mopar 4 speed gear oil

[wilks3]

Hi, What is the best or correct gear oil to use in a "hemi" 4 speed? Mine has trouble shifting to second under wide open power but I can still shift it without the clutch by letting the rpms drop with no gear clash. Any suggetions? Or does the type and weight of the gear oil matter? Some say 90wt, 85w90, 85w140 or red line gear oil. Update, took Red Line 75w90 NS out and put ATF in. WOW!!! Now shifts like its supposed to, can't believe the difference!!!!!!!!!

[rumblefish360]

I last used without problems Mobil sythn 75 - 90 I think it was.
Trouble shifting can probably be traced to the engine twisting under load due to high torque and HP levels. This motion also moves the linkage and Z-bar around. Try a cheap chain install or Schmauchers torque strap (For a cleaner non-maring result) to limit movement.
Worked for me on my '73 Cuda.

[wilks3]

I think I'll try your suggestion. Had looked at that but kept hearing the oil makes a difference, probably doesn't matter after it heats up anyway.

[rumblefish360]

Oil does make a difference, but I drive the street everyday. If my car can not use off the shelf prducts or be mixed with them and work fine, then it's not being used at all.
The gain from Red-Line can be seen at the dyno or track. Not by the seat of your pants. It may provided a measureable "Feel" at the grip. But I have not tried it myself.

[turbododge]

The Red line is usually recommeded because it comes in a version without limited slip friction modifier. I think the suffix is "NS" for that version. Most of the shelf products now have the limited slip additives and don't work very well in the older transmissions.

I put the Red line in my Richmond 5 speed and it is very smooth shifting under both heavy load and normal driving.

[wilks3]

Do you know what wt gear oil was put in back in the "day"? I have the NS Red Line in it now, didn't really see or feel any difference over the 85w90 that was in it before.

[Dick]

Why would they ever put a limited slip additive in an oil used in a conventional (RWD) transmission?

[Dick]

If memory serves me correctly, both my 4 speeds '64 and '68 had ATF in them from the factory.

[wilks3]

I asked the same question to Valvoline about their gear oils and they said most new trans use automatic fluid or a "modified" gear oil, so they don't make any without the friction modifiers.

[Dick]

Originally Posted by wilks3

I asked the same question to Valvoline about their gear oils and they said most new trans use automatic fluid or a "modified" gear oil, so they don't make any without the friction modifiers.

?????????? Manual transmissions have been filled with ATF for years. Why would Valvoline say they only make oils with friction modifiers now? Maybe in a performance car with a front wheel drive and a LSD, friction modifiers would have a place. But a conventional transmission doesn't have clutches, so the FM would be a waste and might even cause problems. I don't know. Maybe the Valvoline man was a younger person who only knows front wheel drive.

[Dick]

I just checked the Valvoline web site and their fully synthetic gear oil is intended for hypoid differentials and has a friction modifier. It can also be used in "conventional or limited slip manual transmissions" (front wheel drive?) as long as it meets the manufacturer's spec. (Too lazy to write the grades down).

They also have a blended oil that doesn't appear to have a friction modifier, but they claim that it can be used in manual transmission with or without LSD. Again, it has to meet the spec of the manufacturer.

[dwc43]

Originally Posted by wilks3

Do you know what wt gear oil was put in back in the "day"? I have the NS Red Line in it now, didn't really see or feel any difference over the 85w90 that was in it before.

Just use the standard 85w90, and you wont have any problems with it. No need for syntho. You wont see any gains from that unless your racing it constantly. It holds up to a little bit more heat abuse before breaking down and that's the only gain you can get from it.

[Dick]

Do some research on manual transmissions. ATF has been OEM spec for years.


My 1964 Dodge 4 speed had it.

My 1968 Dodge Super Bee 4 speed had it.

My 1997 Dodge Ram 2500 5 speed had it.


All of these came new with ATF in the transmissions, not gear oil.

From a performance standpoint, having a box full of glue just doesn't make any sense.

[dwc43]

Sorry, everything I have had from 68 to early 80's had gear oil. All of them still do. I changed the '85 4x4 over to gear oil to keep it from taking a dump with the work load it has on it. Works well. I really could not tell the diff in the swap as far as the shifting goes.

[dgc333]

I tried Mobil 1 synthetic gear oil in my A833OD and I could not upshift or down shift without crunching the gears. I went back to the factory recommened ATF and no problems for the last 30k miles. Latter I learned that many folks have had issues with synthetic gear lube in the A833, apparently it's to slippery for the synchros to work correctly.

[Dick]

Originally Posted by dwc43

Sorry, everything I have had from 68 to early 80's had gear oil. All of them still do. I changed the '85 4x4 over to gear oil to keep it from taking a dump with the work load it has on it. Works well. I really could not tell the diff in the swap as far as the shifting goes.

How many of "everything I have had from '68 to early '80s" did you buy new?

Let me do the math:

DWC age=36
2006-36= 1970.

Cars from 1968=before DWC born.
Cars from mid 1980s=before DWC could drive.
___________________________________________

Answer= NONE! ZIP! NADA!

Therfore, your statement is based on what you have done with your vehicles, not what the manufacturer necessarily put in new.

As far as running glue in your '85 to keep it from taking a dump.........how do you know that it would have taken a dump on what was in it before...........oh, and what WAS in it before? Maybe factory ATF?

