• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

4 speed lube

Mike Szadaj

Well-Known Member
Local time
6:35 AM
Joined
Jan 17, 2019
Messages
999
Reaction score
2,468
Location
St. Clair Shores, Mi
1968 Coronet
1. What weight gear lube is recommended?
2. What is the approximate capacity of an A833?
 
# 1. 90W gear lube.
# 2. 2.5-3 quarts. (my guess) I didn't look it up.
 
I'd say Jerry is right on. The "exact" viscosity of gear lube isn't critical....75W-80, 85W-90, etc should be ok. You can buy these "giant ketchup bottle pumps with hoses" at parts stores that allow you to pump gear lube up-hill (you'll need to do this) that work great. Buy 3 quarts & fill it through the side plug until it just drips out. Piece of cake
 
yeahthat.gif


I had a slight gear clash 1st to 2nd (when cold), so I changed the fluid to the factory suggested 140. WOW!, got clash in all 4 gears. Went to Sta-Lube 85w90, slightly better but still had that 1 - 2 clash. Then I was advised to use Penzoil Synchromesh. Boy, what a difference. I highly recommend it.

P.S.
FSM calls for 7/8 of a gallon. I just put the whole gallon in it. Probably lost a good portion of that extra 1/8th trying to get the plug back in anyway.
 
Last edited:
I switched to this,quieted the syncro noise, now running smooth.
160010.jpg
 
WTF
Do not use rear axle lube in your 4 speed it eats up the synchros
get lube that expressly says for synchromesh trans
AFIK the latest formulations are for the Jap transmissions
as for weight- it depends
but there are much better lubes now than in 1968
Suffix A has not been available for years we used to use it in cold weather
as for Sta Lube
they historically have had excellent tech support
and for a long time were the only source I knew of for PS fluid for the Chrysler/ thompson PS pump
 
As wyrmrider pointed out.. remember that HYPOID gear oil belongs no where near a synchro transmission! Also note that SAE 140 oil = say 50W70... SAE 80 = 15W40. No different than straight weight Shell aircraft oil at 100 weight is the same as 20W50. Kinda like whiskey at 50% alcohol or 100 proof ! Considering that you can use SAE 140 or 80 OR Dexron Auto Trans fluid, I compromised and when I couldn't get any good trans lube in town used some 20W50 engine oil I had on hand. Transmission has NEVER shifted this smooth! No wonder the transmissions are quiet with 80W90 in them.. **** can't move. They are supposed to whine....
beerestoration2017 1998.JPG
 
Last edited:
WTF
Do not use rear axle lube in your 4 speed it eats up the synchros
get lube that expressly says for synchromesh trans
AFIK the latest formulations are for the Jap transmissions
as for weight- it depends
but there are much better lubes now than in 1968
Suffix A has not been available for years we used to use it in cold weather
as for Sta Lube
they historically have had excellent tech support
and for a long time were the only source I knew of for PS fluid for the Chrysler/ thompson PS pump

Exactly Right! DO NOT use GL-5 designated gear oil. It will destroy your synchros because the GL-5 Gear oil is ment to slip so it will make it more difficult to shift smoothly. There are many oils that are good but be sure to read the label first. Make sure they only have GL-4 listed not "GL-5 and capable with GL-4". I heard horror stories from redline and the like, so i ended up going with Brad Penn mineral gear oil for muscle cars GL-4 Rated. Also to be noted cars in the northern Usa and Canada used ATF in manual transmissions because it is not as thick and can shift smoothly even in cold climates. Here's a link of what i used, no gear noise or rough shifts. https://www.summitracing.com/parts/bpo-77296/overview/
 
As wyrmrider pointed out.. remember that HYPOID gear oil belongs no where near a synchro transmission! Also note that SAE 140 oil = say 50W70... SAE 80 = 15W40. No different than straight weight Shell aircraft oil at 100 weight is the same as 20W50. Kinda like whiskey at 50% alcohol or 100 proof ! Considering that you can use SAE 140 or 80 OR Dexron Auto Trans fluid, I compromised and when I couldn't get any good trans lube in town used some 20W50 engine oil I had on hand. Transmission has NEVER shifted this smooth! No wonder the transmissions are quiet with 80W90 in them.. **** can't move. They are supposed to whine....
View attachment 794398
Sir,
You say that hypoid oil should NOT be used is a 4 speed trans. WHY? Just like when we were growing up, parents proclaimed something without reason, when questioned, they replied "because I said so"....why are you negating the use of hypoid oil? Is it because of the use of extreme pressure additives? (Which usually contain sulfur bearing compounds)? Or possibly is it the addition of friction modifiers or antifoam additives. Remember, the gears are in constant mesh with each other all the time. It's the synchonizer sliding sleeves and blocking clutch pawls that actually tie the gears to the main shaft. These sliding sleeves and shifting forks are, usually, a phospher bronze /brass hardened alloy material that require a high extreme pressure lubricant to prevent excessive wear.
For my 18 spline A833 transmission in my RS23V0A GTX, I'll continue to use synthetic 85W-90 hypoid gear oil. Just my opinion of course.
Bob Renton
 
Why
rear end gear lube uses a sulfur based EP chemistry
Sulfur eats brass
simple as that
The Latest Japanese stick shift lube specs are one way to start
another is to Use RedLine or other full synthetic lube that is marked for manual trans
Some trans mfg use ATF and all kinds of lubes
not for your Mopar
finding a lube where the trans and rear end share lube is more of a challange
 
Why
rear end gear lube uses a sulfur based EP chemistry
Sulfur eats brass
simple as that
The Latest Japanese stick shift lube specs are one way to start
another is to Use RedLine or other full synthetic lube that is marked for manual trans
Some trans mfg use ATF and all kinds of lubes
not for your Mopar
finding a lube where the trans and rear end share lube is more of a challange
Personally, I would not use Japanese lubricants in anything i own. As far as the sulfur content of the lubricant goes, it depends on the total percentage of a specific sulfur compound. To which specifiic sulfur compound are you referring to? Please enlighten us to the EP chemistry to which you are referring to. Perhaps some API (American Petroleum Institute) spec. There are a multitude of sulfur bearing compounds produced, some effect brass others do not. The brass components of an A833 trans are ALLOYS, chosen for their strength and durability. These common alloys are 60/40 tin copper, 80/20 tin copper, and some of the high strength alloys are phosphor/bronze, aluminum/phosphor/bronze, navel brass, navel bronze, etc. "Inquiring minds want to know".
Bob Renton
 
Auto Transport Service
Back
Top