Can Royal Purple with LSD additive in R154 cause harder shifts?

[tekdeus]

I recently changed from regular gear oil to Royal Purple synthetic grear oil in my diff and tranny, and it seems much notchier when shifting, as if the syncrhos are not working as well as before. The bottle said it contained an additive for LSD (limited slip differentials). Since these additives reduce friction between non-metallic surfaces such as diff clutch plates, can they also negatively impact the way the transmission synchros work?

I dont know I used Red Line as other people recommend for toyotas I heard nothing but positive for the rear diff on royal purps quality.

I put royal purple top gear in my tranny and diff. Everything seems super smooth to me.

I would not recomend RP Max-Gear in the tranny. Should have used Synchromax instead.

Whoa, why would you put LSD additive in your transmission?

 

[jdub]

This is what I don't like about RP gear oils. The Max Gear can be used in a manual tranny (you can get the correct viscosity), but it contains friction modifiers...what you are experiencing is the friction modifiers in RP Max Gear freeing up gunked up synchros. This gear oil is too slippery for proper synchro engagement in a healthy tranny.

Synchomax is recommended for manual transmissions that specify automatic transmission fluid, multi-viscosity motor oil or straight grade motor oil...Synchromax is much lower viscosity (less than half at ops temp) than what the TRSM calls for (an 80W-90). Personally, I would not use it in either a W58 or R154...it's simply too thin.

Red Line 75W-90NS (no friction modifiers) is a good choice...Red Line MT-90 is a better choice. MT-90 is specifically formulated for manual trannys and meets the TRSM viscosity spec. Both have a high viscosity index that provides a consistent viscosity across the operating temp range for the tranny.

BTW - did you add Bi-Tron to the RP? Not a good idea...it can upset the balance of the friction modifiers in the RP. You don't want to use any additive of any type in the gear oil for a tranny or LSD.

 

[Kckazdude]

Synchomax is recommended for manual transmissions that specify automatic transmission fluid, multi-viscosity motor oil or straight grade motor oil...Synchromax is much lower viscosity (less than half at ops temp) than what the TRSM calls for (an 80W-90). Personally, I would not use it in either a W58 or R154...it's simply too thin.

Well ignore my post then. Never knew the specs for the 5 spd trannies. Still cant say I recommend the Max-Gear for trannies though.

than what the TRSM calls for (an 80W-90). Personally, I would not use it in either a W58 or R154...it's simply too thin.

pretty sure its 75w90.

pretty sure its 75w90.

75W90 or 80W90 for W58
75W90 for R154

 

[tekdeus]

Whoa, why would you put LSD additive in your transmission?

I didn't add it, it was already in the RP gear fluid which said it was OK for use in manual transmissions.

Tekdeus, why don't you have Bi-Tron in your sig anymore?

Awaiting further test results.

Borg Warner, who built the all popular T5 and now T56, had used Dexron/Mercon in the T5 for some time. It shifts pretty well like that. Maybe somebody wants to try it in the R series.

I used Royal Purple in my R154, the tranny has since died. We believe the thrust washer is toast. Not sure if RP was the culprit. But it did seem thin.

it smoothed out my failing second gear... but second gear is going still, and it's no longer helping...

I'd run redline to see if it helped, but I can't find it locally (MVP has it, but he's a good drive away...)

 

[jdub]

75W90 or 80W90 for W58
75W90 for R154

Interesting...my '89 TRSM shows 75W-90 or 80W-90 for both manual trannys :icon_conf

In any case, the point is Synchomax is much too thin for either tranny. Max-Gear will work, but the friction modifiers can cause problems with the syncros on a tight tranny. IMO, the improvements guys see using either RP product come from freeing up worn syncros...the tranny is on the way out and the frictions modifiers grant a reprieve. It's not a matter of if the tranny is going to fail, it's when. But if it works and puts it off for a while, it's a viable technique...I'd save up for a new tranny or a re-build though

Red Line MT-90 is a much better choice for a tranny working as it should.

Tekdeus - You did add the Bi-Tron to the tranny oil huh?

 

[wingman]

I don't know what the R154 calls for offhand as far as fluid type, probably GL4 gear oil, but I do know that any GL5 fluid such as GM's synchromesh and I believe royal purple will react with bronze parts in the transmission.

a bunch of Z31 guys have been running into transmission problems some time after they switched to a GL5 fluid...but I could be wrong.

So if the tranny has lots of miles, and worn synchros...SynchroMax is the best choice because it contains friction modifiers?

And if the transmission isn't worn out, then Redline MT-90 is the way to go?

 

[jdub]

GL-4 and GL-5 are the API specifications for gear oil:
- API GL-1, GL-2, and GL-6 are inactive.
- API Category GL-4 designates the type of service characteristic of spiral-bevel and hypoid gears in automotive axles operated under moderate speeds and loads. These oils may be used in selected manual transmission and transaxle applications.
- API Category GL-5 designates the type of service characteristic of gears, particularly hypoids in automotive axles under high-speed and/or low-speed, high-torque conditions. Lubricants qualified under U.S. Military specification MIL-L-2105D (formerly MIL-L-2015C), MIL-PRF-2105E and SAE J2360 satisfy the requirements of the API GL-5 service designation.

