G58 transmission - OK to use 80w90?
#1
Contributing Member
Thread Starter
G58 transmission - OK to use 80w90?
The FSM calls for GL-4 75w90, but it seems that all 75w90 is synthetic. Is there a conventional 75w90 and/or can I use 80w90 instead?
#3
Contributing Member
Thread Starter
Can't find Sta-lube anywhere locally and the only place that has conventional 75w-90 is the dealer and they only get it by the drum for their service dept.
#4
Registered User
I used this as a temp measure to flush the trans in a few days since it was pretty cheap and fast shipping (with prime) but I wouldn't recommend it for permanent use. It is much thicker than 75w and I have been getting a bit more grinding of synchros unless I double clutch. Probably the most I would go is 1:3 mixed with mostly 75w.
Allegedly the anti corrosion additives in the newer GL5 will not eat brass, but I will probably water some 75w down with the above to be safe. Why not use the full synthetic, other than price? Should be fine to mix with conventional.
#5
Contributing Member
Thread Starter
#7
Sta-Lube GL-4 is 85W90. For the record.
It's basically a matter of personal preference. Like RustBucket says, you could use any kind of GL-4/5 and be ok. Some might help the tranny shift a little better than others. But it'll all work.
It's basically a matter of personal preference. Like RustBucket says, you could use any kind of GL-4/5 and be ok. Some might help the tranny shift a little better than others. But it'll all work.
Trending Topics
#8
Contributing Member
Thread Starter
pretty sure i remember putting castrol 80w90 GL5 in there last time it was changed and haven't had any issues other than it feeling like molasses on cold winter mornings. I have read lots of good stuff about the redline MT-90, but was hoping to come across a conventional 75w90 GL4
#9
Registered User
Something to consider here with GL4 vs GL5: http://www.widman.biz/uploads/Transaxle_oil.pdf
"In normal operation, the sulfur/phosphorous additive forms a black sacrificial coating on the gears and anything it touches with a little pressure and temperature. As the gears turn, instead of wearing, the sacrificial coating of additives is pealed off or worn off. This is normal and acceptable in all steel gears. But when one or more of the surfaces is brass or another soft metal, the sacrificial coating is stronger than the base metal, and instead of just peeling off, it takes with it a few microns of brass that it is bound to. A normal GL-4 gear oil of any given viscosity has about ½ of the level of sulfur/phosphorous additive that would be in the GL-5 product, so the bond is not as strong, and therefore can be peeled off without peeling a layer of brass (or less brass). This means that the GL-4 product provides a little less extreme pressure protection, so in the differential of a high powered car, it would not be the ideal product in the differential."
"But in the transmission, we should consider two factors:
• Due to the fact that the differential applies the final torque, normally we do not need the full EP protection in the transmission where less torque (about 30%) is applied.
• We need to be able to break the EP protection to stop the spinning of the gears long enough to mesh them or synchronize them.
When we use a GL-5 product in a transmission that requires GL-4, we normally find 2 to 4 times as much copper in the used oil as we would with a GL-4 product. Eventually the synchronizers wear to
the point that they no longer make contact with the other half of the cone, bottoming out before stopping the opposing gear. "
If anyone knows of any sources for 75w GL4 please post up, otherwise I plan on mixing the 85w Sta Lube with 75w GL4/5 to hopefully get more life out of the synchros. (Edit - or *gaaahhh* paying $15/qt for this - , depending on how rich I feel that day)
"In normal operation, the sulfur/phosphorous additive forms a black sacrificial coating on the gears and anything it touches with a little pressure and temperature. As the gears turn, instead of wearing, the sacrificial coating of additives is pealed off or worn off. This is normal and acceptable in all steel gears. But when one or more of the surfaces is brass or another soft metal, the sacrificial coating is stronger than the base metal, and instead of just peeling off, it takes with it a few microns of brass that it is bound to. A normal GL-4 gear oil of any given viscosity has about ½ of the level of sulfur/phosphorous additive that would be in the GL-5 product, so the bond is not as strong, and therefore can be peeled off without peeling a layer of brass (or less brass). This means that the GL-4 product provides a little less extreme pressure protection, so in the differential of a high powered car, it would not be the ideal product in the differential."
"But in the transmission, we should consider two factors:
• Due to the fact that the differential applies the final torque, normally we do not need the full EP protection in the transmission where less torque (about 30%) is applied.
