FJ40 '74 Still Running Slow After Having Clutch Replaced (1 Viewer)

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I replaced my FJ40 '74 with a new Clutch Disk, Pressure Plate & Release Bearing because I noticed that it did not have much power to accelerate either driving forward or reverse on city roads and most especially navigating on rolling/steep roads. However, after having it replaced with said parts, i noticed that it is still the same - running with a speed like that of a turtle. I hope you imagine what I mean. Also, the vehicle cannot not run forward or backwards if the Transfer Case is on a Neutral mode. The vehicle will only start to run if i engage/shift first the Transfer Case either H2, H4 or L4 and after having shifted as well the Transmission gear to either 1st Gear or Reverse. Yet, even with the engaged Transfer Case, it is still powerless especially after several revs. I also removed the Profeller Shaft just to find out if it would make a difference. But it still the same, runs like a turtle. Also, do I need to use a Clutch when I engage the Transfer Case? Would really appreciate your inputs folks. Thank you
 
The vehicle isn't supposed to move when the transfer case is in neutral. You should have it in 2H on the street and hard surfaces and engage H4 or L4 as needed off-road. You should use the clutch when shifting the transfer case and do not shift from 2H into 4H unless the locking hubs on the front axle are locked, and do not shift into 4L if the vehicle speed is more than approx. 5 km/h.

We'll need a lot more information to comment on the lack of power. How does the engine start and run? What rpm will it achieve in neutral/with the clutch in, at wide open throttle? How long since the air filter and fuel filter were replaced?
 
- Typically, resurfacing the flywheel will keep the clutch performance optimal. I know it is a lot of work, pulling it apart again.
- You might need to adjust the clutch release fork-to-slave push rod.
- Was there oil on the old clutch assembly, before you replaced it?

Do we know that the clutch is actually slipping?
 
I suspect there is a language issue here. A slipping clutch could indeed rob power to the wheels, but that usually doesn't last long and soon the truck will not move in any gear. Proper placement of all the part you did and more than likely machining the flywheel should fix clutch issues. Poor power/acceleration can be a fuel or spark issue besides compression. Do a dry/wet compression test.
Got any local car "people friends" that could help.
 
The vehicle isn't supposed to move when the transfer case is in neutral. You should have it in 2H on the street and hard surfaces and engage H4 or L4 as needed off-road. You should use the clutch when shifting the transfer case and do not shift from 2H into 4H unless the locking hubs on the front axle are locked, and do not shift into 4L if the vehicle speed is more than approx. 5 km/h.

We'll need a lot more information to comment on the lack of power. How does the engine start and run? What rpm will it achieve in neutral/with the clutch in, at wide open throttle? How long since the air filter and fuel filter were replaced?


40- / 55-Series Tech

FJ40 '74 Still Running Slow After Having Clutch Replaced (5 Viewers)

Thread starterFES74 Start dateToday at 5:20 PM Tags

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FES74

Today at 5:20 PMAdd bookmark#1

I replaced my FJ40 '74 with a new Clutch Disk, Pressure Plate & Release Bearing because I noticed that it did not have much power to accelerate either driving forward or reverse on city roads and most especially navigating on rolling/steep roads. However, after having it replaced with said parts, i noticed that it is still the same - running with a speed like that of a turtle. I hope you imagine what I mean. Also, the vehicle cannot not run forward or backwards if the Transfer Case is on a Neutral mode. The vehicle will only start to run if i engage/shift first the Transfer Case either H2, H4 or L4 and after having shifted as well the Transmission gear to either 1st Gear or Reverse. Yet, even with the engaged Transfer Case, it is still powerless especially after several revs. I also removed the Profeller Shaft just to find out if it would make a difference. But it still the same, runs like a turtle. Also, do I need to use a Clutch when I engage the Transfer Case? Would really appreciate your inputs folks. Thank you

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AussieHJCruza

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Today at 5:33 PMNewAdd bookmark#2

The vehicle isn't supposed to move when the transfer case is in neutral. You should have it in 2H on the street and hard surfaces and engage H4 or L4 as needed off-road. You should use the clutch when shifting the transfer case and do not shift from 2H into 4H unless the locking hubs on the front axle are locked, and do not shift into 4L if the vehicle speed is more than approx. 5 km/h.

We'll need a lot more information to comment on the lack of power. How does the engine start and run? What rpm will it achieve in neutral/with the clutch in, at wide open throttle? How long since the air filter and fuel filter were replaced?

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brian

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Today at 7:53 PMNewAdd bookmark#3

Wow, just wow.

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Grayscale

Today at 8:06 PMNewAdd bookmark#4

- Typically, resurfacing the flywheel will keep the clutch performance optimal. I know it is a lot of work, pulling it apart again.
- You might need to adjust the clutch release fork-to-slave push rod.
- Was there oil on the old clutch assembly, before you replaced it?