GL-4 and GL-5 products typically use the same extreme pressure additive system, with GL-5 having about twice the concentration of a GL-4. Too much of this additive could cause excessive chemical corrosion of the gear surface. If a GL-5 gear oil is used in a application where GL-4 gear oil only is called for, chemical corrosion of "yellow metal" components may occur, such as bronze synchronizers, brass bushings, etc. This may lead to shifting difficulties or shortened tranny life.

In the R154 and W58 transmissions, either GL-4 or GL-5 gear oil is allowed. In gearboxes where a GL-4 *only* is specified, Wingman is correct...using a GL-5 oil can cause damage to the tranny.

Johnathan - What I'm saying here is using RP Synchromax in a tranny with shifting problems *may* help...I'm not recommending it for use in a tranny that is functioning normally. Synchromax has a viscosity of 35.3 cst at 40 deg C and 7.7 cst at 100 deg C...Max-Gear 75W-90 has a viscosity of 144.5 cst at 40 deg C and 21.0 cst at 100 deg C...Max-Gear 80W-90 has a viscosity of 150.3 cst at 40 deg C and 16.8 cst at 100 deg C. Both cold/warm viscosities are much higher than Synchromax and illustrate why a GL-4 or GL-5 gear oil is specified for our manual trannys....per the Red Line tech data sheet:

With most lubricated components, the slipperier the better, but this is not so with manual transmissions. The synchronization of shifting gears requires friction to transfer energy from the synchronizer, which is locked to the input shaft, to its mating surface attached to the gear to be locked in as the drive gear. The drive gear is selected by using the shift forks to slide a synchronizer ring, which rotates at the same speed as the input shaft, in contact with the selected drive gear. Once the drive gear is brought to the same speed as the input shaft, the locking ring on the synchro assembly is allowed to slide over and lock into the drive gear. The time this process takes depends on how easily the synchro ring moves and the rate of frictional energy transfer between the two synchronizer surfaces. Higher viscosity lubricants slow the sliding of the synchro ring on the input shaft and require a longer time for the oil to be squeezed out from between the mating synchronizer surfaces. After the lubricant is squeezed out, the coefficient of friction of the lubricant determines the rate of frictional energy transfer between the two surfaces. Slippery lubricants such as hypoid gear oils (like RP Max-Gear) can take too long to synchronize the gears, which promotes synchronizer wear. Red Line MTL and MT-90 has a coefficient of friction which is greater than conventional oils, allowing a quicker transfer of frictional energy.

The cliff notes version is the R154 and W58 trannys NEED a certain amount of friction to work properly. RP Max-Gear is *too* slippery to provide this friction...RP Synchromax is even more so. It is more an ATF type lubricant and thins out significantly at higher temps. IMO, these 2 gear oils are not well suited for our manual trannys...the success many guys have seen using these oils is due to the slippery characteristics of these gear oils "freeing up" (reducing friction) parts in the R154/W58 that are on the way to failure. This is not fixing the problem...that sound from your tranny is the sound of inevitably.

The reason more modern trannys spec a gear oil like Synchromax (or GM's synchromesh) is to improve cold shifts. The thicker oils in a GL-4/5 category do not shift well at lower temps...they need to warm up. The problem is Synchromax does not have the extreme pressure protection, oil film thickness, and shear stability required...this will increase wear on the gears. Synchromax may help quiet down a worn R154/W58 for a while, but it is not really helping the problem...it's masking it.

Just for comparison, Red Line 75W-90NS is a GL-5 and has a viscosity of 95.0 cst at 40 deg C and 15.6 cst at 100 deg C and Red Line MT-90 is a GL-4 75W-90 and has a viscosity of 90.0 cst at 40 deg C and 15.6 cst at 100 deg C. These two gear oils are almost identical in this respect...the difference is the additives...MT-90 is more suited to the R154/W58. The advantage of these are their low temp viscosities...it will help smooth out shifts until the oil gets warmed up.

BTW - there are quite a few excellent GL-4 gear oils out there, all of with will work fine in a R154/W58...gear oils have a much easier time coping with the enviroment they work in vs motor oil. The biggest reason I like the Red line MT-90 for use in a R154/W58 is it's low temp viscosity characteristics. Especially in the R154...it's not the smoothest shifting tranny and will benefit the most from MT-90.

As usual...the devil is in the details

 

[Nick M]

And that is why Dexron also works.

In the R154 and W58 transmissions, either GL-4 or GL-5 gear oil is allowed. In gearboxes where a GL-4 *only* is specified, Wingman is correct...using a GL-5 oil can cause damage to the tranny.

thanks for clearing that up! I've always been curious, but never looked too deep into the subject.

thanks for the info jdub, I know my tranny is one it's way out, it doesn't like to go into first unless I'm stopped, an second gear grinds pretty bad.

I had normal gear oil in it before and it was hard as hell to get into second, so it did help a bit, but I know it needs a rebuild...

By the way if your looking for readline i bought mine from summit racing got it cheap and fast!

Summit is a good source since most places dont have it i paid about ~7 per quart and well worth it.

