Some odd Clutch/driveline issues

[84sr54wd]

So, I thought I would describe some drive-ability observations I have made with my 84 sr5. I am fairly certain that I am on the original clutch with 123K on the clock. When I got the car, I noticed that there was a fairly high grab point to the clutch pedal...figuring it was well worn, I checked the FSM for clutch pedal adjustment protocol. I found a statement in there which said if there are not 6 or more teeth on the paw left, replace the clutch disk. I have 6-8 teeth left...and my clutch does NOT slip under any circumstance and drive fine once engaged. I adjusted the pedal to grab a little closer down to the floor. So, knowing that all of that.......here are a few observations that I have made and would like someone else's take on that has experience with the AL25. (Apologies that this is long...I am detail oriented and highly analytical...it's what engineering school does to you. HA)

The clutch is not smooth from a stop (disengaged) to starting off in 1st gear (engaged). The same is true for reverse. It is very jumpy, no matter how much gas I give it. (It's worse if I gun the engine a bit...the drivetrain starts hopping). I am not one to slip a clutch and absolutely hate slipping a clutch...so I always tend to lug the engine a bit rather than overs-speed it and slip it and also over-heat the pressure plate. If I sit there and just slowly let out the clutch, the car starts gittering and shaking. The very FIRST thing that comes to mind having a lot of automotive experience is that if this is the original clutch and I know it is....chances are whoever had it in the 3 or 4 owners before me has overheated the drive plate/pressure plate possibly multiple times and glazed it or burned it. From past experience, I know that once you overheat the pressure plate just ONCE, it is never right again. Another reason to never abuse or slip a clutch. I'm fairly sure that is what is going on there, just wanted someone else's assessment. Additionally to back up this diagnosis...I have opened the hood so I could watch the engine on the engine mounts just to make sure that there was not excessive engine movement when this was going on possibly being a worn mount contributing. The engine is very tight on the mounts. I can let the clutch out, get it idling me along in 1st gear in a parking lot, then all of a sudden whack the throttle to throw torque to the driveline and then lay completely off the pedal and do this over and over to torque slam the driveline....and the engine does not hardly move a bit NOR do I feel any banging or clanging underneath where either the engine or trans could be moving on the mounts. The entire front end has been rebuilt minus the mounts and drive axles. I have checked the drive axles doing lock to lock turns in a parking lot and throwing various amounts of power to the front wheels in a lock to lock turn and can get absolutely no noise from them. I would think these are original as well, do not look like they have been replaced...but they seem to be ok. I thought maybe they were worn and there was freeplay in them somewhere such that when I was letting out the clutch, part of the gittering could be coming from that. After careful assessment and testing....I don't think that is the case. I believe the only cure for the symptoms I have described above would be a complete pull down and R/R the entire clutch/pressure plate/all bearings and seals.....

so with that said, here is another thing it does....I'm trying to determine if this is all related to just a well worn clutch assembly....

Here where I live in Va., it has started to really get cool for the winter. I have noticed when I start off cold and start heading down the road, I take off on the main road outside my neighborhood. I granny it to get her going with minimal driveline hop as described above, and then it is time for an upshift from 1st to 2nd gear. I'm in first gear, not really even that hard on throttle because the engine and trans are still cold, I press in the clutch to shift to second and BOOM, I get excessive drivetrain torque backlash. I move the gearshift level into second, out on the clutch, accelerate and time for 3rd. In with the pedal, trans in still in 2nd and BOOM, excessive drivetrain torque comes through the drivetrain and frame again when I depress the clutch. This happens into every gear and it is worse the colder the car is. What I have also noted while this is occurring and my foot still has the pedal depressed is that the gear shift lever, just for a SPLIT second, still appears to be engaged in that lower gear because it is tight and feels, when I try to move it to the next highest gear, as if there is still power going through the trans even though the pedal is depressed. All of this is happening very quickly and simultaneously. In layman's terms, it is like the clutch disk is sticky. I press in the pedal....I am disengaging the trans but it is taking a split second MORE for disengagement to really occur, then when it does, the torque that was being sent through the trans to the front axles now reverses, and comes back into the driveline creating what I am calling excessive drivetrain torque backlash. Once the car is driven for a good while, not just to operating temp., but long enough for the pressure plate and all internal clutch components to get hot, this problem goes away. I can drive it somewhere too and get it hot then park it for a few, and the components continue to heat up...then it goes away slowly. It does not go instantly, but in a decreasing severity manner. You will start noticing there is still backlash, but not as severe. Then finally, it's fine. While this is all going on, if I do a downshift from a higher to lower gear (I always do rev matching downshifts as I am used to being on a racetrack)....when I let the clutch back out...sometimes I will get a very odd grab or harsh kind-of-backlash then too.

