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Complete failure from worn pressure plate fingers?
I've had a complete failure of my transmission or clutch. Opened it up today. Clutch surfaces look good. Pilot and throw out bearing seem a little worn but are intact and are ok I believe. However, as seen in this picture, the pressure plate fingers are extremely worn. Is this enough wear to cause a complete failure? I cannot drive or move the truck at all. It let go very suddenly. Had been making a sort of a mechanical whirling sound on engine braking for some time, but no performance issue. Any tips or advice would be fantastic. Would hate to replace the clutch components only to have it not help because I had a transmission problem all along. Any chance I'm lucky and this pressure plate is the culprit?
What's the clutch look like, still have the lines in it? Are the mating surfaces discolored? The pressure plate fingers do look really worn, did a quick google image search and it appears OEM is completely flat, no groove at all. You'll defo want to replace the throw out bearing, and possibly the pilot bearing when you put it back together. From a little reading, the wear sounds to be from the throw out bearing's clip coming undone or being installed incorrectly where it's hitting all the time. It should only contact when the clutch is pressed in.
I don't really see how that would cause an instant failure on the clutch system though, it would be a slow over time type of wear, atleast in my head. Maybe the "whirling" sound was the clutch slipping on engine braking. Generally the clutch would only slip in higher gears when it gets worn thin enough. Speaking of that, the failure you should be seeing is hard to shift, truck trying to roll forward on it's own when in gear, etc unless something got stuck on one of your shifts.
Since you have the transmission and tcase out, I would reinstall the shifters and shift the transmission through all the gears, and the tcase through its various ranges, and make sure the output shaft turns appropriately when you turn the input shaft. I agree with the previous poster that worn clutch fingers would more normally cause the clutch not to release, rather than to stay disengaged all the time. While I'm not saying your clutch fingers are in good shape, I don't think that's your problem.
Also, it would be nice to know the model and year of 4runner we're talking about. There are some differences in the clutch depending on engine and transmission.
Since you have the transmission and tcase out, I would reinstall the shifters and shift the transmission through all the gears, and the tcase through its various ranges, and make sure the output shaft turns appropriately when you turn the input shaft. I agree with the previous poster that worn clutch fingers would more normally cause the clutch not to release, rather than to stay disengaged all the time. While I'm not saying your clutch fingers are in good shape, I don't think that's your problem.
Also, it would be nice to know the model and year of 4runner we're talking about. There are some differences in the clutch depending on engine and transmission.
It is a an 86 pickup with a G52 transmission. I have a W56 donor transmission from a 94 with 150k on it. We bought a couple junked pickups and salvaged their engines/transmissions. Truth is I'm not 100% positive that the W56 is in perfect shape. I have no reason to believe it doesn't function properly but also not a particular reason to think it works great. I will have to shift through all gears on both the G52 and W56 and see how things feel.
What's the clutch look like, still have the lines in it? Are the mating surfaces discolored? The pressure plate fingers do look really worn, did a quick google image search and it appears OEM is completely flat, no groove at all. You'll defo want to replace the throw out bearing, and possibly the pilot bearing when you put it back together. From a little reading, the wear sounds to be from the throw out bearing's clip coming undone or being installed incorrectly where it's hitting all the time. It should only contact when the clutch is pressed in.
I don't really see how that would cause an instant failure on the clutch system though, it would be a slow over time type of wear, atleast in my head. Maybe the "whirling" sound was the clutch slipping on engine braking. Generally the clutch would only slip in higher gears when it gets worn thin enough. Speaking of that, the failure you should be seeing is hard to shift, truck trying to roll forward on it's own when in gear, etc unless something got stuck on one of your shifts.
Clutch looks surprisingly very good. I think I'm going to swap my G52 transmission for a used W56 that I have. I'm really starting to think it's a transmission problem that I have.
Not trying to beat you up or make you look stupid, but just to be sure, did you happen to knock your t-case into neutral? I have talked to people that were playing grab-ass with their passenger and bumped into the shifter. they thought about the same thing, clutch, driveline, transmission. Turned out there was nothing broken at all. The sounds you are describing and the obvious pressure plate wear show that you really needed a clutch/TO bearing anyway.
Not trying to beat you up or make you look stupid, but just to be sure, did you happen to knock your t-case into neutral? I have talked to people that were playing grab-ass with their passenger and bumped into the shifter. they thought about the same thing, clutch, driveline, transmission. Turned out there was nothing broken at all. The sounds you are describing and the obvious pressure plate wear show that you really needed a clutch/TO bearing anyway.
haha Nope. I know the problem though. It is the transmission I now have the entire transmission out of the truck. I've shifted through every gear while rotating the main output shaft. It grabs and grinds and gets held up in certain gears. I drained the fluid and there are huge chunks of metal. Some type of catastrophic failure happened. I really don't know why. Just regular wear I guess. Although the truck has just 180k miles on it. It is a G52 transmission and I'm replacing it with a used W56 with 150k miles. I hear the W56 is a better transmission. I'm also replacing the clutch and bearings and am doing a full rebuild of the motor.
The G series generally was used in 22r (carb) trucks, W series was used in the 'more powerful" EFI 22re trucks (what 10hp more? lol). The W trans is beefed up a little more but not a crazy amount more. One big thing that you might not care about is check the shifter location. You might need a donor W series trans to get the correct shifter angle etc, or just cut the floor if it interferes. I installed a 86 trans in a 90 pickup and we had to swap a couple parts over, both were W46 (4 speed version of the W56). From memory, the shifter was at a bit of a different angle or the base of the shifter was backwards from one to the other. Switched out the top part and everything lined up fine.
While you have the trans out, might want to remove the shifter out of the socket (which ever one you plan to use) and double check the socket bushing. Factory they are rubber and tend to disappear due to age. Marlin Crawler sells plastic replacements that worked great for the two I've installed. They also sell the replacement bushing for the tip of the shifter. Pretty sure you can also buy the OEM replacements from Toyota yet as well.
A good way to test the trans is to chuck up a drill to the input shaft and spin it up in each gear. If the drill has an electric brake, be sure to slowly bring down the speed. You'll hear bad bearings very well this way. The freshly rebuilt W56 trans I got on a trade/sale made basically zero noise. A 200k mile unit made a very slight noise. And a bad trans you could hear inside the cab sounded like it was about to fall apart, tons of scraping and the input shaft could be moved something like 1/4 in up/down (internal gears actually looked good yet, just the two main bearings are shot).
04-06-2017, 09:07 PM