• We need to be able to break the EP protection to stop the spinning of the gears long enough to mesh them or synchronize them.
When we use a GL-5 product in a transmission that requires GL-4, we normally find 2 to 4 times as much copper in the used oil as we would with a GL-4 product. Eventually the synchronizers wear to
the point that they no longer make contact with the other half of the cone, bottoming out before stopping the opposing gear. "
If anyone knows of any sources for 75w GL4 please post up, otherwise I plan on mixing the 85w Sta Lube with 75w GL4/5 to hopefully get more life out of the synchros. (Edit - or *gaaahhh* paying $15/qt for this - , depending on how rich I feel that day)
Last edited by jbtvt; 06-30-2014 at 01:10 AM.
#10
Registered User
iTrader: (1)
Both Amsoil's and Redline's products are specifically formulated for manual transmission. These are not general-purpose gear lubes. Shift quality is excellent from very cold to very hot temps. Fill it up with this stuff once and leave it alone for the next 50k.
For further technical reading see bobistheoilguy.com
Or, if you want a straight-weight GL-4, pick up some of this:
(P.S. - 40wt motor oil and 90wt gear oil are the same viscosity)
For further technical reading see bobistheoilguy.com
Or, if you want a straight-weight GL-4, pick up some of this:
(P.S. - 40wt motor oil and 90wt gear oil are the same viscosity)
#11
Registered User
$20 for 5 gallons including 2 day shipping?! Whaaat? That's gotta be a misprint.
I will be draining and refilling the trans on my '85 again next week (had some shavings in there) and since I already have the Stalube will do 1:3 Stalube:75w, will report back on performance and any grinding at that time.
For the final flush in ~1000 miles will probably usethe GL4 Redline.
I will be draining and refilling the trans on my '85 again next week (had some shavings in there) and since I already have the Stalube will do 1:3 Stalube:75w, will report back on performance and any grinding at that time.
For the final flush in ~1000 miles will probably usethe GL4 Redline.
#12
Contributing Member
Thread Starter
If anyone knows of any sources for 75w GL4 please post up, otherwise I plan on mixing the 85w Sta Lube with 75w GL4/5 to hopefully get more life out of the synchros. (Edit - or *gaaahhh* paying $15/qt for this - Amazon.com: Red Line (50304) MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant - 1 Quart: Automotive, depending on how rich I feel that day)
Last edited by Brendan; 06-30-2014 at 04:56 PM.
#13
Contributing Member
Thread Starter
The FSM calls for a 3.9 litre capacity in the G58 but the fill hole started spitting out at less than 3 litres. I drained the old stuff until there was no dripping at all. I know that you can never get ALL the old stuff out, but 1 litre is a fair bit. The old stuff is conventional 80w90 and the new stuff is synthetic redline 75w90. Should I be concerned having them mixed together?
Jacking up the front end with the drain hole open and then also the rear may have been a smart idea in hindsight...
Jacking up the front end with the drain hole open and then also the rear may have been a smart idea in hindsight...
Last edited by Brendan; 11-08-2014 at 12:31 PM.
#14
Registered User
The FSM calls for a 3.9 litre capacity in the G58 but the fill hole started spitting out at less than 3 litres. I drained the old stuff until there was no dripping at all. I know that you can never get ALL the old stuff out, but 1 litre is a fair bit. The old stuff is conventional 80w90 and the new stuff is synthetic redline 75w90. Should I be concerned having them mixed together?
Jacking up the front end with the drain hole open and then also the rear may have been a smart idea in hindsight...
Jacking up the front end with the drain hole open and then also the rear may have been a smart idea in hindsight...
#15
Contributing Member
Thread Starter
Will do, thanks.
#17
Contributing Member
Thread Starter
Tranny was still full when I checked a few days ago. Also, is Redline MT-90 OK to use in the transfer case as well?
Last edited by Brendan; 11-17-2014 at 06:15 PM.
Thread
Thread Starter
Forum
Replies
Last Post
TheBFA
Solid Axle Swaps, All Years
8
02-15-2020 06:55 AM
Odin
86-95 Trucks & 4Runners
3
09-26-2015 06:56 PM
FS[PacNorWest]: 1987 4Runner SAS, 22RE, 5Spd, Dual Cases, etc
toyotasaurus
Vehicles - Trailers (Complete)
0
09-24-2015 03:30 PM