So, from all of this, I have concluded that basically....my original clutch is 30 years old at 123K. It has been driven by a multitude of driving styles and most probably the cure for all of this will be R/R the clutch assy. Is this conclusion in alignment with your thoughts? I just am trying to make certain there is not something else going on....worn mounts, worns axles....wear somehow in the transaxle causing there to be freeplay in something...etc.? At 123K I would not think it is a trans issue....but I do think clutch!!?? Thanks for any informative feedback!!

[84sr54wd]

I forgot to ask those that have done it....what kind of job is removing the trans/transaxle and R/R'ing the clutch? I do all of my own work, have a scissor lift in my garage but would probably have to engineer a way to raise the car 4-5 feet in the air, then drop it down on something and drop the lift out of the way from blocking the undercarriage. Im thinking of cutting some solid tree trunks about 4 feet long and at least a foot in diameter (yes, they will be heavy), notching them with the chainsaw for the tires....then lifting the car with the lift and dropping the wheels onto them.....this will leave the car 4 feet in the air and I can then drop the lift out of the way. I have to pull the axles in the front first out of the transaxle...then put the steering knuckles back in place with no axles in the car so the car can sit on the front tires on the logs. How heavy is the trans in these 4wd cars? I don't know what to do about manhandling that gearbox. Looks pretty big under the car? I'm debating all of this vs. paying a shop 700-900 for a clutch job down the road.

[jimcrazy]

it is easer to pull the motor to put a clutch in. having done this many times doing motor swaps,

[84sr54wd]

it is easer to pull the motor to put a clutch in. having done this many times doing motor swaps,

Now, I have never done a clutch OR motor swap on a Tercel, so I give you credit if you have. However, at first glance, I would not even consider pulling the engine for this type of setup. Pulling the engine would require a tremendous level of effort just in and of itself, (all lines, hoses, de-charging the a/c possibly, etc.) then you have to pull the trans and disconnect everything as well? I'm fairly sure that if you took this car to the Toyota dealer or any trans shop for that matter, they would not pull the engine. If you could get the thing in the air, pull the bottom supports and skid plate out and yank the front axles and rear driveshaft then you could just drop out the bell housing bolts and disconnect any linkages and drop it out. It's a standard longitudinal setup which doesn't get any more simple from a configuration perspective.

[jimcrazy]

from my experience I can have the motor out in under 3 hrs, leavening the front end alone. I did one at home in my drive way the car was not towable, had my engine lift cart on my trailer backed up to it lifted it out and drove away, cart and motor hooked together, take rad out,unplug alt, 2 gas lines,gas pedal cable, unscrew p/s hoses from pump,unbolt exhaust pipe, 2 mounts from motor to tran, un bolt starter, 2 motor nuts,unplug distributor, bell housing bolts get most from up top,wires to carb, wires to temp sensors and oil pressure,clutch cable unhook a few vacuum hoses, couple of ground straps to fire wall, stick a jack under trans to hold it, up, lift motor slide ahead twist to left standing in front of car and out. don't think I for got any thing. I done the tranie swap pick motor swap anyday

[jimcrazy]

I knew I forgot something the 2 heater hoses to un hook

[dlb]

it's just a matter of preference, 84sr54wd. do whatever you feel is easiest/best.

i did the clutch on my wife's '91 4wd totyota pickup several years ago and for me, it was easier to drop its trans because i didn't have an engine hoist and my steep gravel driveway precluded the use of a rolling hoist anyway. my neighbour who does lots of wrenching told me how he would have taken the engine out, and that's fine and would have worked well for him, but for me and my situation dropping the trans worked best.

so take advice from people with experience but ultimately do what makes the most sense to you and remember that there are many ways to skin cats.

