably deserving of a new thread topic and in doing a search you'll see a wide range of opinions. While no expert, my advice would be first determine what your goals are in getting the car judged, look over the judging manual and ask questions, and be prepared to receive and act on feedback if that matters to you. Most important I think you have to go into it with a learning mentality. Note that if you choose the 400 point class, it can be helpful in guiding you to achieve a high level of authenticiy, condition and workmanship - people have told me with care you can achieve a high scoring car. By reviewing the results of the judging you can incrementally improve your car - work off the deductions like a checklist - that being said, obviously budget can be a factor. By talking to some of the more experienced people who have had their car judged numerous times they can tell you what attributes are most important to focus on in your restoration. One nice thing is there have been initiatives taken by the Club to be inclusive of all types of Buicks, not just the 400 pointers, and people are really helpful with sharing information.

Your car looks in great shape - get a judging manual, ask questions, and give it a go.

Thanks Ken. I will be starting another thread regarding judging classification. My car is nowhere near a 400 pointer, and probably won't ever be. We drive it. A LOT. But it would be nice to see what the judges view of the car so far.