 

[jdub]

Kept this thread for future reference...Cleaned it up for brevity


After running through the Nashman translator

I have always ran MT-90 in all my trannies except one when I ran ShockProof in one because of a grinding issue, went away afterwards on my W58 tranny

But it was just band-aid and such

 

[jdub]

What's the best way to flush out as much of the old RP gear oil as possible? Is getting it hot and draining it for a long time sufficient?

That should do it

 

[IJ.]

Big danger is some additives will glaze the Syncro surface and is very hard to remove/rectify. While affected it's taking the sharp edges off the inner taper of the Brass rings which are what grip the gear to accel/decell everything. Ford makes an additive that will help in their Motorcraft range.

 

[jdub]

i read through this thread fast..... and i would go back and read it more carefully and try to better understand it..... but im supposed to be studying for 2 finals that i have tomorrow :aigo:

so now that we are on the same page as to why im asking, what are the summarizations to gear and lsd oils? i have redline mt-90, and redline 75w90. i also got a ford racing lsd friction modifier....... am i in the clear????

Red Line MT-90 for the tranny, 75W-90 for the LSD are excellent choices. Red Line 75W-90 already has friction modifier in the formula...you should not need any additional modifier.

The only down side I have seen with the Red Line 75W-90 LSD oil is if you have a noisy LSD, it can make it worse. If you have a worn differential, Ford 75W-90 oil and Ford friction modifier might be a better choice....you add just enough modifier to stop the LSD from chattering.

 

[jdub]

For the LSD do you just get plain old Ford LSD 75w90? Its nothing special?

Yep...you will also need the Ford friction modifier.

 

[jdub]

Update:

Changed the manual transmission oil on my '94 Toyota truck with Red Line MT-90. Been in for 3 weeks...shifts very smooth now...I could feel the difference in shifting on the 1st drive. Previously it had a "dragging" feel going into gear and I could hear the synchros. Not a sound now...I'm very pleased with the Red Line.

Also changed the differential oil and used the Ford 75W-90 synthetic. Had a light hum before...not a sound either. Didn't need the friction modifier. I'm equally impressed with this differential oil.

The truck has an R22 EFI motor, 2 wheel drive, W55 tranny, open differential.

 

[Poodles]

OK, as I now have some first hand experience in this I'll comment:

When I first got the car it had a slight second gear grind. Tranny shop changed the clutch and tranny fluid. Same grind.

Switched to Royal Purple Max-Gear. Shifting was smoother...until I tried to shift fast and then it would grind a bit. Didn't go away with use, and wasn't in that long.

Switched to Royal Purple Synchromax (I know, I grabbed the wrong bottles!!). Worked about the same as max-gear at first. Went to the Austin hill country cruise and it was grinding a LOT going to second, even when going slowly. Rev matching helped, but not entirely, was also quite noisy. Tranny made some noise and did cause some "drag."

Finally switched to Red Line MT-90. Been driving it for a week and the grind is entirely GONE. I have a bit of a click when shifting fast into second, but other than that it's smooth as butter.

Highly recommended.

I also run the Ford gear oil and LSD additive in the diff. It helped a lot, but I'm unsure as to how much really, as the old gear oil looked pitch black and smelled burnt. Anything I put in there might have helped...

 

[jdub]

i just purchase 6 quarts of 75w 90 moblile synthetic gear oil. is this a good choice for my 5 speed tranny and lsd.

Mobil 1 75W-90 gear oil also contains friction modifiers and is intended for an LSD...same type friction modifiers as Royal Purple. It will be fine to use in an LSD, but not in a manual tranny...for the same reasons in post #7 above.

http://www.mobil.com/USA-English/Lubes/PDS/GLXXENPVLMOMobil1_Synthetic_Gear_Lubricant_LS_75W-90.asp

Pick-up some Red Line MT-90 for your tranny...you won't regret it

 

[tekdeus]

I was at my auto parts store today to buy some replacemeny tranny fluid. I was annoyed that all of the brands of synthetic had LSD additives in it. They did not sell red line so I my only choice was havoline standard gear fluid 80-90.

 

[jdub]

Hmmm...here's several synthetic gear oils (no friction modifiers):

Pennzoil Synthetic 75W-90 GL4
Pennzoil Gearplus 80W-90 GL4
Ford 75W-90 Synthetic Gear oil
Amsoil MTG 75W-90

(Edit Mar 08 - Valvoline changed the spec on Valvoline SynPower 75W-85 gear oil...it is now a GL-5 75W-90 & contains friction modifiers)

Plus Red Line MT-90...well worth special order if necessary IMO.

All of the above meet the GL-4 specification suitable for both the W58 and R154.
There are also several non-syn gear oils that meet GL-4 requirements...and you can always go to the Dealer for an appropriate gear oil.

Time to change parts stores?

 

[Evilempire1.3JZ-GTE]

I have used both the Amsoil & Redline MT-90 I liked the way the redline performed better you can still find Amsoil on shelves at Autozone if your to lazy to order the redline from Summit Racing.

 

[Poodles]

no parts stores here carry red line either, summit racing online is where I got it since they're fast and reasonable...