Do we know that the clutch is actually slipping?

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charliemeyer007

Today at 9:56 PMNewAdd bookmark#5

I suspect there is a language issue here. A slipping clutch could indeed rob power to the wheels, but that usually doesn't last long and soon the truck will not move in any gear. Proper placement of all the part you did and more than likely machining the flywheel should fix clutch issues. Poor power/acceleration can be a fuel or spark issue besides compression. Do a dry/wet compression test.
Got any local car "people friends" that could help.

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The vehicle isn't supposed to move when the transfer case is in neutral. You should have it in 2H on the street and hard surfaces and engage H4 or L4 as needed off-road. You should use the clutch when shifting the transfer case and do not shift from 2H into 4H unless the locking hubs on the front axle are locked, and do not shift into 4L if the vehicle speed is more than approx. 5 km/h.

We'll need a lot more information to comment on the lack of power. How does the engine start and run? What rpm will it achieve in neutral/with the clutch in, at wide open throttle? How long since the air filter and fuel filter were replaced?

Thanks a lot @AussieHJCruza. A lot of your info are new to me. Really appreciate it. The engine does start quickly but needs to rev it high just keep it on and running. It stops if I won't floor the Accelerator pedal for gasoline. The RPM can go as high as 2k and up. The fuel filter is new but have not replaced yet the air filter. Thanks again
 
- Typically, resurfacing the flywheel will keep the clutch performance optimal. I know it is a lot of work, pulling it apart again.
- You might need to adjust the clutch release fork-to-slave push rod.
- Was there oil on the old clutch assembly, before you replaced it?

Do we know that the clutch is actually slipping?
Thanks a lot Grayscale. Truly appreciate your inputs. Can you share to me on how resurfacing of the flywheel is being done? We'll try to readjust the clutch release fork-to-slave push rod. Btw, there was no oil on the old clutch assembly when it was removed. Thanks again
 
I suspect there is a language issue here. A slipping clutch could indeed rob power to the wheels, but that usually doesn't last long and soon the truck will not move in any gear. Proper placement of all the part you did and more than 3 machining the flywheel should fix clutch 6issues. Poor power/acceleration can be a fuel or spark issue besides compression. Do a dry/wet compression test.
Got any local car "people friends" that could help.
That's exactly what happened when the clutch slips, my truck gets stock on the road and does not move. I will ask my mechanic if it is still possible to machine the flywheel. Will try to check as well its fuel and spark if they are of good quality. Thanks again Charliemeyer.
 
Thanks a lot @AussieHJCruza. A lot of your info are new to me. Really appreciate it. The engine does start quickly but needs to rev it high just keep it on and running. It stops if I won't floor the Accelerator pedal for gasoline. The RPM can go as high as 2k and up. The fuel filter is new but have not replaced yet the air filter. Thanks again
Sounds like you've got some things to take care of, but we'll need more accurate information, will it rev to 2k or 4k rpm or something else?
I'd expect you'd see 4000+ rpm if everything was running properly. Can you upload a video?
 
Also make sure your parking brake is not binding and boggin you down
 
Would suggest installing a tachometer if your not sure of the problem. The engine RPM will race up and speedometer will not with a slipping clutch disc. If it's not doing that your problem isn't the clutch.
 
If lack of power is the problem then you should look at the engine itself. Compression test, ensure the valves are adjusted properly not to mention everything connected; timing, carb adjustments, plugs and timing.
 
Sounds like you've got some things to take care of, but we'll need more accurate information, will it rev to 2k or 4k rpm or something else?
I'd expect you'd see 4000+ rpm if everything was running properly. Can you upload a video?
Thanks you. Will revert to you on this soonest when I see my mechanic.
 
If lack of power is the problem then you should look at the engine itself. Compression test, ensure the valves are adjusted properly not to mention everything connected; timing, carb adjustments, plugs and timing.
Thanks a lot Bylon. Will revisit all these parts you mentioned.
 
your brake wheel cylinders are SIEZED

and or the rear parking brake DRUM parts inside

same set up

brakes dragging


it is discussed well inn the factory FSM possible causes of your symptoms ....

rust , age , time all at play here ...


adjusting a rear dual wheel cylinders set up can be a failed task for anyone without a real paper print media FSM

pull all the cylinder rubber caps back a bit any fluid ,,,,,? ⛳⛳

Front 4 piston calipers can do this as well

you have 4 wheel drum brakes ....

all new JAPAN parts from Cruiser TEQ out in salt lake is a good place to shop


ROCK AUTO and AMAZON , are well Ghetto Grade Chairman MOE ............stuff


@cruisermatt

CruiserMatt's PowerTrain and Chassis in winter park FL , is my other favorite place All things power train and chassis

both are specialty professionals that are in our community and very knowledgeable


update this thread when you find the causes and remedies , it helps others .....


matt
 

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