[irowiki]

The AC doesn't need to be discharged when you pull the engine, fyi.

[xirdneh]

i have replaced the clutch both ways
i would rate the methods at 50/50 (working under the car sucks but leaning over the fenders is hard on the lower back)
i prefer pulling the tranny by slight margin
pulling the input shaft before removing tranny and re-installing the input shaft after re-installing the tranny makes it tolerable

[Petros]

I have also done it both ways, and much prefer pulling the trans from underneath. After I had a car up on jacks I got the trans dropped in about 48 min once (not normal but knew exactly what to loosen and nothing got stuck or broken, I was removing it from the a wrecked Tercel4wd at pick-n-pull and they were closing soon). I think it is only worth pulling the engine to change the clutch if there is some other reason to get the engine out for other maintenance such as new bearings or piston rings.

Also, you can pull the trans and drop it, and raise it back up into place, using the scissors jack (having two or far easier). pulling and engine takes an overhead hoist or cherry picker.

[84sr54wd]

I have also done it both ways, and much prefer pulling the trans from underneath. After I had a car up on jacks I got the trans dropped in about 48 min once (not normal but knew exactly what to loosen and nothing got stuck or broken, I was removing it from the a wrecked Tercel4wd at pick-n-pull and they were closing soon). I think it is only worth pulling the engine to change the clutch if there is some other reason to get the engine out for other maintenance such as new bearings or piston rings.

Also, you can pull the trans and drop it, and raise it back up into place, using the scissors jack (having two or far easier). pulling and engine takes an overhead hoist or cherry picker.

Lord, that is quick work....48 minutes? The front axles have to come out then you have to remove all the bolts and such that hold the trans in on the bell housing, then the rear mount etc. I think there is an exhaust bracket and such too. I am worried about two major things.....getting it far enough in the air to do it, and manhandling that transmission myself. Looks to me that it is quite big as an entire unit and far as I understand, the entire unit has to come out of the car to do the clutch.

[Petros]

car was already up in the air on high jack stands, a few items may have already been pulled off (I do not remember). I just pulled the lower bolts on each ball joint at the strut to pull the axles, this allowed you to pull the strut out far enough so the cv axle spline stub just clears the diff, so you do not have to remove them, just pop them out of the sides of the trans and let them hang. I just cut wires so I did not have to fight with the connectors, most other things unbolted without incidents or struggles. when you are not worried about saving all the bolts and fasteners, it saves a few min. at each step. Used no jack, just set tire or seat foam or something on the ground and yanked it out and let it drop on the padding. left all mounts and attachments in place to get it out of the car.

Also, I had done it enough times I knew exactly the sequence, and what size sockets, extensions, etc. I needed to grab for the next step. selecting tools and test fitting sockets, pry bars, etc. eats up a lot of time too, so that saved many wasted steps. If I was not in a hurry, and being careful not do damage boots, seals, wires, and save all the fasteners I would plan 1.5 to 2 hours to pull the trans. That is presuming nothing gets stuck, breaks off or is rusted in place, like the exhaust bracket, drain plug, connectors, etc. Just having one bolt head get stripped could add an extra 2 hours of screwing around experimenting with different ways to get it out without futher damage. I hate it when that happens, typically because some shade tree truck mechanic over muscled everything last time it was apart wrong size sockets (one car I had had almost half the screws and bolts broken off in place, or screw heads stripped out, what a PIA to fix).

On a car this old, anything is possible. I have even found stripped out threads that someone had forced into the aluminum housing an SAE bolts to "hold it" in place. Dump sh*t DIY types should just stay way from the tool box, it will make it eaiser to get the car running later.