[turbododge]

My 1970 factory manual says to use 140 wt in hot conditions, 80 wt in normal, and ATF in very cold. Here in Minnesota, the 833's would not work in the cold on gear oil very well and would eat blockers and shift forks because of the increased effort. My Dad worked in a Chysler dealership, and they were constantly taking the gear oil out (put in by gas stations) and replacing it with ATF. Most of the new cars came with ATF already in them.

Sometimes an older 833 can be brought back by filling it with clean ATF and, at idle with the clutch out, lightly and the moderately push the shifter toward the gear you are having trouble shifting into. After a number of pressure on/off cycles of a few seconds each, it will sometimes clean any glazing off the blockers and make the shifting better. This was done a lot at the dealer Dad was at.

[Dick]

Turbho, what you said makes perfect sense. My '64 Dodge Polara 500 383HP 4 speed was purchased new. From the moment I pulled off the dealer's lot, I hammered it. Most shifts were power shifts and I used to knock the pinion snubber off all the time. In addition, I had to have the axle keys doped with white lead to keep them from creaking. I also laid the driveshaft out in the street at least once. The Hurst shifter had to be replaced because I wore it out. Fortunately, my car was covered by the 5/50 warranty.

Back to the tranny. After many hammerings over many months, the box developed a rattle and buzz that could be felt in the shifter while cruising. It drove me crazy and so I returned to the dealer to have the ATF drained out and gear oil put in. The buzz and rattle were gone and I thought all was well, until I started missing shifts and hanging up. I had to change my driving style. The box did feel tighter, but it was just extra drag I was feeling because of the glue.

Soon the winter months came and my car wouldn't shift smoothly at all. It was horrible and every gear change was a challenge to catch the next slot without grinding the synchros. I took it back to the dealer and they drained out the glue and put ATF back in. I could shift once again and soon learned to accept the buzzing and rattle as evidence of severe use/abuse.

[Dick]

"What type of lube is recommended for my TREMEC transmission?


The following types of lube are recommended:

TR-3550/TKO - GM Synchromesh or Dexron III
TR-3650/T-45/T-5 - Dexron III
T-56 (Ford and GM) - Dexron III
T-56 (Viper only) - Castrol Syntorque"

[bandit67]

Ok , guys , I am planning to get my a833 installed and running soon. I live in the south , soooooo what should I use. ATF or 80-95 gear oil. There seems to be a large controverse going on now about the normal gear lube used in the Muncie four speeds. ALL the lubes sold at the auto parts houses have GL5 rateing. Red Line , and some other suppliers, now say you should only run GL4 lubes, in the four speeds because the additive that makes it a GL5 is very corrosive to the brass blocking rings . Some folks call them the syncros. I have not been into a 833 but I assume that it also has these brass blocking rings. Has anybody heard of this.......any thoughts........J

[Dick]

Well, Chrysler used ATF when they built it.

[Dick]

I also posted this in the Performance section, under Transmissions.

http://www.slantsix.org/articles/4-s...fourspeed1.htm

[Dennis Jokela]

Dick is correct, the factory fill was ATF.

Dennis Jokela

[perfmachst]

hello, from experience with mopar four speeds, use mobil synthetic gear oil. it works, cold or hot. also, might have to tie motor down and use a firewall brace to left fender to prevent flex under power shifting. just food for thought.

[dgc333]

Originally Posted by perfmachst

hello, from experience with mopar four speeds, use mobil synthetic gear oil. it works, cold or hot. also, might have to tie motor down and use a firewall brace to left fender to prevent flex under power shifting. just food for thought.

And, My experience and many others is that Mobil 1 synthetic gear oil does not allow the syncros to do there job and you will get lots of gear crunching. I couldn't wait to get it out of mine and get the ATF back in there.

[John Kunkel]

I've used synthetic gear oil in a variety of different manual transmissions and never had any gear clash whatsoever, shifts are much smoother than with dino gear lube. The trick is to use a "synchro friendly" synthetic, one that is formulated with correct friction modifiers.

As an example of right and wrong, Redline 75W-90 synthetic gear oil is for limited slip axles and won't work with synchros but their 75W-90NS is formulated for synchros.

[dwc43]

[QUOTE=Dick]
Let me do the math:

DWC age=36
2006-36= 1970.
QUOTE]

Wrong, try '69. And I have bought a few of them new or got some from my family that bought them new as well.

[turbododge]

From 69 to say 84 is what he is saying, I guess. For my money, I will go with the folks that were actually adults then. I would doubt DWC has ever really seen a 70's transmission with a confirmed factory fill.

[dwc43]

You'ld wrong as usual too. My Dads '68 Correnet with factory 383 and 4 spd. was the first one that I saw, so it actually goes beyond '70. Then there's the Dodge Demon bought new that my Mom drove. First car I actually drove. Hated to see that one leave the family though. Many others, but too many to list. Even a cough,ferd,cough, truck that had a 6 with 3 on tree in '76 and he still has it, very rough now though.

[wilks3]

Hi Guys, Took the Red Line 75w90 NS oil out and replaced with ATF. WOW!!! It now shifts like like its supposed to. Take the tach to 5500 and click-click all the way through to forth gear , no problems. With no other changes I cannot believe the difference!!!