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Hey Guys!
this is my first post so sorry if Im in the wrong spot, I recently bought a 91 yota pickup with 190k on it. a few days ago it started leaking oil at the bellhousing and rear of the engine. Im pretty sure its a rear main seal, I've bought a seal kit, Aisin Heavy Duty clutch kit, oem flywheel, moog ujoints and a couple other small seals I might as well replace while I'm down there. I also will be rust proofing the middle section of the frame while the tranny is out. What Im wondering is if there I anything else I should do while the transmission is out. while not everything goes to plan I would rather not have the tranny out in the next few years again. as far as I know the clutch has never been done so the timing is perfect for everything to get a tune up. Let me know what you guys think. I would also appreciate some general advice since this is my first Toyota! Any tips and tricks will be welcomed since Im 18 and fairly new to this.
I'm assuming it's a 22RE? If so,, check to make sure that it's not the 1/2 moon gasket at the back of the valve cover before doing all the work of the rear main and clutch
It is the 22re, I have checked the rear half moon and it is not leaking. it looks like it was leaking at one time but no longer is. Im pretty sure I ordered the input seal so ill go ahead and order the output. IM only using Toyota seals since I dont want to mess with another failure if the future. another question I had, can I drive the truck with the leak or am I going to cause more damage? id carry oil with me and top it off, I just dont have another car at the time I can use. thanks for the help. If you look close you can see small drips of oil hanging off the bellhousing. set the cardboard under 48 hours ago so its not awful but its still dripping
I would think, something I try very hard to avoid, that you could drive it with a leak in the rear main. Having said that, be very, very cautious!! If that oil gets thrown up onto the clutch, I would believe (see? no thinking! ) that it would make the clutch slipperier, and slipperier, until it would start being a real problem. It could wind up that you couldn't take it out of gear if the critical point was reached while it's IN gear, which can be darn dangerous. I would guess that you can clean the clutch by slipping it once in a while, but even so, I would be very careful.
Also, driving it with the leaking rear main wouldn't hurt it any worse. IE: The rear main is leaking, and it WILL get worse when the engine runs, over time, whether the truck is moving or not. BUT it won't get worse at an accelerated rate. It will keep getting worse, but no faster than if it just sits there.
Finally, if that rear half-moon WAS leaking, what caused it to stop?? Is the oil too low? Did you tighten up the valve cover? If you did, is it now TOO tight? That's a real problem, as it interferes with the valves. Not a good thing. After all, seals don't just leak, and then stop for no reason. Something changed. If it were me, and the kit is very inexpensive, I would replace the valve cover seal, the half-moons, and the grommets. The valve cover seal set is only about $20.00. Not bad at all. All of them are very easy to get to, and very easy to replace. Heck, the hardest part, IMHO, is getting the valve cover gasket to stay in it's groove properly while installing the cover on the engine.
I put a little dab of really thick, sticky grease in various places around the groove the seal rides in, then put the seal in. The grease holds it in place for a short time, but certainly long enough to get it seated without the seal coming out. The grease then squishes around enough it doesn't alter the thickness at all. Good thing, too, as the grommets are hard enough to get started without ANY thickness added to the seal.
Most important thing, really, is to make sure the seal is seated in it's groove the right way up. It's in a slight T shape, and the vertical bar goes up into the groove. I saw an idiot my mechanic hired once, briefly, try to cram the cross bar into the groove, and install it. He didn't take a hint when he couldn't even get one grommet started. He had to put Ultracopper around it to get it to seal up, and used nuts and a stack of washers to try and hold it in. I could have easily fixed, but I took it back, and the mechanic I use fixed it for free, and fired the idiot. Served the idiot right. He was a petty little weasel, too, and stuck a screwdriver in one of my sidewalls. My mech paid for that, too. He's a good man.
Make sure you use the right sealant on the corners of the half-moons. Not a very big area to seal, but important.
Finally, an easy way to start the new grommets, is to put 3 of the old ones on, and tighten them way down, then start the last, new, one. Just use the old grommets to push the valve cover down hard enough to start the new ones. Just work your way through all 4 of them that way, then torque the new ones down to spec. It's not very much, so be cautious. Works great.
Sd long as you have the valve cover off, you might want to adjust the valve lash. It has to be done on a regular basis, and when you change the valve cover gasket is a real good opportunity. OR, if you go to adjust the valves, it's a good chance to replace the gaskets
Also, since it's grommet gets brittle fast, you might think about removing the PCV valve, and testing it. Usually, when you go to remove it, the grommet disintegrates, so if you can do it with the valve cover off, so much the better, you see? If you replace the PCV, always use an OEM, not some auto parts store cheapie. It matters.
But, yeah, definitely replace that rear main ASAP. If it's not leaking, I wouldn't worry about the front, but if you DO do it, you need to remove/reinstall the oil pump, so you'll need a new seal for that, too. The thick grease trick works for the oil pump seal too.
Wow thanks for all the info, I think the half moon seals were replaced once already when the timing chain was done at 150k I’ll be doing them again in the next couple months with 22re performance billet seals when I tune the engine up. Again thanks for all the helpful information. I’ll post some updates once I read into the project next week.
Alrighty... here my update: I have removed everything but the transmission. I wanted to prep myself by breaking free all the transmission bolts, I was able to get all but the one on the very top of the transmission. Does anyone have any tricks on how to break that free? I also decided to go ahead and do the half moon seals now as well as some preventative maintenance. so far everything has been relatively easy just time consuming. After wrestling with that one bolt for a hour now I am in need of help. I've tried from under the truck as well as from the engine bay. I cant really get a socket in but Im going to try again in the morning. I knew some road blocks were inevitable I just wish this wasn't one of them. Looking forward to driving the truck again though!!!!! thanks for everyone's input its helped a lot
Get a 6 point shallow swivel socket and about 3 feet of socket extensions. That was the easiest way I found to reach the top bolt when I did my clutch a few years ago
So i was unable to fine a socked with the swivel already built in, I used a swivel attachment and a bunch of extensions but I cant get it into the space, at this point if I cant get the bolt out the trucks a bust and since I just got it and payed a fair amount for it that would be really frustrating. Im already frustrated that it needed this much work and I didnt even get to drive it for more than a day. Im almost a grand into parts and tools and I'm getting really close to losing my cool. To this point everything has been difficult but doable. I cant get a torch in the area to heat up the bolt and pb blaster is doing nothing for me. Anything that im missing? I can figure this one out guys.
Clutch, pilot bearing, throw-out bearing, flywheel, rear main seal, joints all done as of 9:30 tonight. Waiting on half moon seals, and a few other parts for the truck. will also be replacing the carpet so that will be nice to. thanks for all the help and suggestions. made it easier in the end.
09-09-2021, 08:21 PM
) that it would make the clutch slipperier, and slipperier, until it would start being a real problem. It could wind up that you couldn't take it out of gear if the critical point was reached while it's IN gear, which can be darn dangerous. I would guess that you can clean the clutch by slipping it once in a while, but even so, I would be very careful.