[84sr54wd]

car was already up in the air on high jack stands, a few items may have already been pulled off (I do not remember). I just pulled the lower bolts on each ball joint at the strut to pull the axles, this allowed you to pull the strut out far enough so the cv axle spline stub just clears the diff, so you do not have to remove them, just pop them out of the sides of the trans and let them hang. I just cut wires so I did not have to fight with the connectors, most other things unbolted without incidents or struggles. when you are not worried about saving all the bolts and fasteners, it saves a few min. at each step. Used no jack, just set tire or seat foam or something on the ground and yanked it out and let it drop on the padding. left all mounts and attachments in place to get it out of the car.

Also, I had done it enough times I knew exactly the sequence, and what size sockets, extensions, etc. I needed to grab for the next step. selecting tools and test fitting sockets, pry bars, etc. eats up a lot of time too, so that saved many wasted steps. If I was not in a hurry, and being careful not do damage boots, seals, wires, and save all the fasteners I would plan 1.5 to 2 hours to pull the trans. That is presuming nothing gets stuck, breaks off or is rusted in place, like the exhaust bracket, drain plug, connectors, etc. Just having one bolt head get stripped could add an extra 2 hours of screwing around experimenting with different ways to get it out without futher damage. I hate it when that happens, typically because some shade tree truck mechanic over muscled everything last time it was apart wrong size sockets (one car I had had almost half the screws and bolts broken off in place, or screw heads stripped out, what a PIA to fix).

On a car this old, anything is possible. I have even found stripped out threads that someone had forced into the aluminum housing an SAE bolts to "hold it" in place. Dump sh*t DIY types should just stay way from the tool box, it will make it eaiser to get the car running later.

So Peter,

Since you have done these clutches before....I thought I would ask you what the main areas to focus on are. I have cut some solid trunks of oak about a foot in diameter and have raised the car in the air and then dropped all of the tires down on V-notches I cut with the chainsaw in the top of the trunks. Now the car is about 3.5 feet in the air suspended. I want to also put some jack stands under the frame to be on the safe side...but once I am done engineering this process to hold the car high so I can sit under it, I am going to tackle this clutch. From memory, do you recall what you did under the hood? I want to do all of that before I secure the car in the air on these massive trunks of heavy oak logs so I am not having to move it all every five minutes to raise and lower it. I was curious what the tasks were that were done from under the hood vs. under the car? I will raise the car first, drop the lower ball joint bolts and remove the half shafts from the transaxle in the front then put the ball joints back and tires back on. Once that is done, are there certain things that need to be gotten to/done from above before going to work on dropping the trans underneath? I have sorta looked at the FSM and I think it mentions draining the cooling system but with a manual trans and the looks of this job, I really cannot see that there is much need for that to pull the clutch?

Also, once you remove the rear trans support/mount, does the entire engine pivot on the two front engine mounts so that you can better access the bell housing bolts where the trans bolts up to the engine? I have visually studied it a bit and it seems that aside from some linkages that need disconnecting, maybe a connector or two, there is not much to it. The exhaust does not appear to need to be disconnected, just the bracket on the passenger's side that bolts to the trans. What kind of weight can I expect to have to deal with handling that trans? I assume I need to drain the gear oil first? Also, what is the best way to deal with the rear driveshaft? Once disconnected from the rear pinion gear on the diff, I assume I need to pull the center driveshaft bearing off and then does the yolk slide right out of the trans so I can set the driveshaft aside? I assume that is the main reason for draining the trans gear oil so that when you pull the driveshaft, you don't lose it all.... I'm just curious on a few things that will help me get going. Thanks!

[84sr54wd]

I also know that the flywheel in my car will need to at least be machined.....it is very jumpy now and I am sure it has a high spot in it from someone overheating it not knowing what they were doing. If it cannot be machined..what is the best option to find a flywheel? That is one part it seems is very difficult to find? I pray my disk has not eaten into it and it can be reworked by a machinist.

[dlb]

your flywheel can probably be machined. if not, there are tons of 3a engines at wreckers so grab a flywheel from there. i would machine a used flywheel before using it.