This has been a problem for a few years now. I have not been able to get to the bottom of it. When the engine is cold, it shifts perfectly. The transmission goes into 1st and reverse with no grinding. Once the engine gets to operating temperature it becomes difficult to shift into 1st and it grinds going into reverse.
The clutch has about 4k miles on it. I also replace the master cylinder at the same time as I replaced my clutch. I have replaced all the fluid in the clutch system by vacuuming it out the slave cylinder until clean fluid came out. I am considering replacing the slave cylinder but I am not sure if that would fix anything.
Has anyone else had this same problem? If so, did you find a solution?
88 Base model 4 cylinder
[This message has been edited by Doug85GT (edited 06-04-2023).]
I would measure the throw on slave when engine is cold and when engine is hot. Is the throw the same? If shorter when hot perhaps an indication that heat is affecting the slave cylinder.
------------------ formerly known as sanderson 1984 Quad 4 1886 SE 2.8L 1988 4.9L Cadillac 1988 3800 Supercharged
If you find that you have a problem with your slave cylinder Rodney Dickman has dual seal slave rebuild kits, pistons only and new slave cylinders.
I have had his clutch master and slave cylinders on my car for about 8 years and they work great and have been trouble free as are all of his products that I have on my car.
I would measure the throw on slave when engine is cold and when engine is hot.
I would add that the slave needs to move 1-1/8" for proper disengagement of the clutch. If it's not moving that far, there's either air in the system, the clutch pedal is bent, or the banjo is bent.
This issue has been covered here an enormous number of times.
I would add that the slave needs to move 1-1/8" for proper disengagement of the clutch. If it's not moving that far, there's either air in the system, the clutch pedal is bent, or the banjo is bent.
This issue has been covered here an enormous number of times.
I have heard that number 1-1/8" for the Getrag. He has an Isuzu, is that the same number?
I have heard that number 1-1/8" for the Getrag. He has an Isuzu, is that the same number?
My experience (having both an Isuzu and a Getrag) is that 1-1/8" is critical for the Isuzu, and not as critical for the Getrag. (I have no personal experience with a 4-spd Muncie.)
I measured the throw. 23/32 cold, 21/32 warm. There is a 1/16 throw lower when the engine is warm.
I took a close look at my clutch pedal. It is higher than my brake pedal, made of steel and is not bent. It is a little loose mostly due to the slop on the banjo. While I was looking at the banjo I decided to flip it around to see if that would have any effect on the throw. That resulted in a 28/32 (7/8) throw after the engine had cook for about half an hour. That is still longer than it was previously cold. It is no longer grinding.
The next thing I need to look into is replacing the plastic bushing on the banjo. I am not even sure if that is a separate item I can buy. If I could replace that with something much better fitting it would eliminate the wiggle in my clutch pedal.
I ordered a brass bushing from Rodney. I think it is take up the extra play in my pedal.
As for the banjo direction, wouldn't the best geometry be the one with the most travel? My car is 35 years old and I am not the first nor even the third owner. Could it be possible that this perfect geometry with the banjo up no longer applies due to possible frame damage or warping prior to me owning it? On my car, there is 1/4" more travel with the banjo pointed down. It is still short of the 1 1/8" that people say is needed but it is a 1/4" closer. I will measure it again when I get the new bushing.
The 88 service manual show a straight rod. Go figure.
The clutch has about 4k miles on it. I also replace the master cylinder at the same time as I replaced my clutch.
quote
Originally posted by Doug85GT:
I ordered a brass bushing from Rodney. I think it is take up the extra play in my pedal.
Are you referring to the bushing in the banjo? Didn't your replacement master cylinder come with a new banjo? If so, how did it wear out in 4k miles?
quote
Originally posted by Doug85GT:
Could it be possible that this perfect geometry with the banjo up no longer applies due to possible frame damage or warping prior to me owning it? On my car, there is 1/4" more travel with the banjo pointed down.
If it was my car, I'd want to find out why my clutch pedal alignment was different than everybody else's!
quote
Originally posted by Doug85GT:
I took a close look at my clutch pedal. It is higher than my brake pedal, made of steel and is not bent.
It's the steel part that bends! How much higher is your clutch pedal than your brake pedal? It's supposed to be an inch.
Originally posted by Patrick: Are you referring to the bushing in the banjo? Didn't your replacement master cylinder come with a new banjo? If so, how did it wear out in 4k miles? If it was my car, I'd want to find out why my clutch pedal alignment was different than everybody else's! It's the steel part that bends! How much higher is your clutch pedal than your brake pedal? It's supposed to be an inch.
I don't believe the bushing wore out in 4k miles. I think it was loose when I installed it and I just did not pay attention to it.
I am not sure if my car does have a different geometry. I read through a few threads that mentioned banjo up vs down. The best reference I saw was someone quoted Archie. I did not see anyone actually measure the difference. I measured the difference and based on that I will have my banjo down until I get the new bushing at which time I will measure it again. Even if my car has a slightly different geometry, I have neither the time nor patience to try to figure out what the proper dimensions of the structural members are on my car and whether my car falls into factory specs.
That U piece of my clutch pedal is straight. I measured the top of the U and the bottom and they were the same. The bottom is at a 90 degree angle to the part of the clutch pedal it is attached.
I don't believe the bushing wore out in 4k miles. I think it was loose when I installed it and I just did not pay attention to it.
There are two different size banjo bushing/pedal assemblies. Perhaps you had them mismatched.
quote
Originally posted by Doug85GT:
I am not sure if my car does have a different geometry. I read through a few threads that mentioned banjo up vs down.
I've noticed on my Fieros that if the banjo loop was down, the angle of the banjo in relation to the master cylinder was **** -eyed when the pedal was pushed to the floor. Not so with the loop facing up. Anyway, do what works for you.
Interesting observation. While I've always heard the banjo loop needs to be up, I've never actually heard of anyone that measured throw with it up vs down before. I'd like to hear from anyone else that has measured both ways and what the measurements were.
The effective length of the banjo pushrod is measured from the banjo hole to the spherical (or is it conical) tip which pushes on the master cylinder.
This effective length remains the same whether the banjo is up or down. (No effect on throw)
With the correct banjo orientation, the rod remains better-aligned within the bore of the master cylinder. So, the rubber sealing boot works better, and there is perhaps less risk of the banjo rod scratching the inside the master cylinder.
[This message has been edited by pmbrunelle (edited 06-05-2023).]
I installed the brass bushing. It made no difference. It did not take up the slop in the pedal either. There is still about a 1/4" of wiggle up and down. Since I never noticed it before I'll just live with it since it does not seem to affect how the clutch functions.
This time I measured everything myself. Last time I had my wife do the measurements as I pushed the pedal in. I used my truck bed load bar to hold the pedal down as I did the measurements. There was no difference in the travel distance with the loop up or down. I left it up. I'll blame the erroneous previous reading on my wife.
I replace the slave cylinder. It was just $18 so I figured why not. It made no difference in the travel distance. I am still at 7/8" travel. I used V8 Archie's bleed method including pushing in the slave rod with the bleed screw off. No additional air come out on that step for me.
At this point, I don't think 1 1/8" travel is attainable for my car. I'll just live with 7/8".
I had that issue with my last Fiero, after it got hot, going into first became impossible when the engine was running. I'd have to kill the engine, put it into gear, then hold the clutch down and start the car.
After it was bled again later, the issue went away.
