- Joined
- Jan 6, 2025
- Messages
- 3
So I am restoring a 1990 AE95 (mine is a JDM Sprinter Carib, but in America it's called a corolla all-trac wagon. These are AWD cars based on a transversely-mounted FWD platform. The transaxle is on the side of the engine and reaches back around the engine to connect to the transfer case, which is under the intake manifold. Presumably, this means it drives the prop shaft via a hypoid gear. The transfer case and the transaxle share the same oil. There are two drain plugs but only one fill plug. The whole assembly is filled via the transaxle, and it takes a whopping 5.3 to 5.8 L of gear oil (either 4.5 L for the transmission + 0.8 L for the transfer case or 5.0 L for the transmission + 0.8 L for the transfer case, depending on the specific transmission model: https://toyota-club.net/files/techdata/ttx/sprinter-carib_95.htm). This website specifies 75W90 GL5, but I've read that some older shop manuals say 75w90 or 80w90, and apparently GL4. The transmission is synchronized and has brass synchros.
I have had a super hard time figuring out what oil to put in this thing. My 2nd gear likes to grind sometimes, I think because the synchro between 2nd and 3rd is worn out. I was hoping to improve the situation a little bit. One thing I've read is that GL5 is bad for brass synchros. I suspect that this has something to do with the worn out synchros, since the oil that was in here from the PO was certainly GL5 (stinks like hell). I was thinking a heavier oil might help with this. On the forums and groups, I read that GL4 is better, presumably because of the synchros, and apparently that the original shop manual specified GL4. The argument is that manufacturers have updated their sites to specificy GL5 because it's now the only thong on the market. The problem is that I am filling not only the transaxle but also the transfer case, which has a hypoid gear.
I suppose the best thing would be an 80w90 mineral oil specifcying both GL4 and GL5. Unfortunately, I got fed up with looking for one in local stores and I also sort of bought the hype around redline. I ended up buying redline MT-90, which is a synthetic 75w90 GL4 that is supposed to be especially good for oldschool brass synchros. It was very expensive. It improved my shifting a lot. The 2nd gear still grinds sometimes, but it's easier to avoid now, and it's way easier to shift into all the gears overall. Everything feels much lighter. Now, I am reading threads like this one saying that GL4 should never be used in an application like mine because of the hypoid gears, and I'm worried I have to drop my extremely expensive MT-90 and use something like Valvoline mineral 80w90 GL4/GL5, but I really don't want to do that. One of the most recommended oils for AE95 is Penrite 75w90 GL-4, which is the same as Redline MT-90 and sells itself as specifically a transmission oil and not a differential oil. Other owners say they use this with no problems. What's the deal here? Is there something that will be good for both my brass synchros and my transfer case? Can I keep running the MT-90? The transmission performance has improved a lot and I also really don't want to throw away 200 bucks!
I have had a super hard time figuring out what oil to put in this thing. My 2nd gear likes to grind sometimes, I think because the synchro between 2nd and 3rd is worn out. I was hoping to improve the situation a little bit. One thing I've read is that GL5 is bad for brass synchros. I suspect that this has something to do with the worn out synchros, since the oil that was in here from the PO was certainly GL5 (stinks like hell). I was thinking a heavier oil might help with this. On the forums and groups, I read that GL4 is better, presumably because of the synchros, and apparently that the original shop manual specified GL4. The argument is that manufacturers have updated their sites to specificy GL5 because it's now the only thong on the market. The problem is that I am filling not only the transaxle but also the transfer case, which has a hypoid gear.
I suppose the best thing would be an 80w90 mineral oil specifcying both GL4 and GL5. Unfortunately, I got fed up with looking for one in local stores and I also sort of bought the hype around redline. I ended up buying redline MT-90, which is a synthetic 75w90 GL4 that is supposed to be especially good for oldschool brass synchros. It was very expensive. It improved my shifting a lot. The 2nd gear still grinds sometimes, but it's easier to avoid now, and it's way easier to shift into all the gears overall. Everything feels much lighter. Now, I am reading threads like this one saying that GL4 should never be used in an application like mine because of the hypoid gears, and I'm worried I have to drop my extremely expensive MT-90 and use something like Valvoline mineral 80w90 GL4/GL5, but I really don't want to do that. One of the most recommended oils for AE95 is Penrite 75w90 GL-4, which is the same as Redline MT-90 and sells itself as specifically a transmission oil and not a differential oil. Other owners say they use this with no problems. What's the deal here? Is there something that will be good for both my brass synchros and my transfer case? Can I keep running the MT-90? The transmission performance has improved a lot and I also really don't want to throw away 200 bucks!
